text: /**********************************************************************************************
  *
  *   rlgl v3.1 - raylib OpenGL abstraction layer
  *
  *   rlgl is a wrapper for multiple OpenGL versions (1.1, 2.1, 3.3 Core, ES 2.0) to
  *   pseudo-OpenGL 1.1 style functions (rlVertex, rlTranslate, rlRotate...).
  *
  *   When chosing an OpenGL version greater than OpenGL 1.1, rlgl stores vertex data on internal
  *   VBO buffers (and VAOs if available). It requires calling 3 functions:
  *       rlglInit()  - Initialize internal buffers and auxiliar resources
  *       rlglDraw()  - Process internal buffers and send required draw calls
  *       rlglClose() - De-initialize internal buffers data and other auxiliar resources
  *
  *   CONFIGURATION:
  *
  *   #define GRAPHICS_API_OPENGL_11
  *   #define GRAPHICS_API_OPENGL_21
  *   #define GRAPHICS_API_OPENGL_33
  *   #define GRAPHICS_API_OPENGL_46
  *   #define GRAPHICS_API_OPENGL_ES2
  *       Use selected OpenGL graphics backend, should be supported by platform
  *       Those preprocessor defines are only used on rlgl module, if OpenGL version is
  *       required by any other module, use rlGetVersion() tocheck it
  *
  *   #define RLGL_IMPLEMENTATION
  *       Generates the implementation of the library into the included file.
  *       If not defined, the library is in header only mode and can be included in other headers
  *       or source files without problems. But only ONE file should hold the implementation.
  *
  *   #define RLGL_STANDALONE
  *       Use rlgl as standalone library (no raylib dependency)
  *
  *   #define SUPPORT_VR_SIMULATOR
  *       Support VR simulation functionality (stereo rendering)
  *
  *   #define ANIMATED_WITH_DUALQUATERNIONS
  *       Use DualQuaternions for skeleton animation
  *   #define ANIMATED_WITH_MATRIX
  *       Use Matrix for skeleton animation
  *
  *   DEPENDENCIES:
  *       raymath     - 3D math functionality (Vector3, Matrix, Quaternion)
  *       GLAD        - OpenGL extensions loading (OpenGL 3.3 Core only)
  *
  *
  *   LICENSE: zlib/libpng
  *
  *   Copyright (c) 2014-2020 Ramon Santamaria (@raysan5)
  *
  *   This software is provided "as-is", without any express or implied warranty. In no event
  *   will the authors be held liable for any damages arising from the use of this software.
  *
  *   Permission is granted to anyone to use this software for any purpose, including commercial
  *   applications, and to alter it and redistribute it freely, subject to the following restrictions:
  *
  *     1. The origin of this software must not be misrepresented; you must not claim that you
  *     wrote the original software. If you use this software in a product, an acknowledgment
  *     in the product documentation would be appreciated but is not required.
  *
  *     2. Altered source versions must be plainly marked as such, and must not be misrepresented
  *     as being the original software.
  *
  *     3. This notice may not be removed or altered from any source distribution.
  *
  **********************************************************************************************/
  
  #ifndef RLGL_H
  #define RLGL_H
  
  // The type of Skeleton animation used in default vertex shader (GPU bone animation)
  #define ANIMATED_WITH_DUALQUATERNIONS
  //#define ANIMATED_WITH_MATRIX
  
  #if defined(RLGL_STANDALONE)
      #define RAYMATH_STANDALONE
      #define RAYMATH_HEADER_ONLY
  
      #define RLAPI   // We are building or using rlgl as a static library (or Linux shared library)
  
      #if defined(_WIN32)
          #if defined(BUILD_LIBTYPE_SHARED)
              #define RLAPI __declspec(dllexport)         // We are building raylib as a Win32 shared library (.dll)
          #elif defined(USE_LIBTYPE_SHARED)
              #define RLAPI __declspec(dllimport)         // We are using raylib as a Win32 shared library (.dll)
          #endif
      #endif
  
      // Support TRACELOG macros
      #if !defined(TRACELOG)
          #define TRACELOG(level, ...) (void)0
          #define TRACELOGD(...) (void)0
      #endif
  
      // Allow custom memory allocators
      #ifndef RL_MALLOC
          #define RL_MALLOC(sz)       malloc(sz)
      #endif
      #ifndef RL_CALLOC
          #define RL_CALLOC(n,sz)     calloc(n,sz)
      #endif
      #ifndef RL_REALLOC
          #define RL_REALLOC(n,sz)    realloc(n,sz)
      #endif
      #ifndef RL_FREE
          #define RL_FREE(p)          free(p)
      #endif
  #else
      #include "raylib.h"         // Required for: Model, Shader, Texture2D, TRACELOG()
  #endif
  
  #include "raymath.h"            // Required for: Vector3, Matrix
  
  // Security check in case no GRAPHICS_API_OPENGL_* defined
  #if !defined(GRAPHICS_API_OPENGL_11) && \
      !defined(GRAPHICS_API_OPENGL_21) && \
      !defined(GRAPHICS_API_OPENGL_33) && \
      !defined(GRAPHICS_API_OPENGL_46) && \
      !defined(GRAPHICS_API_OPENGL_ES2)
          #define GRAPHICS_API_OPENGL_46
  #endif
  
  // Security check in case multiple GRAPHICS_API_OPENGL_* defined
  #if defined(GRAPHICS_API_OPENGL_11)
      #if defined(GRAPHICS_API_OPENGL_21)
          #undef GRAPHICS_API_OPENGL_21
      #endif
      #if defined(GRAPHICS_API_OPENGL_33)
          #undef GRAPHICS_API_OPENGL_33
      #endif
      #if defined(GRAPHICS_API_OPENGL_46)
          #undef GRAPHICS_API_OPENGL_46
      #endif
      #if defined(GRAPHICS_API_OPENGL_ES2)
          #undef GRAPHICS_API_OPENGL_ES2
      #endif
  #endif
  
  #if defined(GRAPHICS_API_OPENGL_21)
      #define GRAPHICS_API_OPENGL_33
  #endif
  
  #define SUPPORT_RENDER_TEXTURES_HINT
  
  //----------------------------------------------------------------------------------
  // Defines and Macros
  //----------------------------------------------------------------------------------
  // Default internal render batch limits
  #ifndef DEFAULT_BATCH_BUFFER_ELEMENTS
      #if defined(GRAPHICS_API_OPENGL_11) || defined(GRAPHICS_API_OPENGL_33) || defined(GRAPHICS_API_OPENGL_46)
          // This is the maximum amount of elements (quads) per batch
          // NOTE: Be careful with text, every letter maps to a quad
          #define DEFAULT_BATCH_BUFFER_ELEMENTS   8192
      #elif defined(GRAPHICS_API_OPENGL_ES2)
          // We reduce memory sizes for embedded systems (RPI and HTML5)
          // NOTE: On HTML5 (emscripten) this is allocated on heap,
          // by default it's only 16MB!...just take care...
          #define DEFAULT_BATCH_BUFFER_ELEMENTS   2048
      #endif
  #endif
  #ifndef DEFAULT_BATCH_BUFFERS
      #define DEFAULT_BATCH_BUFFERS            1      // Default number of batch buffers (multi-buffering)
  #endif
  #ifndef DEFAULT_BATCH_DRAWCALLS
      #define DEFAULT_BATCH_DRAWCALLS        256      // Default number of batch draw calls (by state changes: mode, texture)
  #endif
  #ifndef MAX_BATCH_ACTIVE_TEXTURES
      #define MAX_BATCH_ACTIVE_TEXTURES        4      // Maximum number of additional textures that can be activated on batch drawing (SetShaderValueTexture())
  #endif
  
  // Internal Matrix stack
  #ifndef MAX_MATRIX_STACK_SIZE
      #define MAX_MATRIX_STACK_SIZE           32      // Maximum size of Matrix stack
  #endif
  
  // Shader and material limits
  #ifndef MAX_SHADER_LOCATIONS
      #define MAX_SHADER_LOCATIONS            32      // Maximum number of shader locations supported
  #endif
  #ifndef MAX_MATERIAL_MAPS
      #define MAX_MATERIAL_MAPS               12      // Maximum number of shader maps supported
  #endif
  
  // Projection matrix culling
  #ifndef RL_CULL_DISTANCE_NEAR
      #define RL_CULL_DISTANCE_NEAR         0.01      // Default near cull distance
  #endif
  #ifndef RL_CULL_DISTANCE_FAR
      #define RL_CULL_DISTANCE_FAR        1000.0      // Default far cull distance
  #endif
  
  // Texture parameters (equivalent to OpenGL defines)
  #define RL_TEXTURE_WRAP_S               0x2802      // GL_TEXTURE_WRAP_S
  #define RL_TEXTURE_WRAP_T               0x2803      // GL_TEXTURE_WRAP_T
  #define RL_TEXTURE_MAG_FILTER           0x2800      // GL_TEXTURE_MAG_FILTER
  #define RL_TEXTURE_MIN_FILTER           0x2801      // GL_TEXTURE_MIN_FILTER
  #define RL_TEXTURE_ANISOTROPIC_FILTER   0x3000      // Anisotropic filter (custom identifier)
  
  #define RL_FILTER_NEAREST               0x2600      // GL_NEAREST
  #define RL_FILTER_LINEAR                0x2601      // GL_LINEAR
  #define RL_FILTER_MIP_NEAREST           0x2700      // GL_NEAREST_MIPMAP_NEAREST
  #define RL_FILTER_NEAREST_MIP_LINEAR    0x2702      // GL_NEAREST_MIPMAP_LINEAR
  #define RL_FILTER_LINEAR_MIP_NEAREST    0x2701      // GL_LINEAR_MIPMAP_NEAREST
  #define RL_FILTER_MIP_LINEAR            0x2703      // GL_LINEAR_MIPMAP_LINEAR
  
  #define RL_WRAP_REPEAT                  0x2901      // GL_REPEAT
  #define RL_WRAP_CLAMP                   0x812F      // GL_CLAMP_TO_EDGE
  #define RL_WRAP_MIRROR_REPEAT           0x8370      // GL_MIRRORED_REPEAT
  #define RL_WRAP_MIRROR_CLAMP            0x8742      // GL_MIRROR_CLAMP_EXT
  
  // Matrix modes (equivalent to OpenGL)
  #define RL_MODELVIEW                    0x1700      // GL_MODELVIEW
  #define RL_PROJECTION                   0x1701      // GL_PROJECTION
  #define RL_TEXTURE                      0x1702      // GL_TEXTURE
  
  // Primitive assembly draw modes
  #define RL_LINES                        0x0001      // GL_LINES
  #define RL_TRIANGLES                    0x0004      // GL_TRIANGLES
  #define RL_QUADS                        0x0007      // GL_QUADS
  
  //----------------------------------------------------------------------------------
  // Types and Structures Definition
  //----------------------------------------------------------------------------------
  typedef enum { OPENGL_11 = 1, OPENGL_21, OPENGL_33, OPENGL_46, OPENGL_ES_20 } GlVersion;
  
  typedef enum {
      RL_ATTACHMENT_COLOR_CHANNEL0 = 0,
      RL_ATTACHMENT_COLOR_CHANNEL1,
      RL_ATTACHMENT_COLOR_CHANNEL2,
      RL_ATTACHMENT_COLOR_CHANNEL3,
      RL_ATTACHMENT_COLOR_CHANNEL4,
      RL_ATTACHMENT_COLOR_CHANNEL5,
      RL_ATTACHMENT_COLOR_CHANNEL6,
      RL_ATTACHMENT_COLOR_CHANNEL7,
      RL_ATTACHMENT_DEPTH = 100,
      RL_ATTACHMENT_STENCIL = 200,
  } FramebufferAttachType;
  
  typedef enum {
      RL_ATTACHMENT_CUBEMAP_POSITIVE_X = 0,
      RL_ATTACHMENT_CUBEMAP_NEGATIVE_X,
      RL_ATTACHMENT_CUBEMAP_POSITIVE_Y,
      RL_ATTACHMENT_CUBEMAP_NEGATIVE_Y,
      RL_ATTACHMENT_CUBEMAP_POSITIVE_Z,
      RL_ATTACHMENT_CUBEMAP_NEGATIVE_Z,
      RL_ATTACHMENT_TEXTURE2D = 100,
      RL_ATTACHMENT_RENDERBUFFER = 200,
  } FramebufferTexType;
  
  #if defined(RLGL_STANDALONE)
      #ifndef __cplusplus
      // Boolean type
      typedef enum { false, true } bool;
      #endif
  
      // Color type, RGBA (32bit)
      typedef struct Color {
          unsigned char r;
          unsigned char g;
          unsigned char b;
          unsigned char a;
      } Color;
  
      // Rectangle type
      typedef struct Rectangle {
          float x;
          float y;
          float width;
          float height;
      } Rectangle;
  
      // Texture type
      // NOTE: Data stored in GPU memory
      typedef struct Texture {
          unsigned int id;        // OpenGL texture id
          int width;              // Texture base width
          int height;             // Texture base height
          int mipmaps;            // Mipmap levels, 1 by default
          int format;             // Data format (PixelFormat)
      } Texture;
  
      // Texture2D type, same as Texture
      typedef Texture Texture2D;
  
      // TextureCubemap type, actually, same as Texture
      typedef Texture TextureCubemap;
  
      // Vertex data definning a mesh
      typedef struct Mesh {
          int vertexCount;        // number of vertices stored in arrays
          int triangleCount;      // number of triangles stored (indexed or not)
          float *vertices;        // vertex position (XYZ - 3 components per vertex) (shader-location = 0)
          float *texcoords;       // vertex texture coordinates (UV - 2 components per vertex) (shader-location = 1)
          float *texcoords2;      // vertex second texture coordinates (useful for lightmaps) (shader-location = 5)
          float *normals;         // vertex normals (XYZ - 3 components per vertex) (shader-location = 2)
          float *tangents;        // vertex tangents (XYZW - 4 components per vertex) (shader-location = 4)
          unsigned char *colors;  // vertex colors (RGBA - 4 components per vertex) (shader-location = 3)
          unsigned short *indices;// vertex indices (in case vertex data comes indexed)
  
          // Animation vertex data
          float *animVertices;    // Animated vertex positions (after bones transformations)
          float *animNormals;     // Animated normals (after bones transformations)
          int *boneIds;           // Vertex bone ids, up to 4 bones influence by vertex (skinning)
          float *boneWeights;     // Vertex bone weight, up to 4 bones influence by vertex (skinning)
  
          // OpenGL identifiers
          unsigned int vaoId;     // OpenGL Vertex Array Object id
          unsigned int *vboId;    // OpenGL Vertex Buffer Objects id (9 types of vertex data)
      } Mesh;
  
      // Shader type (generic)
      typedef struct Shader {
          unsigned int id;        // Shader program id
          int *locs;              // Shader locations array (MAX_SHADER_LOCATIONS)
      } Shader;
  
      // Material texture map
      typedef struct MaterialMap {
          Texture2D texture;      // Material map texture
          Color color;            // Material map color
          float value;            // Material map value
      } MaterialMap;
  
      // Material type (generic)
      typedef struct Material {
          Shader shader;          // Material shader
          MaterialMap *maps;      // Material maps (MAX_MATERIAL_MAPS)
          float *params;          // Material generic parameters (if required)
      } Material;
  
      // Camera type, defines a camera position/orientation in 3d space
      typedef struct Camera {
          Vector3 position;       // Camera position
          Vector3 target;         // Camera target it looks-at
          Vector3 up;             // Camera up vector (rotation over its axis)
          float fovy;             // Camera field-of-view apperture in Y (degrees)
      } Camera;
  
      // Head-Mounted-Display device parameters
      typedef struct VrDeviceInfo {
          int hResolution;                // HMD horizontal resolution in pixels
          int vResolution;                // HMD vertical resolution in pixels
          float hScreenSize;              // HMD horizontal size in meters
          float vScreenSize;              // HMD vertical size in meters
          float vScreenCenter;            // HMD screen center in meters
          float eyeToScreenDistance;      // HMD distance between eye and display in meters
          float lensSeparationDistance;   // HMD lens separation distance in meters
          float interpupillaryDistance;   // HMD IPD (distance between pupils) in meters
          float lensDistortionValues[4];  // HMD lens distortion constant parameters
          float chromaAbCorrection[4];    // HMD chromatic aberration correction parameters
      } VrDeviceInfo;
  
      // VR Stereo rendering configuration for simulator
      typedef struct VrStereoConfig {
          Shader distortionShader;        // VR stereo rendering distortion shader
          Matrix eyesProjection[2];       // VR stereo rendering eyes projection matrices
          Matrix eyesViewOffset[2];       // VR stereo rendering eyes view offset matrices
          int eyeViewportRight[4];        // VR stereo rendering right eye viewport [x, y, w, h]
          int eyeViewportLeft[4];         // VR stereo rendering left eye viewport [x, y, w, h]
      } VrStereoConfig;
  
      // TraceLog message types
      typedef enum {
          LOG_ALL,
          LOG_TRACE,
          LOG_DEBUG,
          LOG_INFO,
          LOG_WARNING,
          LOG_ERROR,
          LOG_FATAL,
          LOG_NONE
      } TraceLogType;
  
      // Texture formats (support depends on OpenGL version)
      typedef enum {
          UNCOMPRESSED_GRAYSCALE = 1,     // 8 bit per pixel (no alpha)
          UNCOMPRESSED_GRAY_ALPHA,
          UNCOMPRESSED_R5G6B5,            // 16 bpp
          UNCOMPRESSED_R8G8B8,            // 24 bpp
          UNCOMPRESSED_R5G5B5A1,          // 16 bpp (1 bit alpha)
          UNCOMPRESSED_R4G4B4A4,          // 16 bpp (4 bit alpha)
          UNCOMPRESSED_R8G8B8A8,          // 32 bpp
          UNCOMPRESSED_R32,               // 32 bpp (1 channel - float)
          UNCOMPRESSED_R32G32B32,         // 32*3 bpp (3 channels - float)
          UNCOMPRESSED_R32G32B32A32,      // 32*4 bpp (4 channels - float)
          COMPRESSED_DXT1_RGB,            // 4 bpp (no alpha)
          COMPRESSED_DXT1_RGBA,           // 4 bpp (1 bit alpha)
          COMPRESSED_DXT3_RGBA,           // 8 bpp
          COMPRESSED_DXT5_RGBA,           // 8 bpp
          COMPRESSED_ETC1_RGB,            // 4 bpp
          COMPRESSED_ETC2_RGB,            // 4 bpp
          COMPRESSED_ETC2_EAC_RGBA,       // 8 bpp
          COMPRESSED_PVRT_RGB,            // 4 bpp
          COMPRESSED_PVRT_RGBA,           // 4 bpp
          COMPRESSED_ASTC_4x4_RGBA,       // 8 bpp
          COMPRESSED_ASTC_8x8_RGBA        // 2 bpp
      } PixelFormat;
  
      // Texture parameters: filter mode
      // NOTE 1: Filtering considers mipmaps if available in the texture
      // NOTE 2: Filter is accordingly set for minification and magnification
      typedef enum {
          FILTER_POINT = 0,               // No filter, just pixel aproximation
          FILTER_BILINEAR,                // Linear filtering
          FILTER_TRILINEAR,               // Trilinear filtering (linear with mipmaps)
          FILTER_ANISOTROPIC_4X,          // Anisotropic filtering 4x
          FILTER_ANISOTROPIC_8X,          // Anisotropic filtering 8x
          FILTER_ANISOTROPIC_16X,         // Anisotropic filtering 16x
      } TextureFilterMode;
  
      // Color blending modes (pre-defined)
      typedef enum {
          BLEND_ALPHA = 0,                // Blend textures considering alpha (default)
          BLEND_ADDITIVE,                 // Blend textures adding colors
          BLEND_MULTIPLIED,               // Blend textures multiplying colors
          BLEND_ADD_COLORS,               // Blend textures adding colors (alternative)
          BLEND_SUBTRACT_COLORS,          // Blend textures subtracting colors (alternative)
          BLEND_CUSTOM                    // Belnd textures using custom src/dst factors (use SetBlendModeCustom())
      } BlendMode;
  
      // Shader location point type
      typedef enum {
          LOC_VERTEX_POSITION = 0,
          LOC_VERTEX_TEXCOORD01,
          LOC_VERTEX_TEXCOORD02,
          LOC_VERTEX_NORMAL,
          LOC_VERTEX_TANGENT,
          LOC_VERTEX_COLOR,
          LOC_VERTEX_INDEX,
          LOC_VERTEX_BONEID,
          LOC_VERTEX_BONEWEIGHT,
          LOC_MATRIX_MVP,
          LOC_MATRIX_MVIT,
          LOC_MATRIX_MODEL,
          LOC_MATRIX_VIEW,
          LOC_MATRIX_PROJECTION,
          LOC_VECTOR_VIEW,
          LOC_COLOR_DIFFUSE,
          LOC_COLOR_SPECULAR,
          LOC_COLOR_AMBIENT,
          LOC_MAP_ALBEDO,          // LOC_MAP_DIFFUSE
          LOC_MAP_METALNESS,       // LOC_MAP_SPECULAR
          LOC_MAP_NORMAL,
          LOC_MAP_ROUGHNESS,
          LOC_MAP_OCCLUSION,
          LOC_MAP_EMISSION,
          LOC_MAP_HEIGHT,
          LOC_MAP_CUBEMAP,
          LOC_MAP_IRRADIANCE,
          LOC_MAP_PREFILTER,
          LOC_MAP_BRDF
      } ShaderLocationIndex;
  
      // Shader uniform data types
      typedef enum {
          UNIFORM_FLOAT = 0,
          UNIFORM_VEC2,
          UNIFORM_VEC3,
          UNIFORM_VEC4,
          UNIFORM_INT,
          UNIFORM_IVEC2,
          UNIFORM_IVEC3,
          UNIFORM_IVEC4,
          UNIFORM_SAMPLER2D
      } ShaderUniformDataType;
  
      #define LOC_MAP_DIFFUSE      LOC_MAP_ALBEDO
      #define LOC_MAP_SPECULAR     LOC_MAP_METALNESS
  
      // Material map type
      typedef enum {
          MAP_ALBEDO    = 0,       // MAP_DIFFUSE
          MAP_METALNESS = 1,       // MAP_SPECULAR
          MAP_NORMAL    = 2,
          MAP_ROUGHNESS = 3,
          MAP_OCCLUSION,
          MAP_EMISSION,
          MAP_HEIGHT,
          MAP_CUBEMAP,             // NOTE: Uses GL_TEXTURE_CUBE_MAP
          MAP_IRRADIANCE,          // NOTE: Uses GL_TEXTURE_CUBE_MAP
          MAP_PREFILTER,           // NOTE: Uses GL_TEXTURE_CUBE_MAP
          MAP_BRDF
      } MaterialMapType;
  
      #define MAP_DIFFUSE      MAP_ALBEDO
      #define MAP_SPECULAR     MAP_METALNESS
  #endif
  
  #if defined(__cplusplus)
  extern "C" {            // Prevents name mangling of functions
  #endif
  
  //------------------------------------------------------------------------------------
  // Functions Declaration - Matrix operations
  //------------------------------------------------------------------------------------
  RLAPI void rlMatrixMode(int mode);                    // Choose the current matrix to be transformed
  RLAPI void rlPushMatrix(void);                        // Push the current matrix to stack
  RLAPI void rlPopMatrix(void);                         // Pop lattest inserted matrix from stack
  RLAPI void rlLoadIdentity(void);                      // Reset current matrix to identity matrix
  RLAPI void rlTranslatef(float x, float y, float z);   // Multiply the current matrix by a translation matrix
  RLAPI void rlRotatef(float angleDeg, float x, float y, float z);  // Multiply the current matrix by a rotation matrix
  RLAPI void rlScalef(float x, float y, float z);       // Multiply the current matrix by a scaling matrix
  RLAPI void rlMultMatrixf(float *matf);                // Multiply the current matrix by another matrix
  RLAPI void rlFrustum(double left, double right, double bottom, double top, double znear, double zfar);
  RLAPI void rlOrtho(double left, double right, double bottom, double top, double znear, double zfar);
  RLAPI void rlViewport(int x, int y, int width, int height); // Set the viewport area
  
  //------------------------------------------------------------------------------------
  // Functions Declaration - Vertex level operations
  //------------------------------------------------------------------------------------
  RLAPI void rlBegin(int mode);                         // Initialize drawing mode (how to organize vertex)
  RLAPI void rlEnd(void);                               // Finish vertex providing
  RLAPI void rlVertex2i(int x, int y);                  // Define one vertex (position) - 2 int
  RLAPI void rlVertex2f(float x, float y);              // Define one vertex (position) - 2 float
  RLAPI void rlVertex3f(float x, float y, float z);     // Define one vertex (position) - 3 float
  RLAPI void rlTexCoord2f(float x, float y);            // Define one vertex (texture coordinate) - 2 float
  RLAPI void rlNormal3f(float x, float y, float z);     // Define one vertex (normal) - 3 float
  RLAPI void rlColor4ub(unsigned char r, unsigned char g, unsigned char b, unsigned char a);  // Define one vertex (color) - 4 byte
  RLAPI void rlColor3f(float x, float y, float z);          // Define one vertex (color) - 3 float
  RLAPI void rlColor4f(float x, float y, float z, float w); // Define one vertex (color) - 4 float
  
  //------------------------------------------------------------------------------------
  // Functions Declaration - OpenGL equivalent functions (common to 1.1, 3.3+, ES2)
  // NOTE: This functions are used to completely abstract raylib code from OpenGL layer
  //------------------------------------------------------------------------------------
  RLAPI void rlEnableTexture(unsigned int id);                  // Enable texture usage
  RLAPI void rlDisableTexture(void);                            // Disable texture usage
  RLAPI void rlTextureParameters(unsigned int id, int param, int value); // Set texture parameters (filter, wrap)
  RLAPI void rlEnableShader(unsigned int id);                   // Enable shader program usage
  RLAPI void rlDisableShader(void);                             // Disable shader program usage
  RLAPI void rlEnableFramebuffer(unsigned int id);              // Enable render texture (fbo)
  RLAPI void rlDisableFramebuffer(void);                        // Disable render texture (fbo), return to default framebuffer
  RLAPI void rlEnableDepthTest(void);                           // Enable depth test
  RLAPI void rlDisableDepthTest(void);                          // Disable depth test
  RLAPI void rlEnableDepthMask(void);                           // Enable depth write
  RLAPI void rlDisableDepthMask(void);                          // Disable depth write
  RLAPI void rlEnableBackfaceCulling(void);                     // Enable backface culling
  RLAPI void rlDisableBackfaceCulling(void);                    // Disable backface culling
  RLAPI void rlEnableScissorTest(void);                         // Enable scissor test
  RLAPI void rlDisableScissorTest(void);                        // Disable scissor test
  RLAPI void rlScissor(int x, int y, int width, int height);    // Scissor test
  RLAPI void rlEnableWireMode(void);                            // Enable wire mode
  RLAPI void rlDisableWireMode(void);                           // Disable wire mode
  RLAPI void rlSetLineWidth(float width);                       // Set the line drawing width
  RLAPI float rlGetLineWidth(void);                             // Get the line drawing width
  RLAPI void rlEnableSmoothLines(void);                         // Enable line aliasing
  RLAPI void rlDisableSmoothLines(void);                        // Disable line aliasing
  
  RLAPI void rlClearColor(unsigned char r, unsigned char g, unsigned char b, unsigned char a);  // Clear color buffer with color
  RLAPI void rlClearScreenBuffers(void);                        // Clear used screen buffers (color and depth)
  RLAPI void rlUpdateBuffer(int bufferId, void *data, int dataSize); // Update GPU buffer with new data
  #if defined(GRAPHICS_API_OPENGL_33) || defined(GRAPHICS_API_OPENGL_46)
    #if defined(ANIMATED_WITH_DUALQUATERNIONS)
  RLAPI void rlUpdateBones(Quaternion *r, Quaternion *t, int count);
    #elif defined(ANIMATED_WITH_MATRIX)
  RLAPI void rlUpdateBones(Matrix *m, int count);
  	#endif
  RLAPI void rlResetBones();
  #endif
  RLAPI unsigned int rlLoadAttribBuffer(unsigned int vaoId, int shaderLoc, void *buffer, int size, bool dynamic);   // Load a new attributes buffer
  
  //------------------------------------------------------------------------------------
  // Functions Declaration - rlgl functionality
  //------------------------------------------------------------------------------------
  RLAPI void rlglInit(int width, int height);           // Initialize rlgl (buffers, shaders, textures, states)
  RLAPI void rlglClose(void);                           // De-inititialize rlgl (buffers, shaders, textures)
  RLAPI void rlglDraw(void);                            // Update and draw default internal buffers
  RLAPI void rlCheckErrors(void);                       // Check and log OpenGL error codes
  
  RLAPI int rlGetVersion(void);                         // Returns current OpenGL version
  RLAPI bool rlCheckBufferLimit(int vCount);            // Check internal buffer overflow for a given number of vertex
  RLAPI void rlSetDebugMarker(const char *text);        // Set debug marker for analysis
  RLAPI void rlSetBlendMode(int glSrcFactor, int glDstFactor, int glEquation);    // // Set blending mode factor and equation (using OpenGL factors)
  RLAPI void rlLoadExtensions(void *loader);            // Load OpenGL extensions
  
  // Textures data management
  RLAPI unsigned int rlLoadTexture(void *data, int width, int height, int format, int mipmapCount); // Load texture in GPU
  RLAPI unsigned int rlLoadTextureDepth(int width, int height, bool useRenderBuffer);               // Load depth texture/renderbuffer (to be attached to fbo)
  RLAPI unsigned int rlLoadTextureCubemap(void *data, int size, int format);                        // Load texture cubemap
  RLAPI void rlUpdateTexture(unsigned int id, int offsetX, int offsetY, int width, int height, int format, const void *data);  // Update GPU texture with new data
  RLAPI void rlGetGlTextureFormats(int format, unsigned int *glInternalFormat, unsigned int *glFormat, unsigned int *glType);  // Get OpenGL internal formats
  RLAPI void rlUnloadTexture(unsigned int id);                              // Unload texture from GPU memory
  
  RLAPI void rlGenerateMipmaps(Texture2D *texture);                         // Generate mipmap data for selected texture
  RLAPI void *rlReadTexturePixels(Texture2D texture);                       // Read texture pixel data
  RLAPI unsigned char *rlReadScreenPixels(int width, int height);           // Read screen pixel data (color buffer)
  
  // Framebuffer management (fbo)
  RLAPI unsigned int rlLoadFramebuffer(int width, int height);              // Load an empty framebuffer
  RLAPI void rlFramebufferAttach(unsigned int fboId, unsigned int texId, int attachType, int texType);  // Attach texture/renderbuffer to a framebuffer
  RLAPI bool rlFramebufferComplete(unsigned int id);                        // Verify framebuffer is complete
  RLAPI void rlUnloadFramebuffer(unsigned int id);                          // Delete framebuffer from GPU
  
  // Vertex data management
  RLAPI void rlLoadMesh(Mesh *mesh, bool dynamic);                          // Upload vertex data into GPU and provided VAO/VBO ids
  RLAPI void rlUpdateMesh(Mesh mesh, int buffer, int count);                // Update vertex or index data on GPU (upload new data to one buffer)
  RLAPI void rlUpdateMeshAt(Mesh mesh, int buffer, int count, int index);   // Update vertex or index data on GPU, at index
  RLAPI void rlDrawMesh(Mesh mesh, Material material, Matrix transform);    // Draw a 3d mesh with material and transform
  RLAPI void rlDrawMeshInstanced(Mesh mesh, Material material, Matrix *transforms, int count);    // Draw a 3d mesh with material and transform
  RLAPI void rlUnloadMesh(Mesh mesh);                                       // Unload mesh data from CPU and GPU
  
  // NOTE: There is a set of shader related functions that are available to end user,
  // to avoid creating function wrappers through core module, they have been directly declared in raylib.h
  
  #if defined(RLGL_STANDALONE)
  //------------------------------------------------------------------------------------
  // Shaders System Functions (Module: rlgl)
  // NOTE: This functions are useless when using OpenGL 1.1
  //------------------------------------------------------------------------------------
  // Shader loading/unloading functions
  RLAPI Shader LoadShader(const char *vsFileName, const char *fsFileName);  // Load shader from files and bind default locations
  RLAPI Shader LoadShaderCode(const char *vsCode, const char *fsCode);      // Load shader from code strings and bind default locations
  RLAPI void UnloadShader(Shader shader);                                   // Unload shader from GPU memory (VRAM)
  
  RLAPI Shader GetShaderDefault(void);                                      // Get default shader
  RLAPI Texture2D GetTextureDefault(void);                                  // Get default texture
  RLAPI Texture2D GetShapesTexture(void);                                   // Get texture to draw shapes
  RLAPI Rectangle GetShapesTextureRec(void);                                // Get texture rectangle to draw shapes
  
  // Shader configuration functions
  RLAPI int GetShaderLocation(Shader shader, const char *uniformName);              // Get shader uniform location
  RLAPI int GetShaderLocationAttrib(Shader shader, const char *attribName);         // Get shader attribute location
  RLAPI void SetShaderValue(Shader shader, int uniformLoc, const void *value, int uniformType);               // Set shader uniform value
  RLAPI void SetShaderValueV(Shader shader, int uniformLoc, const void *value, int uniformType, int count);   // Set shader uniform value vector
  RLAPI void SetShaderValueMatrix(Shader shader, int uniformLoc, Matrix mat);       // Set shader uniform value (matrix 4x4)
  RLAPI void SetMatrixProjection(Matrix proj);                              // Set a custom projection matrix (replaces internal projection matrix)
  RLAPI void SetMatrixModelview(Matrix view);                               // Set a custom modelview matrix (replaces internal modelview matrix)
  RLAPI Matrix GetMatrixModelview(void);                                    // Get internal modelview matrix
  
  // Texture maps generation (PBR)
  // NOTE: Required shaders should be provided
  RLAPI TextureCubemap GenTextureCubemap(Shader shader, Texture2D panorama, int size, int format); // Generate cubemap texture from 2D panorama texture
  RLAPI TextureCubemap GenTextureIrradiance(Shader shader, TextureCubemap cubemap, int size);      // Generate irradiance texture using cubemap data
  RLAPI TextureCubemap GenTexturePrefilter(Shader shader, TextureCubemap cubemap, int size);       // Generate prefilter texture using cubemap data
  RLAPI Texture2D GenTextureBRDF(Shader shader, int size);                  // Generate BRDF texture using cubemap data
  
  // Shading begin/end functions
  RLAPI void BeginShaderMode(Shader shader);              // Begin custom shader drawing
  RLAPI void EndShaderMode(void);                         // End custom shader drawing (use default shader)
  RLAPI void BeginBlendMode(int mode);                    // Begin blending mode (alpha, additive, multiplied)
  RLAPI void EndBlendMode(void);                          // End blending mode (reset to default: alpha blending)
  
  // VR control functions
  RLAPI void InitVrSimulator(void);                       // Init VR simulator for selected device parameters
  RLAPI void CloseVrSimulator(void);                      // Close VR simulator for current device
  RLAPI void UpdateVrTracking(Camera *camera);            // Update VR tracking (position and orientation) and camera
  RLAPI void SetVrConfiguration(VrDeviceInfo info, Shader distortion);      // Set stereo rendering configuration parameters
  RLAPI bool IsVrSimulatorReady(void);                    // Detect if VR simulator is ready
  RLAPI void ToggleVrMode(void);                          // Enable/Disable VR experience
  RLAPI void BeginVrDrawing(void);                        // Begin VR simulator stereo rendering
  RLAPI void EndVrDrawing(void);                          // End VR simulator stereo rendering
  
  RLAPI char *LoadFileText(const char *fileName);         // Load chars array from text file
  RLAPI int GetPixelDataSize(int width, int height, int format);// Get pixel data size in bytes (image or texture)
  #endif
  
  #if defined(__cplusplus)
  }
  #endif
  
  #endif // RLGL_H
  
  /***********************************************************************************
  *
  *   RLGL IMPLEMENTATION
  *
  ************************************************************************************/
  
  #if defined(RLGL_IMPLEMENTATION)
  
  #if defined(RLGL_STANDALONE)
      #include <stdio.h>                  // Required for: fopen(), fseek(), fread(), fclose() [LoadFileText]
  #else
      // Check if config flags have been externally provided on compilation line
      #if !defined(EXTERNAL_CONFIG_FLAGS)
          #include "config.h"             // Defines module configuration flags
      #endif
      #include "raymath.h"                // Required for: Vector3 and Matrix functions
  #endif
  
  #include <stdlib.h>                     // Required for: malloc(), free()
  #include <string.h>                     // Required for: strcmp(), strlen() [Used in rlglInit(), on extensions loading]
  #include <math.h>                       // Required for: atan2f()
  
  #if defined(GRAPHICS_API_OPENGL_11)
      #if defined(__APPLE__)
          #include <OpenGL/gl.h>          // OpenGL 1.1 library for OSX
          #include <OpenGL/glext.h>
      #else
          // APIENTRY for OpenGL function pointer declarations is required
          #ifndef APIENTRY
              #if defined(_WIN32)
                  #define APIENTRY __stdcall
              #else
                  #define APIENTRY
              #endif
          #endif
          // WINGDIAPI definition. Some Windows OpenGL headers need it
          #if !defined(WINGDIAPI) && defined(_WIN32)
              #define WINGDIAPI __declspec(dllimport)
          #endif
  
          #include <GL/gl.h>              // OpenGL 1.1 library
      #endif
  #endif
  
  #if defined(GRAPHICS_API_OPENGL_21)
      #define GRAPHICS_API_OPENGL_33      // OpenGL 2.1 uses mostly OpenGL 3.3 Core functionality
  #endif
  
  #if defined(GRAPHICS_API_OPENGL_33) || defined(GRAPHICS_API_OPENGL_46)
      #if defined(__APPLE__)
          #include <OpenGL/gl3.h>         // OpenGL 3 library for OSX
          #include <OpenGL/gl3ext.h>      // OpenGL 3 extensions library for OSX
      #else
          #define GLAD_REALLOC RL_REALLOC
          #define GLAD_FREE RL_FREE
  
          #define GLAD_IMPLEMENTATION
          #if defined(RLGL_STANDALONE)
              #include "glad.h"           // GLAD extensions loading library, includes OpenGL headers
          #else
              #include "external/glad.h"  // GLAD extensions loading library, includes OpenGL headers
          #endif
  
          #define SHADERPRINTF 1
          #include "external/shaderprintf.h"
  
      #endif
  #endif
  
  #if defined(GRAPHICS_API_OPENGL_ES2)
      #define GL_GLEXT_PROTOTYPES
      #include <EGL/egl.h>                // EGL library
      #include <GLES2/gl2.h>              // OpenGL ES 2.0 library
      #include <GLES2/gl2ext.h>           // OpenGL ES 2.0 extensions library
  #endif
  
  //----------------------------------------------------------------------------------
  // Defines and Macros
  //----------------------------------------------------------------------------------
  #ifndef GL_SHADING_LANGUAGE_VERSION
      #define GL_SHADING_LANGUAGE_VERSION         0x8B8C
  #endif
  
  #ifndef GL_COMPRESSED_RGB_S3TC_DXT1_EXT
      #define GL_COMPRESSED_RGB_S3TC_DXT1_EXT     0x83F0
  #endif
  #ifndef GL_COMPRESSED_RGBA_S3TC_DXT1_EXT
      #define GL_COMPRESSED_RGBA_S3TC_DXT1_EXT    0x83F1
  #endif
  #ifndef GL_COMPRESSED_RGBA_S3TC_DXT3_EXT
      #define GL_COMPRESSED_RGBA_S3TC_DXT3_EXT    0x83F2
  #endif
  #ifndef GL_COMPRESSED_RGBA_S3TC_DXT5_EXT
      #define GL_COMPRESSED_RGBA_S3TC_DXT5_EXT    0x83F3
  #endif
  #ifndef GL_ETC1_RGB8_OES
      #define GL_ETC1_RGB8_OES                    0x8D64
  #endif
  #ifndef GL_COMPRESSED_RGB8_ETC2
      #define GL_COMPRESSED_RGB8_ETC2             0x9274
  #endif
  #ifndef GL_COMPRESSED_RGBA8_ETC2_EAC
      #define GL_COMPRESSED_RGBA8_ETC2_EAC        0x9278
  #endif
  #ifndef GL_COMPRESSED_RGB_PVRTC_4BPPV1_IMG
      #define GL_COMPRESSED_RGB_PVRTC_4BPPV1_IMG  0x8C00
  #endif
  #ifndef GL_COMPRESSED_RGBA_PVRTC_4BPPV1_IMG
      #define GL_COMPRESSED_RGBA_PVRTC_4BPPV1_IMG 0x8C02
  #endif
  #ifndef GL_COMPRESSED_RGBA_ASTC_4x4_KHR
      #define GL_COMPRESSED_RGBA_ASTC_4x4_KHR     0x93b0
  #endif
  #ifndef GL_COMPRESSED_RGBA_ASTC_8x8_KHR
      #define GL_COMPRESSED_RGBA_ASTC_8x8_KHR     0x93b7
  #endif
  
  #ifndef GL_MAX_TEXTURE_MAX_ANISOTROPY_EXT
      #define GL_MAX_TEXTURE_MAX_ANISOTROPY_EXT   0x84FF
  #endif
  #ifndef GL_TEXTURE_MAX_ANISOTROPY_EXT
      #define GL_TEXTURE_MAX_ANISOTROPY_EXT       0x84FE
  #endif
  
  #if defined(GRAPHICS_API_OPENGL_11)
      #define GL_UNSIGNED_SHORT_5_6_5             0x8363
      #define GL_UNSIGNED_SHORT_5_5_5_1           0x8034
      #define GL_UNSIGNED_SHORT_4_4_4_4           0x8033
  #endif
  #if defined(GRAPHICS_API_OPENGL_21)
      #define GL_LUMINANCE                        0x1909
      #define GL_LUMINANCE_ALPHA                  0x190A
  #endif
  
  #if defined(GRAPHICS_API_OPENGL_ES2)
      #define glClearDepth                 glClearDepthf
      #define GL_READ_FRAMEBUFFER         GL_FRAMEBUFFER
      #define GL_DRAW_FRAMEBUFFER         GL_FRAMEBUFFER
  #endif
  
  // Default shader vertex attribute names to set location points
  #ifndef DEFAULT_SHADER_ATTRIB_NAME_POSITION
      #define DEFAULT_SHADER_ATTRIB_NAME_POSITION    "vertexPosition"    // Binded by default to shader location: 0
  #endif
  #ifndef DEFAULT_SHADER_ATTRIB_NAME_TEXCOORD
      #define DEFAULT_SHADER_ATTRIB_NAME_TEXCOORD    "vertexTexCoord"    // Binded by default to shader location: 1
  #endif
  #ifndef DEFAULT_SHADER_ATTRIB_NAME_NORMAL
      #define DEFAULT_SHADER_ATTRIB_NAME_NORMAL      "vertexNormal"      // Binded by default to shader location: 2
  #endif
  #ifndef DEFAULT_SHADER_ATTRIB_NAME_COLOR
      #define DEFAULT_SHADER_ATTRIB_NAME_COLOR       "vertexColor"       // Binded by default to shader location: 3
  #endif
  #ifndef DEFAULT_SHADER_ATTRIB_NAME_TANGENT
      #define DEFAULT_SHADER_ATTRIB_NAME_TANGENT     "vertexTangent"     // Binded by default to shader location: 4
  #endif
  #ifndef DEFAULT_SHADER_ATTRIB_NAME_TEXCOORD2
      #define DEFAULT_SHADER_ATTRIB_NAME_TEXCOORD2   "vertexTexCoord2"   // Binded by default to shader location: 5
  #endif
  #ifndef DEFAULT_SHADER_ATTRIB_NAME_BONEID
      #define DEFAULT_SHADER_ATTRIB_NAME_BONEID      "vertexBoneId"     // Binded by default to shader location: 7
  #endif
  #ifndef DEFAULT_SHADER_ATTRIB_NAME_BONEWEIGHT
      #define DEFAULT_SHADER_ATTRIB_NAME_BONEWEIGHT  "vertexBoneWeight" // Binded by default to shader location: 8
  #endif
  
  //----------------------------------------------------------------------------------
  // Types and Structures Definition
  //----------------------------------------------------------------------------------
  
  // Dynamic vertex buffers (position + texcoords + colors + indices arrays)
  typedef struct VertexBuffer {
      int elementsCount;          // Number of elements in the buffer (QUADS)
  
      int vCounter;               // Vertex position counter to process (and draw) from full buffer
      int tcCounter;              // Vertex texcoord counter to process (and draw) from full buffer
      int cCounter;               // Vertex color counter to process (and draw) from full buffer
  
      float *vertices;            // Vertex position (XYZ - 3 components per vertex) (shader-location = 0)
      float *texcoords;           // Vertex texture coordinates (UV - 2 components per vertex) (shader-location = 1)
      unsigned char *colors;      // Vertex colors (RGBA - 4 components per vertex) (shader-location = 3)
  #if defined(GRAPHICS_API_OPENGL_11) || defined(GRAPHICS_API_OPENGL_33) || defined(GRAPHICS_API_OPENGL_46)
      unsigned int *indices;      // Vertex indices (in case vertex data comes indexed) (6 indices per quad)
  #elif defined(GRAPHICS_API_OPENGL_ES2)
      unsigned short *indices;    // Vertex indices (in case vertex data comes indexed) (6 indices per quad)
  #endif
  	  int *boneIds;
  	  float *boneWeights;
  
  	  unsigned int vaoId;         // OpenGL Vertex Array Object id
      unsigned int vboId[6];      // OpenGL Vertex Buffer Objects id (6 types of vertex data)
  } VertexBuffer;
  
  // Draw call type
  // NOTE: Only texture changes register a new draw, other state-change-related elements are not
  // used at this moment (vaoId, shaderId, matrices), raylib just forces a batch draw call if any
  // of those state-change happens (this is done in core module)
  typedef struct DrawCall {
      int mode;                   // Drawing mode: LINES, TRIANGLES, QUADS
      int vertexCount;            // Number of vertex of the draw
      int vertexAlignment;        // Number of vertex required for index alignment (LINES, TRIANGLES)
      //unsigned int vaoId;       // Vertex array id to be used on the draw -> Using RLGL.currentBatch->vertexBuffer.vaoId
      //unsigned int shaderId;    // Shader id to be used on the draw -> Using RLGL.currentShader.id
      unsigned int textureId;     // Texture id to be used on the draw -> Use to create new draw call if changes
  
      //Matrix projection;        // Projection matrix for this draw -> Using RLGL.projection
      //Matrix modelview;         // Modelview matrix for this draw -> Using RLGL.modelview
  } DrawCall;
  
  // RenderBatch type
  typedef struct RenderBatch {
      int buffersCount;           // Number of vertex buffers (multi-buffering support)
      int currentBuffer;          // Current buffer tracking in case of multi-buffering
      VertexBuffer *vertexBuffer; // Dynamic buffer(s) for vertex data
  
      DrawCall *draws;            // Draw calls array, depends on textureId
      int drawsCounter;           // Draw calls counter
      float currentDepth;         // Current depth value for next draw
  } RenderBatch;
  
  #if defined(SUPPORT_VR_SIMULATOR)
  // VR Stereo rendering configuration for simulator
  typedef struct VrStereoConfig {
      Shader distortionShader;        // VR stereo rendering distortion shader
      Matrix eyesProjection[2];       // VR stereo rendering eyes projection matrices
      Matrix eyesViewOffset[2];       // VR stereo rendering eyes view offset matrices
      int eyeViewportRight[4];        // VR stereo rendering right eye viewport [x, y, w, h]
      int eyeViewportLeft[4];         // VR stereo rendering left eye viewport [x, y, w, h]
  } VrStereoConfig;
  #endif
  
  #if defined(GRAPHICS_API_OPENGL_33) || defined(GRAPHICS_API_OPENGL_46) || defined(GRAPHICS_API_OPENGL_ES2)
  typedef struct rlglData {
      RenderBatch *currentBatch;              // Current render batch
      RenderBatch defaultBatch;               // Default internal render batch
  
      struct {
          int currentMatrixMode;              // Current matrix mode
          Matrix *currentMatrix;              // Current matrix pointer
          Matrix modelview;                   // Default modelview matrix
          Matrix projection;                  // Default projection matrix
          Matrix transform;                   // Transform matrix to be used with rlTranslate, rlRotate, rlScale
          bool transformRequired;             // Require transform matrix application to current draw-call vertex (if required)
          Matrix stack[MAX_MATRIX_STACK_SIZE];// Matrix stack for push/pop
          int stackCounter;                   // Matrix stack counter
  
          Texture2D shapesTexture;            // Texture used on shapes drawing (usually a white pixel)
          Rectangle shapesTextureRec;         // Texture source rectangle used on shapes drawing
          unsigned int defaultTextureId;      // Default texture used on shapes/poly drawing (required by shader)
          unsigned int activeTextureId[4];    // Active texture ids to be enabled on batch drawing (0 active by default)
          unsigned int defaultVShaderId;      // Default vertex shader id (used by default shader program)
          unsigned int defaultFShaderId;      // Default fragment shader Id (used by default shader program)
          Shader defaultShader;               // Basic shader, support vertex color and diffuse texture
          Shader currentShader;               // Shader to be used on rendering (by default, defaultShader)
    	    int boneRotQuaternionsLoc;          // Shader uniforms array for bones using Dual Quaternions
  	      int boneTransQuaternionsLoc;
  	      int boneMatLoc;
  
          int currentBlendMode;               // Blending mode active
          int glBlendSrcFactor;               // Blending source factor
          int glBlendDstFactor;               // Blending destination factor
          int glBlendEquation;                // Blending equation
  
          int framebufferWidth;               // Default framebuffer width
          int framebufferHeight;              // Default framebuffer height
  
      } State;
      struct {
          bool vao;                           // VAO support (OpenGL ES2 could not support VAO extension)
          bool texNPOT;                       // NPOT textures full support
          bool texDepth;                      // Depth textures supported
          bool texFloat32;                    // float textures support (32 bit per channel)
          bool texCompDXT;                    // DDS texture compression support
          bool texCompETC1;                   // ETC1 texture compression support
          bool texCompETC2;                   // ETC2/EAC texture compression support
          bool texCompPVRT;                   // PVR texture compression support
          bool texCompASTC;                   // ASTC texture compression support
          bool texMirrorClamp;                // Clamp mirror wrap mode supported
          bool texAnisoFilter;                // Anisotropic texture filtering support
          bool debugMarker;                   // Debug marker support
  
          float maxAnisotropicLevel;          // Maximum anisotropy level supported (minimum is 2.0f)
          int maxDepthBits;                   // Maximum bits for depth component
  
      } ExtSupported;     // Extensions supported flags
  #if defined(SUPPORT_VR_SIMULATOR)
      struct {
          VrStereoConfig config;              // VR stereo configuration for simulator
          unsigned int stereoFboId;           // VR stereo rendering framebuffer id
          unsigned int stereoTexId;           // VR stereo color texture (attached to framebuffer)
          bool simulatorReady;                // VR simulator ready flag
          bool stereoRender;                  // VR stereo rendering enabled/disabled flag
      } Vr;
  #endif  // SUPPORT_VR_SIMULATOR
  } rlglData;
  #endif  // GRAPHICS_API_OPENGL_33 || GRAPHICS_API_OPENGL_46  || GRAPHICS_API_OPENGL_ES2
  
  //----------------------------------------------------------------------------------
  // Global Variables Definition
  //----------------------------------------------------------------------------------
  #if defined(GRAPHICS_API_OPENGL_33) || defined(GRAPHICS_API_OPENGL_46) || defined(GRAPHICS_API_OPENGL_ES2)
  static rlglData RLGL = { 0 };
  #endif  // GRAPHICS_API_OPENGL_33 || GRAPHICS_API_OPENGL_ES2
  
  #if defined(GRAPHICS_API_OPENGL_ES2)
  // NOTE: VAO functionality is exposed through extensions (OES)
  static PFNGLGENVERTEXARRAYSOESPROC glGenVertexArrays;        // Entry point pointer to function glGenVertexArrays()
  static PFNGLBINDVERTEXARRAYOESPROC glBindVertexArray;        // Entry point pointer to function glBindVertexArray()
  static PFNGLDELETEVERTEXARRAYSOESPROC glDeleteVertexArrays;  // Entry point pointer to function glDeleteVertexArrays()
  #endif
  
  //----------------------------------------------------------------------------------
  // Module specific Functions Declaration
  //----------------------------------------------------------------------------------
  #if defined(GRAPHICS_API_OPENGL_33) || defined(GRAPHICS_API_OPENGL_46)  || defined(GRAPHICS_API_OPENGL_ES2)
  static unsigned int CompileShader(const char *shaderStr, int type);     // Compile custom shader and return shader id
  static unsigned int LoadShaderProgram(unsigned int vShaderId, unsigned int fShaderId);  // Load custom shader program
  
  static Shader LoadShaderDefault(void);                  // Load default shader (just vertex positioning and texture coloring)
  static void SetShaderDefaultLocations(Shader *shader);  // Bind default shader locations (attributes and uniforms)
  static void UnloadShaderDefault(void);                  // Unload default shader
  
  static RenderBatch LoadRenderBatch(int numBuffers, int bufferElements); // Load a render batch system
  static void UnloadRenderBatch(RenderBatch batch);       // Unload render batch system
  static void DrawRenderBatch(RenderBatch *batch);        // Draw render batch data (Update->Draw->Reset)
  static void SetRenderBatchActive(RenderBatch *batch);   // Set the active render batch for rlgl
  static void SetRenderBatchDefault(void);                // Set default render batch for rlgl
  //static bool CheckRenderBatchLimit(RenderBatch batch, int vCount);   // Check render batch vertex buffer limits
  
  static void GenDrawCube(void);              // Generate and draw cube
  static void GenDrawQuad(void);              // Generate and draw quad
  
  #if defined(SUPPORT_VR_SIMULATOR)
  static void SetStereoView(int eye, Matrix matProjection, Matrix matModelView);  // Set internal projection and modelview matrix depending on eye
  #endif
  
  #endif  // GRAPHICS_API_OPENGL_33 || GRAPHICS_API_OPENGL_46 || GRAPHICS_API_OPENGL_ES2
  
  #if defined(GRAPHICS_API_OPENGL_11)
  static int GenerateMipmaps(unsigned char *data, int baseWidth, int baseHeight);
  static Color *GenNextMipmap(Color *srcData, int srcWidth, int srcHeight);
  #endif
  
  //----------------------------------------------------------------------------------
  // Module Functions Definition - Matrix operations
  //----------------------------------------------------------------------------------
  
  #if defined(GRAPHICS_API_OPENGL_11)
  
  // Fallback to OpenGL 1.1 function calls
  //---------------------------------------
  void rlMatrixMode(int mode)
  {
      switch (mode)
      {
          case RL_PROJECTION: glMatrixMode(GL_PROJECTION); break;
          case RL_MODELVIEW: glMatrixMode(GL_MODELVIEW); break;
          case RL_TEXTURE: glMatrixMode(GL_TEXTURE); break;
          default: break;
      }
  }
  
  void rlFrustum(double left, double right, double bottom, double top, double znear, double zfar)
  {
      glFrustum(left, right, bottom, top, znear, zfar);
  }
  
  void rlOrtho(double left, double right, double bottom, double top, double znear, double zfar)
  {
      glOrtho(left, right, bottom, top, znear, zfar);
  }
  
  void rlPushMatrix(void) { glPushMatrix(); }
  void rlPopMatrix(void) { glPopMatrix(); }
  void rlLoadIdentity(void) { glLoadIdentity(); }
  void rlTranslatef(float x, float y, float z) { glTranslatef(x, y, z); }
  void rlRotatef(float angleDeg, float x, float y, float z) { glRotatef(angleDeg, x, y, z); }
  void rlScalef(float x, float y, float z) { glScalef(x, y, z); }
  void rlMultMatrixf(float *matf) { glMultMatrixf(matf); }
  
  #elif defined(GRAPHICS_API_OPENGL_33) || defined(GRAPHICS_API_OPENGL_46) || defined(GRAPHICS_API_OPENGL_ES2)
  
  // Choose the current matrix to be transformed
  void rlMatrixMode(int mode)
  {
      if (mode == RL_PROJECTION) RLGL.State.currentMatrix = &RLGL.State.projection;
      else if (mode == RL_MODELVIEW) RLGL.State.currentMatrix = &RLGL.State.modelview;
      //else if (mode == RL_TEXTURE) // Not supported
  
      RLGL.State.currentMatrixMode = mode;
  }
  
  // Push the current matrix into RLGL.State.stack
  void rlPushMatrix(void)
  {
      if (RLGL.State.stackCounter >= MAX_MATRIX_STACK_SIZE) TRACELOG(LOG_ERROR, "RLGL: Matrix stack overflow (MAX_MATRIX_STACK_SIZE)");
  
      if (RLGL.State.currentMatrixMode == RL_MODELVIEW)
      {
          RLGL.State.transformRequired = true;
          RLGL.State.currentMatrix = &RLGL.State.transform;
      }
  
      RLGL.State.stack[RLGL.State.stackCounter] = *RLGL.State.currentMatrix;
      RLGL.State.stackCounter++;
  }
  
  // Pop lattest inserted matrix from RLGL.State.stack
  void rlPopMatrix(void)
  {
      if (RLGL.State.stackCounter > 0)
      {
          Matrix mat = RLGL.State.stack[RLGL.State.stackCounter - 1];
          *RLGL.State.currentMatrix = mat;
          RLGL.State.stackCounter--;
      }
  
      if ((RLGL.State.stackCounter == 0) && (RLGL.State.currentMatrixMode == RL_MODELVIEW))
      {
          RLGL.State.currentMatrix = &RLGL.State.modelview;
          RLGL.State.transformRequired = false;
      }
  }
  
  // Reset current matrix to identity matrix
  void rlLoadIdentity(void)
  {
      *RLGL.State.currentMatrix = MatrixIdentity();
  }
  
  // Multiply the current matrix by a translation matrix
  void rlTranslatef(float x, float y, float z)
  {
      Matrix matTranslation = MatrixTranslate(x, y, z);
  
      // NOTE: We transpose matrix with multiplication order
      *RLGL.State.currentMatrix = MatrixMultiply(matTranslation, *RLGL.State.currentMatrix);
  }
  
  // Multiply the current matrix by a rotation matrix
  void rlRotatef(float angleDeg, float x, float y, float z)
  {
      Matrix matRotation = MatrixIdentity();
  
      Vector3 axis = (Vector3){ x, y, z };
      matRotation = MatrixRotate(Vector3Normalize(axis), angleDeg*DEG2RAD);
  
      // NOTE: We transpose matrix with multiplication order
      *RLGL.State.currentMatrix = MatrixMultiply(matRotation, *RLGL.State.currentMatrix);
  }
  
  // Multiply the current matrix by a scaling matrix
  void rlScalef(float x, float y, float z)
  {
      Matrix matScale = MatrixScale(x, y, z);
  
      // NOTE: We transpose matrix with multiplication order
      *RLGL.State.currentMatrix = MatrixMultiply(matScale, *RLGL.State.currentMatrix);
  }
  
  // Multiply the current matrix by another matrix
  void rlMultMatrixf(float *matf)
  {
      // Matrix creation from array
      Matrix mat = { matf[0], matf[4], matf[8], matf[12],
                     matf[1], matf[5], matf[9], matf[13],
                     matf[2], matf[6], matf[10], matf[14],
                     matf[3], matf[7], matf[11], matf[15] };
  
      *RLGL.State.currentMatrix = MatrixMultiply(*RLGL.State.currentMatrix, mat);
  }
  
  // Multiply the current matrix by a perspective matrix generated by parameters
  void rlFrustum(double left, double right, double bottom, double top, double znear, double zfar)
  {
      Matrix matPerps = MatrixFrustum(left, right, bottom, top, znear, zfar);
  
      *RLGL.State.currentMatrix = MatrixMultiply(*RLGL.State.currentMatrix, matPerps);
  }
  
  // Multiply the current matrix by an orthographic matrix generated by parameters
  void rlOrtho(double left, double right, double bottom, double top, double znear, double zfar)
  {
      Matrix matOrtho = MatrixOrtho(left, right, bottom, top, znear, zfar);
  
      *RLGL.State.currentMatrix = MatrixMultiply(*RLGL.State.currentMatrix, matOrtho);
  }
  
  #endif
  
  // Set the viewport area (transformation from normalized device coordinates to window coordinates)
  void rlViewport(int x, int y, int width, int height)
  {
      glViewport(x, y, width, height);
  }
  
  //----------------------------------------------------------------------------------
  // Module Functions Definition - Vertex level operations
  //----------------------------------------------------------------------------------
  #if defined(GRAPHICS_API_OPENGL_11)
  
  // Fallback to OpenGL 1.1 function calls
  //---------------------------------------
  void rlBegin(int mode)
  {
      switch (mode)
      {
          case RL_LINES: glBegin(GL_LINES); break;
          case RL_TRIANGLES: glBegin(GL_TRIANGLES); break;
          case RL_QUADS: glBegin(GL_QUADS); break;
          default: break;
      }
  }
  
  void rlEnd() { glEnd(); }
  void rlVertex2i(int x, int y) { glVertex2i(x, y); }
  void rlVertex2f(float x, float y) { glVertex2f(x, y); }
  void rlVertex3f(float x, float y, float z) { glVertex3f(x, y, z); }
  void rlTexCoord2f(float x, float y) { glTexCoord2f(x, y); }
  void rlNormal3f(float x, float y, float z) { glNormal3f(x, y, z); }
  void rlColor4ub(unsigned char r, unsigned char g, unsigned char b, unsigned char a) { glColor4ub(r, g, b, a); }
  void rlColor3f(float x, float y, float z) { glColor3f(x, y, z); }
  void rlColor4f(float x, float y, float z, float w) { glColor4f(x, y, z, w); }
  
  #elif defined(GRAPHICS_API_OPENGL_33) || defined(GRAPHICS_API_OPENGL_46)  || defined(GRAPHICS_API_OPENGL_ES2)
  
  // Initialize drawing mode (how to organize vertex)
  void rlBegin(int mode)
  {
      // Draw mode can be RL_LINES, RL_TRIANGLES and RL_QUADS
      // NOTE: In all three cases, vertex are accumulated over default internal vertex buffer
      if (RLGL.currentBatch->draws[RLGL.currentBatch->drawsCounter - 1].mode != mode)
      {
          if (RLGL.currentBatch->draws[RLGL.currentBatch->drawsCounter - 1].vertexCount > 0)
          {
              // Make sure current RLGL.currentBatch->draws[i].vertexCount is aligned a multiple of 4,
              // that way, following QUADS drawing will keep aligned with index processing
              // It implies adding some extra alignment vertex at the end of the draw,
              // those vertex are not processed but they are considered as an additional offset
              // for the next set of vertex to be drawn
              if (RLGL.currentBatch->draws[RLGL.currentBatch->drawsCounter - 1].mode == RL_LINES) RLGL.currentBatch->draws[RLGL.currentBatch->drawsCounter - 1].vertexAlignment = ((RLGL.currentBatch->draws[RLGL.currentBatch->drawsCounter - 1].vertexCount < 4)? RLGL.currentBatch->draws[RLGL.currentBatch->drawsCounter - 1].vertexCount : RLGL.currentBatch->draws[RLGL.currentBatch->drawsCounter - 1].vertexCount%4);
              else if (RLGL.currentBatch->draws[RLGL.currentBatch->drawsCounter - 1].mode == RL_TRIANGLES) RLGL.currentBatch->draws[RLGL.currentBatch->drawsCounter - 1].vertexAlignment = ((RLGL.currentBatch->draws[RLGL.currentBatch->drawsCounter - 1].vertexCount < 4)? 1 : (4 - (RLGL.currentBatch->draws[RLGL.currentBatch->drawsCounter - 1].vertexCount%4)));
  
              else RLGL.currentBatch->draws[RLGL.currentBatch->drawsCounter - 1].vertexAlignment = 0;
  
              if (rlCheckBufferLimit(RLGL.currentBatch->draws[RLGL.currentBatch->drawsCounter - 1].vertexAlignment)) DrawRenderBatch(RLGL.currentBatch);
              else
              {
                  RLGL.currentBatch->vertexBuffer[RLGL.currentBatch->currentBuffer].vCounter += RLGL.currentBatch->draws[RLGL.currentBatch->drawsCounter - 1].vertexAlignment;
                  RLGL.currentBatch->vertexBuffer[RLGL.currentBatch->currentBuffer].cCounter += RLGL.currentBatch->draws[RLGL.currentBatch->drawsCounter - 1].vertexAlignment;
                  RLGL.currentBatch->vertexBuffer[RLGL.currentBatch->currentBuffer].tcCounter += RLGL.currentBatch->draws[RLGL.currentBatch->drawsCounter - 1].vertexAlignment;
  
                  RLGL.currentBatch->drawsCounter++;
              }
          }
  
          if (RLGL.currentBatch->drawsCounter >= DEFAULT_BATCH_DRAWCALLS) DrawRenderBatch(RLGL.currentBatch);
  
          RLGL.currentBatch->draws[RLGL.currentBatch->drawsCounter - 1].mode = mode;
          RLGL.currentBatch->draws[RLGL.currentBatch->drawsCounter - 1].vertexCount = 0;
          RLGL.currentBatch->draws[RLGL.currentBatch->drawsCounter - 1].textureId = RLGL.State.defaultTextureId;
      }
  }
  
  // Finish vertex providing
  void rlEnd(void)
  {
      // Make sure vertexCount is the same for vertices, texcoords, colors and normals
      // NOTE: In OpenGL 1.1, one glColor call can be made for all the subsequent glVertex calls
  
      // Make sure colors count match vertex count
      if (RLGL.currentBatch->vertexBuffer[RLGL.currentBatch->currentBuffer].vCounter != RLGL.currentBatch->vertexBuffer[RLGL.currentBatch->currentBuffer].cCounter)
      {
          int addColors = RLGL.currentBatch->vertexBuffer[RLGL.currentBatch->currentBuffer].vCounter - RLGL.currentBatch->vertexBuffer[RLGL.currentBatch->currentBuffer].cCounter;
  
          for (int i = 0; i < addColors; i++)
          {
              RLGL.currentBatch->vertexBuffer[RLGL.currentBatch->currentBuffer].colors[4*RLGL.currentBatch->vertexBuffer[RLGL.currentBatch->currentBuffer].cCounter] = RLGL.currentBatch->vertexBuffer[RLGL.currentBatch->currentBuffer].colors[4*RLGL.currentBatch->vertexBuffer[RLGL.currentBatch->currentBuffer].cCounter - 4];
              RLGL.currentBatch->vertexBuffer[RLGL.currentBatch->currentBuffer].colors[4*RLGL.currentBatch->vertexBuffer[RLGL.currentBatch->currentBuffer].cCounter + 1] = RLGL.currentBatch->vertexBuffer[RLGL.currentBatch->currentBuffer].colors[4*RLGL.currentBatch->vertexBuffer[RLGL.currentBatch->currentBuffer].cCounter - 3];
              RLGL.currentBatch->vertexBuffer[RLGL.currentBatch->currentBuffer].colors[4*RLGL.currentBatch->vertexBuffer[RLGL.currentBatch->currentBuffer].cCounter + 2] = RLGL.currentBatch->vertexBuffer[RLGL.currentBatch->currentBuffer].colors[4*RLGL.currentBatch->vertexBuffer[RLGL.currentBatch->currentBuffer].cCounter - 2];
              RLGL.currentBatch->vertexBuffer[RLGL.currentBatch->currentBuffer].colors[4*RLGL.currentBatch->vertexBuffer[RLGL.currentBatch->currentBuffer].cCounter + 3] = RLGL.currentBatch->vertexBuffer[RLGL.currentBatch->currentBuffer].colors[4*RLGL.currentBatch->vertexBuffer[RLGL.currentBatch->currentBuffer].cCounter - 1];
              RLGL.currentBatch->vertexBuffer[RLGL.currentBatch->currentBuffer].cCounter++;
          }
      }
  
      // Make sure texcoords count match vertex count
      if (RLGL.currentBatch->vertexBuffer[RLGL.currentBatch->currentBuffer].vCounter != RLGL.currentBatch->vertexBuffer[RLGL.currentBatch->currentBuffer].tcCounter)
      {
          int addTexCoords = RLGL.currentBatch->vertexBuffer[RLGL.currentBatch->currentBuffer].vCounter - RLGL.currentBatch->vertexBuffer[RLGL.currentBatch->currentBuffer].tcCounter;
  
          for (int i = 0; i < addTexCoords; i++)
          {
              RLGL.currentBatch->vertexBuffer[RLGL.currentBatch->currentBuffer].texcoords[2*RLGL.currentBatch->vertexBuffer[RLGL.currentBatch->currentBuffer].tcCounter] = 0.0f;
              RLGL.currentBatch->vertexBuffer[RLGL.currentBatch->currentBuffer].texcoords[2*RLGL.currentBatch->vertexBuffer[RLGL.currentBatch->currentBuffer].tcCounter + 1] = 0.0f;
              RLGL.currentBatch->vertexBuffer[RLGL.currentBatch->currentBuffer].tcCounter++;
          }
      }
  
      // TODO: Make sure normals count match vertex count... if normals support is added in a future... :P
  
      // NOTE: Depth increment is dependant on rlOrtho(): z-near and z-far values,
      // as well as depth buffer bit-depth (16bit or 24bit or 32bit)
      // Correct increment formula would be: depthInc = (zfar - znear)/pow(2, bits)
      RLGL.currentBatch->currentDepth += (1.0f/20000.0f);
  
      // Verify internal buffers limits
      // NOTE: This check is combined with usage of rlCheckBufferLimit()
      if ((RLGL.currentBatch->vertexBuffer[RLGL.currentBatch->currentBuffer].vCounter) >= (RLGL.currentBatch->vertexBuffer[RLGL.currentBatch->currentBuffer].elementsCount*4 - 4))
      {
          // WARNING: If we are between rlPushMatrix() and rlPopMatrix() and we need to force a DrawRenderBatch(),
          // we need to call rlPopMatrix() before to recover *RLGL.State.currentMatrix (RLGL.State.modelview) for the next forced draw call!
          // If we have multiple matrix pushed, it will require "RLGL.State.stackCounter" pops before launching the draw
          for (int i = RLGL.State.stackCounter; i >= 0; i--) rlPopMatrix();
          DrawRenderBatch(RLGL.currentBatch);
      }
  }
  
  // Define one vertex (position)
  // NOTE: Vertex position data is the basic information required for drawing
  void rlVertex3f(float x, float y, float z)
  {
      Vector3 vec = { x, y, z };
  
      // Transform provided vector if required
      if (RLGL.State.transformRequired) vec = Vector3Transform(vec, RLGL.State.transform);
  
      // Verify that current vertex buffer elements limit has not been reached
      if (RLGL.currentBatch->vertexBuffer[RLGL.currentBatch->currentBuffer].vCounter < (RLGL.currentBatch->vertexBuffer[RLGL.currentBatch->currentBuffer].elementsCount*4))
      {
          RLGL.currentBatch->vertexBuffer[RLGL.currentBatch->currentBuffer].vertices[3*RLGL.currentBatch->vertexBuffer[RLGL.currentBatch->currentBuffer].vCounter] = vec.x;
          RLGL.currentBatch->vertexBuffer[RLGL.currentBatch->currentBuffer].vertices[3*RLGL.currentBatch->vertexBuffer[RLGL.currentBatch->currentBuffer].vCounter + 1] = vec.y;
          RLGL.currentBatch->vertexBuffer[RLGL.currentBatch->currentBuffer].vertices[3*RLGL.currentBatch->vertexBuffer[RLGL.currentBatch->currentBuffer].vCounter + 2] = vec.z;
  
          RLGL.currentBatch->vertexBuffer[RLGL.currentBatch->currentBuffer].boneIds[4*RLGL.currentBatch->vertexBuffer[RLGL.currentBatch->currentBuffer].vCounter] = 0;
          RLGL.currentBatch->vertexBuffer[RLGL.currentBatch->currentBuffer].boneIds[4*RLGL.currentBatch->vertexBuffer[RLGL.currentBatch->currentBuffer].vCounter + 1] = 0;
          RLGL.currentBatch->vertexBuffer[RLGL.currentBatch->currentBuffer].boneIds[4*RLGL.currentBatch->vertexBuffer[RLGL.currentBatch->currentBuffer].vCounter + 2] = 0;
          RLGL.currentBatch->vertexBuffer[RLGL.currentBatch->currentBuffer].boneIds[4*RLGL.currentBatch->vertexBuffer[RLGL.currentBatch->currentBuffer].vCounter + 3] = 0;
  
          RLGL.currentBatch->vertexBuffer[RLGL.currentBatch->currentBuffer].boneWeights[4*RLGL.currentBatch->vertexBuffer[RLGL.currentBatch->currentBuffer].vCounter] = 1.0f;
          RLGL.currentBatch->vertexBuffer[RLGL.currentBatch->currentBuffer].boneWeights[4*RLGL.currentBatch->vertexBuffer[RLGL.currentBatch->currentBuffer].vCounter + 1] = 0.0f;
          RLGL.currentBatch->vertexBuffer[RLGL.currentBatch->currentBuffer].boneWeights[4*RLGL.currentBatch->vertexBuffer[RLGL.currentBatch->currentBuffer].vCounter + 2] = 0.0f;
          RLGL.currentBatch->vertexBuffer[RLGL.currentBatch->currentBuffer].boneWeights[4*RLGL.currentBatch->vertexBuffer[RLGL.currentBatch->currentBuffer].vCounter + 3] = 0.0f;
  
  
          RLGL.currentBatch->vertexBuffer[RLGL.currentBatch->currentBuffer].vCounter++;
  
          RLGL.currentBatch->draws[RLGL.currentBatch->drawsCounter - 1].vertexCount++;
      }
      else TRACELOG(LOG_ERROR, "RLGL: Batch elements overflow");
  }
  
  // Define one vertex (position)
  void rlVertex2f(float x, float y)
  {
      rlVertex3f(x, y, RLGL.currentBatch->currentDepth);
  }
  
  // Define one vertex (position)
  void rlVertex2i(int x, int y)
  {
      rlVertex3f((float)x, (float)y, RLGL.currentBatch->currentDepth);
  }
  
  // Define one vertex (texture coordinate)
  // NOTE: Texture coordinates are limited to QUADS only
  void rlTexCoord2f(float x, float y)
  {
      RLGL.currentBatch->vertexBuffer[RLGL.currentBatch->currentBuffer].texcoords[2*RLGL.currentBatch->vertexBuffer[RLGL.currentBatch->currentBuffer].tcCounter] = x;
      RLGL.currentBatch->vertexBuffer[RLGL.currentBatch->currentBuffer].texcoords[2*RLGL.currentBatch->vertexBuffer[RLGL.currentBatch->currentBuffer].tcCounter + 1] = y;
      RLGL.currentBatch->vertexBuffer[RLGL.currentBatch->currentBuffer].tcCounter++;
  }
  
  // Define one vertex (normal)
  // NOTE: Normals limited to TRIANGLES only?
  void rlNormal3f(float x, float y, float z)
  {
      // TODO: Normals usage...
  }
  
  // Define one vertex (color)
  void rlColor4ub(unsigned char x, unsigned char y, unsigned char z, unsigned char w)
  {
      RLGL.currentBatch->vertexBuffer[RLGL.currentBatch->currentBuffer].colors[4*RLGL.currentBatch->vertexBuffer[RLGL.currentBatch->currentBuffer].cCounter] = x;
      RLGL.currentBatch->vertexBuffer[RLGL.currentBatch->currentBuffer].colors[4*RLGL.currentBatch->vertexBuffer[RLGL.currentBatch->currentBuffer].cCounter + 1] = y;
      RLGL.currentBatch->vertexBuffer[RLGL.currentBatch->currentBuffer].colors[4*RLGL.currentBatch->vertexBuffer[RLGL.currentBatch->currentBuffer].cCounter + 2] = z;
      RLGL.currentBatch->vertexBuffer[RLGL.currentBatch->currentBuffer].colors[4*RLGL.currentBatch->vertexBuffer[RLGL.currentBatch->currentBuffer].cCounter + 3] = w;
      RLGL.currentBatch->vertexBuffer[RLGL.currentBatch->currentBuffer].cCounter++;
  }
  
  // Define one vertex (color)
  void rlColor4f(float r, float g, float b, float a)
  {
      rlColor4ub((unsigned char)(r*255), (unsigned char)(g*255), (unsigned char)(b*255), (unsigned char)(a*255));
  }
  
  // Define one vertex (color)
  void rlColor3f(float x, float y, float z)
  {
      rlColor4ub((unsigned char)(x*255), (unsigned char)(y*255), (unsigned char)(z*255), 255);
  }
  
  #endif
  
  //----------------------------------------------------------------------------------
  // Module Functions Definition - OpenGL equivalent functions (common to 1.1, 3.3+, ES2)
  //----------------------------------------------------------------------------------
  
  // Enable texture usage
  void rlEnableTexture(unsigned int id)
  {
  #if defined(GRAPHICS_API_OPENGL_11)
      glEnable(GL_TEXTURE_2D);
      glBindTexture(GL_TEXTURE_2D, id);
  #endif
  
  #if defined(GRAPHICS_API_OPENGL_33) || defined(GRAPHICS_API_OPENGL_46)  || defined(GRAPHICS_API_OPENGL_ES2)
      if (RLGL.currentBatch->draws[RLGL.currentBatch->drawsCounter - 1].textureId != id)
      {
          if (RLGL.currentBatch->draws[RLGL.currentBatch->drawsCounter - 1].vertexCount > 0)
          {
              // Make sure current RLGL.currentBatch->draws[i].vertexCount is aligned a multiple of 4,
              // that way, following QUADS drawing will keep aligned with index processing
              // It implies adding some extra alignment vertex at the end of the draw,
              // those vertex are not processed but they are considered as an additional offset
              // for the next set of vertex to be drawn
              if (RLGL.currentBatch->draws[RLGL.currentBatch->drawsCounter - 1].mode == RL_LINES) RLGL.currentBatch->draws[RLGL.currentBatch->drawsCounter - 1].vertexAlignment = ((RLGL.currentBatch->draws[RLGL.currentBatch->drawsCounter - 1].vertexCount < 4)? RLGL.currentBatch->draws[RLGL.currentBatch->drawsCounter - 1].vertexCount : RLGL.currentBatch->draws[RLGL.currentBatch->drawsCounter - 1].vertexCount%4);
              else if (RLGL.currentBatch->draws[RLGL.currentBatch->drawsCounter - 1].mode == RL_TRIANGLES) RLGL.currentBatch->draws[RLGL.currentBatch->drawsCounter - 1].vertexAlignment = ((RLGL.currentBatch->draws[RLGL.currentBatch->drawsCounter - 1].vertexCount < 4)? 1 : (4 - (RLGL.currentBatch->draws[RLGL.currentBatch->drawsCounter - 1].vertexCount%4)));
  
              else RLGL.currentBatch->draws[RLGL.currentBatch->drawsCounter - 1].vertexAlignment = 0;
  
              if (rlCheckBufferLimit(RLGL.currentBatch->draws[RLGL.currentBatch->drawsCounter - 1].vertexAlignment)) DrawRenderBatch(RLGL.currentBatch);
              else
              {
                  RLGL.currentBatch->vertexBuffer[RLGL.currentBatch->currentBuffer].vCounter += RLGL.currentBatch->draws[RLGL.currentBatch->drawsCounter - 1].vertexAlignment;
                  RLGL.currentBatch->vertexBuffer[RLGL.currentBatch->currentBuffer].cCounter += RLGL.currentBatch->draws[RLGL.currentBatch->drawsCounter - 1].vertexAlignment;
                  RLGL.currentBatch->vertexBuffer[RLGL.currentBatch->currentBuffer].tcCounter += RLGL.currentBatch->draws[RLGL.currentBatch->drawsCounter - 1].vertexAlignment;
  
                  RLGL.currentBatch->drawsCounter++;
              }
          }
  
          if (RLGL.currentBatch->drawsCounter >= DEFAULT_BATCH_DRAWCALLS) DrawRenderBatch(RLGL.currentBatch);
  
          RLGL.currentBatch->draws[RLGL.currentBatch->drawsCounter - 1].textureId = id;
          RLGL.currentBatch->draws[RLGL.currentBatch->drawsCounter - 1].vertexCount = 0;
      }
  #endif
  }
  
  // Disable texture usage
  void rlDisableTexture(void)
  {
  #if defined(GRAPHICS_API_OPENGL_11)
      glDisable(GL_TEXTURE_2D);
      glBindTexture(GL_TEXTURE_2D, 0);
  #else
      // NOTE: If quads batch limit is reached,
      // we force a draw call and next batch starts
      if (RLGL.currentBatch->vertexBuffer[RLGL.currentBatch->currentBuffer].vCounter >= (RLGL.currentBatch->vertexBuffer[RLGL.currentBatch->currentBuffer].elementsCount*4)) DrawRenderBatch(RLGL.currentBatch);
  #endif
  }
  
  // Set texture parameters (wrap mode/filter mode)
  void rlTextureParameters(unsigned int id, int param, int value)
  {
      glBindTexture(GL_TEXTURE_2D, id);
  
      switch (param)
      {
          case RL_TEXTURE_WRAP_S:
          case RL_TEXTURE_WRAP_T:
          {
              if (value == RL_WRAP_MIRROR_CLAMP)
              {
  #if !defined(GRAPHICS_API_OPENGL_11)
                  if (RLGL.ExtSupported.texMirrorClamp) glTexParameteri(GL_TEXTURE_2D, param, value);
                  else TRACELOG(LOG_WARNING, "GL: Clamp mirror wrap mode not supported (GL_MIRROR_CLAMP_EXT)");
  #endif
              }
              else glTexParameteri(GL_TEXTURE_2D, param, value);
  
          } break;
          case RL_TEXTURE_MAG_FILTER:
          case RL_TEXTURE_MIN_FILTER: glTexParameteri(GL_TEXTURE_2D, param, value); break;
          case RL_TEXTURE_ANISOTROPIC_FILTER:
          {
  #if !defined(GRAPHICS_API_OPENGL_11)
              if (value <= RLGL.ExtSupported.maxAnisotropicLevel) glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MAX_ANISOTROPY_EXT, (float)value);
              else if (RLGL.ExtSupported.maxAnisotropicLevel > 0.0f)
              {
                  TRACELOG(LOG_WARNING, "GL: Maximum anisotropic filter level supported is %iX", id, RLGL.ExtSupported.maxAnisotropicLevel);
                  glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MAX_ANISOTROPY_EXT, (float)value);
              }
              else TRACELOG(LOG_WARNING, "GL: Anisotropic filtering not supported");
  #endif
          } break;
          default: break;
      }
  
      glBindTexture(GL_TEXTURE_2D, 0);
  }
  
  // Enable shader program usage
  void rlEnableShader(unsigned int id)
  {
  #if (defined(GRAPHICS_API_OPENGL_33) || defined(GRAPHICS_API_OPENGL_46)  || defined(GRAPHICS_API_OPENGL_ES2))
      glUseProgram(id);
  #endif
  }
  
  // Disable shader program usage
  void rlDisableShader(void)
  {
  #if (defined(GRAPHICS_API_OPENGL_33) || defined(GRAPHICS_API_OPENGL_46)  || defined(GRAPHICS_API_OPENGL_ES2))
      glUseProgram(0);
  #endif
  }
  
  // Enable rendering to texture (fbo)
  void rlEnableFramebuffer(unsigned int id)
  {
  #if (defined(GRAPHICS_API_OPENGL_33) || defined(GRAPHICS_API_OPENGL_46)  || defined(GRAPHICS_API_OPENGL_ES2)) && defined(SUPPORT_RENDER_TEXTURES_HINT)
      glBindFramebuffer(GL_FRAMEBUFFER, id);
  #endif
  }
  
  // Disable rendering to texture
  void rlDisableFramebuffer(void)
  {
  #if (defined(GRAPHICS_API_OPENGL_33) || defined(GRAPHICS_API_OPENGL_46)  || defined(GRAPHICS_API_OPENGL_ES2)) && defined(SUPPORT_RENDER_TEXTURES_HINT)
      glBindFramebuffer(GL_FRAMEBUFFER, 0);
  #endif
  }
  
  // Enable depth test
  void rlEnableDepthTest(void) { glEnable(GL_DEPTH_TEST); }
  
  // Disable depth test
  void rlDisableDepthTest(void) { glDisable(GL_DEPTH_TEST); }
  
  // Enable depth write
  void rlEnableDepthMask(void) { glDepthMask(GL_TRUE); }
  
  // Disable depth write
  void rlDisableDepthMask(void) { glDepthMask(GL_FALSE); }
  
  // Enable backface culling
  void rlEnableBackfaceCulling(void) { glEnable(GL_CULL_FACE); }
  
  // Disable backface culling
  void rlDisableBackfaceCulling(void) { glDisable(GL_CULL_FACE); }
  
  // Enable scissor test
  RLAPI void rlEnableScissorTest(void) { glEnable(GL_SCISSOR_TEST); }
  
  // Disable scissor test
  RLAPI void rlDisableScissorTest(void) { glDisable(GL_SCISSOR_TEST); }
  
  // Scissor test
  RLAPI void rlScissor(int x, int y, int width, int height) { glScissor(x, y, width, height); }
  
  // Enable wire mode
  void rlEnableWireMode(void)
  {
  #if defined(GRAPHICS_API_OPENGL_11) || defined(GRAPHICS_API_OPENGL_33) || defined(GRAPHICS_API_OPENGL_46)
      // NOTE: glPolygonMode() not available on OpenGL ES
      glPolygonMode(GL_FRONT_AND_BACK, GL_LINE);
  #endif
  }
  
  // Disable wire mode
  void rlDisableWireMode(void)
  {
  #if defined(GRAPHICS_API_OPENGL_11) || defined(GRAPHICS_API_OPENGL_33) || defined(GRAPHICS_API_OPENGL_46)
      // NOTE: glPolygonMode() not available on OpenGL ES
      glPolygonMode(GL_FRONT_AND_BACK, GL_FILL);
  #endif
  }
  // Set the line drawing width
  void rlSetLineWidth(float width)
  {
      glLineWidth(width);
  }
  
  // Get the line drawing width
  float rlGetLineWidth(void)
  {
      float width = 0;
      glGetFloatv(GL_LINE_WIDTH, &width);
      return width;
  }
  
  // Enable line aliasing
  void rlEnableSmoothLines(void)
  {
  #if defined(GRAPHICS_API_OPENGL_33) || defined(GRAPHICS_API_OPENGL_46) || defined(GRAPHICS_API_OPENGL_21) || defined(GRAPHICS_API_OPENGL_11)
      glEnable(GL_LINE_SMOOTH);
  #endif
  }
  
  // Disable line aliasing
  void rlDisableSmoothLines(void)
  {
  #if defined(GRAPHICS_API_OPENGL_33) || defined(GRAPHICS_API_OPENGL_46) || defined(GRAPHICS_API_OPENGL_21) || defined(GRAPHICS_API_OPENGL_11)
      glDisable(GL_LINE_SMOOTH);
  #endif
  }
  
  // Unload framebuffer from GPU memory
  // NOTE: All attached textures/cubemaps/renderbuffers are also deleted
  void rlUnloadFramebuffer(unsigned int id)
  {
  #if (defined(GRAPHICS_API_OPENGL_33) || defined(GRAPHICS_API_OPENGL_46) || defined(GRAPHICS_API_OPENGL_ES2)) && defined(SUPPORT_RENDER_TEXTURES_HINT)
  
      // Query depth attachment to automatically delete texture/renderbuffer
      int depthType = 0, depthId = 0;
      glBindFramebuffer(GL_FRAMEBUFFER, id);   // Bind framebuffer to query depth texture type
      glGetFramebufferAttachmentParameteriv(GL_FRAMEBUFFER, GL_DEPTH_ATTACHMENT, GL_FRAMEBUFFER_ATTACHMENT_OBJECT_TYPE, &depthType);
      glGetFramebufferAttachmentParameteriv(GL_FRAMEBUFFER, GL_DEPTH_ATTACHMENT, GL_FRAMEBUFFER_ATTACHMENT_OBJECT_NAME, &depthId);
  
      unsigned int depthIdU = (unsigned int)depthId;
      if (depthType == GL_RENDERBUFFER) glDeleteRenderbuffers(1, &depthIdU);
      else if (depthType == GL_RENDERBUFFER) glDeleteTextures(1, &depthIdU);
  
      // NOTE: If a texture object is deleted while its image is attached to the *currently bound* framebuffer,
      // the texture image is automatically detached from the currently bound framebuffer.
  
      glBindFramebuffer(GL_FRAMEBUFFER, 0);
      glDeleteFramebuffers(1, &id);
  
      TRACELOG(LOG_INFO, "FBO: [ID %i] Unloaded framebuffer from VRAM (GPU)", id);
  #endif
  }
  
  // Clear color buffer with color
  void rlClearColor(unsigned char r, unsigned char g, unsigned char b, unsigned char a)
  {
      // Color values clamp to 0.0f(0) and 1.0f(255)
      float cr = (float)r/255;
      float cg = (float)g/255;
      float cb = (float)b/255;
      float ca = (float)a/255;
  
      glClearColor(cr, cg, cb, ca);
  }
  
  // Clear used screen buffers (color and depth)
  void rlClearScreenBuffers(void)
  {
      glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);     // Clear used buffers: Color and Depth (Depth is used for 3D)
      //glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT | GL_STENCIL_BUFFER_BIT);     // Stencil buffer not used...
  }
  
  // Update GPU buffer with new data
  void rlUpdateBuffer(int bufferId, void *data, int dataSize)
  {
  #if defined(GRAPHICS_API_OPENGL_33) || defined(GRAPHICS_API_OPENGL_46) || defined(GRAPHICS_API_OPENGL_ES2)
      glBindBuffer(GL_ARRAY_BUFFER, bufferId);
      glBufferSubData(GL_ARRAY_BUFFER, 0, dataSize, data);
  #endif
  }
  
  #if defined(GRAPHICS_API_OPENGL_33) || defined(GRAPHICS_API_OPENGL_46)
    #if defined(ANIMATED_WITH_DUALQUATERNIONS)
  // Update GPU shader uniforms with new bone data
  void rlUpdateBones(Quaternion *r, Quaternion *t, int count)
  {
  	if (RLGL.State.boneRotQuaternionsLoc == 0)
  		RLGL.State.boneRotQuaternionsLoc = GetShaderLocation(RLGL.State.defaultShader, "boneRotQuaternions");
  	if (RLGL.State.boneTransQuaternionsLoc == 0)
  		RLGL.State.boneTransQuaternionsLoc = GetShaderLocation(RLGL.State.defaultShader, "boneTransQuaternions");
  	SetShaderValueV(RLGL.State.defaultShader, RLGL.State.boneRotQuaternionsLoc, r, UNIFORM_VEC4, count);
  	SetShaderValueV(RLGL.State.defaultShader, RLGL.State.boneTransQuaternionsLoc, t, UNIFORM_VEC4, count);
  }
  void rlResetBones()
  {
  	if (RLGL.State.boneRotQuaternionsLoc == 0)
  		RLGL.State.boneRotQuaternionsLoc = GetShaderLocation(RLGL.State.defaultShader, "boneRotQuaternions");
  	if (RLGL.State.boneTransQuaternionsLoc == 0)
  		RLGL.State.boneTransQuaternionsLoc = GetShaderLocation(RLGL.State.defaultShader, "boneTransQuaternions");
  
  	Quaternion r = {0.0f,0.0f,0.0f,1.0f};//
  	Quaternion t = {0.0f,0.0f,0.0f,0.0f};//
  	SetShaderValueV(RLGL.State.defaultShader, RLGL.State.boneRotQuaternionsLoc, &r, UNIFORM_VEC4, 1);
  	SetShaderValueV(RLGL.State.defaultShader, RLGL.State.boneTransQuaternionsLoc, &t, UNIFORM_VEC4, 1);
  }
    #elif defined(ANIMATED_WITH_MATRIX)
  // Update GPU shader uniforms with new bone data
  void rlUpdateBones(Matrix *m, int count)
  {
  	if (RLGL.State.boneMatLoc == 0)
  		RLGL.State.boneMatLoc = GetShaderLocation(RLGL.State.defaultShader, "boneMat");
  
  	for (int i = 0; i < count; i++)
  		SetShaderValueMatrix(RLGL.State.defaultShader, RLGL.State.boneMatLoc + i, m[i]);
  }
  void rlResetBones()
  {
  	if (RLGL.State.boneMatLoc == 0)
  		RLGL.State.boneMatLoc = GetShaderLocation(RLGL.State.defaultShader, "boneMat");
  
  	SetShaderValueMatrix(RLGL.State.defaultShader, RLGL.State.boneMatLoc, MatrixIdentity());
  }
    #else
  void rlUpdateBones(Matrix *m, int count) {}
  void rlResetBones() {}
  	#endif
  #endif
  
  //----------------------------------------------------------------------------------
  // Module Functions Definition - rlgl Functions
  //----------------------------------------------------------------------------------
  
  // Initialize rlgl: OpenGL extensions, default buffers/shaders/textures, OpenGL states
  void rlglInit(int width, int height)
  {
      // Check OpenGL information and capabilities
      //------------------------------------------------------------------------------
      // Print current OpenGL and GLSL version
      TRACELOG(LOG_INFO, "GL: OpenGL device information:");
      TRACELOG(LOG_INFO, "    > Vendor:   %s", glGetString(GL_VENDOR));
      TRACELOG(LOG_INFO, "    > Renderer: %s", glGetString(GL_RENDERER));
      TRACELOG(LOG_INFO, "    > Version:  %s", glGetString(GL_VERSION));
      TRACELOG(LOG_INFO, "    > GLSL:     %s", glGetString(GL_SHADING_LANGUAGE_VERSION));
  
      // NOTE: We can get a bunch of extra information about GPU capabilities (glGet*)
      //int maxTexSize;
      //glGetIntegerv(GL_MAX_TEXTURE_SIZE, &maxTexSize);
      //TRACELOG(LOG_INFO, "GL: Maximum texture size: %i", maxTexSize);
  
      //GL_MAX_TEXTURE_IMAGE_UNITS
      //GL_MAX_VIEWPORT_DIMS
  
      //int numAuxBuffers;
      //glGetIntegerv(GL_AUX_BUFFERS, &numAuxBuffers);
      //TRACELOG(LOG_INFO, "GL: Number of aixiliar buffers: %i", numAuxBuffers);
  
      //GLint numComp = 0;
      //GLint format[32] = { 0 };
      //glGetIntegerv(GL_NUM_COMPRESSED_TEXTURE_FORMATS, &numComp);
      //glGetIntegerv(GL_COMPRESSED_TEXTURE_FORMATS, format);
      //for (int i = 0; i < numComp; i++) TRACELOG(LOG_INFO, "GL: Supported compressed format: 0x%x", format[i]);
  
      // NOTE: We don't need that much data on screen... right now...
  
      // TODO: Automatize extensions loading using rlLoadExtensions() and GLAD
      // Actually, when rlglInit() is called in InitWindow() in core.c,
      // OpenGL context has already been created and required extensions loaded
  
  #if defined(GRAPHICS_API_OPENGL_33) || defined(GRAPHICS_API_OPENGL_46) || defined(GRAPHICS_API_OPENGL_ES2)
      // Get supported extensions list
      GLint numExt = 0;
  
  #if defined(GRAPHICS_API_OPENGL_33) || defined(GRAPHICS_API_OPENGL_46) && !defined(GRAPHICS_API_OPENGL_21)
      // NOTE: On OpenGL 3.3 VAO and NPOT are supported by default
      RLGL.ExtSupported.vao = true;
  
      // Multiple texture extensions supported by default
      RLGL.ExtSupported.texNPOT = true;
      RLGL.ExtSupported.texFloat32 = true;
      RLGL.ExtSupported.texDepth = true;
  
      // We get a list of available extensions and we check for some of them (compressed textures)
      // NOTE: We don't need to check again supported extensions but we do (GLAD already dealt with that)
      glGetIntegerv(GL_NUM_EXTENSIONS, &numExt);
  
      // Allocate numExt strings pointers
      char **extList = RL_MALLOC(sizeof(char *)*numExt);
  
      // Get extensions strings
      for (int i = 0; i < numExt; i++) extList[i] = (char *)glGetStringi(GL_EXTENSIONS, i);
  
  #endif
  #if defined(GRAPHICS_API_OPENGL_ES2) || defined(GRAPHICS_API_OPENGL_21)
      // Allocate 512 strings pointers (2 KB)
      const char **extList = RL_MALLOC(512*sizeof(const char *));
  
      const char *extensions = (const char *)glGetString(GL_EXTENSIONS);  // One big const string
  
      // NOTE: We have to duplicate string because glGetString() returns a const string
      int len = strlen(extensions) + 1;
      char *extensionsDup = (char *)RL_CALLOC(len, sizeof(char));
      strcpy(extensionsDup, extensions);
  
      extList[numExt] = extensionsDup;
  
      for (int i = 0; i < len; i++)
      {
          if (extensionsDup[i] == ' ')
          {
              extensionsDup[i] = '\0';
  
              numExt++;
              extList[numExt] = &extensionsDup[i + 1];
          }
      }
  
      // NOTE: Duplicated string (extensionsDup) must be deallocated
  #endif
  
      TRACELOG(LOG_INFO, "GL: Supported extensions count: %i", numExt);
  
      // Show supported extensions
      //for (int i = 0; i < numExt; i++)  TRACELOG(LOG_INFO, "Supported extension: %s", extList[i]);
  
      // Check required extensions
      for (int i = 0; i < numExt; i++)
      {
  #if defined(GRAPHICS_API_OPENGL_ES2)
          // Check VAO support
          // NOTE: Only check on OpenGL ES, OpenGL 3.3 has VAO support as core feature
          if (strcmp(extList[i], (const char *)"GL_OES_vertex_array_object") == 0)
          {
              // The extension is supported by our hardware and driver, try to get related functions pointers
              // NOTE: emscripten does not support VAOs natively, it uses emulation and it reduces overall performance...
              glGenVertexArrays = (PFNGLGENVERTEXARRAYSOESPROC)eglGetProcAddress("glGenVertexArraysOES");
              glBindVertexArray = (PFNGLBINDVERTEXARRAYOESPROC)eglGetProcAddress("glBindVertexArrayOES");
              glDeleteVertexArrays = (PFNGLDELETEVERTEXARRAYSOESPROC)eglGetProcAddress("glDeleteVertexArraysOES");
              //glIsVertexArray = (PFNGLISVERTEXARRAYOESPROC)eglGetProcAddress("glIsVertexArrayOES");     // NOTE: Fails in WebGL, omitted
  
              if ((glGenVertexArrays != NULL) && (glBindVertexArray != NULL) && (glDeleteVertexArrays != NULL)) RLGL.ExtSupported.vao = true;
          }
  
          // Check NPOT textures support
          // NOTE: Only check on OpenGL ES, OpenGL 3.3 has NPOT textures full support as core feature
          if (strcmp(extList[i], (const char *)"GL_OES_texture_npot") == 0) RLGL.ExtSupported.texNPOT = true;
  
          // Check texture float support
          if (strcmp(extList[i], (const char *)"GL_OES_texture_float") == 0) RLGL.ExtSupported.texFloat32 = true;
  
          // Check depth texture support
          if ((strcmp(extList[i], (const char *)"GL_OES_depth_texture") == 0) ||
              (strcmp(extList[i], (const char *)"GL_WEBGL_depth_texture") == 0)) RLGL.ExtSupported.texDepth = true;
  
          if (strcmp(extList[i], (const char *)"GL_OES_depth24") == 0) RLGL.ExtSupported.maxDepthBits = 24;
          if (strcmp(extList[i], (const char *)"GL_OES_depth32") == 0) RLGL.ExtSupported.maxDepthBits = 32;
  #endif
          // DDS texture compression support
          if ((strcmp(extList[i], (const char *)"GL_EXT_texture_compression_s3tc") == 0) ||
              (strcmp(extList[i], (const char *)"GL_WEBGL_compressed_texture_s3tc") == 0) ||
              (strcmp(extList[i], (const char *)"GL_WEBKIT_WEBGL_compressed_texture_s3tc") == 0)) RLGL.ExtSupported.texCompDXT = true;
  
          // ETC1 texture compression support
          if ((strcmp(extList[i], (const char *)"GL_OES_compressed_ETC1_RGB8_texture") == 0) ||
              (strcmp(extList[i], (const char *)"GL_WEBGL_compressed_texture_etc1") == 0)) RLGL.ExtSupported.texCompETC1 = true;
  
          // ETC2/EAC texture compression support
          if (strcmp(extList[i], (const char *)"GL_ARB_ES3_compatibility") == 0) RLGL.ExtSupported.texCompETC2 = true;
  
          // PVR texture compression support
          if (strcmp(extList[i], (const char *)"GL_IMG_texture_compression_pvrtc") == 0) RLGL.ExtSupported.texCompPVRT = true;
  
          // ASTC texture compression support
          if (strcmp(extList[i], (const char *)"GL_KHR_texture_compression_astc_hdr") == 0) RLGL.ExtSupported.texCompASTC = true;
  
          // Anisotropic texture filter support
          if (strcmp(extList[i], (const char *)"GL_EXT_texture_filter_anisotropic") == 0)
          {
              RLGL.ExtSupported.texAnisoFilter = true;
              glGetFloatv(0x84FF, &RLGL.ExtSupported.maxAnisotropicLevel);   // GL_MAX_TEXTURE_MAX_ANISOTROPY_EXT
          }
  
          // Clamp mirror wrap mode supported
          if (strcmp(extList[i], (const char *)"GL_EXT_texture_mirror_clamp") == 0) RLGL.ExtSupported.texMirrorClamp = true;
  
          // Debug marker support
          if (strcmp(extList[i], (const char *)"GL_EXT_debug_marker") == 0) RLGL.ExtSupported.debugMarker = true;
      }
  
      // Free extensions pointers
      RL_FREE(extList);
  
  #if defined(GRAPHICS_API_OPENGL_ES2) || defined(GRAPHICS_API_OPENGL_21)
      RL_FREE(extensionsDup);    // Duplicated string must be deallocated
  #endif
  
  #if defined(GRAPHICS_API_OPENGL_ES2)
      if (RLGL.ExtSupported.vao) TRACELOG(LOG_INFO, "GL: VAO extension detected, VAO functions initialized successfully");
      else TRACELOG(LOG_WARNING, "GL: VAO extension not found, VAO usage not supported");
  
      if (RLGL.ExtSupported.texNPOT) TRACELOG(LOG_INFO, "GL: NPOT textures extension detected, full NPOT textures supported");
      else TRACELOG(LOG_WARNING, "GL: NPOT textures extension not found, limited NPOT support (no-mipmaps, no-repeat)");
  #endif
  
      if (RLGL.ExtSupported.texCompDXT) TRACELOG(LOG_INFO, "GL: DXT compressed textures supported");
      if (RLGL.ExtSupported.texCompETC1) TRACELOG(LOG_INFO, "GL: ETC1 compressed textures supported");
      if (RLGL.ExtSupported.texCompETC2) TRACELOG(LOG_INFO, "GL: ETC2/EAC compressed textures supported");
      if (RLGL.ExtSupported.texCompPVRT) TRACELOG(LOG_INFO, "GL: PVRT compressed textures supported");
      if (RLGL.ExtSupported.texCompASTC) TRACELOG(LOG_INFO, "GL: ASTC compressed textures supported");
  
      if (RLGL.ExtSupported.texAnisoFilter) TRACELOG(LOG_INFO, "GL: Anisotropic textures filtering supported (max: %.0fX)", RLGL.ExtSupported.maxAnisotropicLevel);
      if (RLGL.ExtSupported.texMirrorClamp) TRACELOG(LOG_INFO, "GL: Mirror clamp wrap texture mode supported");
  
      if (RLGL.ExtSupported.debugMarker) TRACELOG(LOG_INFO, "GL: Debug Marker supported");
  
      // Initialize buffers, default shaders and default textures
      //----------------------------------------------------------
      // Init default white texture
      unsigned char pixels[4] = { 255, 255, 255, 255 };   // 1 pixel RGBA (4 bytes)
      RLGL.State.defaultTextureId = rlLoadTexture(pixels, 1, 1, UNCOMPRESSED_R8G8B8A8, 1);
  
      if (RLGL.State.defaultTextureId != 0) TRACELOG(LOG_INFO, "TEXTURE: [ID %i] Default texture loaded successfully", RLGL.State.defaultTextureId);
      else TRACELOG(LOG_WARNING, "TEXTURE: Failed to load default texture");
  
      // Init default Shader (customized for GL 3.3 and ES2)
      RLGL.State.defaultShader = LoadShaderDefault();
      RLGL.State.currentShader = RLGL.State.defaultShader;
  
      // Init default vertex arrays buffers
      RLGL.defaultBatch = LoadRenderBatch(DEFAULT_BATCH_BUFFERS, DEFAULT_BATCH_BUFFER_ELEMENTS);
      RLGL.currentBatch = &RLGL.defaultBatch;
  
      // Init stack matrices (emulating OpenGL 1.1)
      for (int i = 0; i < MAX_MATRIX_STACK_SIZE; i++) RLGL.State.stack[i] = MatrixIdentity();
  
      // Init internal matrices
      RLGL.State.transform = MatrixIdentity();
      RLGL.State.projection = MatrixIdentity();
      RLGL.State.modelview = MatrixIdentity();
      RLGL.State.currentMatrix = &RLGL.State.modelview;
  
  #endif      // GRAPHICS_API_OPENGL_33 || GRAPHICS_API_OPENGL_46 || GRAPHICS_API_OPENGL_ES2
  
      // Initialize OpenGL default states
      //----------------------------------------------------------
      // Init state: Depth test
      glDepthFunc(GL_LEQUAL);                                 // Type of depth testing to apply
      glDisable(GL_DEPTH_TEST);                               // Disable depth testing for 2D (only used for 3D)
  
      // Init state: Blending mode
      glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);      // Color blending function (how colors are mixed)
      glEnable(GL_BLEND);                                     // Enable color blending (required to work with transparencies)
  
      // Init state: Culling
      // NOTE: All shapes/models triangles are drawn CCW
      glCullFace(GL_BACK);                                    // Cull the back face (default)
      glFrontFace(GL_CCW);                                    // Front face are defined counter clockwise (default)
      glEnable(GL_CULL_FACE);                                 // Enable backface culling
  
      // Init state: Cubemap seamless
  #if defined(GRAPHICS_API_OPENGL_33) || defined(GRAPHICS_API_OPENGL_46)
      glEnable(GL_TEXTURE_CUBE_MAP_SEAMLESS);                 // Seamless cubemaps (not supported on OpenGL ES 2.0)
  #endif
  
  #if defined(GRAPHICS_API_OPENGL_11)
      // Init state: Color hints (deprecated in OpenGL 3.0+)
      glHint(GL_PERSPECTIVE_CORRECTION_HINT, GL_NICEST);      // Improve quality of color and texture coordinate interpolation
      glShadeModel(GL_SMOOTH);                                // Smooth shading between vertex (vertex colors interpolation)
  #endif
  
  #if defined(GRAPHICS_API_OPENGL_33) || defined(GRAPHICS_API_OPENGL_46) || defined(GRAPHICS_API_OPENGL_ES2)
      // Store screen size into global variables
      RLGL.State.framebufferWidth = width;
      RLGL.State.framebufferHeight = height;
  
      // Init texture and rectangle used on basic shapes drawing
      RLGL.State.shapesTexture = GetTextureDefault();
      RLGL.State.shapesTextureRec = (Rectangle){ 0.0f, 0.0f, 1.0f, 1.0f };
  
  #if defined(GRAPHICS_API_OPENGL_33) || defined(GRAPHICS_API_OPENGL_46)
    #if defined(ANIMATED_WITH_DUALQUATERNIONS)
      // Init dual quaternion bone uniforms in shader
      Quaternion *rots  = RL_MALLOC(58*sizeof(Quaternion));
      Quaternion *trans = RL_MALLOC(58*sizeof(Quaternion));
      Quaternion default_rot = { 0.0f, 0.0f, 0.0f, 1.0f };
      Quaternion default_tran = { 0.0f, 0.0f, 0.0f, 0.0f };
      for (int bc = 0; bc < 58; bc++) {
  	    rots[bc] = default_rot;
  	    trans[bc] = default_tran;
      }
  
      rlUpdateBones(rots, trans, 58);
  
      RL_FREE(rots);
      RL_FREE(trans);
    #elif defined(ANIMATED_WITH_MATRIX)
      // Init matrix bones
      Matrix *m = RL_MALLOC(58*sizeof(Matrix));
      for (int bc = 0; bc < 58; bc++) {
  	    m[bc] = MatrixIdentity();
      }
  
      rlUpdateBones(m, 58);
  
      RL_FREE(m);
    #endif
  #endif
  
      TRACELOG(LOG_INFO, "RLGL: Default state initialized successfully");
  #endif
  
      // Init state: Color/Depth buffers clear
      glClearColor(0.0f, 0.0f, 0.0f, 1.0f);                   // Set clear color (black)
      glClearDepth(1.0f);                                     // Set clear depth value (default)
      glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);     // Clear color and depth buffers (depth buffer required for 3D)
  }
  
  // Vertex Buffer Object deinitialization (memory free)
  void rlglClose(void)
  {
  #if defined(GRAPHICS_API_OPENGL_33) || defined(GRAPHICS_API_OPENGL_46) || defined(GRAPHICS_API_OPENGL_ES2)
      UnloadRenderBatch(RLGL.defaultBatch);
  
      UnloadShaderDefault();          // Unload default shader
      glDeleteTextures(1, &RLGL.State.defaultTextureId); // Unload default texture
  
      TRACELOG(LOG_INFO, "TEXTURE: [ID %i] Unloaded default texture data from VRAM (GPU)", RLGL.State.defaultTextureId);
  #endif
  }
  
  // Update and draw internal buffers
  void rlglDraw(void)
  {
  #if defined(GRAPHICS_API_OPENGL_33) || defined(GRAPHICS_API_OPENGL_46) || defined(GRAPHICS_API_OPENGL_ES2)
      DrawRenderBatch(RLGL.currentBatch);    // NOTE: Stereo rendering is checked inside
  #endif
  }
  
  // Check and log OpenGL error codes
  void rlCheckErrors() {
  #if defined(GRAPHICS_API_OPENGL_21) || defined(GRAPHICS_API_OPENGL_33) || defined(GRAPHICS_API_OPENGL_46) || defined(GRAPHICS_API_OPENGL_ES2)
      int check = 1;
      while (check) {
          const GLenum err = glGetError();
          switch (err) {
              case GL_NO_ERROR:
                  check = 0;
                  break;
              case 0x0500: // GL_INVALID_ENUM:
                  TRACELOG(LOG_WARNING, "GL: Error detected: GL_INVALID_ENUM");
                  break;
              case 0x0501: //GL_INVALID_VALUE:
                  TRACELOG(LOG_WARNING, "GL: Error detected: GL_INVALID_VALUE");
                  break;
              case 0x0502: //GL_INVALID_OPERATION:
                  TRACELOG(LOG_WARNING, "GL: Error detected: GL_INVALID_OPERATION");
                  break;
              case 0x0503: // GL_STACK_OVERFLOW:
                  TRACELOG(LOG_WARNING, "GL: Error detected: GL_STACK_OVERFLOW");
                  break;
              case 0x0504: // GL_STACK_UNDERFLOW:
                  TRACELOG(LOG_WARNING, "GL: Error detected: GL_STACK_UNDERFLOW");
                  break;
              case 0x0505: // GL_OUT_OF_MEMORY:
                  TRACELOG(LOG_WARNING, "GL: Error detected: GL_OUT_OF_MEMORY");
                  break;
              case 0x0506: // GL_INVALID_FRAMEBUFFER_OPERATION:
                  TRACELOG(LOG_WARNING, "GL: Error detected: GL_INVALID_FRAMEBUFFER_OPERATION");
                  break;
              default:
                  TRACELOG(LOG_WARNING, "GL: Error detected: unknown error code %x", err);
                  break;
          }
      }
  #endif
  }
  
  // Returns current OpenGL version
  int rlGetVersion(void)
  {
  #if defined(GRAPHICS_API_OPENGL_11)
      return OPENGL_11;
  #elif defined(GRAPHICS_API_OPENGL_21)
      #if defined(__APPLE__)
          return OPENGL_33;           // NOTE: Force OpenGL 3.3 on OSX
      #else
          return OPENGL_21;
      #endif
  #elif defined(GRAPHICS_API_OPENGL_46)
      return OPENGL_46;
  #elif defined(GRAPHICS_API_OPENGL_33)
      return OPENGL_33;
  #elif defined(GRAPHICS_API_OPENGL_ES2)
      return OPENGL_ES_20;
  #endif
  }
  
  // Check internal buffer overflow for a given number of vertex
  bool rlCheckBufferLimit(int vCount)
  {
      bool overflow = false;
  #if defined(GRAPHICS_API_OPENGL_33) || defined(GRAPHICS_API_OPENGL_46) || defined(GRAPHICS_API_OPENGL_ES2)
      if ((RLGL.currentBatch->vertexBuffer[RLGL.currentBatch->currentBuffer].vCounter + vCount) >= (RLGL.currentBatch->vertexBuffer[RLGL.currentBatch->currentBuffer].elementsCount*4)) overflow = true;
  #endif
      return overflow;
  }
  
  // Set debug marker
  void rlSetDebugMarker(const char *text)
  {
  #if defined(GRAPHICS_API_OPENGL_33) || defined(GRAPHICS_API_OPENGL_46)
      if (RLGL.ExtSupported.debugMarker) glInsertEventMarkerEXT(0, text);
  #endif
  }
  
  // Set blending mode factor and equation
  void rlSetBlendMode(int glSrcFactor, int glDstFactor, int glEquation)
  {
  #if defined(GRAPHICS_API_OPENGL_33) || defined(GRAPHICS_API_OPENGL_46) || defined(GRAPHICS_API_OPENGL_ES2)
      RLGL.State.glBlendSrcFactor = glSrcFactor;
      RLGL.State.glBlendDstFactor = glDstFactor;
      RLGL.State.glBlendEquation = glEquation;
  #endif
  }
  
  // Load OpenGL extensions
  // NOTE: External loader function could be passed as a pointer
  void rlLoadExtensions(void *loader)
  {
  #if defined(GRAPHICS_API_OPENGL_33) || defined(GRAPHICS_API_OPENGL_46)
      // NOTE: glad is generated and contains only required OpenGL 3.3 Core extensions (and lower versions)
      #if !defined(__APPLE__)
          if (!gladLoadGLLoader((GLADloadproc)loader)) TRACELOG(LOG_WARNING, "GLAD: Cannot load OpenGL extensions");
          else TRACELOG(LOG_INFO, "GLAD: OpenGL extensions loaded successfully");
  
          #if defined(GRAPHICS_API_OPENGL_21)
          if (GLAD_GL_VERSION_2_1) TRACELOG(LOG_INFO, "GL: OpenGL 2.1 profile supported");
          #elif defined(GRAPHICS_API_OPENGL_33)
          if (GLAD_GL_VERSION_3_3) TRACELOG(LOG_INFO, "GL: OpenGL 3.3 Core profile supported");
          else TRACELOG(LOG_ERROR, "GL: OpenGL 3.3 Core profile not supported");
          #elif defined(GRAPHICS_API_OPENGL_46)
          if (GLAD_GL_VERSION_4_6) TRACELOG(LOG_INFO, "GL: OpenGL 4.6 Core profile supported");
          else TRACELOG(LOG_ERROR, "GL: OpenGL 4.6 Core profile not supported");
          #endif
      #endif
  
      // With GLAD, we can check if an extension is supported using the GLAD_GL_xxx booleans
      //if (GLAD_GL_ARB_vertex_array_object) // Use GL_ARB_vertex_array_object
  #endif
  }
  
  // Convert image data to OpenGL texture (returns OpenGL valid Id)
  unsigned int rlLoadTexture(void *data, int width, int height, int format, int mipmapCount)
  {
      glBindTexture(GL_TEXTURE_2D, 0);    // Free any old binding
  
      unsigned int id = 0;
  
      // Check texture format support by OpenGL 1.1 (compressed textures not supported)
  #if defined(GRAPHICS_API_OPENGL_11)
      if (format >= COMPRESSED_DXT1_RGB)
      {
          TRACELOG(LOG_WARNING, "GL: OpenGL 1.1 does not support GPU compressed texture formats");
          return id;
      }
  #else
      if ((!RLGL.ExtSupported.texCompDXT) && ((format == COMPRESSED_DXT1_RGB) || (format == COMPRESSED_DXT1_RGBA) ||
          (format == COMPRESSED_DXT3_RGBA) || (format == COMPRESSED_DXT5_RGBA)))
      {
          TRACELOG(LOG_WARNING, "GL: DXT compressed texture format not supported");
          return id;
      }
  #if defined(GRAPHICS_API_OPENGL_33) || defined(GRAPHICS_API_OPENGL_46) || defined(GRAPHICS_API_OPENGL_ES2)
      if ((!RLGL.ExtSupported.texCompETC1) && (format == COMPRESSED_ETC1_RGB))
      {
          TRACELOG(LOG_WARNING, "GL: ETC1 compressed texture format not supported");
          return id;
      }
  
      if ((!RLGL.ExtSupported.texCompETC2) && ((format == COMPRESSED_ETC2_RGB) || (format == COMPRESSED_ETC2_EAC_RGBA)))
      {
          TRACELOG(LOG_WARNING, "GL: ETC2 compressed texture format not supported");
          return id;
      }
  
      if ((!RLGL.ExtSupported.texCompPVRT) && ((format == COMPRESSED_PVRT_RGB) || (format == COMPRESSED_PVRT_RGBA)))
      {
          TRACELOG(LOG_WARNING, "GL: PVRT compressed texture format not supported");
          return id;
      }
  
      if ((!RLGL.ExtSupported.texCompASTC) && ((format == COMPRESSED_ASTC_4x4_RGBA) || (format == COMPRESSED_ASTC_8x8_RGBA)))
      {
          TRACELOG(LOG_WARNING, "GL: ASTC compressed texture format not supported");
          return id;
      }
  #endif
  #endif      // GRAPHICS_API_OPENGL_11
  
      glPixelStorei(GL_UNPACK_ALIGNMENT, 1);
  
      glGenTextures(1, &id);              // Generate texture id
  
  #if defined(GRAPHICS_API_OPENGL_33) || defined(GRAPHICS_API_OPENGL_46) || defined(GRAPHICS_API_OPENGL_ES2)
      //glActiveTexture(GL_TEXTURE0);     // If not defined, using GL_TEXTURE0 by default (shader texture)
  #endif
  
      glBindTexture(GL_TEXTURE_2D, id);
  
      int mipWidth = width;
      int mipHeight = height;
      int mipOffset = 0;          // Mipmap data offset
  
      // Load the different mipmap levels
      for (int i = 0; i < mipmapCount; i++)
      {
          unsigned int mipSize = GetPixelDataSize(mipWidth, mipHeight, format);
  
          unsigned int glInternalFormat, glFormat, glType;
          rlGetGlTextureFormats(format, &glInternalFormat, &glFormat, &glType);
  
          TRACELOGD("TEXTURE: Load mipmap level %i (%i x %i), size: %i, offset: %i", i, mipWidth, mipHeight, mipSize, mipOffset);
  
          if (glInternalFormat != -1)
          {
              if (format < COMPRESSED_DXT1_RGB) glTexImage2D(GL_TEXTURE_2D, i, glInternalFormat, mipWidth, mipHeight, 0, glFormat, glType, (unsigned char *)data + mipOffset);
          #if !defined(GRAPHICS_API_OPENGL_11)
              else glCompressedTexImage2D(GL_TEXTURE_2D, i, glInternalFormat, mipWidth, mipHeight, 0, mipSize, (unsigned char *)data + mipOffset);
          #endif
  
          #if defined(GRAPHICS_API_OPENGL_33) || defined(GRAPHICS_API_OPENGL_46)
              if (format == UNCOMPRESSED_GRAYSCALE)
              {
                  GLint swizzleMask[] = { GL_RED, GL_RED, GL_RED, GL_ONE };
                  glTexParameteriv(GL_TEXTURE_2D, GL_TEXTURE_SWIZZLE_RGBA, swizzleMask);
              }
              else if (format == UNCOMPRESSED_GRAY_ALPHA)
              {
              #if defined(GRAPHICS_API_OPENGL_21)
                  GLint swizzleMask[] = { GL_RED, GL_RED, GL_RED, GL_ALPHA };
              #elif defined(GRAPHICS_API_OPENGL_33) || defined(GRAPHICS_API_OPENGL_46)
                  GLint swizzleMask[] = { GL_RED, GL_RED, GL_RED, GL_GREEN };
              #endif
                  glTexParameteriv(GL_TEXTURE_2D, GL_TEXTURE_SWIZZLE_RGBA, swizzleMask);
              }
          #endif
          }
  
          mipWidth /= 2;
          mipHeight /= 2;
          mipOffset += mipSize;
  
          // Security check for NPOT textures
          if (mipWidth < 1) mipWidth = 1;
          if (mipHeight < 1) mipHeight = 1;
      }
  
      // Texture parameters configuration
      // NOTE: glTexParameteri does NOT affect texture uploading, just the way it's used
  #if defined(GRAPHICS_API_OPENGL_ES2)
      // NOTE: OpenGL ES 2.0 with no GL_OES_texture_npot support (i.e. WebGL) has limited NPOT support, so CLAMP_TO_EDGE must be used
      if (RLGL.ExtSupported.texNPOT)
      {
          glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT);       // Set texture to repeat on x-axis
          glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT);       // Set texture to repeat on y-axis
      }
      else
      {
          // NOTE: If using negative texture coordinates (LoadOBJ()), it does not work!
          glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);       // Set texture to clamp on x-axis
          glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);       // Set texture to clamp on y-axis
      }
  #else
      glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT);       // Set texture to repeat on x-axis
      glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT);       // Set texture to repeat on y-axis
  #endif
  
      // Magnification and minification filters
      glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);  // Alternative: GL_LINEAR
      glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);  // Alternative: GL_LINEAR
  
  #if defined(GRAPHICS_API_OPENGL_33) || defined(GRAPHICS_API_OPENGL_46)
      if (mipmapCount > 1)
      {
          // Activate Trilinear filtering if mipmaps are available
          glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
          glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR_MIPMAP_LINEAR);
      }
  #endif
  
      // At this point we have the texture loaded in GPU and texture parameters configured
  
      // NOTE: If mipmaps were not in data, they are not generated automatically
  
      // Unbind current texture
      glBindTexture(GL_TEXTURE_2D, 0);
  
      if (id > 0) TRACELOG(LOG_INFO, "TEXTURE: [ID %i] Texture created successfully (%ix%i - %i mipmaps)", id, width, height, mipmapCount);
      else TRACELOG(LOG_WARNING, "TEXTURE: Failed to load texture");
  
      return id;
  }
  
  // Load depth texture/renderbuffer (to be attached to fbo)
  // WARNING: OpenGL ES 2.0 requires GL_OES_depth_texture/WEBGL_depth_texture extensions
  unsigned int rlLoadTextureDepth(int width, int height, bool useRenderBuffer)
  {
      unsigned int id = 0;
  
  #if defined(GRAPHICS_API_OPENGL_33) || defined(GRAPHICS_API_OPENGL_46) || defined(GRAPHICS_API_OPENGL_ES2)
      // In case depth textures not supported, we force renderbuffer usage
      if (!RLGL.ExtSupported.texDepth) useRenderBuffer = true;
  
      // NOTE: We let the implementation to choose the best bit-depth
      // Possible formats: GL_DEPTH_COMPONENT16, GL_DEPTH_COMPONENT24, GL_DEPTH_COMPONENT32 and GL_DEPTH_COMPONENT32F
      unsigned int glInternalFormat = GL_DEPTH_COMPONENT;
  
  #if defined(GRAPHICS_API_OPENGL_ES2)
      if (RLGL.ExtSupported.maxDepthBits == 32) glInternalFormat = GL_DEPTH_COMPONENT32_OES;
      else if (RLGL.ExtSupported.maxDepthBits == 24) glInternalFormat = GL_DEPTH_COMPONENT24_OES;
      else glInternalFormat = GL_DEPTH_COMPONENT16;
  #endif
  
      if (!useRenderBuffer && RLGL.ExtSupported.texDepth)
      {
          glGenTextures(1, &id);
          glBindTexture(GL_TEXTURE_2D, id);
          glTexImage2D(GL_TEXTURE_2D, 0, glInternalFormat, width, height, 0, GL_DEPTH_COMPONENT, GL_UNSIGNED_INT, NULL);
  
          glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
          glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
          glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
          glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
  
          glBindTexture(GL_TEXTURE_2D, 0);
  
          TRACELOG(LOG_INFO, "TEXTURE: Depth texture loaded successfully");
      }
      else
      {
          // Create the renderbuffer that will serve as the depth attachment for the framebuffer
          // NOTE: A renderbuffer is simpler than a texture and could offer better performance on embedded devices
          glGenRenderbuffers(1, &id);
          glBindRenderbuffer(GL_RENDERBUFFER, id);
          glRenderbufferStorage(GL_RENDERBUFFER, glInternalFormat, width, height);
  
          glBindRenderbuffer(GL_RENDERBUFFER, 0);
  
          TRACELOG(LOG_INFO, "TEXTURE: [ID %i] Depth renderbuffer loaded successfully (%i bits)", id, (RLGL.ExtSupported.maxDepthBits >= 24)? RLGL.ExtSupported.maxDepthBits : 16);
      }
  #endif
  
      return id;
  }
  
  // Load texture cubemap
  // NOTE: Cubemap data is expected to be 6 images in a single data array (one after the other),
  // expected the following convention: +X, -X, +Y, -Y, +Z, -Z
  unsigned int rlLoadTextureCubemap(void *data, int size, int format)
  {
      unsigned int id = 0;
  
  #if defined(GRAPHICS_API_OPENGL_33) || defined(GRAPHICS_API_OPENGL_46) || defined(GRAPHICS_API_OPENGL_ES2)
      unsigned int dataSize = GetPixelDataSize(size, size, format);
  
      glGenTextures(1, &id);
      glBindTexture(GL_TEXTURE_CUBE_MAP, id);
  
      unsigned int glInternalFormat, glFormat, glType;
      rlGetGlTextureFormats(format, &glInternalFormat, &glFormat, &glType);
  
      if (glInternalFormat != -1)
      {
          // Load cubemap faces
          for (unsigned int i = 0; i < 6; i++)
          {
              if (data == NULL)
              {
                  if (format < COMPRESSED_DXT1_RGB)
                  {
                      if (format == UNCOMPRESSED_R32G32B32)
                      {
                          // Instead of using a sized internal texture format (GL_RGB16F, GL_RGB32F), we let the driver to choose the better format for us (GL_RGB)
                          if (RLGL.ExtSupported.texFloat32) glTexImage2D(GL_TEXTURE_CUBE_MAP_POSITIVE_X + i, 0, GL_RGB, size, size, 0, GL_RGB, GL_FLOAT, NULL);
                          else TRACELOG(LOG_WARNING, "TEXTURES: Cubemap requested format not supported");
                      }
                      else if ((format == UNCOMPRESSED_R32) || (format == UNCOMPRESSED_R32G32B32A32)) TRACELOG(LOG_WARNING, "TEXTURES: Cubemap requested format not supported");
                      else glTexImage2D(GL_TEXTURE_CUBE_MAP_POSITIVE_X + i, 0, glInternalFormat, size, size, 0, glFormat, glType, NULL);
                  }
                  else TRACELOG(LOG_WARNING, "TEXTURES: Empty cubemap creation does not support compressed format");
              }
              else
              {
                  if (format < COMPRESSED_DXT1_RGB) glTexImage2D(GL_TEXTURE_CUBE_MAP_POSITIVE_X + i, 0, glInternalFormat, size, size, 0, glFormat, glType, (unsigned char *)data + i*dataSize);
                  else glCompressedTexImage2D(GL_TEXTURE_CUBE_MAP_POSITIVE_X + i, 0, glInternalFormat, size, size, 0, dataSize, (unsigned char *)data + i*dataSize);
              }
  
  #if defined(GRAPHICS_API_OPENGL_33) || defined(GRAPHICS_API_OPENGL_46)
              if (format == UNCOMPRESSED_GRAYSCALE)
              {
                  GLint swizzleMask[] = { GL_RED, GL_RED, GL_RED, GL_ONE };
                  glTexParameteriv(GL_TEXTURE_CUBE_MAP, GL_TEXTURE_SWIZZLE_RGBA, swizzleMask);
              }
              else if (format == UNCOMPRESSED_GRAY_ALPHA)
              {
  #if defined(GRAPHICS_API_OPENGL_21)
                  GLint swizzleMask[] = { GL_RED, GL_RED, GL_RED, GL_ALPHA };
  #elif defined(GRAPHICS_API_OPENGL_33) || defined(GRAPHICS_API_OPENGL_46)
                  GLint swizzleMask[] = { GL_RED, GL_RED, GL_RED, GL_GREEN };
  #endif
                  glTexParameteriv(GL_TEXTURE_CUBE_MAP, GL_TEXTURE_SWIZZLE_RGBA, swizzleMask);
              }
  #endif
          }
      }
  
      // Set cubemap texture sampling parameters
      glTexParameteri(GL_TEXTURE_CUBE_MAP, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
      glTexParameteri(GL_TEXTURE_CUBE_MAP, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
      glTexParameteri(GL_TEXTURE_CUBE_MAP, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
      glTexParameteri(GL_TEXTURE_CUBE_MAP, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
  #if defined(GRAPHICS_API_OPENGL_33) || defined(GRAPHICS_API_OPENGL_46)
      glTexParameteri(GL_TEXTURE_CUBE_MAP, GL_TEXTURE_WRAP_R, GL_CLAMP_TO_EDGE);  // Flag not supported on OpenGL ES 2.0
  #endif
  
      glBindTexture(GL_TEXTURE_CUBE_MAP, 0);
  #endif
  
      if (id > 0) TRACELOG(LOG_INFO, "TEXTURE: [ID %i] Cubemap texture created successfully (%ix%i)", id, size, size);
      else TRACELOG(LOG_WARNING, "TEXTURE: Failed to load cubemap texture");
  
      return id;
  }
  
  // Update already loaded texture in GPU with new data
  // NOTE: We don't know safely if internal texture format is the expected one...
  void rlUpdateTexture(unsigned int id, int offsetX, int offsetY, int width, int height, int format, const void *data)
  {
      glBindTexture(GL_TEXTURE_2D, id);
  
      unsigned int glInternalFormat, glFormat, glType;
      rlGetGlTextureFormats(format, &glInternalFormat, &glFormat, &glType);
  
      if ((glInternalFormat != -1) && (format < COMPRESSED_DXT1_RGB))
      {
          glTexSubImage2D(GL_TEXTURE_2D, 0, offsetX, offsetY, width, height, glFormat, glType, (unsigned char *)data);
      }
      else TRACELOG(LOG_WARNING, "TEXTURE: [ID %i] Failed to update for current texture format (%i)", id, format);
  }
  
  // Get OpenGL internal formats and data type from raylib PixelFormat
  void rlGetGlTextureFormats(int format, unsigned int *glInternalFormat, unsigned int *glFormat, unsigned int *glType)
  {
      *glInternalFormat = -1;
      *glFormat = -1;
      *glType = -1;
  
      switch (format)
      {
      #if defined(GRAPHICS_API_OPENGL_11) || defined(GRAPHICS_API_OPENGL_21) || defined(GRAPHICS_API_OPENGL_ES2)
          // NOTE: on OpenGL ES 2.0 (WebGL), internalFormat must match format and options allowed are: GL_LUMINANCE, GL_RGB, GL_RGBA
          case UNCOMPRESSED_GRAYSCALE: *glInternalFormat = GL_LUMINANCE; *glFormat = GL_LUMINANCE; *glType = GL_UNSIGNED_BYTE; break;
          case UNCOMPRESSED_GRAY_ALPHA: *glInternalFormat = GL_LUMINANCE_ALPHA; *glFormat = GL_LUMINANCE_ALPHA; *glType = GL_UNSIGNED_BYTE; break;
          case UNCOMPRESSED_R5G6B5: *glInternalFormat = GL_RGB; *glFormat = GL_RGB; *glType = GL_UNSIGNED_SHORT_5_6_5; break;
          case UNCOMPRESSED_R8G8B8: *glInternalFormat = GL_RGB; *glFormat = GL_RGB; *glType = GL_UNSIGNED_BYTE; break;
          case UNCOMPRESSED_R5G5B5A1: *glInternalFormat = GL_RGBA; *glFormat = GL_RGBA; *glType = GL_UNSIGNED_SHORT_5_5_5_1; break;
          case UNCOMPRESSED_R4G4B4A4: *glInternalFormat = GL_RGBA; *glFormat = GL_RGBA; *glType = GL_UNSIGNED_SHORT_4_4_4_4; break;
          case UNCOMPRESSED_R8G8B8A8: *glInternalFormat = GL_RGBA; *glFormat = GL_RGBA; *glType = GL_UNSIGNED_BYTE; break;
          #if !defined(GRAPHICS_API_OPENGL_11)
          case UNCOMPRESSED_R32: if (RLGL.ExtSupported.texFloat32) *glInternalFormat = GL_LUMINANCE; *glFormat = GL_LUMINANCE; *glType = GL_FLOAT; break;   // NOTE: Requires extension OES_texture_float
          case UNCOMPRESSED_R32G32B32: if (RLGL.ExtSupported.texFloat32) *glInternalFormat = GL_RGB; *glFormat = GL_RGB; *glType = GL_FLOAT; break;         // NOTE: Requires extension OES_texture_float
          case UNCOMPRESSED_R32G32B32A32: if (RLGL.ExtSupported.texFloat32) *glInternalFormat = GL_RGBA; *glFormat = GL_RGBA; *glType = GL_FLOAT; break;    // NOTE: Requires extension OES_texture_float
          #endif
      #elif defined(GRAPHICS_API_OPENGL_33) || defined(GRAPHICS_API_OPENGL_46)
          case UNCOMPRESSED_GRAYSCALE: *glInternalFormat = GL_R8; *glFormat = GL_RED; *glType = GL_UNSIGNED_BYTE; break;
          case UNCOMPRESSED_GRAY_ALPHA: *glInternalFormat = GL_RG8; *glFormat = GL_RG; *glType = GL_UNSIGNED_BYTE; break;
          case UNCOMPRESSED_R5G6B5: *glInternalFormat = GL_RGB565; *glFormat = GL_RGB; *glType = GL_UNSIGNED_SHORT_5_6_5; break;
          case UNCOMPRESSED_R8G8B8: *glInternalFormat = GL_RGB8; *glFormat = GL_RGB; *glType = GL_UNSIGNED_BYTE; break;
          case UNCOMPRESSED_R5G5B5A1: *glInternalFormat = GL_RGB5_A1; *glFormat = GL_RGBA; *glType = GL_UNSIGNED_SHORT_5_5_5_1; break;
          case UNCOMPRESSED_R4G4B4A4: *glInternalFormat = GL_RGBA4; *glFormat = GL_RGBA; *glType = GL_UNSIGNED_SHORT_4_4_4_4; break;
          case UNCOMPRESSED_R8G8B8A8: *glInternalFormat = GL_RGBA8; *glFormat = GL_RGBA; *glType = GL_UNSIGNED_BYTE; break;
          case UNCOMPRESSED_R32: if (RLGL.ExtSupported.texFloat32) *glInternalFormat = GL_R32F; *glFormat = GL_RED; *glType = GL_FLOAT; break;
          case UNCOMPRESSED_R32G32B32: if (RLGL.ExtSupported.texFloat32) *glInternalFormat = GL_RGB32F; *glFormat = GL_RGB; *glType = GL_FLOAT; break;
          case UNCOMPRESSED_R32G32B32A32: if (RLGL.ExtSupported.texFloat32) *glInternalFormat = GL_RGBA32F; *glFormat = GL_RGBA; *glType = GL_FLOAT; break;
      #endif
          #if !defined(GRAPHICS_API_OPENGL_11)
          case COMPRESSED_DXT1_RGB: if (RLGL.ExtSupported.texCompDXT) *glInternalFormat = GL_COMPRESSED_RGB_S3TC_DXT1_EXT; break;
          case COMPRESSED_DXT1_RGBA: if (RLGL.ExtSupported.texCompDXT) *glInternalFormat = GL_COMPRESSED_RGBA_S3TC_DXT1_EXT; break;
          case COMPRESSED_DXT3_RGBA: if (RLGL.ExtSupported.texCompDXT) *glInternalFormat = GL_COMPRESSED_RGBA_S3TC_DXT3_EXT; break;
          case COMPRESSED_DXT5_RGBA: if (RLGL.ExtSupported.texCompDXT) *glInternalFormat = GL_COMPRESSED_RGBA_S3TC_DXT5_EXT; break;
          case COMPRESSED_ETC1_RGB: if (RLGL.ExtSupported.texCompETC1) *glInternalFormat = GL_ETC1_RGB8_OES; break;                      // NOTE: Requires OpenGL ES 2.0 or OpenGL 4.3
          case COMPRESSED_ETC2_RGB: if (RLGL.ExtSupported.texCompETC2) *glInternalFormat = GL_COMPRESSED_RGB8_ETC2; break;               // NOTE: Requires OpenGL ES 3.0 or OpenGL 4.3
          case COMPRESSED_ETC2_EAC_RGBA: if (RLGL.ExtSupported.texCompETC2) *glInternalFormat = GL_COMPRESSED_RGBA8_ETC2_EAC; break;     // NOTE: Requires OpenGL ES 3.0 or OpenGL 4.3
          case COMPRESSED_PVRT_RGB: if (RLGL.ExtSupported.texCompPVRT) *glInternalFormat = GL_COMPRESSED_RGB_PVRTC_4BPPV1_IMG; break;    // NOTE: Requires PowerVR GPU
          case COMPRESSED_PVRT_RGBA: if (RLGL.ExtSupported.texCompPVRT) *glInternalFormat = GL_COMPRESSED_RGBA_PVRTC_4BPPV1_IMG; break;  // NOTE: Requires PowerVR GPU
          case COMPRESSED_ASTC_4x4_RGBA: if (RLGL.ExtSupported.texCompASTC) *glInternalFormat = GL_COMPRESSED_RGBA_ASTC_4x4_KHR; break;  // NOTE: Requires OpenGL ES 3.1 or OpenGL 4.3
          case COMPRESSED_ASTC_8x8_RGBA: if (RLGL.ExtSupported.texCompASTC) *glInternalFormat = GL_COMPRESSED_RGBA_ASTC_8x8_KHR; break;  // NOTE: Requires OpenGL ES 3.1 or OpenGL 4.3
          #endif
          default: TRACELOG(LOG_WARNING, "TEXTURE: Current format not supported (%i)", format); break;
      }
  }
  
  // Unload texture from GPU memory
  void rlUnloadTexture(unsigned int id)
  {
      glDeleteTextures(1, &id);
  }
  
  // Load a framebuffer to be used for rendering
  // NOTE: No textures attached
  unsigned int rlLoadFramebuffer(int width, int height)
  {
      unsigned int fboId = 0;
  
  #if (defined(GRAPHICS_API_OPENGL_33) || defined(GRAPHICS_API_OPENGL_46) || defined(GRAPHICS_API_OPENGL_ES2)) && defined(SUPPORT_RENDER_TEXTURES_HINT)
      glGenFramebuffers(1, &fboId);       // Create the framebuffer object
      glBindFramebuffer(GL_FRAMEBUFFER, 0);   // Unbind any framebuffer
  #endif
  
      return fboId;
  }
  
  // Attach color buffer texture to an fbo (unloads previous attachment)
  // NOTE: Attach type: 0-Color, 1-Depth renderbuffer, 2-Depth texture
  void rlFramebufferAttach(unsigned int fboId, unsigned int texId, int attachType, int texType)
  {
  #if (defined(GRAPHICS_API_OPENGL_33) || defined(GRAPHICS_API_OPENGL_46) || defined(GRAPHICS_API_OPENGL_ES2)) && defined(SUPPORT_RENDER_TEXTURES_HINT)
      glBindFramebuffer(GL_FRAMEBUFFER, fboId);
  
      switch (attachType)
      {
          case RL_ATTACHMENT_COLOR_CHANNEL0:
          case RL_ATTACHMENT_COLOR_CHANNEL1:
          case RL_ATTACHMENT_COLOR_CHANNEL2:
          case RL_ATTACHMENT_COLOR_CHANNEL3:
          case RL_ATTACHMENT_COLOR_CHANNEL4:
          case RL_ATTACHMENT_COLOR_CHANNEL5:
          case RL_ATTACHMENT_COLOR_CHANNEL6:
          case RL_ATTACHMENT_COLOR_CHANNEL7:
          {
              if (texType == RL_ATTACHMENT_TEXTURE2D) glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0 + attachType, GL_TEXTURE_2D, texId, 0);
              else if (texType == RL_ATTACHMENT_RENDERBUFFER) glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0 + attachType, GL_RENDERBUFFER, texId);
              else if (texType >= RL_ATTACHMENT_CUBEMAP_POSITIVE_X) glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0 + attachType, GL_TEXTURE_CUBE_MAP_POSITIVE_X + texType, texId, 0);
  
          } break;
          case RL_ATTACHMENT_DEPTH:
          {
              if (texType == RL_ATTACHMENT_TEXTURE2D) glFramebufferTexture2D(GL_FRAMEBUFFER, GL_DEPTH_ATTACHMENT, GL_TEXTURE_2D, texId, 0);
              else if (texType == RL_ATTACHMENT_RENDERBUFFER)  glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_DEPTH_ATTACHMENT, GL_RENDERBUFFER, texId);
  
          } break;
          case RL_ATTACHMENT_STENCIL:
          {
              if (texType == RL_ATTACHMENT_TEXTURE2D) glFramebufferTexture2D(GL_FRAMEBUFFER, GL_STENCIL_ATTACHMENT, GL_TEXTURE_2D, texId, 0);
              else if (texType == RL_ATTACHMENT_RENDERBUFFER)  glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_STENCIL_ATTACHMENT, GL_RENDERBUFFER, texId);
  
          } break;
          default: break;
      }
  
      glBindFramebuffer(GL_FRAMEBUFFER, 0);
  #endif
  }
  
  // Verify render texture is complete
  bool rlFramebufferComplete(unsigned int id)
  {
      bool result = false;
  
  #if (defined(GRAPHICS_API_OPENGL_33) || defined(GRAPHICS_API_OPENGL_46) || defined(GRAPHICS_API_OPENGL_ES2)) && defined(SUPPORT_RENDER_TEXTURES_HINT)
      glBindFramebuffer(GL_FRAMEBUFFER, id);
  
      GLenum status = glCheckFramebufferStatus(GL_FRAMEBUFFER);
  
      if (status != GL_FRAMEBUFFER_COMPLETE)
      {
          switch (status)
          {
              case GL_FRAMEBUFFER_UNSUPPORTED: TRACELOG(LOG_WARNING, "FBO: [ID %i] Framebuffer is unsupported", id); break;
              case GL_FRAMEBUFFER_INCOMPLETE_ATTACHMENT: TRACELOG(LOG_WARNING, "FBO: [ID %i] Framebuffer has incomplete attachment", id); break;
  #if defined(GRAPHICS_API_OPENGL_ES2)
              case GL_FRAMEBUFFER_INCOMPLETE_DIMENSIONS: TRACELOG(LOG_WARNING, "FBO: [ID %i] Framebuffer has incomplete dimensions", id); break;
  #endif
              case GL_FRAMEBUFFER_INCOMPLETE_MISSING_ATTACHMENT: TRACELOG(LOG_WARNING, "FBO: [ID %i] Framebuffer has a missing attachment", id); break;
              default: break;
          }
      }
  
      glBindFramebuffer(GL_FRAMEBUFFER, 0);
  
      result = (status == GL_FRAMEBUFFER_COMPLETE);
  #endif
  
      return result;
  }
  
  // Generate mipmap data for selected texture
  void rlGenerateMipmaps(Texture2D *texture)
  {
      glBindTexture(GL_TEXTURE_2D, texture->id);
  
      // Check if texture is power-of-two (POT)
      bool texIsPOT = false;
  
      if (((texture->width > 0) && ((texture->width & (texture->width - 1)) == 0)) &&
          ((texture->height > 0) && ((texture->height & (texture->height - 1)) == 0))) texIsPOT = true;
  
  #if defined(GRAPHICS_API_OPENGL_11)
      if (texIsPOT)
      {
          // WARNING: Manual mipmap generation only works for RGBA 32bit textures!
          if (texture->format == UNCOMPRESSED_R8G8B8A8)
          {
              // Retrieve texture data from VRAM
              void *data = rlReadTexturePixels(*texture);
  
              // NOTE: data size is reallocated to fit mipmaps data
              // NOTE: CPU mipmap generation only supports RGBA 32bit data
              int mipmapCount = GenerateMipmaps(data, texture->width, texture->height);
  
              int size = texture->width*texture->height*4;
              int offset = size;
  
              int mipWidth = texture->width/2;
              int mipHeight = texture->height/2;
  
              // Load the mipmaps
              for (int level = 1; level < mipmapCount; level++)
              {
                  glTexImage2D(GL_TEXTURE_2D, level, GL_RGBA8, mipWidth, mipHeight, 0, GL_RGBA, GL_UNSIGNED_BYTE, (unsigned char *)data + offset);
  
                  size = mipWidth*mipHeight*4;
                  offset += size;
  
                  mipWidth /= 2;
                  mipHeight /= 2;
              }
  
              texture->mipmaps = mipmapCount + 1;
              RL_FREE(data); // Once mipmaps have been generated and data has been uploaded to GPU VRAM, we can discard RAM data
  
              TRACELOG(LOG_WARNING, "TEXTURE: [ID %i] Mipmaps generated manually on CPU side, total: %i", texture->id, texture->mipmaps);
          }
          else TRACELOG(LOG_WARNING, "TEXTURE: [ID %i] Failed to generate mipmaps for provided texture format", texture->id);
      }
  #elif defined(GRAPHICS_API_OPENGL_33) || defined(GRAPHICS_API_OPENGL_46) || defined(GRAPHICS_API_OPENGL_ES2)
      if ((texIsPOT) || (RLGL.ExtSupported.texNPOT))
      {
          //glHint(GL_GENERATE_MIPMAP_HINT, GL_DONT_CARE);   // Hint for mipmaps generation algorythm: GL_FASTEST, GL_NICEST, GL_DONT_CARE
          glGenerateMipmap(GL_TEXTURE_2D);    // Generate mipmaps automatically
  
          glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
          glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR_MIPMAP_LINEAR);   // Activate Trilinear filtering for mipmaps
  
          #define MIN(a,b) (((a)<(b))?(a):(b))
          #define MAX(a,b) (((a)>(b))?(a):(b))
  
          texture->mipmaps =  1 + (int)floor(log(MAX(texture->width, texture->height))/log(2));
          TRACELOG(LOG_INFO, "TEXTURE: [ID %i] Mipmaps generated automatically, total: %i", texture->id, texture->mipmaps);
      }
  #endif
      else TRACELOG(LOG_WARNING, "TEXTURE: [ID %i] Failed to generate mipmaps", texture->id);
  
      glBindTexture(GL_TEXTURE_2D, 0);
  }
  
  // Upload vertex data into a VAO (if supported) and VBO
  void rlLoadMesh(Mesh *mesh, bool dynamic)
  {
      if (mesh->vaoId > 0)
      {
          // Check if mesh has already been loaded in GPU
          TRACELOG(LOG_WARNING, "VAO: [ID %i] Trying to re-load an already loaded mesh", mesh->vaoId);
          return;
      }
  
      mesh->vaoId = 0;        // Vertex Array Object
      mesh->vboId[0] = 0;     // Vertex positions VBO
      mesh->vboId[1] = 0;     // Vertex texcoords VBO
      mesh->vboId[2] = 0;     // Vertex normals VBO
      mesh->vboId[3] = 0;     // Vertex colors VBO
      mesh->vboId[4] = 0;     // Vertex tangents VBO
      mesh->vboId[5] = 0;     // Vertex texcoords2 VBO
      mesh->vboId[6] = 0;     // Vertex indices VBO
      mesh->vboId[7] = 0;     // Vertex boneIds VBO
      mesh->vboId[8] = 0;     // Vertex boneWeight VBO
  
  #if defined(GRAPHICS_API_OPENGL_33) || defined(GRAPHICS_API_OPENGL_46) || defined(GRAPHICS_API_OPENGL_ES2)
      int drawHint = GL_STATIC_DRAW;
      if (dynamic) drawHint = GL_DYNAMIC_DRAW;
  
      if (RLGL.ExtSupported.vao)
      {
          // Initialize Quads VAO (Buffer A)
          glGenVertexArrays(1, &mesh->vaoId);
          glBindVertexArray(mesh->vaoId);
      }
  
      // NOTE: Attributes must be uploaded considering default locations points
  
      // Enable vertex attributes: position (shader-location = 0)
      glGenBuffers(1, &mesh->vboId[0]);
      glBindBuffer(GL_ARRAY_BUFFER, mesh->vboId[0]);
      glBufferData(GL_ARRAY_BUFFER, mesh->vertexCount*3*sizeof(float), mesh->vertices, drawHint);
      glVertexAttribPointer(0, 3, GL_FLOAT, 0, 0, 0);
      glEnableVertexAttribArray(0);
  
      // Enable vertex attributes: texcoords (shader-location = 1)
      glGenBuffers(1, &mesh->vboId[1]);
      glBindBuffer(GL_ARRAY_BUFFER, mesh->vboId[1]);
      glBufferData(GL_ARRAY_BUFFER, mesh->vertexCount*2*sizeof(float), mesh->texcoords, drawHint);
      glVertexAttribPointer(1, 2, GL_FLOAT, 0, 0, 0);
      glEnableVertexAttribArray(1);
  
      // Enable vertex attributes: normals (shader-location = 2)
      if (mesh->normals != NULL)
      {
          glGenBuffers(1, &mesh->vboId[2]);
          glBindBuffer(GL_ARRAY_BUFFER, mesh->vboId[2]);
          glBufferData(GL_ARRAY_BUFFER, mesh->vertexCount*3*sizeof(float), mesh->normals, drawHint);
          glVertexAttribPointer(2, 3, GL_FLOAT, 0, 0, 0);
          glEnableVertexAttribArray(2);
      }
      else
      {
          // Default color vertex attribute set to WHITE
          glVertexAttrib3f(2, 1.0f, 1.0f, 1.0f);
          glDisableVertexAttribArray(2);
      }
  
      // Default color vertex attribute (shader-location = 3)
      if (mesh->colors != NULL)
      {
          glGenBuffers(1, &mesh->vboId[3]);
          glBindBuffer(GL_ARRAY_BUFFER, mesh->vboId[3]);
          glBufferData(GL_ARRAY_BUFFER, mesh->vertexCount*4*sizeof(unsigned char), mesh->colors, drawHint);
          glVertexAttribPointer(3, 4, GL_UNSIGNED_BYTE, GL_TRUE, 0, 0);
          glEnableVertexAttribArray(3);
      }
      else
      {
          // Default color vertex attribute set to WHITE
          glVertexAttrib4f(3, 1.0f, 1.0f, 1.0f, 1.0f);
          glDisableVertexAttribArray(3);
      }
  
      // Default tangent vertex attribute (shader-location = 4)
      if (mesh->tangents != NULL)
      {
          glGenBuffers(1, &mesh->vboId[4]);
          glBindBuffer(GL_ARRAY_BUFFER, mesh->vboId[4]);
          glBufferData(GL_ARRAY_BUFFER, mesh->vertexCount*4*sizeof(float), mesh->tangents, drawHint);
          glVertexAttribPointer(4, 4, GL_FLOAT, 0, 0, 0);
          glEnableVertexAttribArray(4);
      }
      else
      {
          // Default tangents vertex attribute
          glVertexAttrib4f(4, 0.0f, 0.0f, 0.0f, 0.0f);
          glDisableVertexAttribArray(4);
      }
  
      // Default texcoord2 vertex attribute (shader-location = 5)
      if (mesh->texcoords2 != NULL)
      {
          glGenBuffers(1, &mesh->vboId[5]);
          glBindBuffer(GL_ARRAY_BUFFER, mesh->vboId[5]);
          glBufferData(GL_ARRAY_BUFFER, mesh->vertexCount*2*sizeof(float), mesh->texcoords2, drawHint);
          glVertexAttribPointer(5, 2, GL_FLOAT, 0, 0, 0);
          glEnableVertexAttribArray(5);
      }
      else
      {
          // Default texcoord2 vertex attribute
          glVertexAttrib2f(5, 0.0f, 0.0f);
          glDisableVertexAttribArray(5);
      }
  
      // Indices (shader-location = 6)
      if (mesh->indices != NULL)
      {
          glGenBuffers(1, &mesh->vboId[6]);
          glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, mesh->vboId[6]);
          glBufferData(GL_ELEMENT_ARRAY_BUFFER, mesh->triangleCount*3*sizeof(unsigned short), mesh->indices, drawHint);
      }
  
      // Default boneId vertex attribute (shader-location = 7)
      if (mesh->boneIds != NULL)
      {
          glGenBuffers(1, &mesh->vboId[7]);
          glBindBuffer(GL_ARRAY_BUFFER, mesh->vboId[7]);
          glBufferData(GL_ARRAY_BUFFER, mesh->vertexCount*4*sizeof(int), mesh->boneIds, drawHint);
          glVertexAttribIPointer(7, 4, GL_INT, 0, 0);
          glEnableVertexAttribArray(7);
  
          //for (int i = 0; i <  mesh->vertexCount; i++) {
          //  printf("bone %d idex: %d %d %d %d\n", i, mesh->boneIds[i*4+0], mesh->boneIds[i*4+1],mesh->boneIds[i*4+2],mesh->boneIds[i*4+3]);
          //}
      }
      else
      {
          // Default boneIds vertex attribute
          glVertexAttribI4i(7, 0, 0, 0, 0);
          glDisableVertexAttribArray(7);
      }
  
      // Default boneWeight vertex attribute (shader-location = 8)
      if (mesh->boneWeights != NULL)
      {
          glGenBuffers(1, &mesh->vboId[8]);
          glBindBuffer(GL_ARRAY_BUFFER, mesh->vboId[8]);
          glBufferData(GL_ARRAY_BUFFER, mesh->vertexCount*4*sizeof(float), mesh->boneWeights, drawHint);
          glVertexAttribPointer(8, 4, GL_FLOAT, 0, 0, 0);
          glEnableVertexAttribArray(8);
  
          //for (int i = 0; i <  mesh->vertexCount; i++){
          //  if (mesh->boneWeights[i*4+0] + mesh->boneWeights[i*4+1] + mesh->boneWeights[i*4+2] + mesh->boneWeights[i*4+3] != 1.0f)
          //    printf("bone %d idex: %.2f %.2f %.2f %.2f\n", i, mesh->boneWeights[i*4+0], mesh->boneWeights[i*4+1],mesh->boneWeights[i*4+2],mesh->boneWeights[i*4+3]);
          //}
      }
      else
      {
          // Default boneWeights vertex attribute
          glVertexAttrib4f(8, 1.0f, 0.0f, 0.0f, 0.0f);
          glDisableVertexAttribArray(8);
      }
  
      if (RLGL.ExtSupported.vao)
      {
          if (mesh->vaoId > 0) TRACELOG(LOG_INFO, "VAO: [ID %i] Mesh uploaded successfully to VRAM (GPU)", mesh->vaoId);
          else TRACELOG(LOG_WARNING, "VAO: Failed to load mesh to VRAM (GPU)");
      }
      else
      {
          TRACELOG(LOG_INFO, "VBO: Mesh uploaded successfully to VRAM (GPU)");
      }
  #endif
  }
  
  // Load a new attributes buffer
  unsigned int rlLoadAttribBuffer(unsigned int vaoId, int shaderLoc, void *buffer, int size, bool dynamic)
  {
      unsigned int id = 0;
  
  #if defined(GRAPHICS_API_OPENGL_33) || defined(GRAPHICS_API_OPENGL_46) || defined(GRAPHICS_API_OPENGL_ES2)
      int drawHint = GL_STATIC_DRAW;
      if (dynamic) drawHint = GL_DYNAMIC_DRAW;
  
      if (RLGL.ExtSupported.vao) glBindVertexArray(vaoId);
  
      glGenBuffers(1, &id);
      glBindBuffer(GL_ARRAY_BUFFER, id);
      glBufferData(GL_ARRAY_BUFFER, size, buffer, drawHint);
      glVertexAttribPointer(shaderLoc, 2, GL_FLOAT, 0, 0, 0);
      glEnableVertexAttribArray(shaderLoc);
  
      if (RLGL.ExtSupported.vao) glBindVertexArray(0);
  #endif
  
      return id;
  }
  
  // Update vertex or index data on GPU (upload new data to one buffer)
  void rlUpdateMesh(Mesh mesh, int buffer, int count)
  {
      rlUpdateMeshAt(mesh, buffer, count, 0);
  }
  
  // Update vertex or index data on GPU, at index
  // WARNING: error checking is in place that will cause the data to not be
  //          updated if offset + size exceeds what the buffer can hold
  void rlUpdateMeshAt(Mesh mesh, int buffer, int count, int index)
  {
  #if defined(GRAPHICS_API_OPENGL_33) || defined(GRAPHICS_API_OPENGL_46) || defined(GRAPHICS_API_OPENGL_ES2)
      // Activate mesh VAO
      if (RLGL.ExtSupported.vao) glBindVertexArray(mesh.vaoId);
  
      switch (buffer)
      {
          case 0:     // Update vertices (vertex position)
          {
              glBindBuffer(GL_ARRAY_BUFFER, mesh.vboId[0]);
              if (index == 0 && count >= mesh.vertexCount) glBufferData(GL_ARRAY_BUFFER, count*3*sizeof(float), mesh.vertices, GL_DYNAMIC_DRAW);
              else if (index + count >= mesh.vertexCount) break;
              else glBufferSubData(GL_ARRAY_BUFFER, index*3*sizeof(float), count*3*sizeof(float), mesh.vertices);
  
          } break;
          case 1:     // Update texcoords (vertex texture coordinates)
          {
              glBindBuffer(GL_ARRAY_BUFFER, mesh.vboId[1]);
              if (index == 0 && count >= mesh.vertexCount) glBufferData(GL_ARRAY_BUFFER, count*2*sizeof(float), mesh.texcoords, GL_DYNAMIC_DRAW);
              else if (index + count >= mesh.vertexCount) break;
              else glBufferSubData(GL_ARRAY_BUFFER, index*2*sizeof(float), count*2*sizeof(float), mesh.texcoords);
  
          } break;
          case 2:     // Update normals (vertex normals)
          {
              glBindBuffer(GL_ARRAY_BUFFER, mesh.vboId[2]);
              if (index == 0 && count >= mesh.vertexCount) glBufferData(GL_ARRAY_BUFFER, count*3*sizeof(float), mesh.normals, GL_DYNAMIC_DRAW);
              else if (index + count >= mesh.vertexCount) break;
              else glBufferSubData(GL_ARRAY_BUFFER, index*3*sizeof(float), count*3*sizeof(float), mesh.normals);
  
          } break;
          case 3:     // Update colors (vertex colors)
          {
              glBindBuffer(GL_ARRAY_BUFFER, mesh.vboId[3]);
              if (index == 0 && count >= mesh.vertexCount) glBufferData(GL_ARRAY_BUFFER, count*4*sizeof(unsigned char), mesh.colors, GL_DYNAMIC_DRAW);
              else if (index + count >= mesh.vertexCount) break;
              else glBufferSubData(GL_ARRAY_BUFFER, index*4*sizeof(unsigned char), count*4*sizeof(unsigned char), mesh.colors);
  
          } break;
          case 4:     // Update tangents (vertex tangents)
          {
              glBindBuffer(GL_ARRAY_BUFFER, mesh.vboId[4]);
              if (index == 0 && count >= mesh.vertexCount) glBufferData(GL_ARRAY_BUFFER, count*4*sizeof(float), mesh.tangents, GL_DYNAMIC_DRAW);
              else if (index + count >= mesh.vertexCount) break;
              else glBufferSubData(GL_ARRAY_BUFFER, index*4*sizeof(float), count*4*sizeof(float), mesh.tangents);
  
          } break;
          case 5:     // Update texcoords2 (vertex second texture coordinates)
          {
              glBindBuffer(GL_ARRAY_BUFFER, mesh.vboId[5]);
              if (index == 0 && count >= mesh.vertexCount) glBufferData(GL_ARRAY_BUFFER, count*2*sizeof(float), mesh.texcoords2, GL_DYNAMIC_DRAW);
              else if (index + count >= mesh.vertexCount) break;
              else glBufferSubData(GL_ARRAY_BUFFER, index*2*sizeof(float), count*2*sizeof(float), mesh.texcoords2);
  
          } break;
          case 6:     // Update indices (triangle index buffer)
          {
              // the * 3 is because each triangle has 3 indices
              unsigned short *indices = mesh.indices;
              glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, mesh.vboId[6]);
  
              if (index == 0 && count >= mesh.triangleCount) glBufferData(GL_ELEMENT_ARRAY_BUFFER, count*3*sizeof(*indices), indices, GL_DYNAMIC_DRAW);
              else if (index + count >= mesh.triangleCount) break;
              else glBufferSubData(GL_ELEMENT_ARRAY_BUFFER, index*3*sizeof(*indices), count*3*sizeof(*indices), indices);
  
          } break;
          case 7:     // Update boneIds (vertex boneIds)
          {
              glBindBuffer(GL_ARRAY_BUFFER, mesh.vboId[7]);
              if (index == 0 && count >= mesh.vertexCount) glBufferData(GL_ARRAY_BUFFER, count*4*sizeof(int), mesh.boneIds, GL_DYNAMIC_DRAW);
              else if (index + count >= mesh.vertexCount) break;
              else glBufferSubData(GL_ARRAY_BUFFER, index*4*sizeof(int), count*4*sizeof(int), mesh.boneIds);
  
          } break;
          case 8:     // Update boneWeights (vertex boneWeights)
          {
              glBindBuffer(GL_ARRAY_BUFFER, mesh.vboId[8]);
              if (index == 0 && count >= mesh.vertexCount) glBufferData(GL_ARRAY_BUFFER, count*4*sizeof(float), mesh.boneWeights, GL_DYNAMIC_DRAW);
              else if (index + count >= mesh.vertexCount) break;
              else glBufferSubData(GL_ARRAY_BUFFER, index*4*sizeof(float), count*4*sizeof(float), mesh.boneWeights);
  
          } break;
          default: break;
      }
  
      // Unbind the current VAO
      if (RLGL.ExtSupported.vao) glBindVertexArray(0);
  
      // Another option would be using buffer mapping...
      //mesh.vertices = glMapBuffer(GL_ARRAY_BUFFER, GL_READ_WRITE);
      // Now we can modify vertices
      //glUnmapBuffer(GL_ARRAY_BUFFER);
  #endif
  }
  
  // Draw a 3d mesh with material and transform
  void rlDrawMesh(Mesh mesh, Material material, Matrix transform)
  {
  #if defined(GRAPHICS_API_OPENGL_11)
      glEnable(GL_TEXTURE_2D);
      glBindTexture(GL_TEXTURE_2D, material.maps[MAP_DIFFUSE].texture.id);
  
      // NOTE: On OpenGL 1.1 we use Vertex Arrays to draw model
      glEnableClientState(GL_VERTEX_ARRAY);                   // Enable vertex array
      glEnableClientState(GL_TEXTURE_COORD_ARRAY);            // Enable texture coords array
      if (mesh.normals != NULL) glEnableClientState(GL_NORMAL_ARRAY);     // Enable normals array
      if (mesh.colors != NULL) glEnableClientState(GL_COLOR_ARRAY);       // Enable colors array
  
      glVertexPointer(3, GL_FLOAT, 0, mesh.vertices);         // Pointer to vertex coords array
      glTexCoordPointer(2, GL_FLOAT, 0, mesh.texcoords);      // Pointer to texture coords array
      if (mesh.normals != NULL) glNormalPointer(GL_FLOAT, 0, mesh.normals);           // Pointer to normals array
      if (mesh.colors != NULL) glColorPointer(4, GL_UNSIGNED_BYTE, 0, mesh.colors);   // Pointer to colors array
  
      rlPushMatrix();
          rlMultMatrixf(MatrixToFloat(transform));
          rlColor4ub(material.maps[MAP_DIFFUSE].color.r, material.maps[MAP_DIFFUSE].color.g, material.maps[MAP_DIFFUSE].color.b, material.maps[MAP_DIFFUSE].color.a);
  
          if (mesh.indices != NULL) glDrawElements(GL_TRIANGLES, mesh.triangleCount*3, GL_UNSIGNED_SHORT, mesh.indices);
          else glDrawArrays(GL_TRIANGLES, 0, mesh.vertexCount);
      rlPopMatrix();
  
      glDisableClientState(GL_VERTEX_ARRAY);                  // Disable vertex array
      glDisableClientState(GL_TEXTURE_COORD_ARRAY);           // Disable texture coords array
      if (mesh.normals != NULL) glDisableClientState(GL_NORMAL_ARRAY);    // Disable normals array
      if (mesh.colors != NULL) glDisableClientState(GL_NORMAL_ARRAY);     // Disable colors array
  
      glDisable(GL_TEXTURE_2D);
      glBindTexture(GL_TEXTURE_2D, 0);
  #endif
  
  #if defined(GRAPHICS_API_OPENGL_33) || defined(GRAPHICS_API_OPENGL_46) || defined(GRAPHICS_API_OPENGL_ES2)
      // Bind shader program
      glUseProgram(material.shader.id);
  
      // Matrices and other values required by shader
      //-----------------------------------------------------
      // Calculate and send to shader model matrix (used by PBR shader)
      if (material.shader.locs[LOC_MATRIX_MODEL] != -1) SetShaderValueMatrix(material.shader, material.shader.locs[LOC_MATRIX_MODEL], transform);
  
      // Upload to shader material.colDiffuse
      if (material.shader.locs[LOC_COLOR_DIFFUSE] != -1)
          glUniform4f(material.shader.locs[LOC_COLOR_DIFFUSE], (float)material.maps[MAP_DIFFUSE].color.r/255.0f,
                                                             (float)material.maps[MAP_DIFFUSE].color.g/255.0f,
                                                             (float)material.maps[MAP_DIFFUSE].color.b/255.0f,
                                                             (float)material.maps[MAP_DIFFUSE].color.a/255.0f);
  
      // Upload to shader material.colSpecular (if available)
      if (material.shader.locs[LOC_COLOR_SPECULAR] != -1)
          glUniform4f(material.shader.locs[LOC_COLOR_SPECULAR], (float)material.maps[MAP_SPECULAR].color.r/255.0f,
                                                                 (float)material.maps[MAP_SPECULAR].color.g/255.0f,
                                                                 (float)material.maps[MAP_SPECULAR].color.b/255.0f,
                                                                 (float)material.maps[MAP_SPECULAR].color.a/255.0f);
  
      if (material.shader.locs[LOC_MATRIX_VIEW] != -1) SetShaderValueMatrix(material.shader, material.shader.locs[LOC_MATRIX_VIEW], RLGL.State.modelview);
      if (material.shader.locs[LOC_MATRIX_PROJECTION] != -1) SetShaderValueMatrix(material.shader, material.shader.locs[LOC_MATRIX_PROJECTION], RLGL.State.projection);
  
      // At this point the modelview matrix just contains the view matrix (camera)
      // That's because BeginMode3D() sets it an no model-drawing function modifies it, all use rlPushMatrix() and rlPopMatrix()
      Matrix matView = RLGL.State.modelview;         // View matrix (camera)
      Matrix matProjection = RLGL.State.projection;  // Projection matrix (perspective)
  
      // TODO: Consider possible transform matrices in the RLGL.State.stack
      // Is this the right order? or should we start with the first stored matrix instead of the last one?
      //Matrix matStackTransform = MatrixIdentity();
      //for (int i = RLGL.State.stackCounter; i > 0; i--) matStackTransform = MatrixMultiply(RLGL.State.stack[i], matStackTransform);
  
      // Transform to camera-space coordinates
      Matrix matModelView = MatrixMultiply(transform, MatrixMultiply(RLGL.State.transform, matView));
      //-----------------------------------------------------
  
      // Bind active texture maps (if available)
      for (int i = 0; i < MAX_MATERIAL_MAPS; i++)
      {
          if (material.maps[i].texture.id > 0)
          {
              glActiveTexture(GL_TEXTURE0 + i);
              if ((i == MAP_IRRADIANCE) || (i == MAP_PREFILTER) || (i == MAP_CUBEMAP)) glBindTexture(GL_TEXTURE_CUBE_MAP, material.maps[i].texture.id);
              else glBindTexture(GL_TEXTURE_2D, material.maps[i].texture.id);
  
              glUniform1i(material.shader.locs[LOC_MAP_DIFFUSE + i], i);
          }
      }
  
      // Bind vertex array objects (or VBOs)
      if (RLGL.ExtSupported.vao) glBindVertexArray(mesh.vaoId);
      else
      {
          // Bind mesh VBO data: vertex position (shader-location = 0)
          glBindBuffer(GL_ARRAY_BUFFER, mesh.vboId[0]);
          glVertexAttribPointer(material.shader.locs[LOC_VERTEX_POSITION], 3, GL_FLOAT, 0, 0, 0);
          glEnableVertexAttribArray(material.shader.locs[LOC_VERTEX_POSITION]);
  
          // Bind mesh VBO data: vertex texcoords (shader-location = 1)
          glBindBuffer(GL_ARRAY_BUFFER, mesh.vboId[1]);
          glVertexAttribPointer(material.shader.locs[LOC_VERTEX_TEXCOORD01], 2, GL_FLOAT, 0, 0, 0);
          glEnableVertexAttribArray(material.shader.locs[LOC_VERTEX_TEXCOORD01]);
  
          // Bind mesh VBO data: vertex normals (shader-location = 2, if available)
          if (material.shader.locs[LOC_VERTEX_NORMAL] != -1)
          {
              glBindBuffer(GL_ARRAY_BUFFER, mesh.vboId[2]);
              glVertexAttribPointer(material.shader.locs[LOC_VERTEX_NORMAL], 3, GL_FLOAT, 0, 0, 0);
              glEnableVertexAttribArray(material.shader.locs[LOC_VERTEX_NORMAL]);
          }
  
          // Bind mesh VBO data: vertex colors (shader-location = 3, if available)
          if (material.shader.locs[LOC_VERTEX_COLOR] != -1)
          {
              if (mesh.vboId[3] != 0)
              {
                  glBindBuffer(GL_ARRAY_BUFFER, mesh.vboId[3]);
                  glVertexAttribPointer(material.shader.locs[LOC_VERTEX_COLOR], 4, GL_UNSIGNED_BYTE, GL_TRUE, 0, 0);
                  glEnableVertexAttribArray(material.shader.locs[LOC_VERTEX_COLOR]);
              }
              else
              {
                  // Set default value for unused attribute
                  // NOTE: Required when using default shader and no VAO support
                  glVertexAttrib4f(material.shader.locs[LOC_VERTEX_COLOR], 1.0f, 1.0f, 1.0f, 1.0f);
                  glDisableVertexAttribArray(material.shader.locs[LOC_VERTEX_COLOR]);
              }
          }
  
          // Bind mesh VBO data: vertex tangents (shader-location = 4, if available)
          if (material.shader.locs[LOC_VERTEX_TANGENT] != -1)
          {
              glBindBuffer(GL_ARRAY_BUFFER, mesh.vboId[4]);
              glVertexAttribPointer(material.shader.locs[LOC_VERTEX_TANGENT], 4, GL_FLOAT, 0, 0, 0);
              glEnableVertexAttribArray(material.shader.locs[LOC_VERTEX_TANGENT]);
          }
  
          // Bind mesh VBO data: vertex texcoords2 (shader-location = 5, if available)
          if (material.shader.locs[LOC_VERTEX_TEXCOORD02] != -1)
          {
              glBindBuffer(GL_ARRAY_BUFFER, mesh.vboId[5]);
              glVertexAttribPointer(material.shader.locs[LOC_VERTEX_TEXCOORD02], 2, GL_FLOAT, 0, 0, 0);
              glEnableVertexAttribArray(material.shader.locs[LOC_VERTEX_TEXCOORD02]);
          }
  
          if (mesh.indices != NULL) glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, mesh.vboId[6]);
  
          // Bind mesh VBO data: vertex boneIds (shader-location = 7, if available)
          if (material.shader.locs[LOC_VERTEX_BONEID] != -1)
          {
              glBindBuffer(GL_ARRAY_BUFFER, mesh.vboId[7]);
              glVertexAttribIPointer(material.shader.locs[LOC_VERTEX_BONEID], 4, GL_INT, 0, 0);
              glEnableVertexAttribArray(material.shader.locs[LOC_VERTEX_BONEID]);
          }
  
          // Bind mesh VBO data: vertex boneWeights (shader-location = 8, if available)
          if (material.shader.locs[LOC_VERTEX_BONEWEIGHT] != -1)
          {
              glBindBuffer(GL_ARRAY_BUFFER, mesh.vboId[8]);
              glVertexAttribPointer(material.shader.locs[LOC_VERTEX_BONEWEIGHT], 4, GL_FLOAT, 0, 0, 0);
              glEnableVertexAttribArray(material.shader.locs[LOC_VERTEX_BONEWEIGHT]);
          }
      }
  
      int eyesCount = 1;
  #if defined(SUPPORT_VR_SIMULATOR)
      if (RLGL.Vr.stereoRender) eyesCount = 2;
  #endif
  
      for (int eye = 0; eye < eyesCount; eye++)
      {
          if (eyesCount == 1) RLGL.State.modelview = matModelView;
          #if defined(SUPPORT_VR_SIMULATOR)
          else SetStereoView(eye, matProjection, matModelView);
          #endif
  
          // Calculate model-view-projection matrix (MVP)
          Matrix matMVP = MatrixMultiply(RLGL.State.modelview, RLGL.State.projection);        // Transform to screen-space coordinates
  
          // Send combined model-view-projection matrix to shader
          glUniformMatrix4fv(material.shader.locs[LOC_MATRIX_MVP], 1, false, MatrixToFloat(matMVP));
  
          // Draw call!
          if (mesh.indices != NULL) glDrawElements(GL_TRIANGLES, mesh.triangleCount*3, GL_UNSIGNED_SHORT, 0); // Indexed vertices draw
          else glDrawArrays(GL_TRIANGLES, 0, mesh.vertexCount);
      }
  
      // Unbind all binded texture maps
      for (int i = 0; i < MAX_MATERIAL_MAPS; i++)
      {
          glActiveTexture(GL_TEXTURE0 + i);       // Set shader active texture
          if ((i == MAP_IRRADIANCE) || (i == MAP_PREFILTER) || (i == MAP_CUBEMAP)) glBindTexture(GL_TEXTURE_CUBE_MAP, 0);
          else glBindTexture(GL_TEXTURE_2D, 0);   // Unbind current active texture
      }
  
      // Unind vertex array objects (or VBOs)
      if (RLGL.ExtSupported.vao) glBindVertexArray(0);
      else
      {
          glBindBuffer(GL_ARRAY_BUFFER, 0);
          if (mesh.indices != NULL) glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, 0);
      }
  
      // Unbind shader program
      glUseProgram(0);
  
      // Restore RLGL.State.projection/RLGL.State.modelview matrices
      // NOTE: In stereo rendering matrices are being modified to fit every eye
      RLGL.State.projection = matProjection;
      RLGL.State.modelview = matView;
  #endif
  }
  
  // Draw a 3d mesh with material and transform
  void rlDrawMeshInstanced(Mesh mesh, Material material, Matrix *transforms, int count)
  {
  #if defined(GRAPHICS_API_OPENGL_33) || defined(GRAPHICS_API_OPENGL_46)
      // Bind shader program
      glUseProgram(material.shader.id);
  
      // Upload to shader material.colDiffuse
      if (material.shader.locs[LOC_COLOR_DIFFUSE] != -1)
          glUniform4f(material.shader.locs[LOC_COLOR_DIFFUSE], (float)material.maps[MAP_DIFFUSE].color.r/255.0f,
                                                             (float)material.maps[MAP_DIFFUSE].color.g/255.0f,
                                                             (float)material.maps[MAP_DIFFUSE].color.b/255.0f,
                                                             (float)material.maps[MAP_DIFFUSE].color.a/255.0f);
  
      // Upload to shader material.colSpecular (if available)
      if (material.shader.locs[LOC_COLOR_SPECULAR] != -1)
          glUniform4f(material.shader.locs[LOC_COLOR_SPECULAR], (float)material.maps[MAP_SPECULAR].color.r/255.0f,
                                                                 (float)material.maps[MAP_SPECULAR].color.g/255.0f,
                                                                 (float)material.maps[MAP_SPECULAR].color.b/255.0f,
                                                                 (float)material.maps[MAP_SPECULAR].color.a/255.0f);
  
      // Bind active texture maps (if available)
      for (int i = 0; i < MAX_MATERIAL_MAPS; i++)
      {
          if (material.maps[i].texture.id > 0)
          {
              glActiveTexture(GL_TEXTURE0 + i);
              if ((i == MAP_IRRADIANCE) || (i == MAP_PREFILTER) || (i == MAP_CUBEMAP))
                  glBindTexture(GL_TEXTURE_CUBE_MAP, material.maps[i].texture.id);
              else glBindTexture(GL_TEXTURE_2D, material.maps[i].texture.id);
  
              glUniform1i(material.shader.locs[LOC_MAP_DIFFUSE + i], i);
          }
      }
  
      // Bind vertex array objects (or VBOs)
      glBindVertexArray(mesh.vaoId);
  
      // At this point the modelview matrix just contains the view matrix (camera)
      // For instanced shaders "mvp" is not premultiplied by any instance transform, only RLGL.State.transform
      glUniformMatrix4fv(material.shader.locs[LOC_MATRIX_MVP], 1, false,
                         MatrixToFloat(MatrixMultiply(MatrixMultiply(RLGL.State.transform, RLGL.State.modelview), RLGL.State.projection)));
  
      float16* instances = RL_MALLOC(count*sizeof(float16));
  
      for (int i = 0; i < count; i++) instances[i] = MatrixToFloatV(transforms[i]);
  
      // This could alternatively use a static VBO and either glMapBuffer or glBufferSubData.
      // It isn't clear which would be reliably faster in all cases and on all platforms, and
      // anecdotally glMapBuffer seems very slow (syncs) while glBufferSubData seems no faster
      // since we're transferring all the transform matrices anyway.
      unsigned int instancesB = 0;
      glGenBuffers(1, &instancesB);
      glBindBuffer(GL_ARRAY_BUFFER, instancesB);
      glBufferData(GL_ARRAY_BUFFER, count*sizeof(float16), instances, GL_STATIC_DRAW);
  
      // Instances are put in LOC_MATRIX_MODEL attribute location with space for 4x Vector4, eg:
      // layout (location = 12) in mat4 instance;
      unsigned int instanceA = material.shader.locs[LOC_MATRIX_MODEL];
  
      for (unsigned int i = 0; i < 4; i++)
      {
          glEnableVertexAttribArray(instanceA+i);
          glVertexAttribPointer(instanceA + i, 4, GL_FLOAT, GL_FALSE, sizeof(Matrix), (void *)(i*sizeof(Vector4)));
          glVertexAttribDivisor(instanceA + i, 1);
      }
  
      glBindBuffer(GL_ARRAY_BUFFER, 0);
  
      // Draw call!
      if (mesh.indices != NULL) glDrawElementsInstanced(GL_TRIANGLES, mesh.triangleCount*3, GL_UNSIGNED_SHORT, 0, count);
      else glDrawArraysInstanced(GL_TRIANGLES, 0, mesh.vertexCount, count);
  
      glDeleteBuffers(1, &instancesB);
      RL_FREE(instances);
  
      // Unbind all binded texture maps
      for (int i = 0; i < MAX_MATERIAL_MAPS; i++)
      {
          glActiveTexture(GL_TEXTURE0 + i);       // Set shader active texture
          if ((i == MAP_IRRADIANCE) || (i == MAP_PREFILTER) || (i == MAP_CUBEMAP)) glBindTexture(GL_TEXTURE_CUBE_MAP, 0);
          else glBindTexture(GL_TEXTURE_2D, 0);   // Unbind current active texture
      }
  
      // Unind vertex array objects (or VBOs)
      glBindVertexArray(0);
  
      // Unbind shader program
      glUseProgram(0);
  
  #else
      TRACELOG(LOG_ERROR, "VAO: Instanced rendering requires GRAPHICS_API_OPENGL_33");
  #endif
  }
  
  // Unload mesh data from CPU and GPU
  void rlUnloadMesh(Mesh mesh)
  {
      RL_FREE(mesh.vertices);
      RL_FREE(mesh.texcoords);
      RL_FREE(mesh.normals);
      RL_FREE(mesh.colors);
      RL_FREE(mesh.tangents);
      RL_FREE(mesh.texcoords2);
      RL_FREE(mesh.indices);
  
      RL_FREE(mesh.animVertices);
      RL_FREE(mesh.animNormals);
      RL_FREE(mesh.boneWeights);
      RL_FREE(mesh.boneIds);
  
  #if defined(GRAPHICS_API_OPENGL_33) || defined(GRAPHICS_API_OPENGL_46) || defined(GRAPHICS_API_OPENGL_ES2)
      for (int i = 0; i < 9; i++) glDeleteBuffers(1, &mesh.vboId[i]); // DEFAULT_MESH_VERTEX_BUFFERS (model.c)
      if (RLGL.ExtSupported.vao)
      {
          glBindVertexArray(0);
          glDeleteVertexArrays(1, &mesh.vaoId);
          TRACELOG(LOG_INFO, "VAO: [ID %i] Unloaded vertex data from VRAM (GPU)", mesh.vaoId);
      }
      else TRACELOG(LOG_INFO, "VBO: Unloaded vertex data from VRAM (GPU)");
  #endif
  }
  
  // Read screen pixel data (color buffer)
  unsigned char *rlReadScreenPixels(int width, int height)
  {
      unsigned char *screenData = (unsigned char *)RL_CALLOC(width*height*4, sizeof(unsigned char));
  
      // NOTE 1: glReadPixels returns image flipped vertically -> (0,0) is the bottom left corner of the framebuffer
      // NOTE 2: We are getting alpha channel! Be careful, it can be transparent if not cleared properly!
      glReadPixels(0, 0, width, height, GL_RGBA, GL_UNSIGNED_BYTE, screenData);
  
      // Flip image vertically!
      unsigned char *imgData = (unsigned char *)RL_MALLOC(width*height*4*sizeof(unsigned char));
  
      for (int y = height - 1; y >= 0; y--)
      {
          for (int x = 0; x < (width*4); x++)
          {
              imgData[((height - 1) - y)*width*4 + x] = screenData[(y*width*4) + x];  // Flip line
  
              // Set alpha component value to 255 (no trasparent image retrieval)
              // NOTE: Alpha value has already been applied to RGB in framebuffer, we don't need it!
              if (((x + 1)%4) == 0) imgData[((height - 1) - y)*width*4 + x] = 255;
          }
      }
  
      RL_FREE(screenData);
  
      return imgData;     // NOTE: image data should be freed
  }
  
  // Read texture pixel data
  void *rlReadTexturePixels(Texture2D texture)
  {
      void *pixels = NULL;
  
  #if defined(GRAPHICS_API_OPENGL_11) || defined(GRAPHICS_API_OPENGL_33) || defined(GRAPHICS_API_OPENGL_46)
      glBindTexture(GL_TEXTURE_2D, texture.id);
  
      // NOTE: Using texture.id, we can retrieve some texture info (but not on OpenGL ES 2.0)
      // Possible texture info: GL_TEXTURE_RED_SIZE, GL_TEXTURE_GREEN_SIZE, GL_TEXTURE_BLUE_SIZE, GL_TEXTURE_ALPHA_SIZE
      //int width, height, format;
      //glGetTexLevelParameteriv(GL_TEXTURE_2D, 0, GL_TEXTURE_WIDTH, &width);
      //glGetTexLevelParameteriv(GL_TEXTURE_2D, 0, GL_TEXTURE_HEIGHT, &height);
      //glGetTexLevelParameteriv(GL_TEXTURE_2D, 0, GL_TEXTURE_INTERNAL_FORMAT, &format);
  
      // NOTE: Each row written to or read from by OpenGL pixel operations like glGetTexImage are aligned to a 4 byte boundary by default, which may add some padding.
      // Use glPixelStorei to modify padding with the GL_[UN]PACK_ALIGNMENT setting.
      // GL_PACK_ALIGNMENT affects operations that read from OpenGL memory (glReadPixels, glGetTexImage, etc.)
      // GL_UNPACK_ALIGNMENT affects operations that write to OpenGL memory (glTexImage, etc.)
      glPixelStorei(GL_PACK_ALIGNMENT, 1);
  
      unsigned int glInternalFormat, glFormat, glType;
      rlGetGlTextureFormats(texture.format, &glInternalFormat, &glFormat, &glType);
      unsigned int size = GetPixelDataSize(texture.width, texture.height, texture.format);
  
      if ((glInternalFormat != -1) && (texture.format < COMPRESSED_DXT1_RGB))
      {
          pixels = RL_MALLOC(size);
          glGetTexImage(GL_TEXTURE_2D, 0, glFormat, glType, pixels);
      }
      else TRACELOG(LOG_WARNING, "TEXTURE: [ID %i] Data retrieval not suported for pixel format (%i)", texture.id, texture.format);
  
      glBindTexture(GL_TEXTURE_2D, 0);
  #endif
  
  #if defined(GRAPHICS_API_OPENGL_ES2)
      // glGetTexImage() is not available on OpenGL ES 2.0
      // Texture2D width and height are required on OpenGL ES 2.0. There is no way to get it from texture id.
      // Two possible Options:
      // 1 - Bind texture to color fbo attachment and glReadPixels()
      // 2 - Create an fbo, activate it, render quad with texture, glReadPixels()
      // We are using Option 1, just need to care for texture format on retrieval
      // NOTE: This behaviour could be conditioned by graphic driver...
      unsigned int fboId = rlLoadFramebuffer(texture.width, texture.height);
  
      // TODO: Create depth texture/renderbuffer for fbo?
  
      glBindFramebuffer(GL_FRAMEBUFFER, fboId);
      glBindTexture(GL_TEXTURE_2D, 0);
  
      // Attach our texture to FBO
      glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, texture.id, 0);
  
      // We read data as RGBA because FBO texture is configured as RGBA, despite binding another texture format
      pixels = (unsigned char *)RL_MALLOC(GetPixelDataSize(texture.width, texture.height, UNCOMPRESSED_R8G8B8A8));
      glReadPixels(0, 0, texture.width, texture.height, GL_RGBA, GL_UNSIGNED_BYTE, pixels);
  
      glBindFramebuffer(GL_FRAMEBUFFER, 0);
  
      // Clean up temporal fbo
      rlUnloadFramebuffer(fboId);
  #endif
  
      return pixels;
  }
  
  //----------------------------------------------------------------------------------
  // Module Functions Definition - Shaders Functions
  // NOTE: Those functions are exposed directly to the user in raylib.h
  //----------------------------------------------------------------------------------
  
  // Get default internal texture (white texture)
  Texture2D GetTextureDefault(void)
  {
      Texture2D texture = { 0 };
  #if defined(GRAPHICS_API_OPENGL_33) || defined(GRAPHICS_API_OPENGL_46) || defined(GRAPHICS_API_OPENGL_ES2)
      texture.id = RLGL.State.defaultTextureId;
      texture.width = 1;
      texture.height = 1;
      texture.mipmaps = 1;
      texture.format = UNCOMPRESSED_R8G8B8A8;
  #endif
      return texture;
  }
  
  // Get texture to draw shapes (RAII)
  Texture2D GetShapesTexture(void)
  {
  #if defined(GRAPHICS_API_OPENGL_11)
      Texture2D texture = { 0 };
      return texture;
  #else
      return RLGL.State.shapesTexture;
  #endif
  }
  
  // Get texture rectangle to draw shapes
  Rectangle GetShapesTextureRec(void)
  {
  #if defined(GRAPHICS_API_OPENGL_11)
      Rectangle rec = { 0 };
      return rec;
  #else
      return RLGL.State.shapesTextureRec;
  #endif
  }
  
  // Define default texture used to draw shapes
  void SetShapesTexture(Texture2D texture, Rectangle source)
  {
  #if defined(GRAPHICS_API_OPENGL_33) || defined(GRAPHICS_API_OPENGL_46) || defined(GRAPHICS_API_OPENGL_ES2)
      RLGL.State.shapesTexture = texture;
      RLGL.State.shapesTextureRec = source;
  #endif
  }
  
  // Get default shader
  Shader GetShaderDefault(void)
  {
  #if defined(GRAPHICS_API_OPENGL_33) || defined(GRAPHICS_API_OPENGL_46) || defined(GRAPHICS_API_OPENGL_ES2)
      return RLGL.State.defaultShader;
  #else
      Shader shader = { 0 };
      return shader;
  #endif
  }
  
  // Load shader from files and bind default locations
  // NOTE: If shader string is NULL, using default vertex/fragment shaders
  Shader LoadShader(const char *vsFileName, const char *fsFileName)
  {
      Shader shader = { 0 };
  
      // NOTE: Shader.locs is allocated by LoadShaderCode()
  
      char *vShaderStr = NULL;
      char *fShaderStr = NULL;
  
      if (vsFileName != NULL) vShaderStr = LoadFileText(vsFileName);
      if (fsFileName != NULL) fShaderStr = LoadFileText(fsFileName);
  
      shader = LoadShaderCode(vShaderStr, fShaderStr);
  
      if (vShaderStr != NULL) RL_FREE(vShaderStr);
      if (fShaderStr != NULL) RL_FREE(fShaderStr);
  
      return shader;
  }
  
  // Load shader from code strings
  // NOTE: If shader string is NULL, using default vertex/fragment shaders
  Shader LoadShaderCode(const char *vsCode, const char *fsCode)
  {
      Shader shader = { 0 };
      shader.locs = (int *)RL_CALLOC(MAX_SHADER_LOCATIONS, sizeof(int));
  
      // NOTE: All locations must be reseted to -1 (no location)
      for (int i = 0; i < MAX_SHADER_LOCATIONS; i++) shader.locs[i] = -1;
  
  #if defined(GRAPHICS_API_OPENGL_33) || defined(GRAPHICS_API_OPENGL_46) || defined(GRAPHICS_API_OPENGL_ES2)
      unsigned int vertexShaderId = RLGL.State.defaultVShaderId;
      unsigned int fragmentShaderId = RLGL.State.defaultFShaderId;
  
      if (vsCode != NULL) vertexShaderId = CompileShader(vsCode, GL_VERTEX_SHADER);
      if (fsCode != NULL) fragmentShaderId = CompileShader(fsCode, GL_FRAGMENT_SHADER);
  
      if ((vertexShaderId == RLGL.State.defaultVShaderId) && (fragmentShaderId == RLGL.State.defaultFShaderId)) shader = RLGL.State.defaultShader;
      else
      {
          shader.id = LoadShaderProgram(vertexShaderId, fragmentShaderId);
  
          if (vertexShaderId != RLGL.State.defaultVShaderId)
          {
              // Detach shader before deletion to make sure memory is freed
              glDetachShader(shader.id, vertexShaderId);
              glDeleteShader(vertexShaderId);
          }
          if (fragmentShaderId != RLGL.State.defaultFShaderId)
          {
              // Detach shader before deletion to make sure memory is freed
              glDetachShader(shader.id, fragmentShaderId);
              glDeleteShader(fragmentShaderId);
          }
  
          if (shader.id == 0)
          {
              TRACELOG(LOG_WARNING, "SHADER: Failed to load custom shader code");
              shader = RLGL.State.defaultShader;
          }
  
          // After shader loading, we TRY to set default location names
          if (shader.id > 0) SetShaderDefaultLocations(&shader);
      }
  
      // Get available shader uniforms
      // NOTE: This information is useful for debug...
      int uniformCount = -1;
  
      glGetProgramiv(shader.id, GL_ACTIVE_UNIFORMS, &uniformCount);
  
      for (int i = 0; i < uniformCount; i++)
      {
          int namelen = -1;
          int num = -1;
          char name[256]; // Assume no variable names longer than 256
          GLenum type = GL_ZERO;
  
          // Get the name of the uniforms
          glGetActiveUniform(shader.id, i, sizeof(name) - 1, &namelen, &num, &type, name);
  
          name[namelen] = 0;
  
          TRACELOGD("SHADER: [ID %i] Active uniform (%s) set at location: %i", shader.id, name, glGetUniformLocation(shader.id, name));
      }
  #endif
  
      return shader;
  }
  
  // Unload shader from GPU memory (VRAM)
  void UnloadShader(Shader shader)
  {
  #if defined(GRAPHICS_API_OPENGL_33) || defined(GRAPHICS_API_OPENGL_46) || defined(GRAPHICS_API_OPENGL_ES2)
      if (shader.id != RLGL.State.defaultShader.id)
      {
          glDeleteProgram(shader.id);
          RL_FREE(shader.locs);
  
          TRACELOG(LOG_INFO, "SHADER: [ID %i] Unloaded shader program data from VRAM (GPU)", shader.id);
      }
  #endif
  }
  
  // Begin custom shader mode
  void BeginShaderMode(Shader shader)
  {
  #if defined(GRAPHICS_API_OPENGL_33) || defined(GRAPHICS_API_OPENGL_46) || defined(GRAPHICS_API_OPENGL_ES2)
      if (RLGL.State.currentShader.id != shader.id)
      {
          DrawRenderBatch(RLGL.currentBatch);
          RLGL.State.currentShader = shader;
      }
  #endif
  }
  
  // End custom shader mode (returns to default shader)
  void EndShaderMode(void)
  {
  #if defined(GRAPHICS_API_OPENGL_33) || defined(GRAPHICS_API_OPENGL_46) || defined(GRAPHICS_API_OPENGL_ES2)
      BeginShaderMode(RLGL.State.defaultShader);
  #endif
  }
  
  // Get shader uniform location
  int GetShaderLocation(Shader shader, const char *uniformName)
  {
      int location = -1;
  #if defined(GRAPHICS_API_OPENGL_33) || defined(GRAPHICS_API_OPENGL_46) || defined(GRAPHICS_API_OPENGL_ES2)
      location = glGetUniformLocation(shader.id, uniformName);
  
      if (location == -1) TRACELOG(LOG_WARNING, "SHADER: [ID %i] Failed to find shader uniform: %s", shader.id, uniformName);
      else TRACELOG(LOG_INFO, "SHADER: [ID %i] Shader uniform (%s) set at location: %i", shader.id, uniformName, location);
  #endif
      return location;
  }
  
  // Get shader attribute location
  int GetShaderLocationAttrib(Shader shader, const char *attribName)
  {
      int location = -1;
  #if defined(GRAPHICS_API_OPENGL_33) || defined(GRAPHICS_API_OPENGL_46) || defined(GRAPHICS_API_OPENGL_ES2)
      location = glGetAttribLocation(shader.id, attribName);
  
      if (location == -1) TRACELOG(LOG_WARNING, "SHADER: [ID %i] Failed to find shader attribute: %s", shader.id, attribName);
      else TRACELOG(LOG_INFO, "SHADER: [ID %i] Shader attribute (%s) set at location: %i", shader.id, attribName, location);
  #endif
      return location;
  }
  
  // Set shader uniform value
  void SetShaderValue(Shader shader, int uniformLoc, const void *value, int uniformType)
  {
      SetShaderValueV(shader, uniformLoc, value, uniformType, 1);
  }
  
  // Set shader uniform value vector
  void SetShaderValueV(Shader shader, int uniformLoc, const void *value, int uniformType, int count)
  {
  #if defined(GRAPHICS_API_OPENGL_33) || defined(GRAPHICS_API_OPENGL_46) || defined(GRAPHICS_API_OPENGL_ES2)
      glUseProgram(shader.id);
  
      switch (uniformType)
      {
          case UNIFORM_FLOAT: glUniform1fv(uniformLoc, count, (float *)value); break;
          case UNIFORM_VEC2: glUniform2fv(uniformLoc, count, (float *)value); break;
          case UNIFORM_VEC3: glUniform3fv(uniformLoc, count, (float *)value); break;
          case UNIFORM_VEC4: glUniform4fv(uniformLoc, count, (float *)value); break;
          case UNIFORM_INT: glUniform1iv(uniformLoc, count, (int *)value); break;
          case UNIFORM_IVEC2: glUniform2iv(uniformLoc, count, (int *)value); break;
          case UNIFORM_IVEC3: glUniform3iv(uniformLoc, count, (int *)value); break;
          case UNIFORM_IVEC4: glUniform4iv(uniformLoc, count, (int *)value); break;
          case UNIFORM_SAMPLER2D: glUniform1iv(uniformLoc, count, (int *)value); break;
          default: TRACELOG(LOG_WARNING, "SHADER: [ID %i] Failed to set uniform, data type not recognized", shader.id);
      }
  
      //glUseProgram(0);      // Avoid reseting current shader program, in case other uniforms are set
  #endif
  }
  
  
  // Set shader uniform value (matrix 4x4)
  void SetShaderValueMatrix(Shader shader, int uniformLoc, Matrix mat)
  {
  #if defined(GRAPHICS_API_OPENGL_33) || defined(GRAPHICS_API_OPENGL_46) || defined(GRAPHICS_API_OPENGL_ES2)
      glUseProgram(shader.id);
  
      glUniformMatrix4fv(uniformLoc, 1, false, MatrixToFloat(mat));
  
      //glUseProgram(0);
  #endif
  }
  
  // Set shader uniform value for texture
  void SetShaderValueTexture(Shader shader, int uniformLoc, Texture2D texture)
  {
  #if defined(GRAPHICS_API_OPENGL_33) || defined(GRAPHICS_API_OPENGL_46) || defined(GRAPHICS_API_OPENGL_ES2)
      glUseProgram(shader.id);
  
      // Check if texture is already active
      for (int i = 0; i < MAX_BATCH_ACTIVE_TEXTURES; i++) if (RLGL.State.activeTextureId[i] == texture.id) return;
  
      // Register a new active texture for the internal batch system
      // NOTE: Default texture is always activated as GL_TEXTURE0
      for (int i = 0; i < MAX_BATCH_ACTIVE_TEXTURES; i++)
      {
          if (RLGL.State.activeTextureId[i] == 0)
          {
              glUniform1i(uniformLoc, 1 + i);             // Activate new texture unit
              RLGL.State.activeTextureId[i] = texture.id; // Save texture id for binding on drawing
              break;
          }
      }
  
      //glUseProgram(0);
  #endif
  }
  
  // Set a custom projection matrix (replaces internal projection matrix)
  void SetMatrixProjection(Matrix projection)
  {
  #if defined(GRAPHICS_API_OPENGL_33) || defined(GRAPHICS_API_OPENGL_46) || defined(GRAPHICS_API_OPENGL_ES2)
      RLGL.State.projection = projection;
  #endif
  }
  
  // Return internal projection matrix
  Matrix GetMatrixProjection(void) {
  #if defined(GRAPHICS_API_OPENGL_11)
      float mat[16];
      glGetFloatv(GL_PROJECTION_MATRIX,mat);
      Matrix m;
      m.m0  = mat[0];     m.m1  = mat[1];     m.m2  = mat[2];     m.m3  = mat[3];
      m.m4  = mat[4];     m.m5  = mat[5];     m.m6  = mat[6];     m.m7  = mat[7];
      m.m8  = mat[8];     m.m9  = mat[9];     m.m10 = mat[10];    m.m11 = mat[11];
      m.m12 = mat[12];    m.m13 = mat[13];    m.m14 = mat[14];    m.m15 = mat[15];
      return m;
  #else
      return RLGL.State.projection;
  #endif
  #
  }
  
  // Set a custom modelview matrix (replaces internal modelview matrix)
  void SetMatrixModelview(Matrix view)
  {
  #if defined(GRAPHICS_API_OPENGL_33) || defined(GRAPHICS_API_OPENGL_46) || defined(GRAPHICS_API_OPENGL_ES2)
      RLGL.State.modelview = view;
  #endif
  }
  
  // Return internal modelview matrix
  Matrix GetMatrixModelview(void)
  {
      Matrix matrix = MatrixIdentity();
  #if defined(GRAPHICS_API_OPENGL_11)
      float mat[16];
      glGetFloatv(GL_MODELVIEW_MATRIX, mat);
      matrix.m0  = mat[0];     matrix.m1  = mat[1];     matrix.m2  = mat[2];     matrix.m3  = mat[3];
      matrix.m4  = mat[4];     matrix.m5  = mat[5];     matrix.m6  = mat[6];     matrix.m7  = mat[7];
      matrix.m8  = mat[8];     matrix.m9  = mat[9];     matrix.m10 = mat[10];    matrix.m11 = mat[11];
      matrix.m12 = mat[12];    matrix.m13 = mat[13];    matrix.m14 = mat[14];    matrix.m15 = mat[15];
  #else
      matrix = RLGL.State.modelview;
  #endif
      return matrix;
  }
  
  // Generate cubemap texture from HDR texture
  TextureCubemap GenTextureCubemap(Shader shader, Texture2D panorama, int size, int format)
  {
      TextureCubemap cubemap = { 0 };
  #if defined(GRAPHICS_API_OPENGL_33) || defined(GRAPHICS_API_OPENGL_46) || defined(GRAPHICS_API_OPENGL_ES2)
      rlDisableBackfaceCulling();     // Disable backface culling to render inside the cube
  
      // STEP 1: Setup framebuffer
      //------------------------------------------------------------------------------------------
      unsigned int rbo = rlLoadTextureDepth(size, size, true);
      cubemap.id = rlLoadTextureCubemap(NULL, size, format);
  
      unsigned int fbo = rlLoadFramebuffer(size, size);
      rlFramebufferAttach(fbo, rbo, RL_ATTACHMENT_DEPTH, RL_ATTACHMENT_RENDERBUFFER);
      rlFramebufferAttach(fbo, cubemap.id, RL_ATTACHMENT_COLOR_CHANNEL0, RL_ATTACHMENT_CUBEMAP_POSITIVE_X);
  
      // Check if framebuffer is complete with attachments (valid)
      if (rlFramebufferComplete(fbo)) TRACELOG(LOG_INFO, "FBO: [ID %i] Framebuffer object created successfully", fbo);
      //------------------------------------------------------------------------------------------
  
      // STEP 2: Draw to framebuffer
      //------------------------------------------------------------------------------------------
      // NOTE: Shader is used to convert HDR equirectangular environment map to cubemap equivalent (6 faces)
  
      // Define projection matrix and send it to shader
      Matrix fboProjection = MatrixPerspective(90.0*DEG2RAD, 1.0, RL_CULL_DISTANCE_NEAR, RL_CULL_DISTANCE_FAR);
      SetShaderValueMatrix(shader, shader.locs[LOC_MATRIX_PROJECTION], fboProjection);
  
      // Define view matrix for every side of the cubemap
      Matrix fboViews[6] = {
          MatrixLookAt((Vector3){ 0.0f, 0.0f, 0.0f }, (Vector3){  1.0f,  0.0f,  0.0f }, (Vector3){ 0.0f, -1.0f,  0.0f }),
          MatrixLookAt((Vector3){ 0.0f, 0.0f, 0.0f }, (Vector3){ -1.0f,  0.0f,  0.0f }, (Vector3){ 0.0f, -1.0f,  0.0f }),
          MatrixLookAt((Vector3){ 0.0f, 0.0f, 0.0f }, (Vector3){  0.0f,  1.0f,  0.0f }, (Vector3){ 0.0f,  0.0f,  1.0f }),
          MatrixLookAt((Vector3){ 0.0f, 0.0f, 0.0f }, (Vector3){  0.0f, -1.0f,  0.0f }, (Vector3){ 0.0f,  0.0f, -1.0f }),
          MatrixLookAt((Vector3){ 0.0f, 0.0f, 0.0f }, (Vector3){  0.0f,  0.0f,  1.0f }, (Vector3){ 0.0f, -1.0f,  0.0f }),
          MatrixLookAt((Vector3){ 0.0f, 0.0f, 0.0f }, (Vector3){  0.0f,  0.0f, -1.0f }, (Vector3){ 0.0f, -1.0f,  0.0f })
      };
  
      rlEnableShader(shader.id);
  #if !defined(GENTEXTURECUBEMAP_USE_BATCH_SYSTEM)
      glActiveTexture(GL_TEXTURE0);
      glBindTexture(GL_TEXTURE_2D, panorama.id);
  #endif
  
      rlViewport(0, 0, size, size);   // Set viewport to current fbo dimensions
  
      for (int i = 0; i < 6; i++)
      {
          SetShaderValueMatrix(shader, shader.locs[LOC_MATRIX_VIEW], fboViews[i]);
          rlFramebufferAttach(fbo, cubemap.id, RL_ATTACHMENT_COLOR_CHANNEL0, RL_ATTACHMENT_CUBEMAP_POSITIVE_X + i);
  
          rlEnableFramebuffer(fbo);
  #if defined(GENTEXTURECUBEMAP_USE_BATCH_SYSTEM)
          rlEnableTexture(panorama.id);   // WARNING: It must be called after enabling current framebuffer if using internal batch system!
  #endif
          rlClearScreenBuffers();
          GenDrawCube();
  
  #if defined(GENTEXTURECUBEMAP_USE_BATCH_SYSTEM)
          // Using internal batch system instead of raw OpenGL cube creating+drawing
          // NOTE: DrawCubeV() is actually provided by models.c! -> GenTextureCubemap() should be moved to user code!
          DrawCubeV(Vector3Zero(), Vector3One(), WHITE);
          DrawRenderBatch(RLGL.currentBatch);
  #endif
      }
      //------------------------------------------------------------------------------------------
  
      // STEP 3: Unload framebuffer and reset state
      //------------------------------------------------------------------------------------------
      rlDisableShader();          // Unbind shader
      rlDisableTexture();         // Unbind texture
      rlDisableFramebuffer();     // Unbind framebuffer
      rlUnloadFramebuffer(fbo);   // Unload framebuffer (and automatically attached depth texture/renderbuffer)
  
      // Reset viewport dimensions to default
      rlViewport(0, 0, RLGL.State.framebufferWidth, RLGL.State.framebufferHeight);
      //rlEnableBackfaceCulling();
      //------------------------------------------------------------------------------------------
  
      cubemap.width = size;
      cubemap.height = size;
      cubemap.mipmaps = 1;
      cubemap.format = UNCOMPRESSED_R32G32B32;
  #endif
      return cubemap;
  }
  
  // Generate irradiance texture using cubemap data
  TextureCubemap GenTextureIrradiance(Shader shader, TextureCubemap cubemap, int size)
  {
      TextureCubemap irradiance = { 0 };
  
  #if defined(GRAPHICS_API_OPENGL_33) || defined(GRAPHICS_API_OPENGL_46) || defined(GRAPHICS_API_OPENGL_ES2)
      rlDisableBackfaceCulling();     // Disable backface culling to render inside the cube
  
      // STEP 1: Setup framebuffer
      //------------------------------------------------------------------------------------------
      unsigned int rbo = rlLoadTextureDepth(size, size, true);
      irradiance.id = rlLoadTextureCubemap(NULL, size, UNCOMPRESSED_R32G32B32);
  
      unsigned int fbo = rlLoadFramebuffer(size, size);
      rlFramebufferAttach(fbo, rbo, RL_ATTACHMENT_DEPTH, RL_ATTACHMENT_RENDERBUFFER);
      rlFramebufferAttach(fbo, cubemap.id, RL_ATTACHMENT_COLOR_CHANNEL0, RL_ATTACHMENT_CUBEMAP_POSITIVE_X);
      //------------------------------------------------------------------------------------------
  
      // STEP 2: Draw to framebuffer
      //------------------------------------------------------------------------------------------
      // NOTE: Shader is used to solve diffuse integral by convolution to create an irradiance cubemap
  
      // Define projection matrix and send it to shader
      Matrix fboProjection = MatrixPerspective(90.0*DEG2RAD, 1.0, RL_CULL_DISTANCE_NEAR, RL_CULL_DISTANCE_FAR);
      SetShaderValueMatrix(shader, shader.locs[LOC_MATRIX_PROJECTION], fboProjection);
  
      // Define view matrix for every side of the cubemap
      Matrix fboViews[6] = {
          MatrixLookAt((Vector3){ 0.0f, 0.0f, 0.0f }, (Vector3){  1.0f,  0.0f,  0.0f }, (Vector3){ 0.0f, -1.0f,  0.0f }),
          MatrixLookAt((Vector3){ 0.0f, 0.0f, 0.0f }, (Vector3){ -1.0f,  0.0f,  0.0f }, (Vector3){ 0.0f, -1.0f,  0.0f }),
          MatrixLookAt((Vector3){ 0.0f, 0.0f, 0.0f }, (Vector3){  0.0f,  1.0f,  0.0f }, (Vector3){ 0.0f,  0.0f,  1.0f }),
          MatrixLookAt((Vector3){ 0.0f, 0.0f, 0.0f }, (Vector3){  0.0f, -1.0f,  0.0f }, (Vector3){ 0.0f,  0.0f, -1.0f }),
          MatrixLookAt((Vector3){ 0.0f, 0.0f, 0.0f }, (Vector3){  0.0f,  0.0f,  1.0f }, (Vector3){ 0.0f, -1.0f,  0.0f }),
          MatrixLookAt((Vector3){ 0.0f, 0.0f, 0.0f }, (Vector3){  0.0f,  0.0f, -1.0f }, (Vector3){ 0.0f, -1.0f,  0.0f })
      };
  
      rlEnableShader(shader.id);
      glActiveTexture(GL_TEXTURE0);
      glBindTexture(GL_TEXTURE_CUBE_MAP, cubemap.id);
  
      rlViewport(0, 0, size, size);   // Set viewport to current fbo dimensions
  
      for (int i = 0; i < 6; i++)
      {
          SetShaderValueMatrix(shader, shader.locs[LOC_MATRIX_VIEW], fboViews[i]);
          rlFramebufferAttach(fbo, irradiance.id, RL_ATTACHMENT_COLOR_CHANNEL0, RL_ATTACHMENT_CUBEMAP_POSITIVE_X + i);
  
          rlEnableFramebuffer(fbo);
          rlClearScreenBuffers();
          GenDrawCube();
      }
      //------------------------------------------------------------------------------------------
  
      // STEP 3: Unload framebuffer and reset state
      //------------------------------------------------------------------------------------------
      rlDisableShader();          // Unbind shader
      rlDisableTexture();         // Unbind texture
      rlDisableFramebuffer();     // Unbind framebuffer
      rlUnloadFramebuffer(fbo);   // Unload framebuffer (and automatically attached depth texture/renderbuffer)
  
      // Reset viewport dimensions to default
      rlViewport(0, 0, RLGL.State.framebufferWidth, RLGL.State.framebufferHeight);
      //rlEnableBackfaceCulling();
      //------------------------------------------------------------------------------------------
  
      irradiance.width = size;
      irradiance.height = size;
      irradiance.mipmaps = 1;
      irradiance.format = UNCOMPRESSED_R32G32B32;
  #endif
      return irradiance;
  }
  
  // Generate prefilter texture using cubemap data
  TextureCubemap GenTexturePrefilter(Shader shader, TextureCubemap cubemap, int size)
  {
      TextureCubemap prefilter = { 0 };
  
  #if defined(GRAPHICS_API_OPENGL_33) || defined(GRAPHICS_API_OPENGL_46) // || defined(GRAPHICS_API_OPENGL_ES2)
      rlDisableBackfaceCulling();     // Disable backface culling to render inside the cube
  
      // STEP 1: Setup framebuffer
      //------------------------------------------------------------------------------------------
      unsigned int rbo = rlLoadTextureDepth(size, size, true);
      prefilter.id = rlLoadTextureCubemap(NULL, size, UNCOMPRESSED_R32G32B32);
      rlTextureParameters(prefilter.id, RL_TEXTURE_MIN_FILTER, RL_FILTER_MIP_LINEAR);
  
      unsigned int fbo = rlLoadFramebuffer(size, size);
      rlFramebufferAttach(fbo, rbo, RL_ATTACHMENT_DEPTH, RL_ATTACHMENT_RENDERBUFFER);
      rlFramebufferAttach(fbo, cubemap.id, RL_ATTACHMENT_COLOR_CHANNEL0, RL_ATTACHMENT_CUBEMAP_POSITIVE_X);
      //------------------------------------------------------------------------------------------
  
      // Generate mipmaps for the prefiltered HDR texture
      glGenerateMipmap(GL_TEXTURE_CUBE_MAP);
      //rlGenerateMipmaps(Texture2D *texture); // Only GL_TEXTURE_2D
  
      // STEP 2: Draw to framebuffer
      //------------------------------------------------------------------------------------------
      // NOTE: Shader is used to prefilter HDR and store data into mipmap levels
  
      // Define projection matrix and send it to shader
      Matrix fboProjection = MatrixPerspective(90.0*DEG2RAD, 1.0, RL_CULL_DISTANCE_NEAR, RL_CULL_DISTANCE_FAR);
      SetShaderValueMatrix(shader, shader.locs[LOC_MATRIX_PROJECTION], fboProjection);
  
      // Define view matrix for every side of the cubemap
      Matrix fboViews[6] = {
          MatrixLookAt((Vector3){ 0.0f, 0.0f, 0.0f }, (Vector3){  1.0f,  0.0f,  0.0f }, (Vector3){ 0.0f, -1.0f,  0.0f }),
          MatrixLookAt((Vector3){ 0.0f, 0.0f, 0.0f }, (Vector3){ -1.0f,  0.0f,  0.0f }, (Vector3){ 0.0f, -1.0f,  0.0f }),
          MatrixLookAt((Vector3){ 0.0f, 0.0f, 0.0f }, (Vector3){  0.0f,  1.0f,  0.0f }, (Vector3){ 0.0f,  0.0f,  1.0f }),
          MatrixLookAt((Vector3){ 0.0f, 0.0f, 0.0f }, (Vector3){  0.0f, -1.0f,  0.0f }, (Vector3){ 0.0f,  0.0f, -1.0f }),
          MatrixLookAt((Vector3){ 0.0f, 0.0f, 0.0f }, (Vector3){  0.0f,  0.0f,  1.0f }, (Vector3){ 0.0f, -1.0f,  0.0f }),
          MatrixLookAt((Vector3){ 0.0f, 0.0f, 0.0f }, (Vector3){  0.0f,  0.0f, -1.0f }, (Vector3){ 0.0f, -1.0f,  0.0f })
      };
  
      rlEnableShader(shader.id);
      glActiveTexture(GL_TEXTURE0);
      glBindTexture(GL_TEXTURE_CUBE_MAP, cubemap.id);
  
      // TODO: Locations should be taken out of this function... too shader dependant...
      int roughnessLoc = GetShaderLocation(shader, "roughness");
  
      rlEnableFramebuffer(fbo);
  
      #define MAX_MIPMAP_LEVELS   5   // Max number of prefilter texture mipmaps
  
      for (int mip = 0; mip < MAX_MIPMAP_LEVELS; mip++)
      {
          // Resize framebuffer according to mip-level size.
          unsigned int mipWidth  = size*(int)powf(0.5f, (float)mip);
          unsigned int mipHeight = size*(int)powf(0.5f, (float)mip);
  
          rlViewport(0, 0, mipWidth, mipHeight);
  
          glBindRenderbuffer(GL_RENDERBUFFER, rbo);
          glRenderbufferStorage(GL_RENDERBUFFER, GL_DEPTH_COMPONENT24, mipWidth, mipHeight);
  
          float roughness = (float)mip/(float)(MAX_MIPMAP_LEVELS - 1);
          glUniform1f(roughnessLoc, roughness);
  
          for (int i = 0; i < 6; i++)
          {
              SetShaderValueMatrix(shader, shader.locs[LOC_MATRIX_VIEW], fboViews[i]);
              glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_CUBE_MAP_POSITIVE_X + i, prefilter.id, mip);
              //rlFramebufferAttach(fbo, irradiance.id, RL_ATTACHMENT_COLOR_CHANNEL0, RL_ATTACHMENT_CUBEMAP_POSITIVE_X + i);  // TODO: Support mip levels?
  
              rlEnableFramebuffer(fbo);
              rlClearScreenBuffers();
              GenDrawCube();
          }
      }
      //------------------------------------------------------------------------------------------
  
      // STEP 3: Unload framebuffer and reset state
      //------------------------------------------------------------------------------------------
      rlDisableShader();          // Unbind shader
      rlDisableTexture();         // Unbind texture
      rlDisableFramebuffer();     // Unbind framebuffer
      rlUnloadFramebuffer(fbo);   // Unload framebuffer (and automatically attached depth texture/renderbuffer)
  
      // Reset viewport dimensions to default
      rlViewport(0, 0, RLGL.State.framebufferWidth, RLGL.State.framebufferHeight);
      //rlEnableBackfaceCulling();
      //------------------------------------------------------------------------------------------
  
      prefilter.width = size;
      prefilter.height = size;
      //prefilter.mipmaps = 1 + (int)floor(log(size)/log(2)); // MAX_MIPMAP_LEVELS
      //prefilter.format = UNCOMPRESSED_R32G32B32;
  #endif
      return prefilter;
  }
  
  // Generate BRDF texture using cubemap data
  // TODO: Review implementation: https://github.com/HectorMF/BRDFGenerator
  Texture2D GenTextureBRDF(Shader shader, int size)
  {
      Texture2D brdf = { 0 };
  #if defined(GRAPHICS_API_OPENGL_33) || defined(GRAPHICS_API_OPENGL_46) || defined(GRAPHICS_API_OPENGL_ES2)
      // STEP 1: Setup framebuffer
      //------------------------------------------------------------------------------------------
      unsigned int rbo = rlLoadTextureDepth(size, size, true);
      brdf.id = rlLoadTexture(NULL, size, size, UNCOMPRESSED_R32G32B32, 1);
  
      unsigned int fbo = rlLoadFramebuffer(size, size);
      rlFramebufferAttach(fbo, rbo, RL_ATTACHMENT_DEPTH, RL_ATTACHMENT_RENDERBUFFER);
      rlFramebufferAttach(fbo, brdf.id, RL_ATTACHMENT_COLOR_CHANNEL0, RL_ATTACHMENT_TEXTURE2D);
      //------------------------------------------------------------------------------------------
  
      // STEP 2: Draw to framebuffer
      //------------------------------------------------------------------------------------------
      // NOTE: Render BRDF LUT into a quad using FBO
  
      rlEnableShader(shader.id);
  
      rlViewport(0, 0, size, size);
  
      rlEnableFramebuffer(fbo);
      rlClearScreenBuffers();
      GenDrawQuad();
      //------------------------------------------------------------------------------------------
  
      // STEP 3: Unload framebuffer and reset state
      //------------------------------------------------------------------------------------------
      rlDisableShader();          // Unbind shader
      rlDisableTexture();         // Unbind texture
      rlDisableFramebuffer();     // Unbind framebuffer
      rlUnloadFramebuffer(fbo);   // Unload framebuffer (and automatically attached depth texture/renderbuffer)
  
      // Reset viewport dimensions to default
      rlViewport(0, 0, RLGL.State.framebufferWidth, RLGL.State.framebufferHeight);
      //------------------------------------------------------------------------------------------
  
      brdf.width = size;
      brdf.height = size;
      brdf.mipmaps = 1;
      brdf.format = UNCOMPRESSED_R32G32B32;
  #endif
      return brdf;
  }
  
  // Begin blending mode (alpha, additive, multiplied)
  // NOTE: Only 3 blending modes supported, default blend mode is alpha
  void BeginBlendMode(int mode)
  {
  #if defined(GRAPHICS_API_OPENGL_33) || defined(GRAPHICS_API_OPENGL_46) || defined(GRAPHICS_API_OPENGL_ES2)
      if (RLGL.State.currentBlendMode != mode)
      {
          DrawRenderBatch(RLGL.currentBatch);
  
          switch (mode)
          {
              case BLEND_ALPHA: glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA); glBlendEquation(GL_FUNC_ADD); break;
              case BLEND_ADDITIVE: glBlendFunc(GL_SRC_ALPHA, GL_ONE); glBlendEquation(GL_FUNC_ADD); break;
              case BLEND_MULTIPLIED: glBlendFunc(GL_DST_COLOR, GL_ONE_MINUS_SRC_ALPHA); glBlendEquation(GL_FUNC_ADD); break;
              case BLEND_ADD_COLORS: glBlendFunc(GL_ONE, GL_ONE); glBlendEquation(GL_FUNC_ADD); break;
              case BLEND_SUBTRACT_COLORS: glBlendFunc(GL_ONE, GL_ONE); glBlendEquation(GL_FUNC_SUBTRACT); break;
              case BLEND_CUSTOM: glBlendFunc(RLGL.State.glBlendSrcFactor, RLGL.State.glBlendDstFactor); glBlendEquation(RLGL.State.glBlendEquation); break;
              default: break;
          }
  
          RLGL.State.currentBlendMode = mode;
      }
  #endif
  }
  
  // End blending mode (reset to default: alpha blending)
  void EndBlendMode(void)
  {
      BeginBlendMode(BLEND_ALPHA);
  }
  
  #if defined(SUPPORT_VR_SIMULATOR)
  // Init VR simulator for selected device parameters
  // NOTE: It modifies the global variable: RLGL.Vr.stereoFboId
  void InitVrSimulator(void)
  {
  #if defined(GRAPHICS_API_OPENGL_33) || defined(GRAPHICS_API_OPENGL_46) || defined(GRAPHICS_API_OPENGL_ES2)
      // Initialize framebuffer and textures for stereo rendering
      // NOTE: Screen size should match HMD aspect ratio
      RLGL.Vr.stereoFboId = rlLoadFramebuffer(RLGL.State.framebufferWidth, RLGL.State.framebufferHeight);
  
      // Load color/depth textures to attach to framebuffer
      RLGL.Vr.stereoTexId = rlLoadTexture(NULL, RLGL.State.framebufferWidth, RLGL.State.framebufferHeight, UNCOMPRESSED_R8G8B8A8, 1);
      unsigned int depthId = rlLoadTextureDepth(RLGL.State.framebufferWidth, RLGL.State.framebufferHeight, true);
  
      // Attach color texture and depth renderbuffer/texture to FBO
      rlFramebufferAttach(RLGL.Vr.stereoFboId, RLGL.Vr.stereoTexId, RL_ATTACHMENT_COLOR_CHANNEL0, RL_ATTACHMENT_TEXTURE2D);
      rlFramebufferAttach(RLGL.Vr.stereoFboId, depthId, RL_ATTACHMENT_DEPTH, RL_ATTACHMENT_RENDERBUFFER);
  
      RLGL.Vr.simulatorReady = true;
  #else
      TRACELOG(LOG_WARNING, "RLGL: VR Simulator not supported on OpenGL 1.1");
  #endif
  }
  
  // Update VR tracking (position and orientation) and camera
  // NOTE: Camera (position, target, up) gets update with head tracking information
  void UpdateVrTracking(Camera *camera)
  {
      // TODO: Simulate 1st person camera system
  }
  
  // Close VR simulator for current device
  void CloseVrSimulator(void)
  {
  #if defined(GRAPHICS_API_OPENGL_33) || defined(GRAPHICS_API_OPENGL_46) || defined(GRAPHICS_API_OPENGL_ES2)
      if (RLGL.Vr.simulatorReady)
      {
          rlUnloadTexture(RLGL.Vr.stereoTexId);       // Unload color texture
          rlUnloadFramebuffer(RLGL.Vr.stereoFboId);   // Unload stereo framebuffer and depth texture/renderbuffer
      }
  #endif
  }
  
  // Set stereo rendering configuration parameters
  void SetVrConfiguration(VrDeviceInfo hmd, Shader distortion)
  {
  #if defined(GRAPHICS_API_OPENGL_33) || defined(GRAPHICS_API_OPENGL_46) || defined(GRAPHICS_API_OPENGL_ES2)
      // Reset RLGL.Vr.config for a new values assignment
      memset(&RLGL.Vr.config, 0, sizeof(RLGL.Vr.config));
  
      // Assign distortion shader
      RLGL.Vr.config.distortionShader = distortion;
  
      // Compute aspect ratio
      float aspect = ((float)hmd.hResolution*0.5f)/(float)hmd.vResolution;
  
      // Compute lens parameters
      float lensShift = (hmd.hScreenSize*0.25f - hmd.lensSeparationDistance*0.5f)/hmd.hScreenSize;
      float leftLensCenter[2] = { 0.25f + lensShift, 0.5f };
      float rightLensCenter[2] = { 0.75f - lensShift, 0.5f };
      float leftScreenCenter[2] = { 0.25f, 0.5f };
      float rightScreenCenter[2] = { 0.75f, 0.5f };
  
      // Compute distortion scale parameters
      // NOTE: To get lens max radius, lensShift must be normalized to [-1..1]
      float lensRadius = fabsf(-1.0f - 4.0f*lensShift);
      float lensRadiusSq = lensRadius*lensRadius;
      float distortionScale = hmd.lensDistortionValues[0] +
                              hmd.lensDistortionValues[1]*lensRadiusSq +
                              hmd.lensDistortionValues[2]*lensRadiusSq*lensRadiusSq +
                              hmd.lensDistortionValues[3]*lensRadiusSq*lensRadiusSq*lensRadiusSq;
  
      TRACELOGD("RLGL: VR device configuration:");
      TRACELOGD("    > Distortion Scale: %f", distortionScale);
  
      float normScreenWidth = 0.5f;
      float normScreenHeight = 1.0f;
      float scaleIn[2] = { 2.0f/normScreenWidth, 2.0f/normScreenHeight/aspect };
      float scale[2] = { normScreenWidth*0.5f/distortionScale, normScreenHeight*0.5f*aspect/distortionScale };
  
      TRACELOGD("    > Distortion Shader: LeftLensCenter = { %f, %f }", leftLensCenter[0], leftLensCenter[1]);
      TRACELOGD("    > Distortion Shader: RightLensCenter = { %f, %f }", rightLensCenter[0], rightLensCenter[1]);
      TRACELOGD("    > Distortion Shader: Scale = { %f, %f }", scale[0], scale[1]);
      TRACELOGD("    > Distortion Shader: ScaleIn = { %f, %f }", scaleIn[0], scaleIn[1]);
  
      // Fovy is normally computed with: 2*atan2f(hmd.vScreenSize, 2*hmd.eyeToScreenDistance)
      // ...but with lens distortion it is increased (see Oculus SDK Documentation)
      //float fovy = 2.0f*atan2f(hmd.vScreenSize*0.5f*distortionScale, hmd.eyeToScreenDistance);     // Really need distortionScale?
      float fovy = 2.0f*(float)atan2f(hmd.vScreenSize*0.5f, hmd.eyeToScreenDistance);
  
      // Compute camera projection matrices
      float projOffset = 4.0f*lensShift;      // Scaled to projection space coordinates [-1..1]
      Matrix proj = MatrixPerspective(fovy, aspect, RL_CULL_DISTANCE_NEAR, RL_CULL_DISTANCE_FAR);
      RLGL.Vr.config.eyesProjection[0] = MatrixMultiply(proj, MatrixTranslate(projOffset, 0.0f, 0.0f));
      RLGL.Vr.config.eyesProjection[1] = MatrixMultiply(proj, MatrixTranslate(-projOffset, 0.0f, 0.0f));
  
      // Compute camera transformation matrices
      // NOTE: Camera movement might seem more natural if we model the head.
      // Our axis of rotation is the base of our head, so we might want to add
      // some y (base of head to eye level) and -z (center of head to eye protrusion) to the camera positions.
      RLGL.Vr.config.eyesViewOffset[0] = MatrixTranslate(-hmd.interpupillaryDistance*0.5f, 0.075f, 0.045f);
      RLGL.Vr.config.eyesViewOffset[1] = MatrixTranslate(hmd.interpupillaryDistance*0.5f, 0.075f, 0.045f);
  
      // Compute eyes Viewports
      RLGL.Vr.config.eyeViewportRight[2] = hmd.hResolution/2;
      RLGL.Vr.config.eyeViewportRight[3] = hmd.vResolution;
  
      RLGL.Vr.config.eyeViewportLeft[0] = hmd.hResolution/2;
      RLGL.Vr.config.eyeViewportLeft[1] = 0;
      RLGL.Vr.config.eyeViewportLeft[2] = hmd.hResolution/2;
      RLGL.Vr.config.eyeViewportLeft[3] = hmd.vResolution;
  
      if (RLGL.Vr.config.distortionShader.id > 0)
      {
          // Update distortion shader with lens and distortion-scale parameters
          SetShaderValue(RLGL.Vr.config.distortionShader, GetShaderLocation(RLGL.Vr.config.distortionShader, "leftLensCenter"), leftLensCenter, UNIFORM_VEC2);
          SetShaderValue(RLGL.Vr.config.distortionShader, GetShaderLocation(RLGL.Vr.config.distortionShader, "rightLensCenter"), rightLensCenter, UNIFORM_VEC2);
          SetShaderValue(RLGL.Vr.config.distortionShader, GetShaderLocation(RLGL.Vr.config.distortionShader, "leftScreenCenter"), leftScreenCenter, UNIFORM_VEC2);
          SetShaderValue(RLGL.Vr.config.distortionShader, GetShaderLocation(RLGL.Vr.config.distortionShader, "rightScreenCenter"), rightScreenCenter, UNIFORM_VEC2);
  
          SetShaderValue(RLGL.Vr.config.distortionShader, GetShaderLocation(RLGL.Vr.config.distortionShader, "scale"), scale, UNIFORM_VEC2);
          SetShaderValue(RLGL.Vr.config.distortionShader, GetShaderLocation(RLGL.Vr.config.distortionShader, "scaleIn"), scaleIn, UNIFORM_VEC2);
          SetShaderValue(RLGL.Vr.config.distortionShader, GetShaderLocation(RLGL.Vr.config.distortionShader, "hmdWarpParam"), hmd.lensDistortionValues, UNIFORM_VEC4);
          SetShaderValue(RLGL.Vr.config.distortionShader, GetShaderLocation(RLGL.Vr.config.distortionShader, "chromaAbParam"), hmd.chromaAbCorrection, UNIFORM_VEC4);
      }
  #endif
  }
  
  // Detect if VR simulator is running
  bool IsVrSimulatorReady(void)
  {
  #if defined(GRAPHICS_API_OPENGL_33) || defined(GRAPHICS_API_OPENGL_46) || defined(GRAPHICS_API_OPENGL_ES2)
      return RLGL.Vr.simulatorReady;
  #else
      return false;
  #endif
  }
  
  // Enable/Disable VR experience (device or simulator)
  void ToggleVrMode(void)
  {
  #if defined(GRAPHICS_API_OPENGL_33) || defined(GRAPHICS_API_OPENGL_46) || defined(GRAPHICS_API_OPENGL_ES2)
      RLGL.Vr.simulatorReady = !RLGL.Vr.simulatorReady;
  
      if (!RLGL.Vr.simulatorReady)
      {
          RLGL.Vr.stereoRender = false;
  
          // Reset viewport and default projection-modelview matrices
          rlViewport(0, 0, RLGL.State.framebufferWidth, RLGL.State.framebufferHeight);
          RLGL.State.projection = MatrixOrtho(0.0, RLGL.State.framebufferWidth, RLGL.State.framebufferHeight, 0.0, 0.0, 1.0);
          RLGL.State.modelview = MatrixIdentity();
      }
      else RLGL.Vr.stereoRender = true;
  #endif
  }
  
  // Begin VR drawing configuration
  void BeginVrDrawing(void)
  {
  #if defined(GRAPHICS_API_OPENGL_33) || defined(GRAPHICS_API_OPENGL_46) || defined(GRAPHICS_API_OPENGL_ES2)
      if (RLGL.Vr.simulatorReady)
      {
          rlEnableFramebuffer(RLGL.Vr.stereoFboId);   // Setup framebuffer for stereo rendering
          //glEnable(GL_FRAMEBUFFER_SRGB);          // Enable SRGB framebuffer (only if required)
  
          //rlViewport(0, 0, buffer.width, buffer.height); // Useful if rendering to separate framebuffers (every eye)
          rlClearScreenBuffers();                   // Clear current framebuffer
  
          RLGL.Vr.stereoRender = true;
      }
  #endif
  }
  
  // End VR drawing process (and desktop mirror)
  void EndVrDrawing(void)
  {
  #if defined(GRAPHICS_API_OPENGL_33) || defined(GRAPHICS_API_OPENGL_46) || defined(GRAPHICS_API_OPENGL_ES2)
      if (RLGL.Vr.simulatorReady)
      {
          RLGL.Vr.stereoRender = false;   // Disable stereo render
  
          rlDisableFramebuffer();         // Unbind current framebuffer
  
          rlClearScreenBuffers();         // Clear current framebuffer
  
          // Set viewport to default framebuffer size (screen size)
          rlViewport(0, 0, RLGL.State.framebufferWidth, RLGL.State.framebufferHeight);
  
          // Let rlgl reconfigure internal matrices
          rlMatrixMode(RL_PROJECTION);                            // Enable internal projection matrix
          rlLoadIdentity();                                       // Reset internal projection matrix
          rlOrtho(0.0, RLGL.State.framebufferWidth, RLGL.State.framebufferHeight, 0.0, 0.0, 1.0); // Recalculate internal RLGL.State.projection matrix
          rlMatrixMode(RL_MODELVIEW);                             // Enable internal modelview matrix
          rlLoadIdentity();                                       // Reset internal modelview matrix
  
          // Draw stereo framebuffer texture using distortion shader if available
          if (RLGL.Vr.config.distortionShader.id > 0) RLGL.State.currentShader = RLGL.Vr.config.distortionShader;
          else RLGL.State.currentShader = GetShaderDefault();
  
          rlEnableTexture(RLGL.Vr.stereoTexId);
  
          rlPushMatrix();
              rlBegin(RL_QUADS);
                  rlColor4ub(255, 255, 255, 255);
                  rlNormal3f(0.0f, 0.0f, 1.0f);
  
                  // Bottom-left corner for texture and quad
                  rlTexCoord2f(0.0f, 1.0f);
                  rlVertex2f(0.0f, 0.0f);
  
                  // Bottom-right corner for texture and quad
                  rlTexCoord2f(0.0f, 0.0f);
                  rlVertex2f(0.0f, (float)RLGL.State.framebufferHeight);
  
                  // Top-right corner for texture and quad
                  rlTexCoord2f(1.0f, 0.0f);
                  rlVertex2f((float)RLGL.State.framebufferWidth, (float)RLGL.State.framebufferHeight);
  
                  // Top-left corner for texture and quad
                  rlTexCoord2f(1.0f, 1.0f);
                  rlVertex2f((float)RLGL.State.framebufferWidth, 0.0f);
              rlEnd();
          rlPopMatrix();
  
          rlDisableTexture();
  
          // Update and draw render texture fbo with distortion to backbuffer
          DrawRenderBatch(RLGL.currentBatch);
  
          // Restore RLGL.State.defaultShader
          RLGL.State.currentShader = RLGL.State.defaultShader;
  
          // Reset viewport and default projection-modelview matrices
          rlViewport(0, 0, RLGL.State.framebufferWidth, RLGL.State.framebufferHeight);
          RLGL.State.projection = MatrixOrtho(0.0, RLGL.State.framebufferWidth, RLGL.State.framebufferHeight, 0.0, 0.0, 1.0);
          RLGL.State.modelview = MatrixIdentity();
  
          rlDisableDepthTest();
      }
  #endif
  }
  #endif          // SUPPORT_VR_SIMULATOR
  
  //----------------------------------------------------------------------------------
  // Module specific Functions Definition
  //----------------------------------------------------------------------------------
  
  #if defined(GRAPHICS_API_OPENGL_33) || defined(GRAPHICS_API_OPENGL_46) || defined(GRAPHICS_API_OPENGL_ES2)
  // Compile custom shader and return shader id
  static unsigned int CompileShader(const char *shaderStr, int type)
  {
      unsigned int shader = glCreateShader(type);
  
  #ifdef SHADERPRINTF
      sds newShaderStr = sdsempty(); // to make changes to shaderStr
      newShaderStr = sdscpy(newShaderStr, shaderStr);
  
      glShaderSourcePrint(shader, 1, &newShaderStr, NULL);
  #else
      glShaderSource(shader, 1, &shaderStr, NULL);
  #endif
  
      GLint success = 0;
      glCompileShader(shader);
      glGetShaderiv(shader, GL_COMPILE_STATUS, &success);
  
      if (success != GL_TRUE)
      {
          TRACELOG(LOG_WARNING, "SHADER: [ID %i] Failed to compile shader code", shader);
          int maxLength = 0;
          int length;
          glGetShaderiv(shader, GL_INFO_LOG_LENGTH, &maxLength);
  
  #if defined(_MSC_VER)
          char *log = RL_MALLOC(maxLength);
  #else
          char log[maxLength];
  #endif
          glGetShaderInfoLog(shader, maxLength, &length, log);
  
          TRACELOG(LOG_WARNING, "SHADER: [ID %i] Compile error: %s", shader, log);
  
  #if defined(_MSC_VER)
          RL_FREE(log);
  #endif
      }
      else TRACELOG(LOG_INFO, "SHADER: [ID %i] Compiled successfully", shader);
  
      return shader;
  }
  
  // Load custom shader strings and return program id
  static unsigned int LoadShaderProgram(unsigned int vShaderId, unsigned int fShaderId)
  {
      unsigned int program = 0;
  
  #if defined(GRAPHICS_API_OPENGL_33) || defined(GRAPHICS_API_OPENGL_46) || defined(GRAPHICS_API_OPENGL_ES2)
      GLint success = 0;
      program = glCreateProgram();
  
      glAttachShader(program, vShaderId);
      glAttachShader(program, fShaderId);
  
      // NOTE: Default attribute shader locations must be binded before linking
      glBindAttribLocation(program, 0, DEFAULT_SHADER_ATTRIB_NAME_POSITION);
      glBindAttribLocation(program, 1, DEFAULT_SHADER_ATTRIB_NAME_TEXCOORD);
      glBindAttribLocation(program, 2, DEFAULT_SHADER_ATTRIB_NAME_NORMAL);
      glBindAttribLocation(program, 3, DEFAULT_SHADER_ATTRIB_NAME_COLOR);
      glBindAttribLocation(program, 4, DEFAULT_SHADER_ATTRIB_NAME_TANGENT);
      glBindAttribLocation(program, 5, DEFAULT_SHADER_ATTRIB_NAME_TEXCOORD2);
      glBindAttribLocation(program, 7, DEFAULT_SHADER_ATTRIB_NAME_BONEID);
      glBindAttribLocation(program, 8, DEFAULT_SHADER_ATTRIB_NAME_BONEWEIGHT);
  
      // NOTE: If some attrib name is no found on the shader, it locations becomes -1
  
      glLinkProgram(program);
  
      // NOTE: All uniform variables are intitialised to 0 when a program links
  
      glGetProgramiv(program, GL_LINK_STATUS, &success);
  
      if (success == GL_FALSE)
      {
          TRACELOG(LOG_WARNING, "SHADER: [ID %i] Failed to link shader program", program);
  
          int maxLength = 0;
          int length;
  
          glGetProgramiv(program, GL_INFO_LOG_LENGTH, &maxLength);
  
  #if defined(_MSC_VER)
          char *log = RL_MALLOC(maxLength);
  #else
          char log[maxLength];
  #endif
          glGetProgramInfoLog(program, maxLength, &length, log);
  
          TRACELOG(LOG_WARNING, "SHADER: [ID %i] Link error: %s", program, log);
  
  #if defined(_MSC_VER)
          RL_FREE(log);
  #endif
          glDeleteProgram(program);
  
          program = 0;
      }
      else TRACELOG(LOG_INFO, "SHADER: [ID %i] Program loaded successfully", program);
  #endif
      return program;
  }
  
  
  // Load default shader (just vertex positioning and texture coloring)
  // NOTE: This shader program is used for internal buffers
  static Shader LoadShaderDefault(void)
  {
      Shader shader = { 0 };
      shader.locs = (int *)RL_CALLOC(MAX_SHADER_LOCATIONS, sizeof(int));
  
      // NOTE: All locations must be reseted to -1 (no location)
      for (int i = 0; i < MAX_SHADER_LOCATIONS; i++) shader.locs[i] = -1;
  
      // Vertex shader directly defined, no external file required
      const char *defaultVShaderStr =
  #if defined(GRAPHICS_API_OPENGL_21)
      "#version 120                       \n"
  #elif defined(GRAPHICS_API_OPENGL_ES2)
      "#version 100                       \n"
  #endif
  #if defined(GRAPHICS_API_OPENGL_ES2) || defined(GRAPHICS_API_OPENGL_21)
      "attribute vec3 vertexPosition;     \n"
      "attribute vec2 vertexTexCoord;     \n"
      "attribute vec4 vertexColor;        \n"
      "varying vec2 fragTexCoord;         \n"
      "varying vec4 fragColor;            \n"
  #elif defined(GRAPHICS_API_OPENGL_33) || defined(GRAPHICS_API_OPENGL_46)
    #if defined(GRAPHICS_API_OPENGL_33)
  "#version 330                       \n"
    #else
  "#version 450                       \n"
  	#endif
  "in vec3 vertexPosition;            \n"
  "in vec2 vertexTexCoord;            \n"
  "in vec3 vertexNormal;              \n"
  "in vec4 vertexColor;               \n"
  "in ivec4 vertexBoneId;             \n"
  "in vec4 vertexBoneWeight;          \n"
  "out vec2 fragTexCoord;             \n"
  "out vec4 fragColor;                \n"
  #endif
  "uniform mat4 mvp;                  \n"
  //"uniform mat4 mvit;                 \n"
  #if defined(GRAPHICS_API_OPENGL_33) || defined(GRAPHICS_API_OPENGL_46)
    #if defined(ANIMATED_WITH_DUALQUATERNIONS)
  "uniform vec4 boneRotQuaternions[58];   \n"
  "uniform vec4 boneTransQuaternions[58]; \n"
    #elif defined(ANIMATED_WITH_MATRIX)
  "uniform mat4 boneMat[58];          \n"
  	#endif
  #endif
  "void main()                        \n"
  "{                                  \n"
  #if defined(GRAPHICS_API_OPENGL_33) || defined(GRAPHICS_API_OPENGL_46)
    #if defined(ANIMATED_WITH_DUALQUATERNIONS)
  "  vec4 brqx = boneRotQuaternions[vertexBoneId.x];\n"
  "  vec4 brqy = boneRotQuaternions[vertexBoneId.y];\n"
  "  vec4 brqz = boneRotQuaternions[vertexBoneId.z];\n"
  "  vec4 brqw = boneRotQuaternions[vertexBoneId.w];\n"
  "  vec4 btqx = boneTransQuaternions[vertexBoneId.x];\n"
  "  vec4 btqy = boneTransQuaternions[vertexBoneId.y];\n"
  "  vec4 btqz = boneTransQuaternions[vertexBoneId.z];\n"
  "  vec4 btqw = boneTransQuaternions[vertexBoneId.w];\n"
  "  if (dot(brqx, brqy) < 0.0) { brqy *= -1.0; btqy *= -1.0; }\n"  // per-vertex antipodality handling (TODO: do on the CPU side per-bone? but how?)
  "  if (dot(brqx, brqz) < 0.0) { brqz *= -1.0; btqz *= -1.0; }\n"
  "  if (dot(brqx, brqw) < 0.0) { brqw *= -1.0; btqw *= -1.0; }\n"
  "  vec4 weightedRotQuat =\n"
  "    brqx * vertexBoneWeight.x +\n"
  "    brqy * vertexBoneWeight.y +\n"
  "    brqz * vertexBoneWeight.z +\n"
  "    brqw * vertexBoneWeight.w;\n"
  "  vec4 weightedTransQuat =\n"
  "    btqx * vertexBoneWeight.x +\n"
  "    btqy * vertexBoneWeight.y +\n"
  "    btqz * vertexBoneWeight.z +\n"
  "    btqw * vertexBoneWeight.w;\n"
  "  vec3 position = vertexPosition + 2.0*cross(weightedRotQuat.xyz, cross(weightedRotQuat.xyz, vertexPosition) + weightedRotQuat.w*vertexPosition);\n"
  "	 vec3 trans    = 2.0*(weightedRotQuat.w*weightedTransQuat.xyz - weightedTransQuat.w*weightedRotQuat.xyz + cross(weightedRotQuat.xyz, weightedTransQuat.xyz));\n"
  //"  vec3 normal = vertexNormal + 2.0*cross(weightedRotQuat.xyz, cross(weightedRotQuat.xyz, vertexNormal) + weightedRotQuat.w*vertexNormal);\n"
  "  position += trans;\n"
  "  gl_Position = mvp * vec4(position, 1.0);\n"
  
  //	    "	enablePrintf();\n"
  //	    //"	  if(position.z == vertexPosition.z) { printf(\"%d  %^4i %^4f\\n\", gl_VertexID, vertexBoneId, vertexBoneWeight); printf(\"wrq %^4f\\n\", weightedRotQuat); printf(\"wtq %^4f\\n\", weightedTransQuat); printf(\"vertexPos: %^3f  pos : %^3f\\n\", vertexPosition, position);}\n"
  //	    "	  if(true) { printf(\"%d  %^4i %^4f  -- %^3f\\n\", gl_VertexID, vertexBoneId, vertexBoneWeight, trans ); }\n"
  
  //"  gl_Normal = mvit * vec4(normal, 0.0);\n"
    #elif defined(ANIMATED_WITH_MATRIX)
  "	 mat4 boneTransform = boneMat[vertexBoneId.x] * vertexBoneWeight.x;\n"
  "  boneTransform +=     boneMat[vertexBoneId.y] * vertexBoneWeight.y;\n"
  "  boneTransform +=     boneMat[vertexBoneId.z] * vertexBoneWeight.z;\n"
  "  boneTransform +=     boneMat[vertexBoneId.w] * vertexBoneWeight.w;\n"
  "  vec4 position = boneTransform * vec4(vertexPosition, 1.0);\n"
  "  gl_Position = mvp * position;\n"
    #else
  "  gl_Position = mvp * vec4(vertexPosition, 1.0);\n"
  //"  gl_Normal = mvit * vec4(vertexNormal, 0.0);\n"
    #endif
  #endif
  "    fragTexCoord = vertexTexCoord; \n"
  "    fragColor = vertexColor;       \n"
  "}                                  \n";
      // Fragment shader directly defined, no external file required
      const char *defaultFShaderStr =
  #if defined(GRAPHICS_API_OPENGL_21)
      "#version 120                       \n"
  #elif defined(GRAPHICS_API_OPENGL_ES2)
      "#version 100                       \n"
      "precision mediump float;           \n"     // precision required for OpenGL ES2 (WebGL)
  #endif
  #if defined(GRAPHICS_API_OPENGL_ES2) || defined(GRAPHICS_API_OPENGL_21)
      "varying vec2 fragTexCoord;         \n"
      "varying vec4 fragColor;            \n"
  #elif defined(GRAPHICS_API_OPENGL_33) || defined(GRAPHICS_API_OPENGL_46)
    #if defined(GRAPHICS_API_OPENGL_33)
  "#version 330                       \n"
    #else
  "#version 450                       \n"
  	#endif
      "in vec2 fragTexCoord;              \n"
      "in vec4 fragColor;                 \n"
      "out vec4 finalColor;               \n"
  #endif
      "uniform sampler2D texture0;        \n"
      "uniform vec4 colDiffuse;           \n"
      "void main()                        \n"
      "{                                  \n"
  #if defined(GRAPHICS_API_OPENGL_ES2) || defined(GRAPHICS_API_OPENGL_21)
      "    vec4 texelColor = texture2D(texture0, fragTexCoord); \n" // NOTE: texture2D() is deprecated on OpenGL 3.3 and ES 3.0
      "    gl_FragColor = texelColor*colDiffuse*fragColor;      \n"
  #elif defined(GRAPHICS_API_OPENGL_33) || defined(GRAPHICS_API_OPENGL_46)
      "    vec4 texelColor = texture(texture0, fragTexCoord);   \n"
      "    finalColor = texelColor*colDiffuse*fragColor;        \n"
  #endif
      "}                                  \n";
  
      // NOTE: Compiled vertex/fragment shaders are kept for re-use
      RLGL.State.defaultVShaderId = CompileShader(defaultVShaderStr, GL_VERTEX_SHADER);     // Compile default vertex shader
      RLGL.State.defaultFShaderId = CompileShader(defaultFShaderStr, GL_FRAGMENT_SHADER);   // Compile default fragment shader
  
      shader.id = LoadShaderProgram(RLGL.State.defaultVShaderId, RLGL.State.defaultFShaderId);
  
      if (shader.id > 0)
      {
          TRACELOG(LOG_INFO, "SHADER: [ID %i] Default shader loaded successfully", shader.id);
  
          // Set default shader locations: attributes locations
          shader.locs[LOC_VERTEX_POSITION] = glGetAttribLocation(shader.id, "vertexPosition");
          shader.locs[LOC_VERTEX_TEXCOORD01] = glGetAttribLocation(shader.id, "vertexTexCoord");
          shader.locs[LOC_VERTEX_COLOR] = glGetAttribLocation(shader.id, "vertexColor");
          shader.locs[LOC_VERTEX_BONEID] = glGetAttribLocation(shader.id, "vertexBoneId");
          shader.locs[LOC_VERTEX_BONEWEIGHT] = glGetAttribLocation(shader.id, "vertexBoneWeight");
  
          // Set default shader locations: uniform locations
          shader.locs[LOC_MATRIX_MVP]  = glGetUniformLocation(shader.id, "mvp");
          shader.locs[LOC_MATRIX_MVIT]  = glGetUniformLocation(shader.id, "mvit");
          shader.locs[LOC_COLOR_DIFFUSE] = glGetUniformLocation(shader.id, "colDiffuse");
          shader.locs[LOC_MAP_DIFFUSE] = glGetUniformLocation(shader.id, "texture0");
  
          // NOTE: We could also use below function but in case DEFAULT_ATTRIB_* points are
          // changed for external custom shaders, we just use direct bindings above
          //SetShaderDefaultLocations(&shader);
      }
      else TRACELOG(LOG_WARNING, "SHADER: [ID %i] Failed to load default shader", shader.id);
  
      return shader;
  }
  
  // Get location handlers to for shader attributes and uniforms
  // NOTE: If any location is not found, loc point becomes -1
  static void SetShaderDefaultLocations(Shader *shader)
  {
      // NOTE: Default shader attrib locations have been fixed before linking:
      //          vertex position location    = 0
      //          vertex texcoord location    = 1
      //          vertex normal location      = 2
      //          vertex color location       = 3
      //          vertex tangent location     = 4
      //          vertex texcoord2 location   = 5
      //          vertex boneid location     = 7
      //          vertex boneweight location = 8
  
      // Get handles to GLSL input attibute locations
      shader->locs[LOC_VERTEX_POSITION] = glGetAttribLocation(shader->id, DEFAULT_SHADER_ATTRIB_NAME_POSITION);
      shader->locs[LOC_VERTEX_TEXCOORD01] = glGetAttribLocation(shader->id, DEFAULT_SHADER_ATTRIB_NAME_TEXCOORD);
      shader->locs[LOC_VERTEX_TEXCOORD02] = glGetAttribLocation(shader->id, DEFAULT_SHADER_ATTRIB_NAME_TEXCOORD2);
      shader->locs[LOC_VERTEX_NORMAL] = glGetAttribLocation(shader->id, DEFAULT_SHADER_ATTRIB_NAME_NORMAL);
      shader->locs[LOC_VERTEX_TANGENT] = glGetAttribLocation(shader->id, DEFAULT_SHADER_ATTRIB_NAME_TANGENT);
      shader->locs[LOC_VERTEX_COLOR] = glGetAttribLocation(shader->id, DEFAULT_SHADER_ATTRIB_NAME_COLOR);
      shader->locs[LOC_VERTEX_BONEID]     = glGetAttribLocation(shader->id, DEFAULT_SHADER_ATTRIB_NAME_BONEID);
      shader->locs[LOC_VERTEX_BONEWEIGHT] = glGetAttribLocation(shader->id, DEFAULT_SHADER_ATTRIB_NAME_BONEWEIGHT);
  
      // Get handles to GLSL uniform locations (vertex shader)
      shader->locs[LOC_MATRIX_MVP]  = glGetUniformLocation(shader->id, "mvp");
      shader->locs[LOC_MATRIX_MVIT]       = glGetUniformLocation(shader->id, "mvit");
      shader->locs[LOC_MATRIX_PROJECTION]  = glGetUniformLocation(shader->id, "projection");
      shader->locs[LOC_MATRIX_VIEW]  = glGetUniformLocation(shader->id, "view");
  
      // Get handles to GLSL uniform locations (fragment shader)
      shader->locs[LOC_COLOR_DIFFUSE] = glGetUniformLocation(shader->id, "colDiffuse");
      shader->locs[LOC_MAP_DIFFUSE] = glGetUniformLocation(shader->id, "texture0");
      shader->locs[LOC_MAP_SPECULAR] = glGetUniformLocation(shader->id, "texture1");
      shader->locs[LOC_MAP_NORMAL] = glGetUniformLocation(shader->id, "texture2");
  }
  
  // Unload default shader
  static void UnloadShaderDefault(void)
  {
      glUseProgram(0);
  
      glDetachShader(RLGL.State.defaultShader.id, RLGL.State.defaultVShaderId);
      glDetachShader(RLGL.State.defaultShader.id, RLGL.State.defaultFShaderId);
      glDeleteShader(RLGL.State.defaultVShaderId);
      glDeleteShader(RLGL.State.defaultFShaderId);
  
      glDeleteProgram(RLGL.State.defaultShader.id);
  
      RL_FREE(RLGL.State.defaultShader.locs);
  }
  
  // Load render batch
  static RenderBatch LoadRenderBatch(int numBuffers, int bufferElements)
  {
      RenderBatch batch = { 0 };
  
      // Initialize CPU (RAM) vertex buffers (position, texcoord, color data and indexes)
      //--------------------------------------------------------------------------------------------
      batch.vertexBuffer = (VertexBuffer *)RL_MALLOC(sizeof(VertexBuffer)*numBuffers);
  
      for (int i = 0; i < numBuffers; i++)
      {
          batch.vertexBuffer[i].elementsCount = bufferElements;
  
          batch.vertexBuffer[i].vertices = (float *)RL_MALLOC(bufferElements*3*4*sizeof(float));        // 3 float by vertex, 4 vertex by quad
          batch.vertexBuffer[i].texcoords = (float *)RL_MALLOC(bufferElements*2*4*sizeof(float));       // 2 float by texcoord, 4 texcoord by quad
          batch.vertexBuffer[i].colors = (unsigned char *)RL_MALLOC(bufferElements*4*4*sizeof(unsigned char));   // 4 float by color, 4 colors by quad
  #if defined(GRAPHICS_API_OPENGL_33) || defined(GRAPHICS_API_OPENGL_46)
          batch.vertexBuffer[i].indices = (unsigned int *)RL_MALLOC(bufferElements*6*sizeof(unsigned int));      // 6 int by quad (indices)
  #elif defined(GRAPHICS_API_OPENGL_ES2)
          batch.vertexBuffer[i].indices = (unsigned short *)RL_MALLOC(bufferElements*6*sizeof(unsigned short));  // 6 int by quad (indices)
  #endif
          batch.vertexBuffer[i].boneIds = (int *)RL_MALLOC(bufferElements*4*4*sizeof(int));
          batch.vertexBuffer[i].boneWeights = (float *)RL_MALLOC(bufferElements*4*4*sizeof(float));
  
          for (int j = 0; j < (3*4*bufferElements); j++) batch.vertexBuffer[i].vertices[j] = 0.0f;
          for (int j = 0; j < (2*4*bufferElements); j++) batch.vertexBuffer[i].texcoords[j] = 0.0f;
          for (int j = 0; j < (4*4*bufferElements); j++) batch.vertexBuffer[i].colors[j] = 0;
  
          int k = 0;
  
          // Indices can be initialized right now
          for (int j = 0; j < (6*bufferElements); j += 6)
          {
              batch.vertexBuffer[i].indices[j] = 4*k;
              batch.vertexBuffer[i].indices[j + 1] = 4*k + 1;
              batch.vertexBuffer[i].indices[j + 2] = 4*k + 2;
              batch.vertexBuffer[i].indices[j + 3] = 4*k;
              batch.vertexBuffer[i].indices[j + 4] = 4*k + 2;
              batch.vertexBuffer[i].indices[j + 5] = 4*k + 3;
  
              k++;
          }
  
          batch.vertexBuffer[i].vCounter = 0;
          batch.vertexBuffer[i].tcCounter = 0;
          batch.vertexBuffer[i].cCounter = 0;
      }
  
      TRACELOG(LOG_INFO, "RLGL: Internal vertex buffers initialized successfully in RAM (CPU)");
      //--------------------------------------------------------------------------------------------
  
      // Upload to GPU (VRAM) vertex data and initialize VAOs/VBOs
      //--------------------------------------------------------------------------------------------
      for (int i = 0; i < numBuffers; i++)
      {
          if (RLGL.ExtSupported.vao)
          {
              // Initialize Quads VAO
              glGenVertexArrays(1, &batch.vertexBuffer[i].vaoId);
              glBindVertexArray(batch.vertexBuffer[i].vaoId);
          }
  
          // Quads - Vertex buffers binding and attributes enable
          // Vertex position buffer (shader-location = 0)
          glGenBuffers(1, &batch.vertexBuffer[i].vboId[0]);
          glBindBuffer(GL_ARRAY_BUFFER, batch.vertexBuffer[i].vboId[0]);
          glBufferData(GL_ARRAY_BUFFER, bufferElements*3*4*sizeof(float), batch.vertexBuffer[i].vertices, GL_DYNAMIC_DRAW);
          glEnableVertexAttribArray(RLGL.State.currentShader.locs[LOC_VERTEX_POSITION]);
          glVertexAttribPointer(RLGL.State.currentShader.locs[LOC_VERTEX_POSITION], 3, GL_FLOAT, 0, 0, 0);
  
          // Vertex texcoord buffer (shader-location = 1)
          glGenBuffers(1, &batch.vertexBuffer[i].vboId[1]);
          glBindBuffer(GL_ARRAY_BUFFER, batch.vertexBuffer[i].vboId[1]);
          glBufferData(GL_ARRAY_BUFFER, bufferElements*2*4*sizeof(float), batch.vertexBuffer[i].texcoords, GL_DYNAMIC_DRAW);
          glEnableVertexAttribArray(RLGL.State.currentShader.locs[LOC_VERTEX_TEXCOORD01]);
          glVertexAttribPointer(RLGL.State.currentShader.locs[LOC_VERTEX_TEXCOORD01], 2, GL_FLOAT, 0, 0, 0);
  
          // Vertex color buffer (shader-location = 3)
          glGenBuffers(1, &batch.vertexBuffer[i].vboId[2]);
          glBindBuffer(GL_ARRAY_BUFFER, batch.vertexBuffer[i].vboId[2]);
          glBufferData(GL_ARRAY_BUFFER, bufferElements*4*4*sizeof(unsigned char), batch.vertexBuffer[i].colors, GL_DYNAMIC_DRAW);
          glEnableVertexAttribArray(RLGL.State.currentShader.locs[LOC_VERTEX_COLOR]);
          glVertexAttribPointer(RLGL.State.currentShader.locs[LOC_VERTEX_COLOR], 4, GL_UNSIGNED_BYTE, GL_TRUE, 0, 0);
  
          // Fill index buffer
          glGenBuffers(1, &batch.vertexBuffer[i].vboId[3]);
          glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, batch.vertexBuffer[i].vboId[3]);
  #if defined(GRAPHICS_API_OPENGL_33) || defined(GRAPHICS_API_OPENGL_46)
          glBufferData(GL_ELEMENT_ARRAY_BUFFER, bufferElements*6*sizeof(int), batch.vertexBuffer[i].indices, GL_STATIC_DRAW);
  #elif defined(GRAPHICS_API_OPENGL_ES2)
          glBufferData(GL_ELEMENT_ARRAY_BUFFER, bufferElements*6*sizeof(short), batch.vertexBuffer[i].indices, GL_STATIC_DRAW);
  #endif
  
          // Vertex boneIds buffer
          glGenBuffers(1, &batch.vertexBuffer[i].vboId[4]);
          glBindBuffer(GL_ARRAY_BUFFER, batch.vertexBuffer[i].vboId[4]);
          glBufferData(GL_ARRAY_BUFFER, bufferElements*4*4*sizeof(int), batch.vertexBuffer[i].boneIds, GL_DYNAMIC_DRAW);
          glEnableVertexAttribArray(RLGL.State.currentShader.locs[LOC_VERTEX_BONEID]);
          glVertexAttribIPointer(RLGL.State.currentShader.locs[LOC_VERTEX_BONEID], 4, GL_INT, 0, 0);
  
          // Vertex boneWeights buffer
          glGenBuffers(1, &batch.vertexBuffer[i].vboId[5]);
          glBindBuffer(GL_ARRAY_BUFFER, batch.vertexBuffer[i].vboId[5]);
          glBufferData(GL_ARRAY_BUFFER, bufferElements*4*4*sizeof(unsigned char), batch.vertexBuffer[i].boneWeights, GL_DYNAMIC_DRAW);
          glEnableVertexAttribArray(RLGL.State.currentShader.locs[LOC_VERTEX_BONEWEIGHT]);
          glVertexAttribPointer(RLGL.State.currentShader.locs[LOC_VERTEX_BONEWEIGHT], 4, GL_FLOAT, 0, 0, 0);
      }
  
      TRACELOG(LOG_INFO, "RLGL: Render batch vertex buffers loaded successfully");
  
      // Unbind the current VAO
      if (RLGL.ExtSupported.vao) glBindVertexArray(0);
      //--------------------------------------------------------------------------------------------
  
      // Init draw calls tracking system
      //--------------------------------------------------------------------------------------------
      batch.draws = (DrawCall *)RL_MALLOC(DEFAULT_BATCH_DRAWCALLS*sizeof(DrawCall));
  
      for (int i = 0; i < DEFAULT_BATCH_DRAWCALLS; i++)
      {
          batch.draws[i].mode = RL_QUADS;
          batch.draws[i].vertexCount = 0;
          batch.draws[i].vertexAlignment = 0;
          //batch.draws[i].vaoId = 0;
          //batch.draws[i].shaderId = 0;
          batch.draws[i].textureId = RLGL.State.defaultTextureId;
          //batch.draws[i].RLGL.State.projection = MatrixIdentity();
          //batch.draws[i].RLGL.State.modelview = MatrixIdentity();
      }
  
      batch.buffersCount = numBuffers;    // Record buffer count
      batch.drawsCounter = 1;             // Reset draws counter
      batch.currentDepth = -1.0f;         // Reset depth value
      //--------------------------------------------------------------------------------------------
  
      return batch;
  }
  
  // Draw render batch
  // NOTE: We require a pointer to reset batch and increase current buffer (multi-buffer)
  static void DrawRenderBatch(RenderBatch *batch)
  {
      // Update batch vertex buffers
      //------------------------------------------------------------------------------------------------------------
      // NOTE: If there is not vertex data, buffers doesn't need to be updated (vertexCount > 0)
      // TODO: If no data changed on the CPU arrays --> No need to re-update GPU arrays (change flag required)
      if (batch->vertexBuffer[batch->currentBuffer].vCounter > 0)
      {
          // Activate elements VAO
          if (RLGL.ExtSupported.vao) glBindVertexArray(batch->vertexBuffer[batch->currentBuffer].vaoId);
  
          // Vertex positions buffer
          glBindBuffer(GL_ARRAY_BUFFER, batch->vertexBuffer[batch->currentBuffer].vboId[0]);
          glBufferSubData(GL_ARRAY_BUFFER, 0, batch->vertexBuffer[batch->currentBuffer].vCounter*3*sizeof(float), batch->vertexBuffer[batch->currentBuffer].vertices);
          //glBufferData(GL_ARRAY_BUFFER, sizeof(float)*3*4*batch->vertexBuffer[batch->currentBuffer].elementsCount, batch->vertexBuffer[batch->currentBuffer].vertices, GL_DYNAMIC_DRAW);  // Update all buffer
  
          // Texture coordinates buffer
          glBindBuffer(GL_ARRAY_BUFFER, batch->vertexBuffer[batch->currentBuffer].vboId[1]);
          glBufferSubData(GL_ARRAY_BUFFER, 0, batch->vertexBuffer[batch->currentBuffer].vCounter*2*sizeof(float), batch->vertexBuffer[batch->currentBuffer].texcoords);
          //glBufferData(GL_ARRAY_BUFFER, sizeof(float)*2*4*batch->vertexBuffer[batch->currentBuffer].elementsCount, batch->vertexBuffer[batch->currentBuffer].texcoords, GL_DYNAMIC_DRAW); // Update all buffer
  
          // Colors buffer
          glBindBuffer(GL_ARRAY_BUFFER, batch->vertexBuffer[batch->currentBuffer].vboId[2]);
          glBufferSubData(GL_ARRAY_BUFFER, 0, batch->vertexBuffer[batch->currentBuffer].vCounter*4*sizeof(unsigned char), batch->vertexBuffer[batch->currentBuffer].colors);
          //glBufferData(GL_ARRAY_BUFFER, sizeof(float)*4*4*batch->vertexBuffer[batch->currentBuffer].elementsCount, batch->vertexBuffer[batch->currentBuffer].colors, GL_DYNAMIC_DRAW);    // Update all buffer
  
          // BoneIds buffer
          glBindBuffer(GL_ARRAY_BUFFER, batch->vertexBuffer[batch->currentBuffer].vboId[4]);
          glBufferSubData(GL_ARRAY_BUFFER, 0, batch->vertexBuffer[batch->currentBuffer].vCounter*4*sizeof(int), batch->vertexBuffer[batch->currentBuffer].boneIds);
  
          // BoneWeights buffer
          glBindBuffer(GL_ARRAY_BUFFER, batch->vertexBuffer[batch->currentBuffer].vboId[5]);
          glBufferSubData(GL_ARRAY_BUFFER, 0, batch->vertexBuffer[batch->currentBuffer].vCounter*4*sizeof(float), batch->vertexBuffer[batch->currentBuffer].boneWeights);
  
          // NOTE: glMapBuffer() causes sync issue.
          // If GPU is working with this buffer, glMapBuffer() will wait(stall) until GPU to finish its job.
          // To avoid waiting (idle), you can call first glBufferData() with NULL pointer before glMapBuffer().
          // If you do that, the previous data in PBO will be discarded and glMapBuffer() returns a new
          // allocated pointer immediately even if GPU is still working with the previous data.
  
          // Another option: map the buffer object into client's memory
          // Probably this code could be moved somewhere else...
          // batch->vertexBuffer[batch->currentBuffer].vertices = (float *)glMapBuffer(GL_ARRAY_BUFFER, GL_READ_WRITE);
          // if (batch->vertexBuffer[batch->currentBuffer].vertices)
          // {
              // Update vertex data
          // }
          // glUnmapBuffer(GL_ARRAY_BUFFER);
  
          // Unbind the current VAO
          if (RLGL.ExtSupported.vao) glBindVertexArray(0);
      }
      //------------------------------------------------------------------------------------------------------------
  
      // Draw batch vertex buffers (considering VR stereo if required)
      //------------------------------------------------------------------------------------------------------------
      Matrix matProjection = RLGL.State.projection;
      Matrix matModelView = RLGL.State.modelview;
  
      int eyesCount = 1;
  #if defined(SUPPORT_VR_SIMULATOR)
      if (RLGL.Vr.stereoRender) eyesCount = 2;
  #endif
  
      for (int eye = 0; eye < eyesCount; eye++)
      {
  #if defined(SUPPORT_VR_SIMULATOR)
          if (eyesCount == 2) SetStereoView(eye, matProjection, matModelView);
  #endif
          // Draw buffers
          if (batch->vertexBuffer[batch->currentBuffer].vCounter > 0)
          {
              // Set current shader and upload current MVP matrix
              glUseProgram(RLGL.State.currentShader.id);
  
              // Create modelview-projection matrix and upload to shader
              Matrix matMVP = MatrixMultiply(RLGL.State.modelview, RLGL.State.projection);
              glUniformMatrix4fv(RLGL.State.currentShader.locs[LOC_MATRIX_MVP], 1, false, MatrixToFloat(matMVP));
  
              if (RLGL.ExtSupported.vao) glBindVertexArray(batch->vertexBuffer[batch->currentBuffer].vaoId);
              else
              {
                  // Bind vertex attrib: position (shader-location = 0)
                  glBindBuffer(GL_ARRAY_BUFFER, batch->vertexBuffer[batch->currentBuffer].vboId[0]);
                  glVertexAttribPointer(RLGL.State.currentShader.locs[LOC_VERTEX_POSITION], 3, GL_FLOAT, 0, 0, 0);
                  glEnableVertexAttribArray(RLGL.State.currentShader.locs[LOC_VERTEX_POSITION]);
  
                  // Bind vertex attrib: texcoord (shader-location = 1)
                  glBindBuffer(GL_ARRAY_BUFFER, batch->vertexBuffer[batch->currentBuffer].vboId[1]);
                  glVertexAttribPointer(RLGL.State.currentShader.locs[LOC_VERTEX_TEXCOORD01], 2, GL_FLOAT, 0, 0, 0);
                  glEnableVertexAttribArray(RLGL.State.currentShader.locs[LOC_VERTEX_TEXCOORD01]);
  
                  // Bind vertex attrib: color (shader-location = 3)
                  glBindBuffer(GL_ARRAY_BUFFER, batch->vertexBuffer[batch->currentBuffer].vboId[2]);
                  glVertexAttribPointer(RLGL.State.currentShader.locs[LOC_VERTEX_COLOR], 4, GL_UNSIGNED_BYTE, GL_TRUE, 0, 0);
                  glEnableVertexAttribArray(RLGL.State.currentShader.locs[LOC_VERTEX_COLOR]);
  
                  glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, batch->vertexBuffer[batch->currentBuffer].vboId[3]);
              }
  
              // Setup some default shader values
              glUniform4f(RLGL.State.currentShader.locs[LOC_COLOR_DIFFUSE], 1.0f, 1.0f, 1.0f, 1.0f);
              glUniform1i(RLGL.State.currentShader.locs[LOC_MAP_DIFFUSE], 0);  // Active default sampler2D: texture0
  
              // Activate additional sampler textures
              // Those additional textures will be common for all draw calls of the batch
              for (int i = 0; i < MAX_BATCH_ACTIVE_TEXTURES; i++)
              {
                  if (RLGL.State.activeTextureId[i] > 0)
                  {
                      glActiveTexture(GL_TEXTURE0 + 1 + i);
                      glBindTexture(GL_TEXTURE_2D, RLGL.State.activeTextureId[i]);
                  }
              }
  
              // Activate default sampler2D texture0 (one texture is always active for default batch shader)
              // NOTE: Batch system accumulates calls by texture0 changes, additional textures are enabled for all the draw calls
              glActiveTexture(GL_TEXTURE0);
  
              for (int i = 0, vertexOffset = 0; i < batch->drawsCounter; i++)
              {
                  // Bind current draw call texture, activated as GL_TEXTURE0 and binded to sampler2D texture0 by default
                  glBindTexture(GL_TEXTURE_2D, batch->draws[i].textureId);
  
                  if ((batch->draws[i].mode == RL_LINES) || (batch->draws[i].mode == RL_TRIANGLES)) glDrawArrays(batch->draws[i].mode, vertexOffset, batch->draws[i].vertexCount);
                  else
                  {
  #if defined(GRAPHICS_API_OPENGL_33) || defined(GRAPHICS_API_OPENGL_46)
                      // We need to define the number of indices to be processed: quadsCount*6
                      // NOTE: The final parameter tells the GPU the offset in bytes from the
                      // start of the index buffer to the location of the first index to process
                      glDrawElements(GL_TRIANGLES, batch->draws[i].vertexCount/4*6, GL_UNSIGNED_INT, (GLvoid *)(vertexOffset/4*6*sizeof(GLuint)));
  #elif defined(GRAPHICS_API_OPENGL_ES2)
                      glDrawElements(GL_TRIANGLES, batch->draws[i].vertexCount/4*6, GL_UNSIGNED_SHORT, (GLvoid *)(vertexOffset/4*6*sizeof(GLushort)));
  #endif
                  }
  
                  vertexOffset += (batch->draws[i].vertexCount + batch->draws[i].vertexAlignment);
              }
  
              if (!RLGL.ExtSupported.vao)
              {
                  glBindBuffer(GL_ARRAY_BUFFER, 0);
                  glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, 0);
              }
  
              glBindTexture(GL_TEXTURE_2D, 0);    // Unbind textures
          }
  
          if (RLGL.ExtSupported.vao) glBindVertexArray(0); // Unbind VAO
  
          glUseProgram(0);    // Unbind shader program
      }
      //------------------------------------------------------------------------------------------------------------
  
      // Reset batch buffers
      //------------------------------------------------------------------------------------------------------------
      // Reset vertex counters for next frame
      batch->vertexBuffer[batch->currentBuffer].vCounter = 0;
      batch->vertexBuffer[batch->currentBuffer].tcCounter = 0;
      batch->vertexBuffer[batch->currentBuffer].cCounter = 0;
  
      // Reset depth for next draw
      batch->currentDepth = -1.0f;
  
      // Restore projection/modelview matrices
      RLGL.State.projection = matProjection;
      RLGL.State.modelview = matModelView;
  
      // Reset RLGL.currentBatch->draws array
      for (int i = 0; i < DEFAULT_BATCH_DRAWCALLS; i++)
      {
          batch->draws[i].mode = RL_QUADS;
          batch->draws[i].vertexCount = 0;
          batch->draws[i].textureId = RLGL.State.defaultTextureId;
      }
  
      // Reset active texture units for next batch
      for (int i = 0; i < MAX_BATCH_ACTIVE_TEXTURES; i++) RLGL.State.activeTextureId[i] = 0;
  
      // Reset draws counter to one draw for the batch
      batch->drawsCounter = 1;
      //------------------------------------------------------------------------------------------------------------
  
      // Change to next buffer in the list (in case of multi-buffering)
      batch->currentBuffer++;
      if (batch->currentBuffer >= batch->buffersCount) batch->currentBuffer = 0;
  }
  
  // Unload default internal buffers vertex data from CPU and GPU
  static void UnloadRenderBatch(RenderBatch batch)
  {
      // Unbind everything
      if (RLGL.ExtSupported.vao) glBindVertexArray(0);
      glDisableVertexAttribArray(0);
      glDisableVertexAttribArray(1);
      glDisableVertexAttribArray(2);
      glDisableVertexAttribArray(3);
      glDisableVertexAttribArray(4);
      glDisableVertexAttribArray(5);
      glBindBuffer(GL_ARRAY_BUFFER, 0);
      glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, 0);
  
      // Unload all vertex buffers data
      for (int i = 0; i < batch.buffersCount; i++)
      {
          // Delete VBOs from GPU (VRAM)
          glDeleteBuffers(1, &batch.vertexBuffer[i].vboId[0]);
          glDeleteBuffers(1, &batch.vertexBuffer[i].vboId[1]);
          glDeleteBuffers(1, &batch.vertexBuffer[i].vboId[2]);
          glDeleteBuffers(1, &batch.vertexBuffer[i].vboId[3]);
          glDeleteBuffers(1, &batch.vertexBuffer[i].vboId[4]);
          glDeleteBuffers(1, &batch.vertexBuffer[i].vboId[5]);
  
          // Delete VAOs from GPU (VRAM)
          if (RLGL.ExtSupported.vao) glDeleteVertexArrays(1, &batch.vertexBuffer[i].vaoId);
  
          // Free vertex arrays memory from CPU (RAM)
          RL_FREE(batch.vertexBuffer[i].vertices);
          RL_FREE(batch.vertexBuffer[i].texcoords);
          RL_FREE(batch.vertexBuffer[i].colors);
          RL_FREE(batch.vertexBuffer[i].indices);
          RL_FREE(batch.vertexBuffer[i].boneIds);
          RL_FREE(batch.vertexBuffer[i].boneWeights);
      }
  
      // Unload arrays
      RL_FREE(batch.vertexBuffer);
      RL_FREE(batch.draws);
  }
  
  // Set the active render batch for rlgl
  static void SetRenderBatchActive(RenderBatch *batch)
  {
      DrawRenderBatch(RLGL.currentBatch);
      RLGL.currentBatch = batch;
  }
  
  // Set default render batch for rlgl
  static void SetRenderBatchDefault(void)
  {
      DrawRenderBatch(RLGL.currentBatch);
      RLGL.currentBatch = &RLGL.defaultBatch;
  }
  
  // Renders a 1x1 XY quad in NDC
  static void GenDrawQuad(void)
  {
      unsigned int quadVAO = 0;
      unsigned int quadVBO = 0;
  
      float vertices[] = {
           // Positions         Texcoords
          -1.0f,  1.0f, 0.0f,   0.0f, 1.0f,
          -1.0f, -1.0f, 0.0f,   0.0f, 0.0f,
           1.0f,  1.0f, 0.0f,   1.0f, 1.0f,
           1.0f, -1.0f, 0.0f,   1.0f, 0.0f,
      };
  
      // Gen VAO to contain VBO
      glGenVertexArrays(1, &quadVAO);
      glBindVertexArray(quadVAO);
  
      // Gen and fill vertex buffer (VBO)
      glGenBuffers(1, &quadVBO);
      glBindBuffer(GL_ARRAY_BUFFER, quadVBO);
      glBufferData(GL_ARRAY_BUFFER, sizeof(vertices), &vertices, GL_STATIC_DRAW);
  
      // Bind vertex attributes (position, texcoords)
      glEnableVertexAttribArray(0);
      glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 5*sizeof(float), (void *)0); // Positions
      glEnableVertexAttribArray(1);
      glVertexAttribPointer(1, 2, GL_FLOAT, GL_FALSE, 5*sizeof(float), (void *)(3*sizeof(float))); // Texcoords
  
      // Draw quad
      glBindVertexArray(quadVAO);
      glDrawArrays(GL_TRIANGLE_STRIP, 0, 4);
      glBindVertexArray(0);
  
      // Delete buffers (VBO and VAO)
      glDeleteBuffers(1, &quadVBO);
      glDeleteVertexArrays(1, &quadVAO);
  }
  
  // Renders a 1x1 3D cube in NDC
  static void GenDrawCube(void)
  {
      unsigned int cubeVAO = 0;
      unsigned int cubeVBO = 0;
  
      float vertices[] = {
           // Positions          Normals               Texcoords
          -1.0f, -1.0f, -1.0f,   0.0f,  0.0f, -1.0f,   0.0f, 0.0f,
           1.0f,  1.0f, -1.0f,   0.0f,  0.0f, -1.0f,   1.0f, 1.0f,
           1.0f, -1.0f, -1.0f,   0.0f,  0.0f, -1.0f,   1.0f, 0.0f,
           1.0f,  1.0f, -1.0f,   0.0f,  0.0f, -1.0f,   1.0f, 1.0f,
          -1.0f, -1.0f, -1.0f,   0.0f,  0.0f, -1.0f,   0.0f, 0.0f,
          -1.0f,  1.0f, -1.0f,   0.0f,  0.0f, -1.0f,   0.0f, 1.0f,
          -1.0f, -1.0f,  1.0f,   0.0f,  0.0f,  1.0f,   0.0f, 0.0f,
           1.0f, -1.0f,  1.0f,   0.0f,  0.0f,  1.0f,   1.0f, 0.0f,
           1.0f,  1.0f,  1.0f,   0.0f,  0.0f,  1.0f,   1.0f, 1.0f,
           1.0f,  1.0f,  1.0f,   0.0f,  0.0f,  1.0f,   1.0f, 1.0f,
          -1.0f,  1.0f,  1.0f,   0.0f,  0.0f,  1.0f,   0.0f, 1.0f,
          -1.0f, -1.0f,  1.0f,   0.0f,  0.0f,  1.0f,   0.0f, 0.0f,
          -1.0f,  1.0f,  1.0f,  -1.0f,  0.0f,  0.0f,   1.0f, 0.0f,
          -1.0f,  1.0f, -1.0f,  -1.0f,  0.0f,  0.0f,   1.0f, 1.0f,
          -1.0f, -1.0f, -1.0f,  -1.0f,  0.0f,  0.0f,   0.0f, 1.0f,
          -1.0f, -1.0f, -1.0f,  -1.0f,  0.0f,  0.0f,   0.0f, 1.0f,
          -1.0f, -1.0f,  1.0f,  -1.0f,  0.0f,  0.0f,   0.0f, 0.0f,
          -1.0f,  1.0f,  1.0f,  -1.0f,  0.0f,  0.0f,   1.0f, 0.0f,
           1.0f,  1.0f,  1.0f,   1.0f,  0.0f,  0.0f,   1.0f, 0.0f,
           1.0f, -1.0f, -1.0f,   1.0f,  0.0f,  0.0f,   0.0f, 1.0f,
           1.0f,  1.0f, -1.0f,   1.0f,  0.0f,  0.0f,   1.0f, 1.0f,
           1.0f, -1.0f, -1.0f,   1.0f,  0.0f,  0.0f,   0.0f, 1.0f,
           1.0f,  1.0f,  1.0f,   1.0f,  0.0f,  0.0f,   1.0f, 0.0f,
           1.0f, -1.0f,  1.0f,   1.0f,  0.0f,  0.0f,   0.0f, 0.0f,
          -1.0f, -1.0f, -1.0f,   0.0f, -1.0f,  0.0f,   0.0f, 1.0f,
           1.0f, -1.0f, -1.0f,   0.0f, -1.0f,  0.0f,   1.0f, 1.0f,
           1.0f, -1.0f,  1.0f,   0.0f, -1.0f,  0.0f,   1.0f, 0.0f,
           1.0f, -1.0f,  1.0f,   0.0f, -1.0f,  0.0f,   1.0f, 0.0f,
          -1.0f, -1.0f,  1.0f,   0.0f, -1.0f,  0.0f,   0.0f, 0.0f,
          -1.0f, -1.0f, -1.0f,   0.0f, -1.0f,  0.0f,   0.0f, 1.0f,
          -1.0f,  1.0f, -1.0f,   0.0f,  1.0f,  0.0f,   0.0f, 1.0f,
           1.0f,  1.0f,  1.0f,   0.0f,  1.0f,  0.0f,   1.0f, 0.0f,
           1.0f,  1.0f, -1.0f,   0.0f,  1.0f,  0.0f,   1.0f, 1.0f,
           1.0f,  1.0f,  1.0f,   0.0f,  1.0f,  0.0f,   1.0f, 0.0f,
          -1.0f,  1.0f, -1.0f,   0.0f,  1.0f,  0.0f,   0.0f, 1.0f,
          -1.0f,  1.0f,  1.0f,   0.0f,  1.0f,  0.0f,   0.0f, 0.0f
      };
  
      // Gen VAO to contain VBO
      glGenVertexArrays(1, &cubeVAO);
      glBindVertexArray(cubeVAO);
  
      // Gen and fill vertex buffer (VBO)
      glGenBuffers(1, &cubeVBO);
      glBindBuffer(GL_ARRAY_BUFFER, cubeVBO);
      glBufferData(GL_ARRAY_BUFFER, sizeof(vertices), vertices, GL_STATIC_DRAW);
  
      // Bind vertex attributes (position, normals, texcoords)
      glBindVertexArray(cubeVAO);
      glEnableVertexAttribArray(0);
      glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 8*sizeof(float), (void *)0); // Positions
      glEnableVertexAttribArray(1);
      glVertexAttribPointer(1, 3, GL_FLOAT, GL_FALSE, 8*sizeof(float), (void *)(3*sizeof(float))); // Normals
      glEnableVertexAttribArray(2);
      glVertexAttribPointer(2, 2, GL_FLOAT, GL_FALSE, 8*sizeof(float), (void *)(6*sizeof(float))); // Texcoords
      glBindBuffer(GL_ARRAY_BUFFER, 0);
      glBindVertexArray(0);
  
      // Draw cube
      glBindVertexArray(cubeVAO);
      glDrawArrays(GL_TRIANGLES, 0, 36);
      glBindVertexArray(0);
  
      // Delete VBO and VAO
      glDeleteBuffers(1, &cubeVBO);
      glDeleteVertexArrays(1, &cubeVAO);
  }
  
  #if defined(SUPPORT_VR_SIMULATOR)
  // Set internal projection and modelview matrix depending on eyes tracking data
  static void SetStereoView(int eye, Matrix matProjection, Matrix matModelView)
  {
      Matrix eyeProjection = matProjection;
      Matrix eyeModelView = matModelView;
  
      // Setup viewport and projection/modelview matrices using tracking data
      rlViewport(eye*RLGL.State.framebufferWidth/2, 0, RLGL.State.framebufferWidth/2, RLGL.State.framebufferHeight);
  
      // Apply view offset to modelview matrix
      eyeModelView = MatrixMultiply(matModelView, RLGL.Vr.config.eyesViewOffset[eye]);
  
      // Set current eye projection matrix
      eyeProjection = RLGL.Vr.config.eyesProjection[eye];
  
      SetMatrixModelview(eyeModelView);
      SetMatrixProjection(eyeProjection);
  }
  #endif  // SUPPORT_VR_SIMULATOR
  
  #endif  // GRAPHICS_API_OPENGL_33 || GRAPHICS_API_OPENGL_ES2
  
  #if defined(GRAPHICS_API_OPENGL_11)
  // Mipmaps data is generated after image data
  // NOTE: Only works with RGBA (4 bytes) data!
  static int GenerateMipmaps(unsigned char *data, int baseWidth, int baseHeight)
  {
      int mipmapCount = 1;                // Required mipmap levels count (including base level)
      int width = baseWidth;
      int height = baseHeight;
      int size = baseWidth*baseHeight*4;  // Size in bytes (will include mipmaps...), RGBA only
  
      // Count mipmap levels required
      while ((width != 1) && (height != 1))
      {
          if (width != 1) width /= 2;
          if (height != 1) height /= 2;
  
          TRACELOGD("TEXTURE: Next mipmap size: %i x %i", width, height);
  
          mipmapCount++;
  
          size += (width*height*4);       // Add mipmap size (in bytes)
      }
  
      TRACELOGD("TEXTURE: Total mipmaps required: %i", mipmapCount);
      TRACELOGD("TEXTURE: Total size of data required: %i", size);
  
      unsigned char *temp = RL_REALLOC(data, size);
  
      if (temp != NULL) data = temp;
      else TRACELOG(LOG_WARNING, "TEXTURE: Failed to allocate required mipmaps memory");
  
      width = baseWidth;
      height = baseHeight;
      size = (width*height*4);
  
      // Generate mipmaps
      // NOTE: Every mipmap data is stored after data
      Color *image = (Color *)RL_MALLOC(width*height*sizeof(Color));
      Color *mipmap = NULL;
      int offset = 0;
      int j = 0;
  
      for (int i = 0; i < size; i += 4)
      {
          image[j].r = data[i];
          image[j].g = data[i + 1];
          image[j].b = data[i + 2];
          image[j].a = data[i + 3];
          j++;
      }
  
      TRACELOGD("TEXTURE: Mipmap base size (%ix%i)", width, height);
  
      for (int mip = 1; mip < mipmapCount; mip++)
      {
          mipmap = GenNextMipmap(image, width, height);
  
          offset += (width*height*4); // Size of last mipmap
          j = 0;
  
          width /= 2;
          height /= 2;
          size = (width*height*4);    // Mipmap size to store after offset
  
          // Add mipmap to data
          for (int i = 0; i < size; i += 4)
          {
              data[offset + i] = mipmap[j].r;
              data[offset + i + 1] = mipmap[j].g;
              data[offset + i + 2] = mipmap[j].b;
              data[offset + i + 3] = mipmap[j].a;
              j++;
          }
  
          RL_FREE(image);
  
          image = mipmap;
          mipmap = NULL;
      }
  
      RL_FREE(mipmap);       // free mipmap data
  
      return mipmapCount;
  }
  
  // Manual mipmap generation (basic scaling algorithm)
  static Color *GenNextMipmap(Color *srcData, int srcWidth, int srcHeight)
  {
      int x2, y2;
      Color prow, pcol;
  
      int width = srcWidth/2;
      int height = srcHeight/2;
  
      Color *mipmap = (Color *)RL_MALLOC(width*height*sizeof(Color));
  
      // Scaling algorithm works perfectly (box-filter)
      for (int y = 0; y < height; y++)
      {
          y2 = 2*y;
  
          for (int x = 0; x < width; x++)
          {
              x2 = 2*x;
  
              prow.r = (srcData[y2*srcWidth + x2].r + srcData[y2*srcWidth + x2 + 1].r)/2;
              prow.g = (srcData[y2*srcWidth + x2].g + srcData[y2*srcWidth + x2 + 1].g)/2;
              prow.b = (srcData[y2*srcWidth + x2].b + srcData[y2*srcWidth + x2 + 1].b)/2;
              prow.a = (srcData[y2*srcWidth + x2].a + srcData[y2*srcWidth + x2 + 1].a)/2;
  
              pcol.r = (srcData[(y2+1)*srcWidth + x2].r + srcData[(y2+1)*srcWidth + x2 + 1].r)/2;
              pcol.g = (srcData[(y2+1)*srcWidth + x2].g + srcData[(y2+1)*srcWidth + x2 + 1].g)/2;
              pcol.b = (srcData[(y2+1)*srcWidth + x2].b + srcData[(y2+1)*srcWidth + x2 + 1].b)/2;
              pcol.a = (srcData[(y2+1)*srcWidth + x2].a + srcData[(y2+1)*srcWidth + x2 + 1].a)/2;
  
              mipmap[y*width + x].r = (prow.r + pcol.r)/2;
              mipmap[y*width + x].g = (prow.g + pcol.g)/2;
              mipmap[y*width + x].b = (prow.b + pcol.b)/2;
              mipmap[y*width + x].a = (prow.a + pcol.a)/2;
          }
      }
  
      TRACELOGD("TEXTURE: Mipmap generated successfully (%ix%i)", width, height);
  
      return mipmap;
  }
  #endif
  
  #if defined(RLGL_STANDALONE)
  // Load text data from file, returns a '\0' terminated string
  // NOTE: text chars array should be freed manually
  char *LoadFileText(const char *fileName)
  {
      char *text = NULL;
  
      if (fileName != NULL)
      {
          FILE *textFile = fopen(fileName, "rt");
  
          if (textFile != NULL)
          {
              // WARNING: When reading a file as 'text' file,
              // text mode causes carriage return-linefeed translation...
              // ...but using fseek() should return correct byte-offset
              fseek(textFile, 0, SEEK_END);
              int size = ftell(textFile);
              fseek(textFile, 0, SEEK_SET);
  
              if (size > 0)
              {
                  text = (char *)RL_MALLOC((size + 1)*sizeof(char));
                  int count = fread(text, sizeof(char), size, textFile);
  
                  // WARNING: \r\n is converted to \n on reading, so,
                  // read bytes count gets reduced by the number of lines
                  if (count < size) text = RL_REALLOC(text, count + 1);
  
                  // Zero-terminate the string
                  text[count] = '\0';
  
                  TRACELOG(LOG_INFO, "FILEIO: [%s] Text file loaded successfully", fileName);
              }
              else TRACELOG(LOG_WARNING, "FILEIO: [%s] Failed to read text file", fileName);
  
              fclose(textFile);
          }
          else TRACELOG(LOG_WARNING, "FILEIO: [%s] Failed to open text file", fileName);
      }
      else TRACELOG(LOG_WARNING, "FILEIO: File name provided is not valid");
  
      return text;
  }
  
  // Get pixel data size in bytes (image or texture)
  // NOTE: Size depends on pixel format
  int GetPixelDataSize(int width, int height, int format)
  {
      int dataSize = 0;       // Size in bytes
      int bpp = 0;            // Bits per pixel
  
      switch (format)
      {
          case UNCOMPRESSED_GRAYSCALE: bpp = 8; break;
          case UNCOMPRESSED_GRAY_ALPHA:
          case UNCOMPRESSED_R5G6B5:
          case UNCOMPRESSED_R5G5B5A1:
          case UNCOMPRESSED_R4G4B4A4: bpp = 16; break;
          case UNCOMPRESSED_R8G8B8A8: bpp = 32; break;
          case UNCOMPRESSED_R8G8B8: bpp = 24; break;
          case UNCOMPRESSED_R32: bpp = 32; break;
          case UNCOMPRESSED_R32G32B32: bpp = 32*3; break;
          case UNCOMPRESSED_R32G32B32A32: bpp = 32*4; break;
          case COMPRESSED_DXT1_RGB:
          case COMPRESSED_DXT1_RGBA:
          case COMPRESSED_ETC1_RGB:
          case COMPRESSED_ETC2_RGB:
          case COMPRESSED_PVRT_RGB:
          case COMPRESSED_PVRT_RGBA: bpp = 4; break;
          case COMPRESSED_DXT3_RGBA:
          case COMPRESSED_DXT5_RGBA:
          case COMPRESSED_ETC2_EAC_RGBA:
          case COMPRESSED_ASTC_4x4_RGBA: bpp = 8; break;
          case COMPRESSED_ASTC_8x8_RGBA: bpp = 2; break;
          default: break;
      }
  
      dataSize = width*height*bpp/8;  // Total data size in bytes
  
      // Most compressed formats works on 4x4 blocks,
      // if texture is smaller, minimum dataSize is 8 or 16
      if ((width < 4) && (height < 4))
      {
          if ((format >= COMPRESSED_DXT1_RGB) && (format < COMPRESSED_DXT3_RGBA)) dataSize = 8;
          else if ((format >= COMPRESSED_DXT3_RGBA) && (format < COMPRESSED_ASTC_8x8_RGBA)) dataSize = 16;
      }
  
      return dataSize;
  }
  #endif  // RLGL_STANDALONE
  
  #endif  // RLGL_IMPLEMENTATION
  