text: /***********************************************************************
      created:    Sun Jan 11 2009
      author:     Paul D Turner
  *************************************************************************/
  /***************************************************************************
   *   Copyright (C) 2004 - 2009 Paul D Turner & The CEGUI Development Team
   *
   *   Permission is hereby granted, free of charge, to any person obtaining
   *   a copy of this software and associated documentation files (the
   *   "Software"), to deal in the Software without restriction, including
   *   without limitation the rights to use, copy, modify, merge, publish,
   *   distribute, sublicense, and/or sell copies of the Software, and to
   *   permit persons to whom the Software is furnished to do so, subject to
   *   the following conditions:
   *
   *   The above copyright notice and this permission notice shall be
   *   included in all copies or substantial portions of the Software.
   *
   *   THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
   *   EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
   *   MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
   *   IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY CLAIM, DAMAGES OR
   *   OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
   *   ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
   *   OTHER DEALINGS IN THE SOFTWARE.
   ***************************************************************************/
  #ifndef _CEGUIOpenGLESRenderer_h_
  #define _CEGUIOpenGLESRenderer_h_
  
  #include "CEGUI/Base.h"
  #include "CEGUI/Renderer.h"
  #include "CEGUI/Sizef.h"
  #include "CEGUI/RendererModules/OpenGLES/GLES.h"
  #include <vector>
  #include <unordered_map>
  
  #if (defined( __WIN32__ ) || defined( _WIN32 )) && !defined(CEGUI_STATIC)
  #   ifdef CEGUIOPENGLESRENDERER_EXPORTS
  #       define OPENGLES_GUIRENDERER_API __declspec(dllexport)
  #   else
  #       define OPENGLES_GUIRENDERER_API __declspec(dllimport)
  #   endif
  #else
  #   define OPENGLES_GUIRENDERER_API
  #endif
  
  #if defined(_MSC_VER)
  #   pragma warning(push)
  #   pragma warning(disable : 4251)
  #endif
  
  
  // Start of CEGUI namespace section
  namespace CEGUI
  {
  class OpenGLESTexture;
  class OpenGLESTextureTarget;
  class OpenGLESGeometryBuffer;
  class OGLTextureTargetFactory;
  
  /*!
  \brief
      Renderer class to interface with OpenGLES
  */
  class OPENGLES_GUIRENDERER_API OpenGLESRenderer : public Renderer
  {
  public:
      //! Enumeration of valid texture target types.
      enum TextureTargetType
      {
          //! Automatically choose the best type available.
          TTT_AUTO,
          //! Use targets based on frame buffer objects if available, else none.
          TTT_FBO,
          //! Use targets based on pbuffer support if available, else none.
          TTT_PBUFFER,
          //! Disable texture targets.
          TTT_NONE
      };
  
      /*!
      \brief
          Convenience function that creates the required objects to initialise the
          CEGUI system.
  
          The created Renderer will use the current OpenGL ES viewport as it's
          default surface size.
  
          This will create and initialise the following objects for you:
          - CEGUI::OpenGLESRenderer
          - CEGUI::DefaultResourceProvider
          - CEGUI::System
  
      \param tt_type
          Specifies one of the TextureTargetType enumerated values indicating the
          desired TextureTarget type to be used.  Defaults to TTT_AUTO.
  
      \param abi
          This must be set to CEGUI_VERSION_ABI
  
      \return
          Reference to the CEGUI::OpenGLESRenderer object that was created.
      */
      static OpenGLESRenderer& bootstrapSystem(
                                  const TextureTargetType tt_type = TTT_AUTO,
                                  const int abi = CEGUI_VERSION_ABI);
  
      /*!
      \brief
          Convenience function that creates the required objects to initialise the
          CEGUI system.
  
          The created Renderer will use /a display_size as the default surface
          size.
  
          This will create and initialise the following objects for you:
          - CEGUI::OpenGLESRenderer
          - CEGUI::DefaultResourceProvider
          - CEGUI::System
  
      \param display_size
          Size object describing the initial display dimensions.
  
      \param tt_type
          Specifies one of the TextureTargetType enumerated values indicating the
          desired TextureTarget type to be used.  Defaults to TTT_AUTO.
  
      \param abi
          This must be set to CEGUI_VERSION_ABI
  
      \return
          Reference to the CEGUI::OpenGLESRenderer object that was created.
      */
      static OpenGLESRenderer& bootstrapSystem(
                                  const Sizef& display_size,
                                  const TextureTargetType tt_type = TTT_AUTO,
                                  const int abi = CEGUI_VERSION_ABI);
  
      /*!
      \brief
          Convenience function to cleanup the CEGUI system and related objects
          that were created by calling the bootstrapSystem function.
  
          This function will destroy the following objects for you:
          - CEGUI::System
          - CEGUI::DefaultResourceProvider
          - CEGUI::OpenGLRenderer
  
      \note
          If you did not initialise CEGUI by calling the bootstrapSystem function,
          you should \e not call this, but rather delete any objects you created
          manually.
      */
      static void destroySystem();
  
      /*!
      \brief
          Create an OpenGLESRenderer object.
  
      \param tt_type
          Specifies one of the TextureTargetType enumerated values indicating the
          desired TextureTarget type to be used.
  
      \param abi
          This must be set to CEGUI_VERSION_ABI
      */
      static OpenGLESRenderer& create(const TextureTargetType tt_type = TTT_AUTO,
                                      const int abi = CEGUI_VERSION_ABI);
  
      /*!
      \brief
          Create an OpenGLESRenderer object.
  
      \param display_size
          Size object describing the initial display resolution.
  
      \param tt_type
          Specifies one of the TextureTargetType enumerated values indicating the
          desired TextureTarget type to be used.
  
      \param abi
          This must be set to CEGUI_VERSION_ABI
      */
      static OpenGLESRenderer& create(const Sizef& display_size,
                                      const TextureTargetType tt_type = TTT_AUTO,
                                      const int abi = CEGUI_VERSION_ABI);
  
      /*!
      \brief
          Destroy an OpenGLESRenderer object.
  
      \param renderer
          The OpenGLESRenderer object to be destroyed.
      */
      static void destroy(OpenGLESRenderer& renderer);
  
  	/*!
      \brief
          Check if provided extension is supported on current platform.
  		Khronos reference implementation.
  
      \param extension
          Provided extension string identification
      */
  	static bool isGLExtensionSupported( const char* extension );
  
      // implement Renderer interface
      virtual RenderTarget& getDefaultRenderTarget();
      virtual GeometryBuffer& createGeometryBuffer();
      virtual void destroyGeometryBuffer(const GeometryBuffer& buffer);
      virtual void destroyAllGeometryBuffers();
      virtual TextureTarget* createTextureTarget(bool addStencilBuffer);
      virtual void destroyTextureTarget(TextureTarget* target);
      virtual void destroyAllTextureTargets();
      virtual Texture& createTexture(const String& name);
      virtual Texture& createTexture(const String& name,
                             const String& filename,
                             const String& resourceGroup);
      virtual Texture& createTexture(const String& name, const Sizef& size);
      virtual void destroyTexture(Texture& texture);
      virtual void destroyTexture(const String& name);
      virtual void destroyAllTextures();
      virtual Texture& getTexture(const String& name) const;
      virtual bool isTextureDefined(const String& name) const;
      virtual void beginRendering();
      virtual void endRendering();
      virtual void setDisplaySize(const Sizef& sz);
      virtual const Sizef& getDisplaySize() const;
      virtual const glm::vec2& getDisplayDPI() const;
      virtual unsigned int getMaxTextureSize() const;
      virtual const String& getIdentifierString() const;
      virtual bool isTexCoordSystemFlipped() const;
  
      /*!
      \brief
          Create a texture that uses an existing OpenGLES texture with the specified
          size.  Note that it is your responsibility to ensure that the OpenGLES
          texture is valid and that the specified size is accurate.
  
      \param sz
          Size object that describes the pixel size of the OpenGLES texture
          identified by \a tex.
  
      \return
          Texture object that wraps the OpenGLES texture \a tex, and whose size is
          specified to be \a sz.
      */
      Texture& createTexture(const String& name, GLuint tex, const Sizef& sz);
  
      /*!
      \brief
          Tells the renderer to initialise some extra states beyond what it
          directly needs itself for CEGUI.
  
          This option is useful in cases where you've made changes to the default
          OpenGLES state and do not want to save/restore those between CEGUI
          rendering calls.  Note that this option will not deal with every
          possible state or extension - if you want a state added here, make a
          request and we'll consider it ;)
      */
      void enableExtraStateSettings(bool setting);
  
      /*!
      \brief
          Grabs all the loaded textures from Texture RAM and stores them in a
          local data buffer.  This function invalidates all textures, and
          restoreTextures must be called before any CEGUI rendering is done for
          predictable results.
      */
      void grabTextures();
  
      /*!
      \brief
          Restores all the loaded textures from the local data buffers previously
          created by 'grabTextures'
      */
      void restoreTextures();
  
      /*!
      \brief
          Helper to return a valid texture size according to reported OpenGLES
          capabilities.
  
      \param sz
          Size object containing input size.
  
      \return
          Size object containing - possibly different - output size.
      */
      Sizef getAdjustedTextureSize(const Sizef& sz) const;
  
      /*!
      \brief
          Utility function that will return \a f if it's a power of two, or the
          next power of two up from \a f if it's not.
      */
      static float getNextPOTSize(const float f);
  
  private:
      /*!
      \brief
          Constructor for OpenGLES Renderer objects
  
      \param tt_type
          Specifies one of the TextureTargetType enumerated values indicating the
          desired TextureTarget type to be used.
      */
      OpenGLESRenderer(const TextureTargetType tt_type);
  
      /*!
      \brief
          Constructor for OpenGLES Renderer objects.
  
      \param display_size
          Size object describing the initial display resolution.
  
      \param tt_type
          Specifies one of the TextureTargetType enumerated values indicating the
          desired TextureTarget type to be used.
      */
      OpenGLESRenderer(const Sizef& display_size, const TextureTargetType tt_type);
  
      /*!
      \brief
          Destructor for OpenGLESRenderer objects
      */
      virtual ~OpenGLESRenderer();
  
      //! init the extra GL states enabled via enableExtraStateSettings
      void setupExtraStates();
  
      //! cleanup the extra GL states enabled via enableExtraStateSettings
      void cleanupExtraStates();
  
      //! initialise OGLTextureTargetFactory that will generate TextureTargets
      void initialiseTextureTargetFactory(const TextureTargetType tt_type);
  
      //! Log about the fact we destroyed a named texture.
      void logTextureDestruction(const String& name);
  
  	//! Replacement for glPushAttrib =(
  	struct RenderStates
  	{
  		GLboolean glScissorTest;
  		GLboolean texturing;
  		GLboolean blend;
  		GLint arrayBuffer;
  		GLint texture;
  		GLint texEnvParam;
  	} glPreRenderStates;
  
      //! String holding the renderer identification text.
      static String d_rendererID;
      //! What the renderer considers to be the current display size.
      Sizef d_displaySize;
      //! What the renderer considers to be the current display DPI resolution.
      glm::vec2 d_displayDPI;
      //! The default RenderTarget
      RenderTarget* d_defaultTarget;
      //! container type used to hold TextureTargets we create.
      typedef std::vector<TextureTarget*> TextureTargetList;
      //! Container used to track texture targets.
      TextureTargetList d_textureTargets;
      //! container type used to hold GeometryBuffers we create.
      typedef std::vector<OpenGLESGeometryBuffer*> GeometryBufferList;
      //! Container used to track geometry buffers.
      GeometryBufferList d_geometryBuffers;
      //! container type used to hold Textures we create.
      typedef std::unordered_map<String, OpenGLESTexture*> TextureMap;
      //! Container used to track textures.
      TextureMap d_textures;
      //! What the renderer thinks the max texture size is.
      unsigned int d_maxTextureSize;
      //! option of whether to initialise extra states that may not be at default
      bool d_initExtraStates;
      //! pointer to a helper that creates TextureTargets supported by the system.
      OGLTextureTargetFactory* d_textureTargetFactory;
    };
  
  } // End of  CEGUI namespace section
  
  #if defined(_MSC_VER)
  #   pragma warning(pop)
  #endif
  
  #endif // end of guard _CEGUIOpenGLESRenderer_h_
  
  