text: /*
   * Copyright (c) 2021, Jesse Buhagiar <jooster669@gmail.com>
   * Copyright (c) 2021, Stephan Unverwerth <s.unverwerth@serenityos.org>
   * Copyright (c) 2022, Jelle Raaijmakers <jelle@gmta.nl>
   *
   * SPDX-License-Identifier: BSD-2-Clause
   */
  
  #include <AK/Assertions.h>
  #include <AK/Debug.h>
  #include <AK/Format.h>
  #include <AK/QuickSort.h>
  #include <AK/StringBuilder.h>
  #include <AK/TemporaryChange.h>
  #include <AK/Variant.h>
  #include <AK/Vector.h>
  #include <LibGL/GLContext.h>
  #include <LibGfx/Bitmap.h>
  #include <LibGfx/Painter.h>
  #include <LibGfx/Vector4.h>
  #include <LibSoftGPU/Device.h>
  #include <LibSoftGPU/Enums.h>
  #include <LibSoftGPU/ImageFormat.h>
  
  __attribute__((visibility("hidden"))) GL::GLContext* g_gl_context;
  
  namespace GL {
  
  static constexpr size_t MODELVIEW_MATRIX_STACK_LIMIT = 64;
  static constexpr size_t PROJECTION_MATRIX_STACK_LIMIT = 8;
  static constexpr size_t TEXTURE_MATRIX_STACK_LIMIT = 8;
  
  #define APPEND_TO_CALL_LIST_AND_RETURN_IF_NEEDED(name, ...) \
      if (should_append_to_listing()) {                       \
          append_to_listing<&GLContext::name>(__VA_ARGS__);   \
          if (!should_execute_after_appending_to_listing())   \
              return;                                         \
      }
  
  #define APPEND_TO_CALL_LIST_WITH_ARG_AND_RETURN_IF_NEEDED(name, arg) \
      if (should_append_to_listing()) {                                \
          auto ptr = store_in_listing(arg);                            \
          append_to_listing<&GLContext::name>(*ptr);                   \
          if (!should_execute_after_appending_to_listing())            \
              return;                                                  \
      }
  
  #define RETURN_WITH_ERROR_IF(condition, error)                    \
      if (condition) {                                              \
          dbgln_if(GL_DEBUG, "{}(): error {:#x}", __func__, error); \
          if (m_error == GL_NO_ERROR)                               \
              m_error = error;                                      \
          return;                                                   \
      }
  
  #define RETURN_VALUE_WITH_ERROR_IF(condition, error, return_value) \
      if (condition) {                                               \
          dbgln_if(GL_DEBUG, "{}(): error {:#x}", __func__, error);  \
          if (m_error == GL_NO_ERROR)                                \
              m_error = error;                                       \
          return return_value;                                       \
      }
  
  GLContext::GLContext(Gfx::Bitmap& frontbuffer)
      : m_viewport(frontbuffer.rect())
      , m_frontbuffer(frontbuffer)
      , m_rasterizer(frontbuffer.size())
      , m_device_info(m_rasterizer.info())
  {
      m_texture_units.resize(m_device_info.num_texture_units);
      m_active_texture_unit = &m_texture_units[0];
  
      // All texture units are initialized with default textures for all targets; these
      // can be referenced later on with texture name 0 in operations like glBindTexture().
      auto default_texture_2d = adopt_ref(*new Texture2D());
      m_default_textures.set(GL_TEXTURE_2D, default_texture_2d);
      for (auto& texture_unit : m_texture_units)
          texture_unit.set_texture_2d_target_texture(default_texture_2d);
  
      // Query the number lights from the device and set set up their state
      // locally in the GL
      m_light_states.resize(m_device_info.num_lights);
  
      // Set-up light0's state, as it has a different default state
      // to the other lights, as per the OpenGL 1.5 spec
      auto& light0 = m_light_states.at(0);
      light0.diffuse_intensity = { 1.0f, 1.0f, 1.0f, 1.0f };
      light0.specular_intensity = { 1.0f, 1.0f, 1.0f, 1.0f };
      m_light_state_is_dirty = true;
  
      m_client_side_texture_coord_array_enabled.resize(m_device_info.num_texture_units);
      m_client_tex_coord_pointer.resize(m_device_info.num_texture_units);
      m_current_vertex_tex_coord.resize(m_device_info.num_texture_units);
      for (auto& tex_coord : m_current_vertex_tex_coord)
          tex_coord = { 0.0f, 0.0f, 0.0f, 1.0f };
  
      // Initialize the texture coordinate generation coefficients
      // Indices 0,1,2,3 refer to the S,T,R and Q coordinate of the respective texture
      // coordinate generation config.
      m_texture_coordinate_generation.resize(m_device_info.num_texture_units);
      for (auto& texture_coordinate_generation : m_texture_coordinate_generation) {
          texture_coordinate_generation[0].object_plane_coefficients = { 1.0f, 0.0f, 0.0f, 0.0f };
          texture_coordinate_generation[0].eye_plane_coefficients = { 1.0f, 0.0f, 0.0f, 0.0f };
          texture_coordinate_generation[1].object_plane_coefficients = { 0.0f, 1.0f, 0.0f, 0.0f };
          texture_coordinate_generation[1].eye_plane_coefficients = { 0.0f, 1.0f, 0.0f, 0.0f };
          texture_coordinate_generation[2].object_plane_coefficients = { 0.0f, 0.0f, 0.0f, 0.0f };
          texture_coordinate_generation[2].eye_plane_coefficients = { 0.0f, 0.0f, 0.0f, 0.0f };
          texture_coordinate_generation[3].object_plane_coefficients = { 0.0f, 0.0f, 0.0f, 0.0f };
          texture_coordinate_generation[3].eye_plane_coefficients = { 0.0f, 0.0f, 0.0f, 0.0f };
      }
  
      build_extension_string();
  }
  
  GLContext::~GLContext()
  {
      dbgln_if(GL_DEBUG, "GLContext::~GLContext() {:p}", this);
      if (g_gl_context == this)
          make_context_current(nullptr);
  }
  
  Optional<ContextParameter> GLContext::get_context_parameter(GLenum name)
  {
      switch (name) {
      case GL_ALPHA_BITS:
          return ContextParameter { .type = GL_INT, .value = { .integer_value = sizeof(float) * 8 } };
      case GL_ALPHA_TEST:
          return ContextParameter { .type = GL_BOOL, .is_capability = true, .value = { .boolean_value = m_alpha_test_enabled } };
      case GL_BLEND:
          return ContextParameter { .type = GL_BOOL, .is_capability = true, .value = { .boolean_value = m_blend_enabled } };
      case GL_BLEND_DST_ALPHA:
          return ContextParameter { .type = GL_INT, .value = { .integer_value = static_cast<GLint>(m_blend_destination_factor) } };
      case GL_BLEND_SRC_ALPHA:
          return ContextParameter { .type = GL_INT, .value = { .integer_value = static_cast<GLint>(m_blend_source_factor) } };
      case GL_BLUE_BITS:
          return ContextParameter { .type = GL_INT, .value = { .integer_value = sizeof(float) * 8 } };
      case GL_COLOR_MATERIAL:
          return ContextParameter { .type = GL_BOOL, .is_capability = true, .value = { .boolean_value = m_color_material_enabled } };
      case GL_COLOR_MATERIAL_FACE:
          return ContextParameter { .type = GL_INT, .value = { .integer_value = static_cast<GLint>(m_color_material_face) } };
      case GL_COLOR_MATERIAL_MODE:
          return ContextParameter { .type = GL_INT, .value = { .integer_value = static_cast<GLint>(m_color_material_mode) } };
      case GL_CULL_FACE:
          return ContextParameter { .type = GL_BOOL, .is_capability = true, .value = { .boolean_value = m_cull_faces } };
      case GL_DEPTH_BITS:
          return ContextParameter { .type = GL_INT, .value = { .integer_value = sizeof(float) * 8 } };
      case GL_DEPTH_TEST:
          return ContextParameter { .type = GL_BOOL, .is_capability = true, .value = { .boolean_value = m_depth_test_enabled } };
      case GL_DITHER:
          return ContextParameter { .type = GL_BOOL, .is_capability = true, .value = { .boolean_value = m_dither_enabled } };
      case GL_DOUBLEBUFFER:
          return ContextParameter { .type = GL_BOOL, .value = { .boolean_value = true } };
      case GL_FOG: {
          auto fog_enabled = m_rasterizer.options().fog_enabled;
          return ContextParameter { .type = GL_BOOL, .is_capability = true, .value = { .boolean_value = fog_enabled } };
      }
      case GL_GREEN_BITS:
          return ContextParameter { .type = GL_INT, .value = { .integer_value = sizeof(float) * 8 } };
      case GL_LIGHTING:
          return ContextParameter { .type = GL_BOOL, .is_capability = true, .value = { .boolean_value = m_lighting_enabled } };
      case GL_MAX_LIGHTS:
          return ContextParameter { .type = GL_INT, .value = { .integer_value = static_cast<GLint>(m_device_info.num_lights) } };
      case GL_MAX_MODELVIEW_STACK_DEPTH:
          return ContextParameter { .type = GL_INT, .value = { .integer_value = MODELVIEW_MATRIX_STACK_LIMIT } };
      case GL_MAX_PROJECTION_STACK_DEPTH:
          return ContextParameter { .type = GL_INT, .value = { .integer_value = PROJECTION_MATRIX_STACK_LIMIT } };
      case GL_MAX_TEXTURE_SIZE:
          return ContextParameter { .type = GL_INT, .value = { .integer_value = 4096 } };
      case GL_MAX_TEXTURE_STACK_DEPTH:
          return ContextParameter { .type = GL_INT, .value = { .integer_value = TEXTURE_MATRIX_STACK_LIMIT } };
      case GL_MAX_TEXTURE_UNITS:
          return ContextParameter { .type = GL_INT, .value = { .integer_value = static_cast<GLint>(m_texture_units.size()) } };
      case GL_NORMALIZE:
          return ContextParameter { .type = GL_BOOL, .is_capability = true, .value = { .boolean_value = m_normalize } };
      case GL_PACK_ALIGNMENT:
          return ContextParameter { .type = GL_INT, .value = { .integer_value = m_pack_alignment } };
      case GL_PACK_IMAGE_HEIGHT:
          return ContextParameter { .type = GL_BOOL, .value = { .integer_value = 0 } };
      case GL_PACK_LSB_FIRST:
          return ContextParameter { .type = GL_BOOL, .value = { .boolean_value = false } };
      case GL_PACK_ROW_LENGTH:
          return ContextParameter { .type = GL_INT, .value = { .integer_value = 0 } };
      case GL_PACK_SKIP_PIXELS:
          return ContextParameter { .type = GL_INT, .value = { .integer_value = 0 } };
      case GL_PACK_SKIP_ROWS:
          return ContextParameter { .type = GL_INT, .value = { .integer_value = 0 } };
      case GL_PACK_SWAP_BYTES:
          return ContextParameter { .type = GL_BOOL, .value = { .boolean_value = false } };
      case GL_POLYGON_OFFSET_FILL:
          return ContextParameter { .type = GL_BOOL, .is_capability = true, .value = { .boolean_value = m_depth_offset_enabled } };
      case GL_RED_BITS:
          return ContextParameter { .type = GL_INT, .value = { .integer_value = sizeof(float) * 8 } };
      case GL_SCISSOR_BOX: {
          auto scissor_box = m_rasterizer.options().scissor_box;
          return ContextParameter {
              .type = GL_INT,
              .count = 4,
              .value = {
                  .integer_list = {
                      scissor_box.x(),
                      scissor_box.y(),
                      scissor_box.width(),
                      scissor_box.height(),
                  } }
          };
      } break;
      case GL_SCISSOR_TEST: {
          auto scissor_enabled = m_rasterizer.options().scissor_enabled;
          return ContextParameter { .type = GL_BOOL, .is_capability = true, .value = { .boolean_value = scissor_enabled } };
      }
      case GL_STENCIL_BITS:
          return ContextParameter { .type = GL_INT, .value = { .integer_value = m_device_info.stencil_bits } };
      case GL_STENCIL_CLEAR_VALUE:
          return ContextParameter { .type = GL_INT, .value = { .integer_value = m_clear_stencil } };
      case GL_STENCIL_TEST:
          return ContextParameter { .type = GL_BOOL, .is_capability = true, .value = { .boolean_value = m_stencil_test_enabled } };
      case GL_TEXTURE_1D:
          return ContextParameter { .type = GL_BOOL, .value = { .boolean_value = m_active_texture_unit->texture_1d_enabled() } };
      case GL_TEXTURE_2D:
          return ContextParameter { .type = GL_BOOL, .value = { .boolean_value = m_active_texture_unit->texture_2d_enabled() } };
      case GL_TEXTURE_3D:
          return ContextParameter { .type = GL_BOOL, .value = { .boolean_value = m_active_texture_unit->texture_3d_enabled() } };
      case GL_TEXTURE_CUBE_MAP:
          return ContextParameter { .type = GL_BOOL, .value = { .boolean_value = m_active_texture_unit->texture_cube_map_enabled() } };
      case GL_TEXTURE_GEN_Q:
      case GL_TEXTURE_GEN_R:
      case GL_TEXTURE_GEN_S:
      case GL_TEXTURE_GEN_T: {
          auto generation_enabled = texture_coordinate_generation(m_active_texture_unit_index, name).enabled;
          return ContextParameter { .type = GL_BOOL, .is_capability = true, .value = { .boolean_value = generation_enabled } };
      }
      case GL_UNPACK_ALIGNMENT:
          return ContextParameter { .type = GL_INT, .value = { .integer_value = m_unpack_alignment } };
      case GL_UNPACK_IMAGE_HEIGHT:
          return ContextParameter { .type = GL_BOOL, .value = { .integer_value = 0 } };
      case GL_UNPACK_LSB_FIRST:
          return ContextParameter { .type = GL_BOOL, .value = { .boolean_value = false } };
      case GL_UNPACK_ROW_LENGTH:
          return ContextParameter { .type = GL_INT, .value = { .integer_value = m_unpack_row_length } };
      case GL_UNPACK_SKIP_PIXELS:
          return ContextParameter { .type = GL_INT, .value = { .integer_value = 0 } };
      case GL_UNPACK_SKIP_ROWS:
          return ContextParameter { .type = GL_INT, .value = { .integer_value = 0 } };
      case GL_UNPACK_SWAP_BYTES:
          return ContextParameter { .type = GL_BOOL, .value = { .boolean_value = false } };
      case GL_VIEWPORT:
          return ContextParameter {
              .type = GL_INT,
              .count = 4,
              .value = {
                  .integer_list = {
                      m_viewport.x(),
                      m_viewport.y(),
                      m_viewport.width(),
                      m_viewport.height(),
                  } }
          };
      default:
          dbgln_if(GL_DEBUG, "get_context_parameter({:#x}): unknown context parameter", name);
          return {};
      }
  }
  
  void GLContext::gl_begin(GLenum mode)
  {
      APPEND_TO_CALL_LIST_AND_RETURN_IF_NEEDED(gl_begin, mode);
  
      RETURN_WITH_ERROR_IF(m_in_draw_state, GL_INVALID_OPERATION);
      RETURN_WITH_ERROR_IF(mode > GL_POLYGON, GL_INVALID_ENUM);
  
      m_current_draw_mode = mode;
      m_in_draw_state = true; // Certain commands will now generate an error
  }
  
  void GLContext::gl_clear(GLbitfield mask)
  {
      APPEND_TO_CALL_LIST_AND_RETURN_IF_NEEDED(gl_clear, mask);
  
      RETURN_WITH_ERROR_IF(m_in_draw_state, GL_INVALID_OPERATION);
      RETURN_WITH_ERROR_IF(mask & ~(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT | GL_STENCIL_BUFFER_BIT), GL_INVALID_ENUM);
  
      if (mask & GL_COLOR_BUFFER_BIT)
          m_rasterizer.clear_color(m_clear_color);
  
      if (mask & GL_DEPTH_BUFFER_BIT)
          m_rasterizer.clear_depth(m_clear_depth);
  
      if (mask & GL_STENCIL_BUFFER_BIT)
          m_rasterizer.clear_stencil(m_clear_stencil);
  }
  
  void GLContext::gl_clear_color(GLclampf red, GLclampf green, GLclampf blue, GLclampf alpha)
  {
      APPEND_TO_CALL_LIST_AND_RETURN_IF_NEEDED(gl_clear_color, red, green, blue, alpha);
  
      RETURN_WITH_ERROR_IF(m_in_draw_state, GL_INVALID_OPERATION);
  
      m_clear_color = { red, green, blue, alpha };
      m_clear_color.clamp(0.f, 1.f);
  }
  
  void GLContext::gl_clear_depth(GLdouble depth)
  {
      APPEND_TO_CALL_LIST_AND_RETURN_IF_NEEDED(gl_clear_depth, depth);
  
      RETURN_WITH_ERROR_IF(m_in_draw_state, GL_INVALID_OPERATION);
  
      m_clear_depth = clamp(static_cast<float>(depth), 0.f, 1.f);
  }
  
  void GLContext::gl_clear_stencil(GLint s)
  {
      APPEND_TO_CALL_LIST_AND_RETURN_IF_NEEDED(gl_clear_stencil, s);
  
      RETURN_WITH_ERROR_IF(m_in_draw_state, GL_INVALID_OPERATION);
  
      m_clear_stencil = static_cast<u8>(s & ((1 << m_device_info.stencil_bits) - 1));
  }
  
  void GLContext::gl_color(GLdouble r, GLdouble g, GLdouble b, GLdouble a)
  {
      APPEND_TO_CALL_LIST_AND_RETURN_IF_NEEDED(gl_color, r, g, b, a);
  
      m_current_vertex_color = {
          static_cast<float>(r),
          static_cast<float>(g),
          static_cast<float>(b),
          static_cast<float>(a),
      };
  }
  
  void GLContext::gl_end()
  {
      APPEND_TO_CALL_LIST_AND_RETURN_IF_NEEDED(gl_end);
  
      // Make sure we had a `glBegin` before this call...
      RETURN_WITH_ERROR_IF(!m_in_draw_state, GL_INVALID_OPERATION);
  
      m_in_draw_state = false;
  
      // FIXME: Add support for the remaining primitive types.
      if (m_current_draw_mode != GL_TRIANGLES
          && m_current_draw_mode != GL_TRIANGLE_FAN
          && m_current_draw_mode != GL_TRIANGLE_STRIP
          && m_current_draw_mode != GL_QUADS
          && m_current_draw_mode != GL_QUAD_STRIP
          && m_current_draw_mode != GL_POLYGON) {
  
          m_vertex_list.clear_with_capacity();
          dbgln_if(GL_DEBUG, "gl_end(): draw mode {:#x} unsupported", m_current_draw_mode);
          RETURN_WITH_ERROR_IF(true, GL_INVALID_ENUM);
      }
  
      Vector<size_t, 32> enabled_texture_units;
      for (size_t i = 0; i < m_texture_units.size(); ++i) {
          if (m_texture_units[i].texture_2d_enabled())
              enabled_texture_units.append(i);
      }
  
      sync_device_config();
  
      SoftGPU::PrimitiveType primitive_type;
      switch (m_current_draw_mode) {
      case GL_TRIANGLES:
          primitive_type = SoftGPU::PrimitiveType::Triangles;
          break;
      case GL_TRIANGLE_STRIP:
      case GL_QUAD_STRIP:
          primitive_type = SoftGPU::PrimitiveType::TriangleStrip;
          break;
      case GL_TRIANGLE_FAN:
      case GL_POLYGON:
          primitive_type = SoftGPU::PrimitiveType::TriangleFan;
          break;
      case GL_QUADS:
          primitive_type = SoftGPU::PrimitiveType::Quads;
          break;
      default:
          VERIFY_NOT_REACHED();
      }
  
      // Set up normals transform by taking the upper left 3x3 elements from the model view matrix
      // See section 2.11.3 of the OpenGL 1.5 spec
      auto const& mv_elements = m_model_view_matrix.elements();
      auto const model_view_transposed = FloatMatrix3x3(
          mv_elements[0][0], mv_elements[1][0], mv_elements[2][0],
          mv_elements[0][1], mv_elements[1][1], mv_elements[2][1],
          mv_elements[0][2], mv_elements[1][2], mv_elements[2][2]);
      auto const& normal_transform = model_view_transposed.inverse();
  
      m_rasterizer.draw_primitives(primitive_type, m_model_view_matrix, normal_transform, m_projection_matrix, m_texture_matrix, m_vertex_list, enabled_texture_units);
  
      m_vertex_list.clear_with_capacity();
  }
  
  void GLContext::gl_frustum(GLdouble left, GLdouble right, GLdouble bottom, GLdouble top, GLdouble near_val, GLdouble far_val)
  {
      APPEND_TO_CALL_LIST_AND_RETURN_IF_NEEDED(gl_frustum, left, right, bottom, top, near_val, far_val);
  
      RETURN_WITH_ERROR_IF(m_in_draw_state, GL_INVALID_OPERATION);
      RETURN_WITH_ERROR_IF(near_val < 0 || far_val < 0, GL_INVALID_VALUE);
      RETURN_WITH_ERROR_IF(left == right || bottom == top || near_val == far_val, GL_INVALID_VALUE);
  
      // Let's do some math!
      auto a = static_cast<float>((right + left) / (right - left));
      auto b = static_cast<float>((top + bottom) / (top - bottom));
      auto c = static_cast<float>(-((far_val + near_val) / (far_val - near_val)));
      auto d = static_cast<float>(-((2 * far_val * near_val) / (far_val - near_val)));
  
      FloatMatrix4x4 frustum {
          static_cast<float>(2 * near_val / (right - left)), 0, a, 0,
          0, static_cast<float>(2 * near_val / (top - bottom)), b, 0,
          0, 0, c, d,
          0, 0, -1, 0
      };
  
      if (m_current_matrix_mode == GL_PROJECTION)
          m_projection_matrix = m_projection_matrix * frustum;
      else if (m_current_matrix_mode == GL_MODELVIEW)
          m_model_view_matrix = m_model_view_matrix * frustum;
      else if (m_current_matrix_mode == GL_TEXTURE)
          m_texture_matrix = m_texture_matrix * frustum;
      else
          VERIFY_NOT_REACHED();
  }
  
  void GLContext::gl_ortho(GLdouble left, GLdouble right, GLdouble bottom, GLdouble top, GLdouble near_val, GLdouble far_val)
  {
      APPEND_TO_CALL_LIST_AND_RETURN_IF_NEEDED(gl_ortho, left, right, bottom, top, near_val, far_val);
  
      RETURN_WITH_ERROR_IF(m_in_draw_state, GL_INVALID_OPERATION);
      RETURN_WITH_ERROR_IF(left == right || bottom == top || near_val == far_val, GL_INVALID_VALUE);
  
      auto rl = right - left;
      auto tb = top - bottom;
      auto fn = far_val - near_val;
      auto tx = -(right + left) / rl;
      auto ty = -(top + bottom) / tb;
      auto tz = -(far_val + near_val) / fn;
  
      FloatMatrix4x4 projection {
          static_cast<float>(2 / rl), 0, 0, static_cast<float>(tx),
          0, static_cast<float>(2 / tb), 0, static_cast<float>(ty),
          0, 0, static_cast<float>(-2 / fn), static_cast<float>(tz),
          0, 0, 0, 1
      };
  
      if (m_current_matrix_mode == GL_PROJECTION)
          m_projection_matrix = m_projection_matrix * projection;
      else if (m_current_matrix_mode == GL_MODELVIEW)
          m_model_view_matrix = m_model_view_matrix * projection;
      else if (m_current_matrix_mode == GL_TEXTURE)
          m_texture_matrix = m_texture_matrix * projection;
      else
          VERIFY_NOT_REACHED();
  }
  
  GLenum GLContext::gl_get_error()
  {
      if (m_in_draw_state)
          return GL_INVALID_OPERATION;
  
      auto last_error = m_error;
      m_error = GL_NO_ERROR;
      return last_error;
  }
  
  GLubyte* GLContext::gl_get_string(GLenum name)
  {
      RETURN_VALUE_WITH_ERROR_IF(m_in_draw_state, GL_INVALID_OPERATION, nullptr);
  
      switch (name) {
      case GL_VENDOR:
          return reinterpret_cast<GLubyte*>(const_cast<char*>(m_device_info.vendor_name.characters()));
      case GL_RENDERER:
          return reinterpret_cast<GLubyte*>(const_cast<char*>(m_device_info.device_name.characters()));
      case GL_VERSION:
          return reinterpret_cast<GLubyte*>(const_cast<char*>("1.5"));
      case GL_EXTENSIONS:
          return reinterpret_cast<GLubyte*>(const_cast<char*>(m_extensions.characters()));
      case GL_SHADING_LANGUAGE_VERSION:
          return reinterpret_cast<GLubyte*>(const_cast<char*>("0.0"));
      default:
          dbgln_if(GL_DEBUG, "gl_get_string({:#x}): unknown name", name);
          break;
      }
  
      RETURN_VALUE_WITH_ERROR_IF(true, GL_INVALID_ENUM, nullptr);
  }
  
  void GLContext::gl_load_identity()
  {
      APPEND_TO_CALL_LIST_AND_RETURN_IF_NEEDED(gl_load_identity);
  
      RETURN_WITH_ERROR_IF(m_in_draw_state, GL_INVALID_OPERATION);
  
      if (m_current_matrix_mode == GL_PROJECTION)
          m_projection_matrix = FloatMatrix4x4::identity();
      else if (m_current_matrix_mode == GL_MODELVIEW)
          m_model_view_matrix = FloatMatrix4x4::identity();
      else if (m_current_matrix_mode == GL_TEXTURE)
          m_texture_matrix = FloatMatrix4x4::identity();
      else
          VERIFY_NOT_REACHED();
  }
  
  void GLContext::gl_load_matrix(const FloatMatrix4x4& matrix)
  {
      APPEND_TO_CALL_LIST_WITH_ARG_AND_RETURN_IF_NEEDED(gl_load_matrix, matrix);
  
      RETURN_WITH_ERROR_IF(m_in_draw_state, GL_INVALID_OPERATION);
  
      if (m_current_matrix_mode == GL_PROJECTION)
          m_projection_matrix = matrix;
      else if (m_current_matrix_mode == GL_MODELVIEW)
          m_model_view_matrix = matrix;
      else if (m_current_matrix_mode == GL_TEXTURE)
          m_texture_matrix = matrix;
      else
          VERIFY_NOT_REACHED();
  }
  
  void GLContext::gl_matrix_mode(GLenum mode)
  {
      APPEND_TO_CALL_LIST_AND_RETURN_IF_NEEDED(gl_matrix_mode, mode);
  
      RETURN_WITH_ERROR_IF(m_in_draw_state, GL_INVALID_OPERATION);
      RETURN_WITH_ERROR_IF(mode < GL_MODELVIEW || mode > GL_TEXTURE, GL_INVALID_ENUM);
  
      m_current_matrix_mode = mode;
  }
  
  void GLContext::gl_push_matrix()
  {
      APPEND_TO_CALL_LIST_AND_RETURN_IF_NEEDED(gl_push_matrix);
  
      RETURN_WITH_ERROR_IF(m_in_draw_state, GL_INVALID_OPERATION);
  
      switch (m_current_matrix_mode) {
      case GL_PROJECTION:
          RETURN_WITH_ERROR_IF(m_projection_matrix_stack.size() >= PROJECTION_MATRIX_STACK_LIMIT, GL_STACK_OVERFLOW);
          m_projection_matrix_stack.append(m_projection_matrix);
          break;
      case GL_MODELVIEW:
          RETURN_WITH_ERROR_IF(m_model_view_matrix_stack.size() >= MODELVIEW_MATRIX_STACK_LIMIT, GL_STACK_OVERFLOW);
          m_model_view_matrix_stack.append(m_model_view_matrix);
          break;
      case GL_TEXTURE:
          RETURN_WITH_ERROR_IF(m_texture_matrix_stack.size() >= TEXTURE_MATRIX_STACK_LIMIT, GL_STACK_OVERFLOW);
          m_texture_matrix_stack.append(m_texture_matrix);
          break;
      default:
          VERIFY_NOT_REACHED();
      }
  }
  
  void GLContext::gl_pop_matrix()
  {
      APPEND_TO_CALL_LIST_AND_RETURN_IF_NEEDED(gl_pop_matrix);
  
      RETURN_WITH_ERROR_IF(m_in_draw_state, GL_INVALID_OPERATION);
  
      switch (m_current_matrix_mode) {
      case GL_PROJECTION:
          RETURN_WITH_ERROR_IF(m_projection_matrix_stack.size() == 0, GL_STACK_UNDERFLOW);
          m_projection_matrix = m_projection_matrix_stack.take_last();
          break;
      case GL_MODELVIEW:
          RETURN_WITH_ERROR_IF(m_model_view_matrix_stack.size() == 0, GL_STACK_UNDERFLOW);
          m_model_view_matrix = m_model_view_matrix_stack.take_last();
          break;
      case GL_TEXTURE:
          RETURN_WITH_ERROR_IF(m_texture_matrix_stack.size() == 0, GL_STACK_UNDERFLOW);
          m_texture_matrix = m_texture_matrix_stack.take_last();
          break;
      default:
          VERIFY_NOT_REACHED();
      }
  }
  
  void GLContext::gl_mult_matrix(FloatMatrix4x4 const& matrix)
  {
      APPEND_TO_CALL_LIST_WITH_ARG_AND_RETURN_IF_NEEDED(gl_mult_matrix, matrix);
  
      RETURN_WITH_ERROR_IF(m_in_draw_state, GL_INVALID_OPERATION);
  
      if (m_current_matrix_mode == GL_MODELVIEW)
          m_model_view_matrix = m_model_view_matrix * matrix;
      else if (m_current_matrix_mode == GL_PROJECTION)
          m_projection_matrix = m_projection_matrix * matrix;
      else if (m_current_matrix_mode == GL_TEXTURE)
          m_texture_matrix = m_texture_matrix * matrix;
      else
          VERIFY_NOT_REACHED();
  }
  
  void GLContext::gl_rotate(GLdouble angle, GLdouble x, GLdouble y, GLdouble z)
  {
      APPEND_TO_CALL_LIST_AND_RETURN_IF_NEEDED(gl_rotate, angle, x, y, z);
  
      RETURN_WITH_ERROR_IF(m_in_draw_state, GL_INVALID_OPERATION);
  
      FloatVector3 axis = { (float)x, (float)y, (float)z };
      axis.normalize();
      auto rotation_mat = Gfx::rotation_matrix(axis, static_cast<float>(angle * M_PI * 2 / 360));
  
      if (m_current_matrix_mode == GL_MODELVIEW)
          m_model_view_matrix = m_model_view_matrix * rotation_mat;
      else if (m_current_matrix_mode == GL_PROJECTION)
          m_projection_matrix = m_projection_matrix * rotation_mat;
      else if (m_current_matrix_mode == GL_TEXTURE)
          m_texture_matrix = m_texture_matrix * rotation_mat;
      else
          VERIFY_NOT_REACHED();
  }
  
  void GLContext::gl_scale(GLdouble x, GLdouble y, GLdouble z)
  {
      APPEND_TO_CALL_LIST_AND_RETURN_IF_NEEDED(gl_scale, x, y, z);
  
      RETURN_WITH_ERROR_IF(m_in_draw_state, GL_INVALID_OPERATION);
  
      auto scale_matrix = Gfx::scale_matrix(FloatVector3 { static_cast<float>(x), static_cast<float>(y), static_cast<float>(z) });
  
      if (m_current_matrix_mode == GL_MODELVIEW)
          m_model_view_matrix = m_model_view_matrix * scale_matrix;
      else if (m_current_matrix_mode == GL_PROJECTION)
          m_projection_matrix = m_projection_matrix * scale_matrix;
      else if (m_current_matrix_mode == GL_TEXTURE)
          m_texture_matrix = m_texture_matrix * scale_matrix;
      else
          VERIFY_NOT_REACHED();
  }
  
  void GLContext::gl_translate(GLdouble x, GLdouble y, GLdouble z)
  {
      APPEND_TO_CALL_LIST_AND_RETURN_IF_NEEDED(gl_translate, x, y, z);
  
      RETURN_WITH_ERROR_IF(m_in_draw_state, GL_INVALID_OPERATION);
  
      auto translation_matrix = Gfx::translation_matrix(FloatVector3 { static_cast<float>(x), static_cast<float>(y), static_cast<float>(z) });
  
      if (m_current_matrix_mode == GL_MODELVIEW)
          m_model_view_matrix = m_model_view_matrix * translation_matrix;
      else if (m_current_matrix_mode == GL_PROJECTION)
          m_projection_matrix = m_projection_matrix * translation_matrix;
      else if (m_current_matrix_mode == GL_TEXTURE)
          m_texture_matrix = m_texture_matrix * translation_matrix;
      else
          VERIFY_NOT_REACHED();
  }
  
  void GLContext::gl_vertex(GLdouble x, GLdouble y, GLdouble z, GLdouble w)
  {
      APPEND_TO_CALL_LIST_AND_RETURN_IF_NEEDED(gl_vertex, x, y, z, w);
  
      SoftGPU::Vertex vertex;
  
      vertex.position = { static_cast<float>(x), static_cast<float>(y), static_cast<float>(z), static_cast<float>(w) };
      vertex.color = m_current_vertex_color;
      for (size_t i = 0; i < m_device_info.num_texture_units; ++i)
          vertex.tex_coords[i] = m_current_vertex_tex_coord[i];
      vertex.normal = m_current_vertex_normal;
  
      m_vertex_list.append(vertex);
  }
  
  void GLContext::gl_tex_coord(GLfloat s, GLfloat t, GLfloat r, GLfloat q)
  {
      APPEND_TO_CALL_LIST_AND_RETURN_IF_NEEDED(gl_tex_coord, s, t, r, q);
  
      m_current_vertex_tex_coord[0] = { s, t, r, q };
  }
  
  void GLContext::gl_multi_tex_coord(GLenum target, GLfloat s, GLfloat t, GLfloat r, GLfloat q)
  {
      APPEND_TO_CALL_LIST_AND_RETURN_IF_NEEDED(gl_multi_tex_coord, target, s, t, r, q);
  
      RETURN_WITH_ERROR_IF(target < GL_TEXTURE0 || target >= GL_TEXTURE0 + m_device_info.num_texture_units, GL_INVALID_ENUM);
  
      m_current_vertex_tex_coord[target - GL_TEXTURE0] = { s, t, r, q };
  }
  
  void GLContext::gl_viewport(GLint x, GLint y, GLsizei width, GLsizei height)
  {
      APPEND_TO_CALL_LIST_AND_RETURN_IF_NEEDED(gl_viewport, x, y, width, height);
  
      RETURN_WITH_ERROR_IF(m_in_draw_state, GL_INVALID_OPERATION);
      RETURN_WITH_ERROR_IF(width < 0 || height < 0, GL_INVALID_VALUE);
  
      m_viewport = { x, y, width, height };
  
      auto rasterizer_options = m_rasterizer.options();
      rasterizer_options.viewport = m_viewport;
      m_rasterizer.set_options(rasterizer_options);
  }
  
  void GLContext::gl_enable(GLenum capability)
  {
      APPEND_TO_CALL_LIST_AND_RETURN_IF_NEEDED(gl_enable, capability);
  
      RETURN_WITH_ERROR_IF(m_in_draw_state, GL_INVALID_OPERATION);
  
      auto rasterizer_options = m_rasterizer.options();
      bool update_rasterizer_options = false;
  
      switch (capability) {
      case GL_COLOR_MATERIAL:
          m_color_material_enabled = true;
          break;
      case GL_CULL_FACE:
          m_cull_faces = true;
          rasterizer_options.enable_culling = true;
          update_rasterizer_options = true;
          break;
      case GL_DEPTH_TEST:
          m_depth_test_enabled = true;
          rasterizer_options.enable_depth_test = true;
          update_rasterizer_options = true;
          break;
      case GL_BLEND:
          m_blend_enabled = true;
          rasterizer_options.enable_blending = true;
          update_rasterizer_options = true;
          break;
      case GL_ALPHA_TEST:
          m_alpha_test_enabled = true;
          rasterizer_options.enable_alpha_test = true;
          update_rasterizer_options = true;
          break;
      case GL_DITHER:
          m_dither_enabled = true;
          break;
      case GL_FOG:
          rasterizer_options.fog_enabled = true;
          update_rasterizer_options = true;
          break;
      case GL_LIGHTING:
          m_lighting_enabled = true;
          rasterizer_options.lighting_enabled = true;
          update_rasterizer_options = true;
          break;
      case GL_NORMALIZE:
          m_normalize = true;
          rasterizer_options.normalization_enabled = true;
          update_rasterizer_options = true;
          break;
      case GL_POLYGON_OFFSET_FILL:
          m_depth_offset_enabled = true;
          rasterizer_options.depth_offset_enabled = true;
          update_rasterizer_options = true;
          break;
      case GL_SCISSOR_TEST:
          rasterizer_options.scissor_enabled = true;
          update_rasterizer_options = true;
          break;
      case GL_STENCIL_TEST:
          m_stencil_test_enabled = true;
          rasterizer_options.enable_stencil_test = true;
          update_rasterizer_options = true;
          break;
      case GL_TEXTURE_1D:
          m_active_texture_unit->set_texture_1d_enabled(true);
          m_sampler_config_is_dirty = true;
          break;
      case GL_TEXTURE_2D:
          m_active_texture_unit->set_texture_2d_enabled(true);
          m_sampler_config_is_dirty = true;
          break;
      case GL_TEXTURE_3D:
          m_active_texture_unit->set_texture_3d_enabled(true);
          m_sampler_config_is_dirty = true;
          break;
      case GL_TEXTURE_CUBE_MAP:
          m_active_texture_unit->set_texture_cube_map_enabled(true);
          m_sampler_config_is_dirty = true;
          break;
      case GL_LIGHT0:
      case GL_LIGHT1:
      case GL_LIGHT2:
      case GL_LIGHT3:
      case GL_LIGHT4:
      case GL_LIGHT5:
      case GL_LIGHT6:
      case GL_LIGHT7:
          m_light_states.at(capability - GL_LIGHT0).is_enabled = true;
          m_light_state_is_dirty = true;
          break;
      case GL_TEXTURE_GEN_Q:
      case GL_TEXTURE_GEN_R:
      case GL_TEXTURE_GEN_S:
      case GL_TEXTURE_GEN_T:
          texture_coordinate_generation(m_active_texture_unit_index, capability).enabled = true;
          m_texcoord_generation_dirty = true;
          break;
      default:
          dbgln_if(GL_DEBUG, "gl_enable({:#x}): unknown parameter", capability);
          RETURN_WITH_ERROR_IF(true, GL_INVALID_ENUM);
      }
  
      if (update_rasterizer_options)
          m_rasterizer.set_options(rasterizer_options);
  }
  
  void GLContext::gl_disable(GLenum capability)
  {
      APPEND_TO_CALL_LIST_AND_RETURN_IF_NEEDED(gl_disable, capability);
  
      RETURN_WITH_ERROR_IF(m_in_draw_state, GL_INVALID_OPERATION);
  
      auto rasterizer_options = m_rasterizer.options();
      bool update_rasterizer_options = false;
  
      switch (capability) {
      case GL_COLOR_MATERIAL:
          m_color_material_enabled = false;
          break;
      case GL_CULL_FACE:
          m_cull_faces = false;
          rasterizer_options.enable_culling = false;
          update_rasterizer_options = true;
          break;
      case GL_DEPTH_TEST:
          m_depth_test_enabled = false;
          rasterizer_options.enable_depth_test = false;
          update_rasterizer_options = true;
          break;
      case GL_BLEND:
          m_blend_enabled = false;
          rasterizer_options.enable_blending = false;
          update_rasterizer_options = true;
          break;
      case GL_ALPHA_TEST:
          m_alpha_test_enabled = false;
          rasterizer_options.enable_alpha_test = false;
          update_rasterizer_options = true;
          break;
      case GL_DITHER:
          m_dither_enabled = false;
          break;
      case GL_FOG:
          rasterizer_options.fog_enabled = false;
          update_rasterizer_options = true;
          break;
      case GL_LIGHTING:
          m_lighting_enabled = false;
          rasterizer_options.lighting_enabled = false;
          update_rasterizer_options = true;
          break;
      case GL_LIGHT0:
      case GL_LIGHT1:
      case GL_LIGHT2:
      case GL_LIGHT3:
      case GL_LIGHT4:
      case GL_LIGHT5:
      case GL_LIGHT6:
      case GL_LIGHT7:
          m_light_states.at(capability - GL_LIGHT0).is_enabled = false;
          m_light_state_is_dirty = true;
          break;
      case GL_NORMALIZE:
          m_normalize = false;
          rasterizer_options.normalization_enabled = false;
          update_rasterizer_options = true;
          break;
      case GL_POLYGON_OFFSET_FILL:
          m_depth_offset_enabled = false;
          rasterizer_options.depth_offset_enabled = false;
          update_rasterizer_options = true;
          break;
      case GL_SCISSOR_TEST:
          rasterizer_options.scissor_enabled = false;
          update_rasterizer_options = true;
          break;
      case GL_STENCIL_TEST:
          m_stencil_test_enabled = false;
          rasterizer_options.enable_stencil_test = false;
          update_rasterizer_options = true;
          break;
      case GL_TEXTURE_1D:
          m_active_texture_unit->set_texture_1d_enabled(false);
          m_sampler_config_is_dirty = true;
          break;
      case GL_TEXTURE_2D:
          m_active_texture_unit->set_texture_2d_enabled(false);
          m_sampler_config_is_dirty = true;
          break;
      case GL_TEXTURE_3D:
          m_active_texture_unit->set_texture_3d_enabled(false);
          m_sampler_config_is_dirty = true;
          break;
      case GL_TEXTURE_CUBE_MAP:
          m_active_texture_unit->set_texture_cube_map_enabled(false);
          m_sampler_config_is_dirty = true;
          break;
      case GL_TEXTURE_GEN_Q:
      case GL_TEXTURE_GEN_R:
      case GL_TEXTURE_GEN_S:
      case GL_TEXTURE_GEN_T:
          texture_coordinate_generation(m_active_texture_unit_index, capability).enabled = false;
          m_texcoord_generation_dirty = true;
          break;
      default:
          dbgln_if(GL_DEBUG, "gl_disable({:#x}): unknown parameter", capability);
          RETURN_WITH_ERROR_IF(true, GL_INVALID_ENUM);
      }
  
      if (update_rasterizer_options)
          m_rasterizer.set_options(rasterizer_options);
  }
  
  GLboolean GLContext::gl_is_enabled(GLenum capability)
  {
      RETURN_VALUE_WITH_ERROR_IF(m_in_draw_state, GL_INVALID_OPERATION, 0);
  
      auto optional_parameter = get_context_parameter(capability);
      RETURN_VALUE_WITH_ERROR_IF(!optional_parameter.has_value(), GL_INVALID_ENUM, 0);
  
      auto parameter = optional_parameter.release_value();
      RETURN_VALUE_WITH_ERROR_IF(!parameter.is_capability, GL_INVALID_ENUM, 0);
  
      return parameter.value.boolean_value;
  }
  
  void GLContext::gl_gen_textures(GLsizei n, GLuint* textures)
  {
      RETURN_WITH_ERROR_IF(n < 0, GL_INVALID_VALUE);
      RETURN_WITH_ERROR_IF(m_in_draw_state, GL_INVALID_OPERATION);
  
      m_name_allocator.allocate(n, textures);
  
      // Initialize all texture names with a nullptr
      for (auto i = 0; i < n; ++i) {
          GLuint name = textures[i];
          m_allocated_textures.set(name, nullptr);
      }
  }
  
  void GLContext::gl_delete_textures(GLsizei n, const GLuint* textures)
  {
      RETURN_WITH_ERROR_IF(n < 0, GL_INVALID_VALUE);
      RETURN_WITH_ERROR_IF(m_in_draw_state, GL_INVALID_OPERATION);
  
      for (auto i = 0; i < n; i++) {
          GLuint name = textures[i];
          if (name == 0)
              continue;
  
          m_name_allocator.free(name);
  
          auto texture_object = m_allocated_textures.find(name);
          if (texture_object == m_allocated_textures.end() || texture_object->value.is_null())
              continue;
          auto texture = texture_object->value;
  
          // Check all texture units
          for (auto& texture_unit : m_texture_units) {
              if (texture->is_texture_2d() && texture_unit.texture_2d_target_texture() == texture) {
                  // If a texture that is currently bound is deleted, the binding reverts to 0 (the default texture)
                  texture_unit.set_texture_2d_target_texture(get_default_texture<Texture2D>(GL_TEXTURE_2D));
              }
          }
  
          m_allocated_textures.remove(name);
      }
  }
  
  void GLContext::gl_tex_image_2d(GLenum target, GLint level, GLint internal_format, GLsizei width, GLsizei height, GLint border, GLenum format, GLenum type, GLvoid const* data)
  {
      RETURN_WITH_ERROR_IF(m_in_draw_state, GL_INVALID_OPERATION);
  
      // We only support GL_TEXTURE_2D for now
      RETURN_WITH_ERROR_IF(target != GL_TEXTURE_2D, GL_INVALID_ENUM);
  
      // Internal format can also be a number between 1 and 4. Symbolic formats were only added with EXT_texture, promoted to core in OpenGL 1.1
      if (internal_format == 1)
          internal_format = GL_ALPHA;
      else if (internal_format == 2)
          internal_format = GL_LUMINANCE_ALPHA;
      else if (internal_format == 3)
          internal_format = GL_RGB;
      else if (internal_format == 4)
          internal_format = GL_RGBA;
  
      // We only support symbolic constants for now
      RETURN_WITH_ERROR_IF(!(internal_format == GL_RGB || internal_format == GL_RGBA || internal_format == GL_LUMINANCE8 || internal_format == GL_LUMINANCE8_ALPHA8), GL_INVALID_ENUM);
      RETURN_WITH_ERROR_IF(!(type == GL_UNSIGNED_BYTE || type == GL_UNSIGNED_SHORT_5_6_5), GL_INVALID_VALUE);
      RETURN_WITH_ERROR_IF(level < 0 || level > Texture2D::LOG2_MAX_TEXTURE_SIZE, GL_INVALID_VALUE);
      RETURN_WITH_ERROR_IF(width < 0 || height < 0 || width > (2 + Texture2D::MAX_TEXTURE_SIZE) || height > (2 + Texture2D::MAX_TEXTURE_SIZE), GL_INVALID_VALUE);
      // Check if width and height are a power of 2
      if (!m_device_info.supports_npot_textures) {
          RETURN_WITH_ERROR_IF(!is_power_of_two(width), GL_INVALID_VALUE);
          RETURN_WITH_ERROR_IF(!is_power_of_two(height), GL_INVALID_VALUE);
      }
      RETURN_WITH_ERROR_IF(border != 0, GL_INVALID_VALUE);
  
      auto texture_2d = m_active_texture_unit->texture_2d_target_texture();
      VERIFY(!texture_2d.is_null());
  
      if (level == 0) {
          // FIXME: OpenGL has the concept of texture and mipmap completeness. A texture has to fulfill certain criteria to be considered complete.
          // Trying to render while an incomplete texture is bound will result in an error.
          // Here we simply create a complete device image when mipmap level 0 is attached to the texture object. This has the unfortunate side effect
          // that constructing GL textures in any but the default mipmap order, going from level 0 upwards will cause mip levels to stay uninitialized.
          // To be spec compliant we should create the device image once the texture has become complete and is used for rendering the first time.
          // All images that were attached before the device image was created need to be stored somewhere to be used to initialize the device image once complete.
          texture_2d->set_device_image(m_rasterizer.create_image(SoftGPU::ImageFormat::BGRA8888, width, height, 1, 999, 1));
          m_sampler_config_is_dirty = true;
      }
  
      texture_2d->upload_texture_data(level, internal_format, width, height, format, type, data, m_unpack_row_length, m_unpack_alignment);
  }
  
  void GLContext::gl_tex_sub_image_2d(GLenum target, GLint level, GLint xoffset, GLint yoffset, GLsizei width, GLsizei height, GLenum format, GLenum type, GLvoid const* data)
  {
      RETURN_WITH_ERROR_IF(m_in_draw_state, GL_INVALID_OPERATION);
  
      // We only support GL_TEXTURE_2D for now
      RETURN_WITH_ERROR_IF(target != GL_TEXTURE_2D, GL_INVALID_ENUM);
  
      // We only support symbolic constants for now
      RETURN_WITH_ERROR_IF(!(format == GL_RGBA || format == GL_RGB), GL_INVALID_VALUE);
      RETURN_WITH_ERROR_IF(!(type == GL_UNSIGNED_BYTE || type == GL_UNSIGNED_SHORT_5_6_5), GL_INVALID_VALUE);
      RETURN_WITH_ERROR_IF(level < 0 || level > Texture2D::LOG2_MAX_TEXTURE_SIZE, GL_INVALID_VALUE);
      RETURN_WITH_ERROR_IF(width < 0 || height < 0 || width > (2 + Texture2D::MAX_TEXTURE_SIZE) || height > (2 + Texture2D::MAX_TEXTURE_SIZE), GL_INVALID_VALUE);
  
      // A 2D texture array must have been defined by a previous glTexImage2D operation
      auto texture_2d = m_active_texture_unit->texture_2d_target_texture();
      RETURN_WITH_ERROR_IF(texture_2d.is_null(), GL_INVALID_OPERATION);
  
      RETURN_WITH_ERROR_IF(xoffset < 0 || yoffset < 0 || xoffset + width > texture_2d->width_at_lod(level) || yoffset + height > texture_2d->height_at_lod(level), GL_INVALID_VALUE);
  
      texture_2d->replace_sub_texture_data(level, xoffset, yoffset, width, height, format, type, data, m_unpack_row_length, m_unpack_alignment);
  }
  
  void GLContext::gl_tex_parameter(GLenum target, GLenum pname, GLfloat param)
  {
      APPEND_TO_CALL_LIST_AND_RETURN_IF_NEEDED(gl_tex_parameter, target, pname, param);
  
      RETURN_WITH_ERROR_IF(m_in_draw_state, GL_INVALID_OPERATION);
  
      // FIXME: We currently only support GL_TETXURE_2D targets. 1D, 3D and CUBE should also be supported (https://docs.gl/gl2/glTexParameter)
      RETURN_WITH_ERROR_IF(target != GL_TEXTURE_2D, GL_INVALID_ENUM);
  
      // FIXME: implement the remaining parameters. (https://docs.gl/gl2/glTexParameter)
      RETURN_WITH_ERROR_IF(!(pname == GL_TEXTURE_MIN_FILTER
                               || pname == GL_TEXTURE_MAG_FILTER
                               || pname == GL_TEXTURE_WRAP_S
                               || pname == GL_TEXTURE_WRAP_T),
          GL_INVALID_ENUM);
  
      // We assume GL_TEXTURE_2D (see above)
      auto texture_2d = m_active_texture_unit->texture_2d_target_texture();
      if (texture_2d.is_null())
          return;
  
      switch (pname) {
      case GL_TEXTURE_MIN_FILTER:
          RETURN_WITH_ERROR_IF(!(param == GL_NEAREST
                                   || param == GL_LINEAR
                                   || param == GL_NEAREST_MIPMAP_NEAREST
                                   || param == GL_LINEAR_MIPMAP_NEAREST
                                   || param == GL_NEAREST_MIPMAP_LINEAR
                                   || param == GL_LINEAR_MIPMAP_LINEAR),
              GL_INVALID_ENUM);
  
          texture_2d->sampler().set_min_filter(param);
          break;
  
      case GL_TEXTURE_MAG_FILTER:
          RETURN_WITH_ERROR_IF(!(param == GL_NEAREST
                                   || param == GL_LINEAR),
              GL_INVALID_ENUM);
  
          texture_2d->sampler().set_mag_filter(param);
          break;
  
      case GL_TEXTURE_WRAP_S:
          RETURN_WITH_ERROR_IF(!(param == GL_CLAMP
                                   || param == GL_CLAMP_TO_BORDER
                                   || param == GL_CLAMP_TO_EDGE
                                   || param == GL_MIRRORED_REPEAT
                                   || param == GL_REPEAT),
              GL_INVALID_ENUM);
  
          texture_2d->sampler().set_wrap_s_mode(param);
          break;
  
      case GL_TEXTURE_WRAP_T:
          RETURN_WITH_ERROR_IF(!(param == GL_CLAMP
                                   || param == GL_CLAMP_TO_BORDER
                                   || param == GL_CLAMP_TO_EDGE
                                   || param == GL_MIRRORED_REPEAT
                                   || param == GL_REPEAT),
              GL_INVALID_ENUM);
  
          texture_2d->sampler().set_wrap_t_mode(param);
          break;
  
      default:
          VERIFY_NOT_REACHED();
      }
  
      m_sampler_config_is_dirty = true;
  }
  
  void GLContext::gl_front_face(GLenum face)
  {
      APPEND_TO_CALL_LIST_AND_RETURN_IF_NEEDED(gl_front_face, face);
  
      RETURN_WITH_ERROR_IF(face < GL_CW || face > GL_CCW, GL_INVALID_ENUM);
  
      m_front_face = face;
  
      auto rasterizer_options = m_rasterizer.options();
      rasterizer_options.front_face = (face == GL_CW) ? SoftGPU::WindingOrder::Clockwise : SoftGPU::WindingOrder::CounterClockwise;
      m_rasterizer.set_options(rasterizer_options);
  }
  
  void GLContext::gl_cull_face(GLenum cull_mode)
  {
      APPEND_TO_CALL_LIST_AND_RETURN_IF_NEEDED(gl_cull_face, cull_mode);
  
      RETURN_WITH_ERROR_IF(cull_mode < GL_FRONT || cull_mode > GL_FRONT_AND_BACK, GL_INVALID_ENUM);
  
      m_culled_sides = cull_mode;
  
      auto rasterizer_options = m_rasterizer.options();
      rasterizer_options.cull_back = cull_mode == GL_BACK || cull_mode == GL_FRONT_AND_BACK;
      rasterizer_options.cull_front = cull_mode == GL_FRONT || cull_mode == GL_FRONT_AND_BACK;
      m_rasterizer.set_options(rasterizer_options);
  }
  
  GLuint GLContext::gl_gen_lists(GLsizei range)
  {
      RETURN_VALUE_WITH_ERROR_IF(range <= 0, GL_INVALID_VALUE, 0);
      RETURN_VALUE_WITH_ERROR_IF(m_in_draw_state, GL_INVALID_OPERATION, 0);
  
      auto initial_entry = m_listings.size();
      m_listings.resize(range + initial_entry);
      return initial_entry + 1;
  }
  
  void GLContext::invoke_list(size_t list_index)
  {
      auto& listing = m_listings[list_index - 1];
      for (auto& entry : listing.entries) {
          entry.function.visit([&](auto& function) {
              entry.arguments.visit([&](auto& arguments) {
                  auto apply = [&]<typename... Args>(Args && ... args)
                  {
                      if constexpr (requires { (this->*function)(forward<Args>(args)...); })
                          (this->*function)(forward<Args>(args)...);
                  };
  
                  arguments.apply_as_args(apply);
              });
          });
      }
  }
  
  void GLContext::gl_call_list(GLuint list)
  {
      if (m_gl_call_depth > max_allowed_gl_call_depth)
          return;
  
      APPEND_TO_CALL_LIST_AND_RETURN_IF_NEEDED(gl_call_list, list);
  
      if (m_listings.size() < list)
          return;
  
      TemporaryChange change { m_gl_call_depth, m_gl_call_depth + 1 };
  
      invoke_list(list);
  }
  
  void GLContext::gl_call_lists(GLsizei n, GLenum type, void const* lists)
  {
      if (m_gl_call_depth > max_allowed_gl_call_depth)
          return;
  
      APPEND_TO_CALL_LIST_AND_RETURN_IF_NEEDED(gl_call_lists, n, type, lists);
  
      RETURN_WITH_ERROR_IF(n < 0, GL_INVALID_VALUE);
      RETURN_WITH_ERROR_IF(!(type == GL_BYTE
                               || type == GL_UNSIGNED_BYTE
                               || type == GL_SHORT
                               || type == GL_UNSIGNED_SHORT
                               || type == GL_INT
                               || type == GL_UNSIGNED_INT
                               || type == GL_FLOAT
                               || type == GL_2_BYTES
                               || type == GL_3_BYTES
                               || type == GL_4_BYTES),
          GL_INVALID_ENUM);
  
      TemporaryChange change { m_gl_call_depth, m_gl_call_depth + 1 };
  
      auto invoke_all_lists = [&]<typename T>(T const* lists) {
          for (int i = 0; i < n; ++i) {
              auto list = static_cast<size_t>(lists[i]);
              invoke_list(m_list_base + list);
          }
      };
      switch (type) {
      case GL_BYTE:
          invoke_all_lists(static_cast<GLbyte const*>(lists));
          break;
      case GL_UNSIGNED_BYTE:
          invoke_all_lists(static_cast<GLubyte const*>(lists));
          break;
      case GL_SHORT:
          invoke_all_lists(static_cast<GLshort const*>(lists));
          break;
      case GL_UNSIGNED_SHORT:
          invoke_all_lists(static_cast<GLushort const*>(lists));
          break;
      case GL_INT:
          invoke_all_lists(static_cast<GLint const*>(lists));
          break;
      case GL_UNSIGNED_INT:
          invoke_all_lists(static_cast<GLuint const*>(lists));
          break;
      case GL_FLOAT:
          invoke_all_lists(static_cast<GLfloat const*>(lists));
          break;
      case GL_2_BYTES:
      case GL_3_BYTES:
      case GL_4_BYTES:
          dbgln("GLContext FIXME: unimplemented glCallLists() with type {}", type);
          break;
      default:
          VERIFY_NOT_REACHED();
      }
  }
  
  void GLContext::gl_delete_lists(GLuint list, GLsizei range)
  {
      if (m_listings.size() < list || m_listings.size() <= list + range)
          return;
  
      for (auto& entry : m_listings.span().slice(list - 1, range))
          entry.entries.clear_with_capacity();
  }
  
  void GLContext::gl_list_base(GLuint base)
  {
      APPEND_TO_CALL_LIST_AND_RETURN_IF_NEEDED(gl_list_base, base);
  
      RETURN_WITH_ERROR_IF(m_in_draw_state, GL_INVALID_OPERATION);
  
      m_list_base = base;
  }
  
  void GLContext::gl_end_list()
  {
      RETURN_WITH_ERROR_IF(m_in_draw_state, GL_INVALID_OPERATION);
      RETURN_WITH_ERROR_IF(!m_current_listing_index.has_value(), GL_INVALID_OPERATION);
  
      m_listings[m_current_listing_index->index] = move(m_current_listing_index->listing);
      m_current_listing_index.clear();
  }
  
  void GLContext::gl_new_list(GLuint list, GLenum mode)
  {
      RETURN_WITH_ERROR_IF(list == 0, GL_INVALID_VALUE);
      RETURN_WITH_ERROR_IF(mode != GL_COMPILE && mode != GL_COMPILE_AND_EXECUTE, GL_INVALID_ENUM);
      RETURN_WITH_ERROR_IF(m_in_draw_state, GL_INVALID_OPERATION);
      RETURN_WITH_ERROR_IF(m_current_listing_index.has_value(), GL_INVALID_OPERATION);
  
      if (m_listings.size() < list)
          return;
  
      m_current_listing_index = CurrentListing { {}, static_cast<size_t>(list - 1), mode };
  }
  
  GLboolean GLContext::gl_is_list(GLuint list)
  {
      RETURN_VALUE_WITH_ERROR_IF(m_in_draw_state, GL_INVALID_OPERATION, GL_FALSE);
  
      return list < m_listings.size() ? GL_TRUE : GL_FALSE;
  }
  
  void GLContext::gl_flush()
  {
      RETURN_WITH_ERROR_IF(m_in_draw_state, GL_INVALID_OPERATION);
  
      // No-op since GLContext is completely synchronous at the moment
  }
  
  void GLContext::gl_finish()
  {
      RETURN_WITH_ERROR_IF(m_in_draw_state, GL_INVALID_OPERATION);
  
      // No-op since GLContext is completely synchronous at the moment
  }
  
  void GLContext::gl_blend_func(GLenum src_factor, GLenum dst_factor)
  {
      APPEND_TO_CALL_LIST_AND_RETURN_IF_NEEDED(gl_blend_func, src_factor, dst_factor);
  
      RETURN_WITH_ERROR_IF(m_in_draw_state, GL_INVALID_OPERATION);
  
      // FIXME: The list of allowed enums differs between API versions
      // This was taken from the 2.0 spec on https://docs.gl/gl2/glBlendFunc
  
      RETURN_WITH_ERROR_IF(!(src_factor == GL_ZERO
                               || src_factor == GL_ONE
                               || src_factor == GL_SRC_COLOR
                               || src_factor == GL_ONE_MINUS_SRC_COLOR
                               || src_factor == GL_DST_COLOR
                               || src_factor == GL_ONE_MINUS_DST_COLOR
                               || src_factor == GL_SRC_ALPHA
                               || src_factor == GL_ONE_MINUS_SRC_ALPHA
                               || src_factor == GL_DST_ALPHA
                               || src_factor == GL_ONE_MINUS_DST_ALPHA
                               || src_factor == GL_CONSTANT_COLOR
                               || src_factor == GL_ONE_MINUS_CONSTANT_COLOR
                               || src_factor == GL_CONSTANT_ALPHA
                               || src_factor == GL_ONE_MINUS_CONSTANT_ALPHA
                               || src_factor == GL_SRC_ALPHA_SATURATE),
          GL_INVALID_ENUM);
  
      RETURN_WITH_ERROR_IF(!(dst_factor == GL_ZERO
                               || dst_factor == GL_ONE
                               || dst_factor == GL_SRC_COLOR
                               || dst_factor == GL_ONE_MINUS_SRC_COLOR
                               || dst_factor == GL_DST_COLOR
                               || dst_factor == GL_ONE_MINUS_DST_COLOR
                               || dst_factor == GL_SRC_ALPHA
                               || dst_factor == GL_ONE_MINUS_SRC_ALPHA
                               || dst_factor == GL_DST_ALPHA
                               || dst_factor == GL_ONE_MINUS_DST_ALPHA
                               || dst_factor == GL_CONSTANT_COLOR
                               || dst_factor == GL_ONE_MINUS_CONSTANT_COLOR
                               || dst_factor == GL_CONSTANT_ALPHA
                               || dst_factor == GL_ONE_MINUS_CONSTANT_ALPHA),
          GL_INVALID_ENUM);
  
      m_blend_source_factor = src_factor;
      m_blend_destination_factor = dst_factor;
  
      auto map_gl_blend_factor_to_device = [](GLenum factor) constexpr
      {
          switch (factor) {
          case GL_ZERO:
              return SoftGPU::BlendFactor::Zero;
          case GL_ONE:
              return SoftGPU::BlendFactor::One;
          case GL_SRC_ALPHA:
              return SoftGPU::BlendFactor::SrcAlpha;
          case GL_ONE_MINUS_SRC_ALPHA:
              return SoftGPU::BlendFactor::OneMinusSrcAlpha;
          case GL_SRC_COLOR:
              return SoftGPU::BlendFactor::SrcColor;
          case GL_ONE_MINUS_SRC_COLOR:
              return SoftGPU::BlendFactor::OneMinusSrcColor;
          case GL_DST_ALPHA:
              return SoftGPU::BlendFactor::DstAlpha;
          case GL_ONE_MINUS_DST_ALPHA:
              return SoftGPU::BlendFactor::OneMinusDstAlpha;
          case GL_DST_COLOR:
              return SoftGPU::BlendFactor::DstColor;
          case GL_ONE_MINUS_DST_COLOR:
              return SoftGPU::BlendFactor::OneMinusDstColor;
          case GL_SRC_ALPHA_SATURATE:
              return SoftGPU::BlendFactor::SrcAlphaSaturate;
          default:
              VERIFY_NOT_REACHED();
          }
      };
  
      auto options = m_rasterizer.options();
      options.blend_source_factor = map_gl_blend_factor_to_device(m_blend_source_factor);
      options.blend_destination_factor = map_gl_blend_factor_to_device(m_blend_destination_factor);
      m_rasterizer.set_options(options);
  }
  
  void GLContext::gl_shade_model(GLenum mode)
  {
      APPEND_TO_CALL_LIST_AND_RETURN_IF_NEEDED(gl_shade_model, mode);
  
      RETURN_WITH_ERROR_IF(m_in_draw_state, GL_INVALID_OPERATION);
      RETURN_WITH_ERROR_IF(mode != GL_FLAT && mode != GL_SMOOTH, GL_INVALID_ENUM);
  
      auto options = m_rasterizer.options();
      options.shade_smooth = (mode == GL_SMOOTH);
      m_rasterizer.set_options(options);
  }
  
  void GLContext::gl_alpha_func(GLenum func, GLclampf ref)
  {
      APPEND_TO_CALL_LIST_AND_RETURN_IF_NEEDED(gl_alpha_func, func, ref);
  
      RETURN_WITH_ERROR_IF(m_in_draw_state, GL_INVALID_OPERATION);
      RETURN_WITH_ERROR_IF(func < GL_NEVER || func > GL_ALWAYS, GL_INVALID_ENUM);
  
      m_alpha_test_func = func;
      m_alpha_test_ref_value = ref;
  
      auto options = m_rasterizer.options();
  
      switch (func) {
      case GL_NEVER:
          options.alpha_test_func = SoftGPU::AlphaTestFunction::Never;
          break;
      case GL_ALWAYS:
          options.alpha_test_func = SoftGPU::AlphaTestFunction::Always;
          break;
      case GL_LESS:
          options.alpha_test_func = SoftGPU::AlphaTestFunction::Less;
          break;
      case GL_LEQUAL:
          options.alpha_test_func = SoftGPU::AlphaTestFunction::LessOrEqual;
          break;
      case GL_EQUAL:
          options.alpha_test_func = SoftGPU::AlphaTestFunction::Equal;
          break;
      case GL_NOTEQUAL:
          options.alpha_test_func = SoftGPU::AlphaTestFunction::NotEqual;
          break;
      case GL_GEQUAL:
          options.alpha_test_func = SoftGPU::AlphaTestFunction::GreaterOrEqual;
          break;
      case GL_GREATER:
          options.alpha_test_func = SoftGPU::AlphaTestFunction::Greater;
          break;
      default:
          VERIFY_NOT_REACHED();
      }
  
      options.alpha_test_ref_value = m_alpha_test_ref_value;
      m_rasterizer.set_options(options);
  }
  
  void GLContext::gl_hint(GLenum target, GLenum mode)
  {
      APPEND_TO_CALL_LIST_AND_RETURN_IF_NEEDED(gl_hint, target, mode);
  
      RETURN_WITH_ERROR_IF(m_in_draw_state, GL_INVALID_OPERATION);
  
      RETURN_WITH_ERROR_IF(target != GL_PERSPECTIVE_CORRECTION_HINT
              && target != GL_POINT_SMOOTH_HINT
              && target != GL_LINE_SMOOTH_HINT
              && target != GL_POLYGON_SMOOTH_HINT
              && target != GL_FOG_HINT
              && target != GL_GENERATE_MIPMAP_HINT
              && target != GL_TEXTURE_COMPRESSION_HINT,
          GL_INVALID_ENUM);
  
      RETURN_WITH_ERROR_IF(mode != GL_DONT_CARE
              && mode != GL_FASTEST
              && mode != GL_NICEST,
          GL_INVALID_ENUM);
  
      // According to the spec implementors are free to ignore glHint. So we do.
  }
  
  void GLContext::gl_read_buffer(GLenum mode)
  {
      APPEND_TO_CALL_LIST_AND_RETURN_IF_NEEDED(gl_read_buffer, mode);
  
      RETURN_WITH_ERROR_IF(m_in_draw_state, GL_INVALID_OPERATION);
  
      // FIXME: Also allow aux buffers GL_AUX0 through GL_AUX3 here
      // plus any aux buffer between 0 and GL_AUX_BUFFERS
      RETURN_WITH_ERROR_IF(mode != GL_FRONT_LEFT
              && mode != GL_FRONT_RIGHT
              && mode != GL_BACK_LEFT
              && mode != GL_BACK_RIGHT
              && mode != GL_FRONT
              && mode != GL_BACK
              && mode != GL_LEFT
              && mode != GL_RIGHT,
          GL_INVALID_ENUM);
  
      // FIXME: We do not currently have aux buffers, so make it an invalid
      // operation to select anything but front or back buffers. Also we do
      // not allow selecting the stereoscopic RIGHT buffers since we do not
      // have them configured.
      RETURN_WITH_ERROR_IF(mode != GL_FRONT_LEFT
              && mode != GL_FRONT
              && mode != GL_BACK_LEFT
              && mode != GL_BACK
              && mode != GL_FRONT
              && mode != GL_BACK
              && mode != GL_LEFT,
          GL_INVALID_OPERATION);
  
      m_current_read_buffer = mode;
  }
  
  void GLContext::gl_draw_buffer(GLenum buffer)
  {
      APPEND_TO_CALL_LIST_AND_RETURN_IF_NEEDED(gl_draw_buffer, buffer);
  
      RETURN_WITH_ERROR_IF(m_in_draw_state, GL_INVALID_OPERATION);
  
      // FIXME: Also allow aux buffers GL_AUX0 through GL_AUX3 here
      // plus any aux buffer between 0 and GL_AUX_BUFFERS
      RETURN_WITH_ERROR_IF(buffer != GL_NONE
              && buffer != GL_FRONT_LEFT
              && buffer != GL_FRONT_RIGHT
              && buffer != GL_BACK_LEFT
              && buffer != GL_BACK_RIGHT
              && buffer != GL_FRONT
              && buffer != GL_BACK
              && buffer != GL_LEFT
              && buffer != GL_RIGHT,
          GL_INVALID_ENUM);
  
      // FIXME: We do not currently have aux buffers, so make it an invalid
      // operation to select anything but front or back buffers. Also we do
      // not allow selecting the stereoscopic RIGHT buffers since we do not
      // have them configured.
      RETURN_WITH_ERROR_IF(buffer != GL_NONE
              && buffer != GL_FRONT_LEFT
              && buffer != GL_FRONT
              && buffer != GL_BACK_LEFT
              && buffer != GL_BACK
              && buffer != GL_FRONT
              && buffer != GL_BACK
              && buffer != GL_LEFT,
          GL_INVALID_OPERATION);
  
      m_current_draw_buffer = buffer;
  
      auto rasterizer_options = m_rasterizer.options();
      // FIXME: We only have a single draw buffer in SoftGPU at the moment,
      // so we simply disable color writes if GL_NONE is selected
      rasterizer_options.enable_color_write = m_current_draw_buffer != GL_NONE;
      m_rasterizer.set_options(rasterizer_options);
  }
  
  void GLContext::gl_read_pixels(GLint x, GLint y, GLsizei width, GLsizei height, GLenum format, GLenum type, GLvoid* pixels)
  {
      RETURN_WITH_ERROR_IF(m_in_draw_state, GL_INVALID_OPERATION);
      RETURN_WITH_ERROR_IF(width < 0 || height < 0, GL_INVALID_VALUE);
  
      RETURN_WITH_ERROR_IF(format != GL_COLOR_INDEX
              && format != GL_STENCIL_INDEX
              && format != GL_DEPTH_COMPONENT
              && format != GL_RED
              && format != GL_GREEN
              && format != GL_BLUE
              && format != GL_ALPHA
              && format != GL_RGB
              && format != GL_RGBA
              && format != GL_LUMINANCE
              && format != GL_LUMINANCE_ALPHA,
          GL_INVALID_ENUM);
  
      RETURN_WITH_ERROR_IF(type != GL_UNSIGNED_BYTE
              && type != GL_BYTE
              && type != GL_BITMAP
              && type != GL_UNSIGNED_SHORT
              && type != GL_SHORT
              && type != GL_BLUE
              && type != GL_UNSIGNED_INT
              && type != GL_INT
              && type != GL_FLOAT,
          GL_INVALID_ENUM);
  
      // FIXME: We only support RGBA buffers for now.
      // Once we add support for indexed color modes do the correct check here
      RETURN_WITH_ERROR_IF(format == GL_COLOR_INDEX, GL_INVALID_OPERATION);
  
      // FIXME: We do not have stencil buffers yet
      // Once we add support for stencil buffers do the correct check here
      RETURN_WITH_ERROR_IF(format == GL_STENCIL_INDEX, GL_INVALID_OPERATION);
  
      if (format == GL_DEPTH_COMPONENT) {
          // FIXME: This check needs to be a bit more sophisticated. Currently the buffers
          // are hardcoded. Once we add proper structures for them we need to correct this check
  
          // Error because only back buffer has a depth buffer
          RETURN_WITH_ERROR_IF(m_current_read_buffer == GL_FRONT
                  || m_current_read_buffer == GL_FRONT_LEFT
                  || m_current_read_buffer == GL_FRONT_RIGHT,
              GL_INVALID_OPERATION);
      }
  
      // Some helper functions for converting float values to integer types
      auto float_to_i8 = [](float f) -> GLchar {
          return static_cast<GLchar>((0x7f * min(max(f, 0.0f), 1.0f) - 1) / 2);
      };
  
      auto float_to_i16 = [](float f) -> GLshort {
          return static_cast<GLshort>((0x7fff * min(max(f, 0.0f), 1.0f) - 1) / 2);
      };
  
      auto float_to_i32 = [](float f) -> GLint {
          return static_cast<GLint>((0x7fffffff * min(max(f, 0.0f), 1.0f) - 1) / 2);
      };
  
      auto float_to_u8 = [](float f) -> GLubyte {
          return static_cast<GLubyte>(0xff * min(max(f, 0.0f), 1.0f));
      };
  
      auto float_to_u16 = [](float f) -> GLushort {
          return static_cast<GLushort>(0xffff * min(max(f, 0.0f), 1.0f));
      };
  
      auto float_to_u32 = [](float f) -> GLuint {
          return static_cast<GLuint>(0xffffffff * min(max(f, 0.0f), 1.0f));
      };
  
      u8 component_size = 0;
      switch (type) {
      case GL_BYTE:
      case GL_UNSIGNED_BYTE:
          component_size = 1;
          break;
      case GL_SHORT:
      case GL_UNSIGNED_SHORT:
          component_size = 2;
          break;
      case GL_INT:
      case GL_UNSIGNED_INT:
      case GL_FLOAT:
          component_size = 4;
          break;
      }
  
      if (format == GL_DEPTH_COMPONENT) {
          auto const row_stride = (width * component_size + m_pack_alignment - 1) / m_pack_alignment * m_pack_alignment;
  
          // Read from depth buffer
          for (GLsizei i = 0; i < height; ++i) {
              for (GLsizei j = 0; j < width; ++j) {
                  float depth = m_rasterizer.get_depthbuffer_value(x + j, y + i);
                  auto char_ptr = reinterpret_cast<char*>(pixels) + i * row_stride + j * component_size;
  
                  switch (type) {
                  case GL_BYTE:
                      *reinterpret_cast<GLchar*>(char_ptr) = float_to_i8(depth);
                      break;
                  case GL_SHORT:
                      *reinterpret_cast<GLshort*>(char_ptr) = float_to_i16(depth);
                      break;
                  case GL_INT:
                      *reinterpret_cast<GLint*>(char_ptr) = float_to_i32(depth);
                      break;
                  case GL_UNSIGNED_BYTE:
                      *reinterpret_cast<GLubyte*>(char_ptr) = float_to_u8(depth);
                      break;
                  case GL_UNSIGNED_SHORT:
                      *reinterpret_cast<GLushort*>(char_ptr) = float_to_u16(depth);
                      break;
                  case GL_UNSIGNED_INT:
                      *reinterpret_cast<GLuint*>(char_ptr) = float_to_u32(depth);
                      break;
                  case GL_FLOAT:
                      *reinterpret_cast<GLfloat*>(char_ptr) = min(max(depth, 0.0f), 1.0f);
                      break;
                  }
              }
          }
          return;
      }
  
      bool write_red = false;
      bool write_green = false;
      bool write_blue = false;
      bool write_alpha = false;
      size_t component_count = 0;
      size_t red_offset = 0;
      size_t green_offset = 0;
      size_t blue_offset = 0;
      size_t alpha_offset = 0;
      char* red_ptr = nullptr;
      char* green_ptr = nullptr;
      char* blue_ptr = nullptr;
      char* alpha_ptr = nullptr;
  
      switch (format) {
      case GL_RGB:
          write_red = true;
          write_green = true;
          write_blue = true;
          component_count = 3;
          red_offset = 2;
          green_offset = 1;
          blue_offset = 0;
          break;
      case GL_RGBA:
          write_red = true;
          write_green = true;
          write_blue = true;
          write_alpha = true;
          component_count = 4;
          red_offset = 3;
          green_offset = 2;
          blue_offset = 1;
          alpha_offset = 0;
          break;
      case GL_RED:
          write_red = true;
          component_count = 1;
          red_offset = 0;
          break;
      case GL_GREEN:
          write_green = true;
          component_count = 1;
          green_offset = 0;
          break;
      case GL_BLUE:
          write_blue = true;
          component_count = 1;
          blue_offset = 0;
          break;
      case GL_ALPHA:
          write_alpha = true;
          component_count = 1;
          alpha_offset = 0;
          break;
      }
  
      auto const pixel_bytes = component_size * component_count;
      auto const row_alignment_bytes = (m_pack_alignment - ((width * pixel_bytes) % m_pack_alignment)) % m_pack_alignment;
  
      char* out_ptr = reinterpret_cast<char*>(pixels);
      for (int i = 0; i < (int)height; ++i) {
          for (int j = 0; j < (int)width; ++j) {
              Gfx::ARGB32 color {};
              if (m_current_read_buffer == GL_FRONT || m_current_read_buffer == GL_LEFT || m_current_read_buffer == GL_FRONT_LEFT) {
                  if (y + i >= m_frontbuffer->width() || x + j >= m_frontbuffer->height())
                      color = 0;
                  else
                      color = m_frontbuffer->scanline(y + i)[x + j];
              } else {
                  color = m_rasterizer.get_color_buffer_pixel(x + j, y + i);
              }
  
              float red = ((color >> 24) & 0xff) / 255.0f;
              float green = ((color >> 16) & 0xff) / 255.0f;
              float blue = ((color >> 8) & 0xff) / 255.0f;
              float alpha = (color & 0xff) / 255.0f;
  
              // FIXME: Set up write pointers based on selected endianness (glPixelStore)
              red_ptr = out_ptr + (component_size * red_offset);
              green_ptr = out_ptr + (component_size * green_offset);
              blue_ptr = out_ptr + (component_size * blue_offset);
              alpha_ptr = out_ptr + (component_size * alpha_offset);
  
              switch (type) {
              case GL_BYTE:
                  if (write_red)
                      *reinterpret_cast<GLchar*>(red_ptr) = float_to_i8(red);
                  if (write_green)
                      *reinterpret_cast<GLchar*>(green_ptr) = float_to_i8(green);
                  if (write_blue)
                      *reinterpret_cast<GLchar*>(blue_ptr) = float_to_i8(blue);
                  if (write_alpha)
                      *reinterpret_cast<GLchar*>(alpha_ptr) = float_to_i8(alpha);
                  break;
              case GL_UNSIGNED_BYTE:
                  if (write_red)
                      *reinterpret_cast<GLubyte*>(red_ptr) = float_to_u8(red);
                  if (write_green)
                      *reinterpret_cast<GLubyte*>(green_ptr) = float_to_u8(green);
                  if (write_blue)
                      *reinterpret_cast<GLubyte*>(blue_ptr) = float_to_u8(blue);
                  if (write_alpha)
                      *reinterpret_cast<GLubyte*>(alpha_ptr) = float_to_u8(alpha);
                  break;
              case GL_SHORT:
                  if (write_red)
                      *reinterpret_cast<GLshort*>(red_ptr) = float_to_i16(red);
                  if (write_green)
                      *reinterpret_cast<GLshort*>(green_ptr) = float_to_i16(green);
                  if (write_blue)
                      *reinterpret_cast<GLshort*>(blue_ptr) = float_to_i16(blue);
                  if (write_alpha)
                      *reinterpret_cast<GLshort*>(alpha_ptr) = float_to_i16(alpha);
                  break;
              case GL_UNSIGNED_SHORT:
                  if (write_red)
                      *reinterpret_cast<GLushort*>(red_ptr) = float_to_u16(red);
                  if (write_green)
                      *reinterpret_cast<GLushort*>(green_ptr) = float_to_u16(green);
                  if (write_blue)
                      *reinterpret_cast<GLushort*>(blue_ptr) = float_to_u16(blue);
                  if (write_alpha)
                      *reinterpret_cast<GLushort*>(alpha_ptr) = float_to_u16(alpha);
                  break;
              case GL_INT:
                  if (write_red)
                      *reinterpret_cast<GLint*>(red_ptr) = float_to_i32(red);
                  if (write_green)
                      *reinterpret_cast<GLint*>(green_ptr) = float_to_i32(green);
                  if (write_blue)
                      *reinterpret_cast<GLint*>(blue_ptr) = float_to_i32(blue);
                  if (write_alpha)
                      *reinterpret_cast<GLint*>(alpha_ptr) = float_to_i32(alpha);
                  break;
              case GL_UNSIGNED_INT:
                  if (write_red)
                      *reinterpret_cast<GLuint*>(red_ptr) = float_to_u32(red);
                  if (write_green)
                      *reinterpret_cast<GLuint*>(green_ptr) = float_to_u32(green);
                  if (write_blue)
                      *reinterpret_cast<GLuint*>(blue_ptr) = float_to_u32(blue);
                  if (write_alpha)
                      *reinterpret_cast<GLuint*>(alpha_ptr) = float_to_u32(alpha);
                  break;
              case GL_FLOAT:
                  if (write_red)
                      *reinterpret_cast<GLfloat*>(red_ptr) = min(max(red, 0.0f), 1.0f);
                  if (write_green)
                      *reinterpret_cast<GLfloat*>(green_ptr) = min(max(green, 0.0f), 1.0f);
                  if (write_blue)
                      *reinterpret_cast<GLfloat*>(blue_ptr) = min(max(blue, 0.0f), 1.0f);
                  if (write_alpha)
                      *reinterpret_cast<GLfloat*>(alpha_ptr) = min(max(alpha, 0.0f), 1.0f);
                  break;
              }
  
              out_ptr += pixel_bytes;
          }
  
          out_ptr += row_alignment_bytes;
      }
  }
  
  void GLContext::gl_bind_texture(GLenum target, GLuint texture)
  {
      RETURN_WITH_ERROR_IF(m_in_draw_state, GL_INVALID_OPERATION);
      RETURN_WITH_ERROR_IF(target != GL_TEXTURE_1D
              && target != GL_TEXTURE_2D
              && target != GL_TEXTURE_3D
              && target != GL_TEXTURE_1D_ARRAY
              && target != GL_TEXTURE_2D_ARRAY
              && target != GL_TEXTURE_CUBE_MAP,
          GL_INVALID_ENUM);
  
      // FIXME: We only support GL_TEXTURE_2D for now
      if (target != GL_TEXTURE_2D) {
          dbgln("gl_bind_texture(target = {:#x}): currently only GL_TEXTURE_2D is supported", target);
          return;
      }
  
      RefPtr<Texture2D> texture_2d;
  
      if (texture == 0) {
          // Texture name 0 refers to the default texture
          texture_2d = get_default_texture<Texture2D>(target);
      } else {
          // Find this texture name in our previously allocated textures
          auto it = m_allocated_textures.find(texture);
          if (it != m_allocated_textures.end()) {
              auto texture_object = it->value;
              if (!texture_object.is_null()) {
                  // Texture must have been created with the same target
                  RETURN_WITH_ERROR_IF(!texture_object->is_texture_2d(), GL_INVALID_OPERATION);
                  texture_2d = static_cast<Texture2D*>(texture_object.ptr());
              }
          }
  
          // OpenGL 1.x supports binding texture names that were not previously generated by glGenTextures.
          // If there is not an allocated texture, meaning it was not previously generated by glGenTextures,
          // we can keep texture_object null to both allocate and bind the texture with the passed in texture name.
          // FIXME: Later OpenGL versions such as 4.x enforce that texture names being bound were previously generated
          //        by glGenTextures.
          if (!texture_2d) {
              texture_2d = adopt_ref(*new Texture2D());
              m_allocated_textures.set(texture, texture_2d);
          }
      }
  
      m_active_texture_unit->set_texture_2d_target_texture(texture_2d);
      m_sampler_config_is_dirty = true;
  }
  
  GLboolean GLContext::gl_is_texture(GLuint texture)
  {
      RETURN_VALUE_WITH_ERROR_IF(m_in_draw_state, GL_INVALID_OPERATION, GL_FALSE);
  
      if (texture == 0)
          return GL_FALSE;
  
      auto it = m_allocated_textures.find(texture);
      if (it == m_allocated_textures.end())
          return GL_FALSE;
  
      return it->value.is_null() ? GL_FALSE : GL_TRUE;
  }
  
  void GLContext::gl_active_texture(GLenum texture)
  {
      RETURN_WITH_ERROR_IF(texture < GL_TEXTURE0 || texture >= GL_TEXTURE0 + m_device_info.num_texture_units, GL_INVALID_ENUM);
  
      m_active_texture_unit_index = texture - GL_TEXTURE0;
      m_active_texture_unit = &m_texture_units.at(m_active_texture_unit_index);
  }
  
  void GLContext::gl_get_booleanv(GLenum pname, GLboolean* data)
  {
      RETURN_WITH_ERROR_IF(m_in_draw_state, GL_INVALID_OPERATION);
  
      auto optional_parameter = get_context_parameter(pname);
      RETURN_WITH_ERROR_IF(!optional_parameter.has_value(), GL_INVALID_ENUM);
      auto parameter = optional_parameter.release_value();
  
      switch (parameter.type) {
      case GL_BOOL:
          *data = parameter.value.boolean_value ? GL_TRUE : GL_FALSE;
          break;
      case GL_DOUBLE:
          *data = (parameter.value.double_value == 0.0) ? GL_FALSE : GL_TRUE;
          break;
      case GL_INT:
          *data = (parameter.value.integer_value == 0) ? GL_FALSE : GL_TRUE;
          break;
      default:
          VERIFY_NOT_REACHED();
      }
  }
  
  void GLContext::gl_get_doublev(GLenum pname, GLdouble* params)
  {
      get_floating_point(pname, params);
  }
  
  void GLContext::gl_get_floatv(GLenum pname, GLfloat* params)
  {
      get_floating_point(pname, params);
  }
  
  template<typename T>
  void GLContext::get_floating_point(GLenum pname, T* params)
  {
      RETURN_WITH_ERROR_IF(m_in_draw_state, GL_INVALID_OPERATION);
  
      // Handle matrix retrieval first
      auto flatten_and_assign_matrix = [&params](FloatMatrix4x4 const& matrix) {
          auto elements = matrix.elements();
          for (size_t i = 0; i < 4; ++i) {
              for (size_t j = 0; j < 4; ++j) {
                  // Return transposed matrix since OpenGL defines them as column-major
                  params[i * 4 + j] = static_cast<T>(elements[j][i]);
              }
          }
      };
      switch (pname) {
      case GL_MODELVIEW_MATRIX:
          flatten_and_assign_matrix(m_model_view_matrix);
          return;
      case GL_PROJECTION_MATRIX:
          flatten_and_assign_matrix(m_projection_matrix);
          return;
      }
  
      // Regular parameters
      auto optional_parameter = get_context_parameter(pname);
      RETURN_WITH_ERROR_IF(!optional_parameter.has_value(), GL_INVALID_ENUM);
      auto parameter = optional_parameter.release_value();
  
      switch (parameter.type) {
      case GL_BOOL:
          *params = parameter.value.boolean_value ? GL_TRUE : GL_FALSE;
          break;
      case GL_DOUBLE:
          for (size_t i = 0; i < parameter.count; ++i)
              params[i] = parameter.value.double_list[i];
          break;
      case GL_INT:
          for (size_t i = 0; i < parameter.count; ++i)
              params[i] = parameter.value.integer_list[i];
          break;
      default:
          VERIFY_NOT_REACHED();
      }
  }
  
  void GLContext::gl_get_integerv(GLenum pname, GLint* data)
  {
      RETURN_WITH_ERROR_IF(m_in_draw_state, GL_INVALID_OPERATION);
  
      auto optional_parameter = get_context_parameter(pname);
      RETURN_WITH_ERROR_IF(!optional_parameter.has_value(), GL_INVALID_ENUM);
      auto parameter = optional_parameter.release_value();
  
      switch (parameter.type) {
      case GL_BOOL:
          *data = parameter.value.boolean_value ? GL_TRUE : GL_FALSE;
          break;
      case GL_DOUBLE: {
          double const int_range = static_cast<double>(NumericLimits<GLint>::max()) - NumericLimits<GLint>::min();
          for (size_t i = 0; i < parameter.count; ++i) {
              double const result_factor = (clamp(parameter.value.double_list[i], -1.0, 1.0) + 1.0) / 2.0;
              data[i] = static_cast<GLint>(NumericLimits<GLint>::min() + result_factor * int_range);
          }
          break;
      }
      case GL_INT:
          for (size_t i = 0; i < parameter.count; ++i)
              data[i] = parameter.value.integer_list[i];
          break;
      default:
          VERIFY_NOT_REACHED();
      }
  }
  
  void GLContext::gl_depth_mask(GLboolean flag)
  {
      APPEND_TO_CALL_LIST_AND_RETURN_IF_NEEDED(gl_depth_mask, flag);
  
      RETURN_WITH_ERROR_IF(m_in_draw_state, GL_INVALID_OPERATION);
  
      auto options = m_rasterizer.options();
      options.enable_depth_write = (flag != GL_FALSE);
      m_rasterizer.set_options(options);
  }
  
  void GLContext::gl_enable_client_state(GLenum cap)
  {
      RETURN_WITH_ERROR_IF(m_in_draw_state, GL_INVALID_OPERATION);
  
      switch (cap) {
      case GL_COLOR_ARRAY:
          m_client_side_color_array_enabled = true;
          break;
      case GL_NORMAL_ARRAY:
          m_client_side_normal_array_enabled = true;
          break;
      case GL_TEXTURE_COORD_ARRAY:
          m_client_side_texture_coord_array_enabled[m_client_active_texture] = true;
          break;
      case GL_VERTEX_ARRAY:
          m_client_side_vertex_array_enabled = true;
          break;
      default:
          RETURN_WITH_ERROR_IF(true, GL_INVALID_ENUM);
      }
  }
  
  void GLContext::gl_disable_client_state(GLenum cap)
  {
      RETURN_WITH_ERROR_IF(m_in_draw_state, GL_INVALID_OPERATION);
  
      switch (cap) {
      case GL_COLOR_ARRAY:
          m_client_side_color_array_enabled = false;
          break;
      case GL_NORMAL_ARRAY:
          m_client_side_normal_array_enabled = false;
          break;
      case GL_TEXTURE_COORD_ARRAY:
          m_client_side_texture_coord_array_enabled[m_client_active_texture] = false;
          break;
      case GL_VERTEX_ARRAY:
          m_client_side_vertex_array_enabled = false;
          break;
      default:
          RETURN_WITH_ERROR_IF(true, GL_INVALID_ENUM);
      }
  }
  
  void GLContext::gl_client_active_texture(GLenum target)
  {
      RETURN_WITH_ERROR_IF(target < GL_TEXTURE0 || target >= GL_TEXTURE0 + m_device_info.num_texture_units, GL_INVALID_ENUM);
  
      m_client_active_texture = target - GL_TEXTURE0;
  }
  
  void GLContext::gl_vertex_pointer(GLint size, GLenum type, GLsizei stride, const void* pointer)
  {
      RETURN_WITH_ERROR_IF(m_in_draw_state, GL_INVALID_OPERATION);
      RETURN_WITH_ERROR_IF(!(size == 2 || size == 3 || size == 4), GL_INVALID_VALUE);
      RETURN_WITH_ERROR_IF(!(type == GL_SHORT || type == GL_INT || type == GL_FLOAT || type == GL_DOUBLE), GL_INVALID_ENUM);
      RETURN_WITH_ERROR_IF(stride < 0, GL_INVALID_VALUE);
  
      m_client_vertex_pointer = { .size = size, .type = type, .stride = stride, .pointer = pointer };
  }
  
  void GLContext::gl_color_pointer(GLint size, GLenum type, GLsizei stride, const void* pointer)
  {
      RETURN_WITH_ERROR_IF(m_in_draw_state, GL_INVALID_OPERATION);
      RETURN_WITH_ERROR_IF(!(size == 3 || size == 4), GL_INVALID_VALUE);
      RETURN_WITH_ERROR_IF(type != GL_BYTE
              && type != GL_UNSIGNED_BYTE
              && type != GL_SHORT
              && type != GL_UNSIGNED_SHORT
              && type != GL_INT
              && type != GL_UNSIGNED_INT
              && type != GL_FLOAT
              && type != GL_DOUBLE,
          GL_INVALID_ENUM);
      RETURN_WITH_ERROR_IF(stride < 0, GL_INVALID_VALUE);
  
      m_client_color_pointer = { .size = size, .type = type, .stride = stride, .pointer = pointer };
  }
  
  void GLContext::gl_tex_coord_pointer(GLint size, GLenum type, GLsizei stride, const void* pointer)
  {
      RETURN_WITH_ERROR_IF(m_in_draw_state, GL_INVALID_OPERATION);
      RETURN_WITH_ERROR_IF(!(size == 1 || size == 2 || size == 3 || size == 4), GL_INVALID_VALUE);
      RETURN_WITH_ERROR_IF(!(type == GL_SHORT || type == GL_INT || type == GL_FLOAT || type == GL_DOUBLE), GL_INVALID_ENUM);
      RETURN_WITH_ERROR_IF(stride < 0, GL_INVALID_VALUE);
  
      auto& tex_coord_pointer = m_client_tex_coord_pointer[m_client_active_texture];
      tex_coord_pointer = { .size = size, .type = type, .stride = stride, .pointer = pointer };
  }
  
  void GLContext::gl_normal_pointer(GLenum type, GLsizei stride, void const* pointer)
  {
      RETURN_WITH_ERROR_IF(m_in_draw_state, GL_INVALID_OPERATION);
      RETURN_WITH_ERROR_IF(type != GL_BYTE
              && type != GL_SHORT
              && type != GL_INT
              && type != GL_FLOAT
              && type != GL_DOUBLE,
          GL_INVALID_ENUM);
      RETURN_WITH_ERROR_IF(stride < 0, GL_INVALID_VALUE);
  
      m_client_normal_pointer = { .size = 3, .type = type, .stride = stride, .pointer = pointer };
  }
  
  void GLContext::gl_tex_env(GLenum target, GLenum pname, GLfloat param)
  {
      APPEND_TO_CALL_LIST_AND_RETURN_IF_NEEDED(gl_tex_env, target, pname, param);
      RETURN_WITH_ERROR_IF(m_in_draw_state, GL_INVALID_OPERATION);
  
      // FIXME: We currently only support a subset of possible target values. Implement the rest!
      RETURN_WITH_ERROR_IF(target != GL_TEXTURE_ENV, GL_INVALID_ENUM);
  
      // FIXME: We currently only support a subset of possible pname values. Implement the rest!
      RETURN_WITH_ERROR_IF(pname != GL_TEXTURE_ENV_MODE, GL_INVALID_ENUM);
  
      auto param_enum = static_cast<GLenum>(param);
  
      switch (param_enum) {
      case GL_MODULATE:
      case GL_REPLACE:
      case GL_DECAL:
          m_active_texture_unit->set_env_mode(param_enum);
          m_sampler_config_is_dirty = true;
          break;
      default:
          // FIXME: We currently only support a subset of possible param values. Implement the rest!
          dbgln_if(GL_DEBUG, "gl_tex_env({:#x}, {:#x}, {}): param unimplemented", target, pname, param);
          RETURN_WITH_ERROR_IF(true, GL_INVALID_ENUM);
      }
  }
  
  void GLContext::gl_draw_arrays(GLenum mode, GLint first, GLsizei count)
  {
      APPEND_TO_CALL_LIST_AND_RETURN_IF_NEEDED(gl_draw_arrays, mode, first, count);
      RETURN_WITH_ERROR_IF(m_in_draw_state, GL_INVALID_OPERATION);
  
      // FIXME: Some modes are still missing (GL_POINTS, GL_LINE_STRIP, GL_LINE_LOOP, GL_LINES)
      RETURN_WITH_ERROR_IF(!(mode == GL_TRIANGLE_STRIP
                               || mode == GL_TRIANGLE_FAN
                               || mode == GL_TRIANGLES
                               || mode == GL_QUADS
                               || mode == GL_QUAD_STRIP
                               || mode == GL_POLYGON),
          GL_INVALID_ENUM);
  
      RETURN_WITH_ERROR_IF(count < 0, GL_INVALID_VALUE);
  
      // At least the vertex array needs to be enabled
      if (!m_client_side_vertex_array_enabled)
          return;
  
      auto last = first + count;
      gl_begin(mode);
      for (int i = first; i < last; i++) {
          if (m_client_side_color_array_enabled) {
              float color[4] { 0, 0, 0, 1 };
              read_from_vertex_attribute_pointer(m_client_color_pointer, i, color, true);
              gl_color(color[0], color[1], color[2], color[3]);
          }
  
          for (size_t t = 0; t < m_client_tex_coord_pointer.size(); ++t) {
              if (m_client_side_texture_coord_array_enabled[t]) {
                  float tex_coords[4] { 0, 0, 0, 0 };
                  read_from_vertex_attribute_pointer(m_client_tex_coord_pointer[t], i, tex_coords, false);
                  gl_multi_tex_coord(GL_TEXTURE0 + t, tex_coords[0], tex_coords[1], tex_coords[2], tex_coords[3]);
              }
          }
  
          if (m_client_side_normal_array_enabled) {
              float normal[3];
              read_from_vertex_attribute_pointer(m_client_normal_pointer, i, normal, false);
              gl_normal(normal[0], normal[1], normal[2]);
          }
  
          float vertex[4] { 0, 0, 0, 1 };
          read_from_vertex_attribute_pointer(m_client_vertex_pointer, i, vertex, false);
          gl_vertex(vertex[0], vertex[1], vertex[2], vertex[3]);
      }
      gl_end();
  }
  
  void GLContext::gl_draw_elements(GLenum mode, GLsizei count, GLenum type, const void* indices)
  {
      APPEND_TO_CALL_LIST_AND_RETURN_IF_NEEDED(gl_draw_elements, mode, count, type, indices);
      RETURN_WITH_ERROR_IF(m_in_draw_state, GL_INVALID_OPERATION);
  
      // FIXME: Some modes are still missing (GL_POINTS, GL_LINE_STRIP, GL_LINE_LOOP, GL_LINES)
      RETURN_WITH_ERROR_IF(!(mode == GL_TRIANGLE_STRIP
                               || mode == GL_TRIANGLE_FAN
                               || mode == GL_TRIANGLES
                               || mode == GL_QUADS
                               || mode == GL_QUAD_STRIP
                               || mode == GL_POLYGON),
          GL_INVALID_ENUM);
  
      RETURN_WITH_ERROR_IF(!(type == GL_UNSIGNED_BYTE
                               || type == GL_UNSIGNED_SHORT
                               || type == GL_UNSIGNED_INT),
          GL_INVALID_ENUM);
  
      RETURN_WITH_ERROR_IF(count < 0, GL_INVALID_VALUE);
  
      // At least the vertex array needs to be enabled
      if (!m_client_side_vertex_array_enabled)
          return;
  
      gl_begin(mode);
      for (int index = 0; index < count; index++) {
          int i = 0;
          switch (type) {
          case GL_UNSIGNED_BYTE:
              i = reinterpret_cast<const GLubyte*>(indices)[index];
              break;
          case GL_UNSIGNED_SHORT:
              i = reinterpret_cast<const GLushort*>(indices)[index];
              break;
          case GL_UNSIGNED_INT:
              i = reinterpret_cast<const GLuint*>(indices)[index];
              break;
          }
  
          if (m_client_side_color_array_enabled) {
              float color[4] { 0, 0, 0, 1 };
              read_from_vertex_attribute_pointer(m_client_color_pointer, i, color, true);
              gl_color(color[0], color[1], color[2], color[3]);
          }
  
          for (size_t t = 0; t < m_client_tex_coord_pointer.size(); ++t) {
              if (m_client_side_texture_coord_array_enabled[t]) {
                  float tex_coords[4] { 0, 0, 0, 0 };
                  read_from_vertex_attribute_pointer(m_client_tex_coord_pointer[t], i, tex_coords, false);
                  gl_multi_tex_coord(GL_TEXTURE0 + t, tex_coords[0], tex_coords[1], tex_coords[2], tex_coords[3]);
              }
          }
  
          if (m_client_side_normal_array_enabled) {
              float normal[3];
              read_from_vertex_attribute_pointer(m_client_normal_pointer, i, normal, false);
              gl_normal(normal[0], normal[1], normal[2]);
          }
  
          float vertex[4] { 0, 0, 0, 1 };
          read_from_vertex_attribute_pointer(m_client_vertex_pointer, i, vertex, false);
          gl_vertex(vertex[0], vertex[1], vertex[2], vertex[3]);
      }
      gl_end();
  }
  
  void GLContext::gl_draw_pixels(GLsizei width, GLsizei height, GLenum format, GLenum type, const void* data)
  {
      APPEND_TO_CALL_LIST_AND_RETURN_IF_NEEDED(gl_draw_pixels, width, height, format, type, data);
  
      RETURN_WITH_ERROR_IF(format < GL_COLOR_INDEX || format > GL_BGRA, GL_INVALID_ENUM);
  
      RETURN_WITH_ERROR_IF((type < GL_BYTE || type > GL_FLOAT)
              && (type < GL_UNSIGNED_BYTE_3_3_2 || type > GL_UNSIGNED_INT_10_10_10_2)
              && (type < GL_UNSIGNED_BYTE_2_3_3_REV || type > GL_UNSIGNED_INT_2_10_10_10_REV),
          GL_INVALID_ENUM);
  
      RETURN_WITH_ERROR_IF(type == GL_BITMAP && !(format == GL_COLOR_INDEX || format == GL_STENCIL_INDEX), GL_INVALID_ENUM);
  
      RETURN_WITH_ERROR_IF(width < 0 || height < 0, GL_INVALID_VALUE);
  
      // FIXME: GL_INVALID_OPERATION is generated if format is GL_STENCIL_INDEX and there is no stencil buffer
      // FIXME: GL_INVALID_OPERATION is generated if format is GL_RED, GL_GREEN, GL_BLUE, GL_ALPHA, GL_RGB, GL_RGBA,
      //        GL_BGR, GL_BGRA, GL_LUMINANCE, or GL_LUMINANCE_ALPHA, and the GL is in color index mode
  
      RETURN_WITH_ERROR_IF(format != GL_RGB
              && (type == GL_UNSIGNED_BYTE_3_3_2
                  || type == GL_UNSIGNED_BYTE_2_3_3_REV
                  || type == GL_UNSIGNED_SHORT_5_6_5
                  || type == GL_UNSIGNED_SHORT_5_6_5_REV),
          GL_INVALID_OPERATION);
  
      RETURN_WITH_ERROR_IF(!(format == GL_RGBA || format == GL_BGRA)
              && (type == GL_UNSIGNED_SHORT_4_4_4_4
                  || type == GL_UNSIGNED_SHORT_4_4_4_4_REV
                  || type == GL_UNSIGNED_SHORT_5_5_5_1
                  || type == GL_UNSIGNED_SHORT_1_5_5_5_REV
                  || type == GL_UNSIGNED_INT_8_8_8_8
                  || type == GL_UNSIGNED_INT_8_8_8_8_REV
                  || type == GL_UNSIGNED_INT_10_10_10_2
                  || type == GL_UNSIGNED_INT_2_10_10_10_REV),
          GL_INVALID_OPERATION);
  
      // FIXME: GL_INVALID_OPERATION is generated if a non-zero buffer object name is bound to the GL_PIXEL_UNPACK_BUFFER
      //        target and the buffer object's data store is currently mapped.
      // FIXME: GL_INVALID_OPERATION is generated if a non-zero buffer object name is bound to the GL_PIXEL_UNPACK_BUFFER
      //        target and the data would be unpacked from the buffer object such that the memory reads required would
      //        exceed the data store size.
      // FIXME: GL_INVALID_OPERATION is generated if a non-zero buffer object name is bound to the GL_PIXEL_UNPACK_BUFFER
      //        target and data is not evenly divisible into the number of bytes needed to store in memory a datum
      //        indicated by type.
  
      RETURN_WITH_ERROR_IF(m_in_draw_state, GL_INVALID_OPERATION);
  
      // FIXME: we only support RGBA + UNSIGNED_BYTE and DEPTH_COMPONENT + UNSIGNED_SHORT, implement all combinations!
      if (!((format == GL_RGBA && type == GL_UNSIGNED_BYTE) || (format == GL_DEPTH_COMPONENT && type == GL_UNSIGNED_SHORT))) {
          dbgln_if(GL_DEBUG, "gl_draw_pixels(): support for format {:#x} and/or type {:#x} not implemented", format, type);
          return;
      }
  
      // FIXME: implement support for pixel parameters such as GL_UNPACK_ALIGNMENT
  
      if (format == GL_RGBA) {
          auto bitmap_or_error = Gfx::Bitmap::try_create(Gfx::BitmapFormat::BGRA8888, { width, height });
          RETURN_WITH_ERROR_IF(bitmap_or_error.is_error(), GL_OUT_OF_MEMORY);
          auto bitmap = bitmap_or_error.release_value();
  
          auto pixel_data = static_cast<u32 const*>(data);
          for (int y = 0; y < height; ++y)
              for (int x = 0; x < width; ++x)
                  bitmap->set_pixel(x, y, Color::from_argb(*(pixel_data++)));
  
          m_rasterizer.blit_to_color_buffer_at_raster_position(bitmap);
      } else if (format == GL_DEPTH_COMPONENT) {
          Vector<float> depth_values;
          depth_values.ensure_capacity(width * height);
  
          auto depth_data = static_cast<u16 const*>(data);
          for (int y = 0; y < height; ++y) {
              for (int x = 0; x < width; ++x) {
                  auto u16_value = *(depth_data++);
                  auto float_value = static_cast<float>(u16_value) / NumericLimits<u16>::max();
                  depth_values.append(float_value);
              }
          }
  
          m_rasterizer.blit_to_depth_buffer_at_raster_position(depth_values, width, height);
      } else {
          VERIFY_NOT_REACHED();
      }
  }
  
  void GLContext::gl_depth_range(GLdouble min, GLdouble max)
  {
      APPEND_TO_CALL_LIST_AND_RETURN_IF_NEEDED(gl_depth_range, min, max);
  
      RETURN_WITH_ERROR_IF(m_in_draw_state, GL_INVALID_OPERATION);
  
      auto options = m_rasterizer.options();
      options.depth_min = clamp<float>(min, 0.f, 1.f);
      options.depth_max = clamp<float>(max, 0.f, 1.f);
      m_rasterizer.set_options(options);
  }
  
  void GLContext::gl_depth_func(GLenum func)
  {
      APPEND_TO_CALL_LIST_AND_RETURN_IF_NEEDED(gl_depth_func, func);
  
      RETURN_WITH_ERROR_IF(m_in_draw_state, GL_INVALID_OPERATION);
  
      RETURN_WITH_ERROR_IF(!(func == GL_NEVER
                               || func == GL_LESS
                               || func == GL_EQUAL
                               || func == GL_LEQUAL
                               || func == GL_GREATER
                               || func == GL_NOTEQUAL
                               || func == GL_GEQUAL
                               || func == GL_ALWAYS),
          GL_INVALID_ENUM);
  
      auto options = m_rasterizer.options();
  
      switch (func) {
      case GL_NEVER:
          options.depth_func = SoftGPU::DepthTestFunction::Never;
          break;
      case GL_ALWAYS:
          options.depth_func = SoftGPU::DepthTestFunction::Always;
          break;
      case GL_LESS:
          options.depth_func = SoftGPU::DepthTestFunction::Less;
          break;
      case GL_LEQUAL:
          options.depth_func = SoftGPU::DepthTestFunction::LessOrEqual;
          break;
      case GL_EQUAL:
          options.depth_func = SoftGPU::DepthTestFunction::Equal;
          break;
      case GL_NOTEQUAL:
          options.depth_func = SoftGPU::DepthTestFunction::NotEqual;
          break;
      case GL_GEQUAL:
          options.depth_func = SoftGPU::DepthTestFunction::GreaterOrEqual;
          break;
      case GL_GREATER:
          options.depth_func = SoftGPU::DepthTestFunction::Greater;
          break;
      default:
          VERIFY_NOT_REACHED();
      }
  
      m_rasterizer.set_options(options);
  }
  
  // General helper function to read arbitrary vertex attribute data into a float array
  void GLContext::read_from_vertex_attribute_pointer(VertexAttribPointer const& attrib, int index, float* elements, bool normalize)
  {
      auto byte_ptr = reinterpret_cast<const char*>(attrib.pointer);
      size_t stride = attrib.stride;
  
      switch (attrib.type) {
      case GL_BYTE: {
          if (stride == 0)
              stride = sizeof(GLbyte) * attrib.size;
  
          for (int i = 0; i < attrib.size; i++) {
              elements[i] = *(reinterpret_cast<const GLbyte*>(byte_ptr + stride * index) + i);
              if (normalize)
                  elements[i] /= 0x80;
          }
          break;
      }
      case GL_UNSIGNED_BYTE: {
          if (stride == 0)
              stride = sizeof(GLubyte) * attrib.size;
  
          for (int i = 0; i < attrib.size; i++) {
              elements[i] = *(reinterpret_cast<const GLubyte*>(byte_ptr + stride * index) + i);
              if (normalize)
                  elements[i] /= 0xff;
          }
          break;
      }
      case GL_SHORT: {
          if (stride == 0)
              stride = sizeof(GLshort) * attrib.size;
  
          for (int i = 0; i < attrib.size; i++) {
              elements[i] = *(reinterpret_cast<const GLshort*>(byte_ptr + stride * index) + i);
              if (normalize)
                  elements[i] /= 0x8000;
          }
          break;
      }
      case GL_UNSIGNED_SHORT: {
          if (stride == 0)
              stride = sizeof(GLushort) * attrib.size;
  
          for (int i = 0; i < attrib.size; i++) {
              elements[i] = *(reinterpret_cast<const GLushort*>(byte_ptr + stride * index) + i);
              if (normalize)
                  elements[i] /= 0xffff;
          }
          break;
      }
      case GL_INT: {
          if (stride == 0)
              stride = sizeof(GLint) * attrib.size;
  
          for (int i = 0; i < attrib.size; i++) {
              elements[i] = *(reinterpret_cast<const GLint*>(byte_ptr + stride * index) + i);
              if (normalize)
                  elements[i] /= 0x80000000;
          }
          break;
      }
      case GL_UNSIGNED_INT: {
          if (stride == 0)
              stride = sizeof(GLuint) * attrib.size;
  
          for (int i = 0; i < attrib.size; i++) {
              elements[i] = *(reinterpret_cast<const GLuint*>(byte_ptr + stride * index) + i);
              if (normalize)
                  elements[i] /= 0xffffffff;
          }
          break;
      }
      case GL_FLOAT: {
          if (stride == 0)
              stride = sizeof(GLfloat) * attrib.size;
  
          for (int i = 0; i < attrib.size; i++)
              elements[i] = *(reinterpret_cast<const GLfloat*>(byte_ptr + stride * index) + i);
          break;
      }
      case GL_DOUBLE: {
          if (stride == 0)
              stride = sizeof(GLdouble) * attrib.size;
  
          for (int i = 0; i < attrib.size; i++)
              elements[i] = static_cast<float>(*(reinterpret_cast<const GLdouble*>(byte_ptr + stride * index) + i));
          break;
      }
      }
  }
  
  void GLContext::gl_color_mask(GLboolean red, GLboolean green, GLboolean blue, GLboolean alpha)
  {
      auto options = m_rasterizer.options();
      auto mask = options.color_mask;
  
      if (!red)
          mask &= ~0x000000ff;
      else
          mask |= 0x000000ff;
  
      if (!green)
          mask &= ~0x0000ff00;
      else
          mask |= 0x0000ff00;
  
      if (!blue)
          mask &= ~0x00ff0000;
      else
          mask |= 0x00ff0000;
  
      if (!alpha)
          mask &= ~0xff000000;
      else
          mask |= 0xff000000;
  
      options.color_mask = mask;
      m_rasterizer.set_options(options);
  }
  
  void GLContext::gl_polygon_mode(GLenum face, GLenum mode)
  {
      RETURN_WITH_ERROR_IF(!(face == GL_BACK || face == GL_FRONT || face == GL_FRONT_AND_BACK), GL_INVALID_ENUM);
      RETURN_WITH_ERROR_IF(!(mode == GL_POINT || mode == GL_LINE || mode == GL_FILL), GL_INVALID_ENUM);
      RETURN_WITH_ERROR_IF(m_in_draw_state, GL_INVALID_OPERATION);
  
      auto options = m_rasterizer.options();
  
      // FIXME: This must support different polygon modes for front- and backside
      if (face == GL_BACK) {
          dbgln_if(GL_DEBUG, "gl_polygon_mode(GL_BACK, {:#x}): unimplemented", mode);
          return;
      }
  
      auto map_mode = [](GLenum mode) -> SoftGPU::PolygonMode {
          switch (mode) {
          case GL_FILL:
              return SoftGPU::PolygonMode::Fill;
          case GL_LINE:
              return SoftGPU::PolygonMode::Line;
          case GL_POINT:
              return SoftGPU::PolygonMode::Point;
          default:
              VERIFY_NOT_REACHED();
          }
      };
  
      options.polygon_mode = map_mode(mode);
      m_rasterizer.set_options(options);
  }
  
  void GLContext::gl_polygon_offset(GLfloat factor, GLfloat units)
  {
      APPEND_TO_CALL_LIST_AND_RETURN_IF_NEEDED(gl_polygon_offset, factor, units);
      RETURN_WITH_ERROR_IF(m_in_draw_state, GL_INVALID_OPERATION);
  
      auto rasterizer_options = m_rasterizer.options();
      rasterizer_options.depth_offset_factor = factor;
      rasterizer_options.depth_offset_constant = units;
      m_rasterizer.set_options(rasterizer_options);
  }
  
  void GLContext::gl_fogfv(GLenum pname, GLfloat* params)
  {
      APPEND_TO_CALL_LIST_AND_RETURN_IF_NEEDED(gl_fogfv, pname, params);
      RETURN_WITH_ERROR_IF(m_in_draw_state, GL_INVALID_OPERATION);
  
      auto options = m_rasterizer.options();
  
      switch (pname) {
      case GL_FOG_COLOR:
          options.fog_color = { params[0], params[1], params[2], params[3] };
          break;
      default:
          RETURN_WITH_ERROR_IF(true, GL_INVALID_ENUM);
      }
  
      m_rasterizer.set_options(options);
  }
  
  void GLContext::gl_fogf(GLenum pname, GLfloat param)
  {
      APPEND_TO_CALL_LIST_AND_RETURN_IF_NEEDED(gl_fogf, pname, param);
      RETURN_WITH_ERROR_IF(m_in_draw_state, GL_INVALID_OPERATION);
      RETURN_WITH_ERROR_IF(param < 0.0f, GL_INVALID_VALUE);
  
      auto options = m_rasterizer.options();
  
      switch (pname) {
      case GL_FOG_DENSITY:
          options.fog_density = param;
          break;
      case GL_FOG_END:
          options.fog_end = param;
          break;
      case GL_FOG_START:
          options.fog_start = param;
          break;
      default:
          RETURN_WITH_ERROR_IF(true, GL_INVALID_ENUM);
      }
  
      m_rasterizer.set_options(options);
  }
  
  void GLContext::gl_fogi(GLenum pname, GLint param)
  {
      APPEND_TO_CALL_LIST_AND_RETURN_IF_NEEDED(gl_fogi, pname, param);
      RETURN_WITH_ERROR_IF(m_in_draw_state, GL_INVALID_OPERATION);
      RETURN_WITH_ERROR_IF(param != GL_LINEAR && param != GL_EXP && param != GL_EXP2, GL_INVALID_ENUM);
  
      auto options = m_rasterizer.options();
  
      switch (pname) {
      case GL_FOG_MODE:
          switch (param) {
          case GL_LINEAR:
              options.fog_mode = SoftGPU::FogMode::Linear;
              break;
          case GL_EXP:
              options.fog_mode = SoftGPU::FogMode::Exp;
              break;
          case GL_EXP2:
              options.fog_mode = SoftGPU::FogMode::Exp2;
              break;
          }
          break;
      default:
          RETURN_WITH_ERROR_IF(true, GL_INVALID_ENUM);
      }
  
      m_rasterizer.set_options(options);
  }
  
  void GLContext::gl_pixel_storei(GLenum pname, GLint param)
  {
      // FIXME: Implement missing parameters
      switch (pname) {
      case GL_PACK_ALIGNMENT:
          RETURN_WITH_ERROR_IF(param != 1 && param != 2 && param != 4 && param != 8, GL_INVALID_VALUE);
          m_pack_alignment = param;
          break;
      case GL_UNPACK_ROW_LENGTH:
          RETURN_WITH_ERROR_IF(param < 0, GL_INVALID_VALUE);
          m_unpack_row_length = static_cast<size_t>(param);
          break;
      case GL_UNPACK_ALIGNMENT:
          RETURN_WITH_ERROR_IF(param != 1 && param != 2 && param != 4 && param != 8, GL_INVALID_VALUE);
          m_unpack_alignment = param;
          break;
      default:
          RETURN_WITH_ERROR_IF(true, GL_INVALID_ENUM);
          break;
      }
  }
  
  void GLContext::gl_scissor(GLint x, GLint y, GLsizei width, GLsizei height)
  {
      APPEND_TO_CALL_LIST_AND_RETURN_IF_NEEDED(gl_scissor, x, y, width, height);
      RETURN_WITH_ERROR_IF(width < 0 || height < 0, GL_INVALID_VALUE);
  
      auto options = m_rasterizer.options();
      options.scissor_box = { x, y, width, height };
      m_rasterizer.set_options(options);
  }
  
  void GLContext::gl_stencil_func_separate(GLenum face, GLenum func, GLint ref, GLuint mask)
  {
      APPEND_TO_CALL_LIST_AND_RETURN_IF_NEEDED(gl_stencil_func_separate, face, func, ref, mask);
      RETURN_WITH_ERROR_IF(m_in_draw_state, GL_INVALID_OPERATION);
  
      RETURN_WITH_ERROR_IF(!(face == GL_FRONT || face == GL_BACK || face == GL_FRONT_AND_BACK), GL_INVALID_ENUM);
  
      RETURN_WITH_ERROR_IF(!(func == GL_NEVER
                               || func == GL_LESS
                               || func == GL_LEQUAL
                               || func == GL_GREATER
                               || func == GL_GEQUAL
                               || func == GL_EQUAL
                               || func == GL_NOTEQUAL
                               || func == GL_ALWAYS),
          GL_INVALID_ENUM);
  
      ref = clamp(ref, 0, (1 << m_device_info.stencil_bits) - 1);
  
      StencilFunctionOptions new_options = { func, ref, mask };
      if (face == GL_FRONT || face == GL_FRONT_AND_BACK)
          m_stencil_function[Face::Front] = new_options;
      if (face == GL_BACK || face == GL_FRONT_AND_BACK)
          m_stencil_function[Face::Back] = new_options;
  
      m_stencil_configuration_dirty = true;
  }
  
  void GLContext::gl_stencil_mask_separate(GLenum face, GLuint mask)
  {
      APPEND_TO_CALL_LIST_AND_RETURN_IF_NEEDED(gl_stencil_mask_separate, face, mask);
      RETURN_WITH_ERROR_IF(m_in_draw_state, GL_INVALID_OPERATION);
  
      if (face == GL_FRONT || face == GL_FRONT_AND_BACK)
          m_stencil_operation[Face::Front].write_mask = mask;
      if (face == GL_BACK || face == GL_FRONT_AND_BACK)
          m_stencil_operation[Face::Back].write_mask = mask;
  
      m_stencil_configuration_dirty = true;
  }
  
  void GLContext::gl_stencil_op_separate(GLenum face, GLenum sfail, GLenum dpfail, GLenum dppass)
  {
      APPEND_TO_CALL_LIST_AND_RETURN_IF_NEEDED(gl_stencil_op_separate, face, sfail, dpfail, dppass);
      RETURN_WITH_ERROR_IF(m_in_draw_state, GL_INVALID_OPERATION);
  
      RETURN_WITH_ERROR_IF(!(face == GL_FRONT || face == GL_BACK || face == GL_FRONT_AND_BACK), GL_INVALID_ENUM);
  
      auto is_valid_op = [](GLenum op) -> bool {
          return op == GL_KEEP || op == GL_ZERO || op == GL_REPLACE || op == GL_INCR || op == GL_INCR_WRAP
              || op == GL_DECR || op == GL_DECR_WRAP || op == GL_INVERT;
      };
      RETURN_WITH_ERROR_IF(!is_valid_op(sfail), GL_INVALID_ENUM);
      RETURN_WITH_ERROR_IF(!is_valid_op(dpfail), GL_INVALID_ENUM);
      RETURN_WITH_ERROR_IF(!is_valid_op(dppass), GL_INVALID_ENUM);
  
      auto update_stencil_operation = [&](Face face, GLenum sfail, GLenum dpfail, GLenum dppass) {
          auto& stencil_operation = m_stencil_operation[face];
          stencil_operation.op_fail = sfail;
          stencil_operation.op_depth_fail = dpfail;
          stencil_operation.op_pass = dppass;
      };
      if (face == GL_FRONT || face == GL_FRONT_AND_BACK)
          update_stencil_operation(Face::Front, sfail, dpfail, dppass);
      if (face == GL_BACK || face == GL_FRONT_AND_BACK)
          update_stencil_operation(Face::Back, sfail, dpfail, dppass);
  
      m_stencil_configuration_dirty = true;
  }
  
  void GLContext::gl_normal(GLfloat nx, GLfloat ny, GLfloat nz)
  {
      APPEND_TO_CALL_LIST_AND_RETURN_IF_NEEDED(gl_normal, nx, ny, nz);
  
      m_current_vertex_normal = { nx, ny, nz };
  }
  
  void GLContext::gl_raster_pos(GLfloat x, GLfloat y, GLfloat z, GLfloat w)
  {
      APPEND_TO_CALL_LIST_AND_RETURN_IF_NEEDED(gl_raster_pos, x, y, z, w);
      RETURN_WITH_ERROR_IF(m_in_draw_state, GL_INVALID_OPERATION);
  
      m_rasterizer.set_raster_position({ x, y, z, w }, m_model_view_matrix, m_projection_matrix);
  }
  
  void GLContext::gl_line_width(GLfloat width)
  {
      APPEND_TO_CALL_LIST_AND_RETURN_IF_NEEDED(gl_line_width, width);
  
      RETURN_WITH_ERROR_IF(width <= 0, GL_INVALID_VALUE);
  
      m_line_width = width;
  }
  
  void GLContext::gl_push_attrib(GLbitfield mask)
  {
      APPEND_TO_CALL_LIST_AND_RETURN_IF_NEEDED(gl_push_attrib, mask);
      RETURN_WITH_ERROR_IF(m_in_draw_state, GL_INVALID_OPERATION);
  
      // FIXME: implement
      dbgln_if(GL_DEBUG, "GLContext FIXME: implement gl_push_attrib({})", mask);
  }
  
  void GLContext::gl_pop_attrib()
  {
      APPEND_TO_CALL_LIST_AND_RETURN_IF_NEEDED(gl_pop_attrib);
      RETURN_WITH_ERROR_IF(m_in_draw_state, GL_INVALID_OPERATION);
  
      // FIXME: implement
      dbgln_if(GL_DEBUG, "GLContext FIXME: implement gl_pop_attrib()");
  }
  
  void GLContext::gl_light_model(GLenum pname, GLfloat x, GLfloat y, GLfloat z, GLfloat w)
  {
      APPEND_TO_CALL_LIST_AND_RETURN_IF_NEEDED(gl_light_model, pname, x, y, z, w);
  
      RETURN_WITH_ERROR_IF(pname != GL_LIGHT_MODEL_LOCAL_VIEWER
              && pname != GL_LIGHT_MODEL_TWO_SIDE
              && pname != GL_LIGHT_MODEL_AMBIENT,
          GL_INVALID_ENUM);
  
      auto lighting_params = m_rasterizer.light_model();
      bool update_lighting_model = false;
  
      switch (pname) {
      case GL_LIGHT_MODEL_AMBIENT:
          lighting_params.scene_ambient_color = { x, y, z, w };
          update_lighting_model = true;
          break;
      case GL_LIGHT_MODEL_TWO_SIDE:
          VERIFY(y == 0.0f && z == 0.0f && w == 0.0f);
          lighting_params.two_sided_lighting = x;
          update_lighting_model = true;
          break;
      case GL_LIGHT_MODEL_LOCAL_VIEWER:
          // 0 means the viewer is at infinity
          // 1 means they're in local (eye) space
          lighting_params.viewer_at_infinity = (x != 1.0f);
          update_lighting_model = true;
          break;
      default:
          VERIFY_NOT_REACHED();
      }
  
      if (update_lighting_model)
          m_rasterizer.set_light_model_params(lighting_params);
  }
  
  void GLContext::gl_bitmap(GLsizei width, GLsizei height, GLfloat xorig, GLfloat yorig, GLfloat xmove, GLfloat ymove, GLubyte const* bitmap)
  {
      APPEND_TO_CALL_LIST_AND_RETURN_IF_NEEDED(gl_bitmap, width, height, xorig, yorig, xmove, ymove, bitmap);
      RETURN_WITH_ERROR_IF(m_in_draw_state, GL_INVALID_OPERATION);
  
      if (bitmap != nullptr) {
          // FIXME: implement
          dbgln_if(GL_DEBUG, "gl_bitmap({}, {}, {}, {}, {}, {}, {}): unimplemented", width, height, xorig, yorig, xmove, ymove, bitmap);
      }
  
      auto raster_position = m_rasterizer.raster_position();
      raster_position.window_coordinates += { xmove, ymove, 0.f, 0.f };
      m_rasterizer.set_raster_position(raster_position);
  }
  
  void GLContext::gl_copy_tex_image_2d(GLenum target, GLint level, GLenum internalformat, GLint x, GLint y, GLsizei width, GLsizei height, GLint border)
  {
      APPEND_TO_CALL_LIST_AND_RETURN_IF_NEEDED(gl_copy_tex_image_2d, target, level, internalformat, x, y, width, height, border);
      RETURN_WITH_ERROR_IF(m_in_draw_state, GL_INVALID_OPERATION);
  
      // FIXME: implement
      dbgln_if(GL_DEBUG, "GLContext FIXME: implement gl_copy_tex_image_2d({:#x}, {}, {:#x}, {}, {}, {}, {}, {})",
          target, level, internalformat, x, y, width, height, border);
  }
  
  void GLContext::gl_get_tex_parameter_integerv(GLenum target, GLint level, GLenum pname, GLint* params)
  {
      RETURN_WITH_ERROR_IF(m_in_draw_state, GL_INVALID_OPERATION);
      // FIXME: support targets other than GL_TEXTURE_2D
      RETURN_WITH_ERROR_IF(target != GL_TEXTURE_2D, GL_INVALID_ENUM);
      // FIXME: support other parameter names
      RETURN_WITH_ERROR_IF(pname < GL_TEXTURE_WIDTH || pname > GL_TEXTURE_HEIGHT, GL_INVALID_ENUM);
      RETURN_WITH_ERROR_IF(level < 0 || level > Texture2D::LOG2_MAX_TEXTURE_SIZE, GL_INVALID_VALUE);
      // FIXME: GL_INVALID_VALUE is generated if target is GL_TEXTURE_BUFFER and level is not zero
      // FIXME: GL_INVALID_OPERATION is generated if GL_TEXTURE_COMPRESSED_IMAGE_SIZE is queried on texture images with an uncompressed internal format or on proxy targets
  
      VERIFY(!m_active_texture_unit->texture_2d_target_texture().is_null());
      auto const texture_2d = m_active_texture_unit->texture_2d_target_texture();
  
      switch (pname) {
      case GL_TEXTURE_HEIGHT:
          *params = texture_2d->height_at_lod(level);
          break;
      case GL_TEXTURE_WIDTH:
          *params = texture_2d->width_at_lod(level);
          break;
      }
  }
  
  void GLContext::gl_rect(GLdouble x1, GLdouble y1, GLdouble x2, GLdouble y2)
  {
      APPEND_TO_CALL_LIST_AND_RETURN_IF_NEEDED(gl_rect, x1, y1, x2, y2);
      RETURN_WITH_ERROR_IF(m_in_draw_state, GL_INVALID_OPERATION);
  
      gl_begin(GL_POLYGON);
      gl_vertex(x1, y1, 0.0, 0.0);
      gl_vertex(x2, y1, 0.0, 0.0);
      gl_vertex(x2, y2, 0.0, 0.0);
      gl_vertex(x1, y2, 0.0, 0.0);
      gl_end();
  }
  
  void GLContext::gl_tex_gen(GLenum coord, GLenum pname, GLint param)
  {
      APPEND_TO_CALL_LIST_AND_RETURN_IF_NEEDED(gl_tex_gen, coord, pname, param);
      RETURN_WITH_ERROR_IF(m_in_draw_state, GL_INVALID_OPERATION);
  
      RETURN_WITH_ERROR_IF(coord < GL_S || coord > GL_Q, GL_INVALID_ENUM);
      RETURN_WITH_ERROR_IF(pname != GL_TEXTURE_GEN_MODE, GL_INVALID_ENUM);
      RETURN_WITH_ERROR_IF(param != GL_EYE_LINEAR
              && param != GL_OBJECT_LINEAR
              && param != GL_SPHERE_MAP
              && param != GL_NORMAL_MAP
              && param != GL_REFLECTION_MAP,
          GL_INVALID_ENUM);
      RETURN_WITH_ERROR_IF((coord == GL_R || coord == GL_Q) && param == GL_SPHERE_MAP, GL_INVALID_ENUM);
      RETURN_WITH_ERROR_IF(coord == GL_Q && (param == GL_REFLECTION_MAP || param == GL_NORMAL_MAP), GL_INVALID_ENUM);
  
      GLenum const capability = GL_TEXTURE_GEN_S + (coord - GL_S);
      texture_coordinate_generation(m_active_texture_unit_index, capability).generation_mode = param;
      m_texcoord_generation_dirty = true;
  }
  
  void GLContext::gl_tex_gen_floatv(GLenum coord, GLenum pname, GLfloat const* params)
  {
      APPEND_TO_CALL_LIST_AND_RETURN_IF_NEEDED(gl_tex_gen_floatv, coord, pname, params);
      RETURN_WITH_ERROR_IF(m_in_draw_state, GL_INVALID_OPERATION);
  
      RETURN_WITH_ERROR_IF(coord < GL_S || coord > GL_Q, GL_INVALID_ENUM);
      RETURN_WITH_ERROR_IF(pname != GL_TEXTURE_GEN_MODE
              && pname != GL_OBJECT_PLANE
              && pname != GL_EYE_PLANE,
          GL_INVALID_ENUM);
  
      GLenum const capability = GL_TEXTURE_GEN_S + (coord - GL_S);
  
      switch (pname) {
      case GL_TEXTURE_GEN_MODE: {
          auto param = static_cast<GLenum>(params[0]);
          RETURN_WITH_ERROR_IF(param != GL_EYE_LINEAR
                  && param != GL_OBJECT_LINEAR
                  && param != GL_SPHERE_MAP
                  && param != GL_NORMAL_MAP
                  && param != GL_REFLECTION_MAP,
              GL_INVALID_ENUM);
          RETURN_WITH_ERROR_IF((coord == GL_R || coord == GL_Q) && param == GL_SPHERE_MAP, GL_INVALID_ENUM);
          RETURN_WITH_ERROR_IF(coord == GL_Q && (param == GL_REFLECTION_MAP || param == GL_NORMAL_MAP), GL_INVALID_ENUM);
  
          texture_coordinate_generation(m_active_texture_unit_index, capability).generation_mode = param;
          break;
      }
      case GL_OBJECT_PLANE:
          texture_coordinate_generation(m_active_texture_unit_index, capability).object_plane_coefficients = { params[0], params[1], params[2], params[3] };
          break;
      case GL_EYE_PLANE: {
          auto const& inverse_model_view = m_model_view_matrix.inverse();
          auto input_coefficients = FloatVector4 { params[0], params[1], params[2], params[3] };
  
          // Note: we are allowed to store transformed coefficients here, according to the documentation on
          //       `glGetTexGen`:
          //
          // "The returned values are those maintained in eye coordinates. They are not equal to the values
          //  specified using glTexGen, unless the modelview matrix was identity when glTexGen was called."
  
          texture_coordinate_generation(m_active_texture_unit_index, capability).eye_plane_coefficients = inverse_model_view * input_coefficients;
          break;
      }
      default:
          VERIFY_NOT_REACHED();
      }
  
      m_texcoord_generation_dirty = true;
  }
  
  void GLContext::present()
  {
      m_rasterizer.blit_color_buffer_to(*m_frontbuffer);
  }
  
  void GLContext::sync_device_config()
  {
      sync_device_sampler_config();
      sync_device_texcoord_config();
      sync_light_state();
      sync_stencil_configuration();
  }
  
  void GLContext::sync_device_sampler_config()
  {
      if (!m_sampler_config_is_dirty)
          return;
  
      m_sampler_config_is_dirty = false;
  
      for (unsigned i = 0; i < m_texture_units.size(); ++i) {
          auto const& texture_unit = m_texture_units[i];
  
          if (!texture_unit.texture_2d_enabled())
              continue;
  
          SoftGPU::SamplerConfig config;
  
          auto texture_2d = texture_unit.texture_2d_target_texture();
          if (texture_2d.is_null()) {
              config.bound_image = nullptr;
              m_rasterizer.set_sampler_config(i, config);
              continue;
          }
  
          config.bound_image = texture_2d->device_image();
  
          auto const& sampler = texture_2d->sampler();
  
          switch (sampler.min_filter()) {
          case GL_NEAREST:
              config.texture_min_filter = SoftGPU::TextureFilter::Nearest;
              config.mipmap_filter = SoftGPU::MipMapFilter::None;
              break;
          case GL_LINEAR:
              config.texture_min_filter = SoftGPU::TextureFilter::Linear;
              config.mipmap_filter = SoftGPU::MipMapFilter::None;
              break;
          case GL_NEAREST_MIPMAP_NEAREST:
              config.texture_min_filter = SoftGPU::TextureFilter::Nearest;
              config.mipmap_filter = SoftGPU::MipMapFilter::Nearest;
              break;
          case GL_LINEAR_MIPMAP_NEAREST:
              config.texture_min_filter = SoftGPU::TextureFilter::Linear;
              config.mipmap_filter = SoftGPU::MipMapFilter::Nearest;
              break;
          case GL_NEAREST_MIPMAP_LINEAR:
              config.texture_min_filter = SoftGPU::TextureFilter::Nearest;
              config.mipmap_filter = SoftGPU::MipMapFilter::Linear;
              break;
          case GL_LINEAR_MIPMAP_LINEAR:
              config.texture_min_filter = SoftGPU::TextureFilter::Linear;
              config.mipmap_filter = SoftGPU::MipMapFilter::Linear;
              break;
          default:
              VERIFY_NOT_REACHED();
          }
  
          switch (sampler.mag_filter()) {
          case GL_NEAREST:
              config.texture_mag_filter = SoftGPU::TextureFilter::Nearest;
              break;
          case GL_LINEAR:
              config.texture_mag_filter = SoftGPU::TextureFilter::Linear;
              break;
          default:
              VERIFY_NOT_REACHED();
          }
  
          switch (sampler.wrap_s_mode()) {
          case GL_CLAMP:
              config.texture_wrap_u = SoftGPU::TextureWrapMode::Clamp;
              break;
          case GL_CLAMP_TO_BORDER:
              config.texture_wrap_u = SoftGPU::TextureWrapMode::ClampToBorder;
              break;
          case GL_CLAMP_TO_EDGE:
              config.texture_wrap_u = SoftGPU::TextureWrapMode::ClampToEdge;
              break;
          case GL_REPEAT:
              config.texture_wrap_u = SoftGPU::TextureWrapMode::Repeat;
              break;
          case GL_MIRRORED_REPEAT:
              config.texture_wrap_u = SoftGPU::TextureWrapMode::MirroredRepeat;
              break;
          default:
              VERIFY_NOT_REACHED();
          }
  
          switch (sampler.wrap_t_mode()) {
          case GL_CLAMP:
              config.texture_wrap_v = SoftGPU::TextureWrapMode::Clamp;
              break;
          case GL_CLAMP_TO_BORDER:
              config.texture_wrap_v = SoftGPU::TextureWrapMode::ClampToBorder;
              break;
          case GL_CLAMP_TO_EDGE:
              config.texture_wrap_v = SoftGPU::TextureWrapMode::ClampToEdge;
              break;
          case GL_REPEAT:
              config.texture_wrap_v = SoftGPU::TextureWrapMode::Repeat;
              break;
          case GL_MIRRORED_REPEAT:
              config.texture_wrap_v = SoftGPU::TextureWrapMode::MirroredRepeat;
              break;
          default:
              VERIFY_NOT_REACHED();
          }
  
          switch (texture_unit.env_mode()) {
          case GL_MODULATE:
              config.fixed_function_texture_env_mode = SoftGPU::TextureEnvMode::Modulate;
              break;
          case GL_REPLACE:
              config.fixed_function_texture_env_mode = SoftGPU::TextureEnvMode::Replace;
              break;
          case GL_DECAL:
              config.fixed_function_texture_env_mode = SoftGPU::TextureEnvMode::Decal;
              break;
          default:
              VERIFY_NOT_REACHED();
          }
  
          m_rasterizer.set_sampler_config(i, config);
      }
  }
  
  void GLContext::sync_light_state()
  {
      if (!m_light_state_is_dirty)
          return;
  
      m_light_state_is_dirty = false;
  
      auto options = m_rasterizer.options();
      options.color_material_enabled = m_color_material_enabled;
      switch (m_color_material_face) {
      case GL_BACK:
          options.color_material_face = SoftGPU::ColorMaterialFace::Back;
          break;
      case GL_FRONT:
          options.color_material_face = SoftGPU::ColorMaterialFace::Front;
          break;
      case GL_FRONT_AND_BACK:
          options.color_material_face = SoftGPU::ColorMaterialFace::FrontAndBack;
          break;
      default:
          VERIFY_NOT_REACHED();
      }
      switch (m_color_material_mode) {
      case GL_AMBIENT:
          options.color_material_mode = SoftGPU::ColorMaterialMode::Ambient;
          break;
      case GL_AMBIENT_AND_DIFFUSE:
          options.color_material_mode = SoftGPU::ColorMaterialMode::Ambient;
          options.color_material_mode = SoftGPU::ColorMaterialMode::Diffuse;
          break;
      case GL_DIFFUSE:
          options.color_material_mode = SoftGPU::ColorMaterialMode::Diffuse;
          break;
      case GL_EMISSION:
          options.color_material_mode = SoftGPU::ColorMaterialMode::Emissive;
          break;
      case GL_SPECULAR:
          options.color_material_mode = SoftGPU::ColorMaterialMode::Specular;
          break;
      default:
          VERIFY_NOT_REACHED();
      }
      m_rasterizer.set_options(options);
  
      for (auto light_id = 0u; light_id < SoftGPU::NUM_LIGHTS; light_id++) {
          auto const& current_light_state = m_light_states.at(light_id);
          m_rasterizer.set_light_state(light_id, current_light_state);
      }
  
      m_rasterizer.set_material_state(SoftGPU::Face::Front, m_material_states[Face::Front]);
      m_rasterizer.set_material_state(SoftGPU::Face::Back, m_material_states[Face::Back]);
  }
  
  void GLContext::sync_device_texcoord_config()
  {
      if (!m_texcoord_generation_dirty)
          return;
      m_texcoord_generation_dirty = false;
  
      auto options = m_rasterizer.options();
  
      for (size_t i = 0; i < m_device_info.num_texture_units; ++i) {
  
          u8 enabled_coordinates = SoftGPU::TexCoordGenerationCoordinate::None;
          for (GLenum capability = GL_TEXTURE_GEN_S; capability <= GL_TEXTURE_GEN_Q; ++capability) {
              auto const context_coordinate_config = texture_coordinate_generation(i, capability);
              if (!context_coordinate_config.enabled)
                  continue;
  
              SoftGPU::TexCoordGenerationConfig* texcoord_generation_config;
              switch (capability) {
              case GL_TEXTURE_GEN_S:
                  enabled_coordinates |= SoftGPU::TexCoordGenerationCoordinate::S;
                  texcoord_generation_config = &options.texcoord_generation_config[i][0];
                  break;
              case GL_TEXTURE_GEN_T:
                  enabled_coordinates |= SoftGPU::TexCoordGenerationCoordinate::T;
                  texcoord_generation_config = &options.texcoord_generation_config[i][1];
                  break;
              case GL_TEXTURE_GEN_R:
                  enabled_coordinates |= SoftGPU::TexCoordGenerationCoordinate::R;
                  texcoord_generation_config = &options.texcoord_generation_config[i][2];
                  break;
              case GL_TEXTURE_GEN_Q:
                  enabled_coordinates |= SoftGPU::TexCoordGenerationCoordinate::Q;
                  texcoord_generation_config = &options.texcoord_generation_config[i][3];
                  break;
              default:
                  VERIFY_NOT_REACHED();
              }
  
              switch (context_coordinate_config.generation_mode) {
              case GL_OBJECT_LINEAR:
                  texcoord_generation_config->mode = SoftGPU::TexCoordGenerationMode::ObjectLinear;
                  texcoord_generation_config->coefficients = context_coordinate_config.object_plane_coefficients;
                  break;
              case GL_EYE_LINEAR:
                  texcoord_generation_config->mode = SoftGPU::TexCoordGenerationMode::EyeLinear;
                  texcoord_generation_config->coefficients = context_coordinate_config.eye_plane_coefficients;
                  break;
              case GL_SPHERE_MAP:
                  texcoord_generation_config->mode = SoftGPU::TexCoordGenerationMode::SphereMap;
                  break;
              case GL_REFLECTION_MAP:
                  texcoord_generation_config->mode = SoftGPU::TexCoordGenerationMode::ReflectionMap;
                  break;
              case GL_NORMAL_MAP:
                  texcoord_generation_config->mode = SoftGPU::TexCoordGenerationMode::NormalMap;
                  break;
              }
          }
          options.texcoord_generation_enabled_coordinates[i] = enabled_coordinates;
      }
  
      m_rasterizer.set_options(options);
  }
  
  void GLContext::sync_stencil_configuration()
  {
      if (!m_stencil_configuration_dirty)
          return;
      m_stencil_configuration_dirty = false;
  
      auto set_device_stencil = [&](SoftGPU::Face face, StencilFunctionOptions func, StencilOperationOptions op) {
          SoftGPU::StencilConfiguration device_configuration;
  
          // Stencil test function
          auto map_func = [](GLenum func) -> SoftGPU::StencilTestFunction {
              switch (func) {
              case GL_ALWAYS:
                  return SoftGPU::StencilTestFunction::Always;
              case GL_EQUAL:
                  return SoftGPU::StencilTestFunction::Equal;
              case GL_GEQUAL:
                  return SoftGPU::StencilTestFunction::GreaterOrEqual;
              case GL_GREATER:
                  return SoftGPU::StencilTestFunction::Greater;
              case GL_LESS:
                  return SoftGPU::StencilTestFunction::Less;
              case GL_LEQUAL:
                  return SoftGPU::StencilTestFunction::LessOrEqual;
              case GL_NEVER:
                  return SoftGPU::StencilTestFunction::Never;
              case GL_NOTEQUAL:
                  return SoftGPU::StencilTestFunction::NotEqual;
              }
              VERIFY_NOT_REACHED();
          };
          device_configuration.test_function = map_func(func.func);
          device_configuration.reference_value = func.reference_value;
          device_configuration.test_mask = func.mask;
  
          // Stencil operation
          auto map_operation = [](GLenum operation) -> SoftGPU::StencilOperation {
              switch (operation) {
              case GL_DECR:
                  return SoftGPU::StencilOperation::Decrement;
              case GL_DECR_WRAP:
                  return SoftGPU::StencilOperation::DecrementWrap;
              case GL_INCR:
                  return SoftGPU::StencilOperation::Increment;
              case GL_INCR_WRAP:
                  return SoftGPU::StencilOperation::IncrementWrap;
              case GL_INVERT:
                  return SoftGPU::StencilOperation::Invert;
              case GL_KEEP:
                  return SoftGPU::StencilOperation::Keep;
              case GL_REPLACE:
                  return SoftGPU::StencilOperation::Replace;
              case GL_ZERO:
                  return SoftGPU::StencilOperation::Zero;
              }
              VERIFY_NOT_REACHED();
          };
          device_configuration.on_stencil_test_fail = map_operation(op.op_fail);
          device_configuration.on_depth_test_fail = map_operation(op.op_depth_fail);
          device_configuration.on_pass = map_operation(op.op_pass);
          device_configuration.write_mask = op.write_mask;
  
          m_rasterizer.set_stencil_configuration(face, device_configuration);
      };
      set_device_stencil(SoftGPU::Face::Front, m_stencil_function[Face::Front], m_stencil_operation[Face::Front]);
      set_device_stencil(SoftGPU::Face::Back, m_stencil_function[Face::Back], m_stencil_operation[Face::Back]);
  }
  
  void GLContext::build_extension_string()
  {
      Vector<StringView> extensions;
  
      // FIXME: npot texture support became a required core feature starting with OpenGL 2.0 (https://www.khronos.org/opengl/wiki/NPOT_Texture)
      // Ideally we would verify if the selected device adheres to the requested OpenGL context version before context creation
      // and refuse to create a context if it doesn't.
      if (m_device_info.supports_npot_textures)
          extensions.append("GL_ARB_texture_non_power_of_two");
  
      if (m_device_info.num_texture_units > 1)
          extensions.append("GL_ARB_multitexture");
  
      m_extensions = String::join(" ", extensions);
  }
  
  void GLContext::gl_lightf(GLenum light, GLenum pname, GLfloat param)
  {
      APPEND_TO_CALL_LIST_AND_RETURN_IF_NEEDED(gl_lightf, light, pname, param);
  
      RETURN_WITH_ERROR_IF(m_in_draw_state, GL_INVALID_OPERATION);
      RETURN_WITH_ERROR_IF(light < GL_LIGHT0 || light >= (GL_LIGHT0 + m_device_info.num_lights), GL_INVALID_ENUM);
      RETURN_WITH_ERROR_IF(!(pname == GL_CONSTANT_ATTENUATION || pname == GL_LINEAR_ATTENUATION || pname == GL_QUADRATIC_ATTENUATION || pname != GL_SPOT_EXPONENT || pname != GL_SPOT_CUTOFF), GL_INVALID_ENUM);
      RETURN_WITH_ERROR_IF(param < 0.f, GL_INVALID_VALUE);
  
      auto& light_state = m_light_states.at(light - GL_LIGHT0);
  
      switch (pname) {
      case GL_CONSTANT_ATTENUATION:
          light_state.constant_attenuation = param;
          break;
      case GL_LINEAR_ATTENUATION:
          light_state.linear_attenuation = param;
          break;
      case GL_QUADRATIC_ATTENUATION:
          light_state.quadratic_attenuation = param;
          break;
      case GL_SPOT_EXPONENT:
          RETURN_WITH_ERROR_IF(param > 128.f, GL_INVALID_VALUE);
          light_state.spotlight_exponent = param;
          break;
      case GL_SPOT_CUTOFF:
          RETURN_WITH_ERROR_IF(param > 90.f && param != 180.f, GL_INVALID_VALUE);
          light_state.spotlight_cutoff_angle = param;
          break;
      default:
          VERIFY_NOT_REACHED();
      }
  
      m_light_state_is_dirty = true;
  }
  
  void GLContext::gl_lightfv(GLenum light, GLenum pname, GLfloat const* params)
  {
      APPEND_TO_CALL_LIST_AND_RETURN_IF_NEEDED(gl_lightfv, light, pname, params);
      RETURN_WITH_ERROR_IF(m_in_draw_state, GL_INVALID_OPERATION);
      RETURN_WITH_ERROR_IF(light < GL_LIGHT0 || light >= (GL_LIGHT0 + m_device_info.num_lights), GL_INVALID_ENUM);
      RETURN_WITH_ERROR_IF(!(pname == GL_AMBIENT || pname == GL_DIFFUSE || pname == GL_SPECULAR || pname == GL_POSITION || pname == GL_CONSTANT_ATTENUATION || pname == GL_LINEAR_ATTENUATION || pname == GL_QUADRATIC_ATTENUATION || pname == GL_SPOT_CUTOFF || pname == GL_SPOT_EXPONENT || pname == GL_SPOT_DIRECTION), GL_INVALID_ENUM);
  
      auto& light_state = m_light_states.at(light - GL_LIGHT0);
  
      switch (pname) {
      case GL_AMBIENT:
          light_state.ambient_intensity = { params[0], params[1], params[2], params[3] };
          break;
      case GL_DIFFUSE:
          light_state.diffuse_intensity = { params[0], params[1], params[2], params[3] };
          break;
      case GL_SPECULAR:
          light_state.specular_intensity = { params[0], params[1], params[2], params[3] };
          break;
      case GL_POSITION:
          light_state.position = { params[0], params[1], params[2], params[3] };
          light_state.position = m_model_view_matrix * light_state.position;
          break;
      case GL_CONSTANT_ATTENUATION:
          RETURN_WITH_ERROR_IF(params[0] < 0.f, GL_INVALID_VALUE);
          light_state.constant_attenuation = params[0];
          break;
      case GL_LINEAR_ATTENUATION:
          RETURN_WITH_ERROR_IF(params[0] < 0.f, GL_INVALID_VALUE);
          light_state.linear_attenuation = params[0];
          break;
      case GL_QUADRATIC_ATTENUATION:
          RETURN_WITH_ERROR_IF(params[0] < 0.f, GL_INVALID_VALUE);
          light_state.quadratic_attenuation = params[0];
          break;
      case GL_SPOT_EXPONENT: {
          auto exponent = params[0];
          RETURN_WITH_ERROR_IF(exponent < 0.f || exponent > 128.f, GL_INVALID_VALUE);
          light_state.spotlight_exponent = exponent;
          break;
      }
      case GL_SPOT_CUTOFF: {
          auto cutoff = params[0];
          RETURN_WITH_ERROR_IF((cutoff < 0.f || cutoff > 90.f) && cutoff != 180.f, GL_INVALID_VALUE);
          light_state.spotlight_cutoff_angle = cutoff;
          break;
      }
      case GL_SPOT_DIRECTION: {
          FloatVector4 direction_vector = { params[0], params[1], params[2], 0.f };
          direction_vector = m_model_view_matrix * direction_vector;
          light_state.spotlight_direction = direction_vector.xyz();
          break;
      }
      default:
          VERIFY_NOT_REACHED();
      }
  
      m_light_state_is_dirty = true;
  }
  
  void GLContext::gl_lightiv(GLenum light, GLenum pname, GLint const* params)
  {
      APPEND_TO_CALL_LIST_AND_RETURN_IF_NEEDED(gl_lightiv, light, pname, params);
      RETURN_WITH_ERROR_IF(m_in_draw_state, GL_INVALID_OPERATION);
      RETURN_WITH_ERROR_IF(light < GL_LIGHT0 || light >= (GL_LIGHT0 + m_device_info.num_lights), GL_INVALID_ENUM);
      RETURN_WITH_ERROR_IF(!(pname == GL_AMBIENT || pname == GL_DIFFUSE || pname == GL_SPECULAR || pname == GL_POSITION || pname == GL_CONSTANT_ATTENUATION || pname == GL_LINEAR_ATTENUATION || pname == GL_QUADRATIC_ATTENUATION || pname == GL_SPOT_CUTOFF || pname == GL_SPOT_EXPONENT || pname == GL_SPOT_DIRECTION), GL_INVALID_ENUM);
  
      auto& light_state = m_light_states[light - GL_LIGHT0];
  
      auto const to_float_vector = [](GLfloat x, GLfloat y, GLfloat z, GLfloat w) {
          return FloatVector4(x, y, z, w);
      };
  
      switch (pname) {
      case GL_AMBIENT:
          light_state.ambient_intensity = to_float_vector(params[0], params[1], params[2], params[3]);
          break;
      case GL_DIFFUSE:
          light_state.diffuse_intensity = to_float_vector(params[0], params[1], params[2], params[3]);
          break;
      case GL_SPECULAR:
          light_state.specular_intensity = to_float_vector(params[0], params[1], params[2], params[3]);
          break;
      case GL_POSITION:
          light_state.position = to_float_vector(params[0], params[1], params[2], params[3]);
          light_state.position = m_model_view_matrix * light_state.position;
          break;
      case GL_CONSTANT_ATTENUATION:
          RETURN_WITH_ERROR_IF(params[0] < 0, GL_INVALID_VALUE);
          light_state.constant_attenuation = static_cast<float>(params[0]);
          break;
      case GL_LINEAR_ATTENUATION:
          RETURN_WITH_ERROR_IF(params[0] < 0, GL_INVALID_VALUE);
          light_state.linear_attenuation = static_cast<float>(params[0]);
          break;
      case GL_QUADRATIC_ATTENUATION:
          RETURN_WITH_ERROR_IF(params[0] < 0, GL_INVALID_VALUE);
          light_state.quadratic_attenuation = static_cast<float>(params[0]);
          break;
      case GL_SPOT_EXPONENT: {
          auto exponent = static_cast<float>(params[0]);
          RETURN_WITH_ERROR_IF(exponent < 0.f || exponent > 128.f, GL_INVALID_VALUE);
          light_state.spotlight_exponent = exponent;
          break;
      }
      case GL_SPOT_CUTOFF: {
          auto cutoff = static_cast<float>(params[0]);
          RETURN_WITH_ERROR_IF((cutoff < 0.f || cutoff > 90.f) && cutoff != 180.f, GL_INVALID_VALUE);
          light_state.spotlight_cutoff_angle = cutoff;
          break;
      }
      case GL_SPOT_DIRECTION: {
          auto direction_vector = to_float_vector(params[0], params[1], params[2], 0.0f);
          direction_vector = m_model_view_matrix * direction_vector;
          light_state.spotlight_direction = direction_vector.xyz();
          break;
      }
      default:
          VERIFY_NOT_REACHED();
      }
  
      m_light_state_is_dirty = true;
  }
  
  void GLContext::gl_materialf(GLenum face, GLenum pname, GLfloat param)
  {
      APPEND_TO_CALL_LIST_AND_RETURN_IF_NEEDED(gl_materialf, face, pname, param);
      RETURN_WITH_ERROR_IF(!(face == GL_FRONT || face == GL_BACK || face == GL_FRONT_AND_BACK), GL_INVALID_ENUM);
      RETURN_WITH_ERROR_IF(pname != GL_SHININESS, GL_INVALID_ENUM);
      RETURN_WITH_ERROR_IF(param > 128.0f, GL_INVALID_VALUE);
  
      switch (face) {
      case GL_FRONT:
          m_material_states[Face::Front].shininess = param;
          break;
      case GL_BACK:
          m_material_states[Face::Back].shininess = param;
          break;
      case GL_FRONT_AND_BACK:
          m_material_states[Face::Front].shininess = param;
          m_material_states[Face::Back].shininess = param;
          break;
      default:
          VERIFY_NOT_REACHED();
      }
  
      m_light_state_is_dirty = true;
  }
  
  void GLContext::gl_materialfv(GLenum face, GLenum pname, GLfloat const* params)
  {
      APPEND_TO_CALL_LIST_AND_RETURN_IF_NEEDED(gl_materialfv, face, pname, params);
      RETURN_WITH_ERROR_IF(!(face == GL_FRONT || face == GL_BACK || face == GL_FRONT_AND_BACK), GL_INVALID_ENUM);
      RETURN_WITH_ERROR_IF(!(pname == GL_AMBIENT || pname == GL_DIFFUSE || pname == GL_SPECULAR || pname == GL_EMISSION || pname == GL_SHININESS || pname == GL_AMBIENT_AND_DIFFUSE), GL_INVALID_ENUM);
      RETURN_WITH_ERROR_IF((pname == GL_SHININESS && *params > 128.0f), GL_INVALID_VALUE);
  
      auto update_material = [](SoftGPU::Material& material, GLenum pname, GLfloat const* params) {
          switch (pname) {
          case GL_AMBIENT:
              material.ambient = { params[0], params[1], params[2], params[3] };
              break;
          case GL_DIFFUSE:
              material.diffuse = { params[0], params[1], params[2], params[3] };
              break;
          case GL_SPECULAR:
              material.specular = { params[0], params[1], params[2], params[3] };
              break;
          case GL_EMISSION:
              material.emissive = { params[0], params[1], params[2], params[3] };
              break;
          case GL_SHININESS:
              material.shininess = *params;
              break;
          case GL_AMBIENT_AND_DIFFUSE:
              material.ambient = { params[0], params[1], params[2], params[3] };
              material.diffuse = { params[0], params[1], params[2], params[3] };
              break;
          }
      };
  
      switch (face) {
      case GL_FRONT:
          update_material(m_material_states[Face::Front], pname, params);
          break;
      case GL_BACK:
          update_material(m_material_states[Face::Back], pname, params);
          break;
      case GL_FRONT_AND_BACK:
          update_material(m_material_states[Face::Front], pname, params);
          update_material(m_material_states[Face::Back], pname, params);
          break;
      }
  
      m_light_state_is_dirty = true;
  }
  
  void GLContext::gl_materialiv(GLenum face, GLenum pname, GLint const* params)
  {
      APPEND_TO_CALL_LIST_AND_RETURN_IF_NEEDED(gl_materialiv, face, pname, params);
      RETURN_WITH_ERROR_IF(!(face == GL_FRONT || face == GL_BACK || face == GL_FRONT_AND_BACK), GL_INVALID_ENUM);
      RETURN_WITH_ERROR_IF(!(pname == GL_AMBIENT || pname == GL_DIFFUSE || pname == GL_SPECULAR || pname == GL_EMISSION || pname == GL_SHININESS || pname == GL_AMBIENT_AND_DIFFUSE), GL_INVALID_ENUM);
      RETURN_WITH_ERROR_IF((pname == GL_SHININESS && *params > 128), GL_INVALID_VALUE);
  
      auto update_material = [](SoftGPU::Material& material, GLenum pname, GLint const* params) {
          switch (pname) {
          case GL_AMBIENT:
              material.ambient = { static_cast<float>(params[0]), static_cast<float>(params[1]), static_cast<float>(params[2]), static_cast<float>(params[3]) };
              break;
          case GL_DIFFUSE:
              material.diffuse = { static_cast<float>(params[0]), static_cast<float>(params[1]), static_cast<float>(params[2]), static_cast<float>(params[3]) };
              break;
          case GL_SPECULAR:
              material.specular = { static_cast<float>(params[0]), static_cast<float>(params[1]), static_cast<float>(params[2]), static_cast<float>(params[3]) };
              break;
          case GL_EMISSION:
              material.emissive = { static_cast<float>(params[0]), static_cast<float>(params[1]), static_cast<float>(params[2]), static_cast<float>(params[3]) };
              break;
          case GL_SHININESS:
              material.shininess = static_cast<float>(params[0]);
              break;
          case GL_AMBIENT_AND_DIFFUSE:
              material.ambient = { static_cast<float>(params[0]), static_cast<float>(params[1]), static_cast<float>(params[2]), static_cast<float>(params[3]) };
              material.diffuse = { static_cast<float>(params[0]), static_cast<float>(params[1]), static_cast<float>(params[2]), static_cast<float>(params[3]) };
              break;
          }
      };
  
      switch (face) {
      case GL_FRONT:
          update_material(m_material_states[Face::Front], pname, params);
          break;
      case GL_BACK:
          update_material(m_material_states[Face::Back], pname, params);
          break;
      case GL_FRONT_AND_BACK:
          update_material(m_material_states[Face::Front], pname, params);
          update_material(m_material_states[Face::Back], pname, params);
          break;
      }
  
      m_light_state_is_dirty = true;
  }
  
  void GLContext::gl_color_material(GLenum face, GLenum mode)
  {
      APPEND_TO_CALL_LIST_AND_RETURN_IF_NEEDED(gl_color_material, face, mode);
      RETURN_WITH_ERROR_IF(m_in_draw_state, GL_INVALID_OPERATION);
  
      RETURN_WITH_ERROR_IF(face != GL_FRONT
              && face != GL_BACK
              && face != GL_FRONT_AND_BACK,
          GL_INVALID_ENUM);
      RETURN_WITH_ERROR_IF(mode != GL_EMISSION
              && mode != GL_AMBIENT
              && mode != GL_DIFFUSE
              && mode != GL_SPECULAR
              && mode != GL_AMBIENT_AND_DIFFUSE,
          GL_INVALID_ENUM);
  
      m_color_material_face = face;
      m_color_material_mode = mode;
  
      m_light_state_is_dirty = true;
  }
  
  void GLContext::gl_get_light(GLenum light, GLenum pname, void* params, GLenum type)
  {
      APPEND_TO_CALL_LIST_AND_RETURN_IF_NEEDED(gl_get_light, light, pname, params, type);
      RETURN_WITH_ERROR_IF(m_in_draw_state, GL_INVALID_OPERATION);
      RETURN_WITH_ERROR_IF(light < GL_LIGHT0 || light > GL_LIGHT0 + m_device_info.num_lights, GL_INVALID_ENUM);
      RETURN_WITH_ERROR_IF(!(pname == GL_AMBIENT || pname == GL_DIFFUSE || pname == GL_SPECULAR || pname == GL_SPOT_DIRECTION || pname == GL_SPOT_EXPONENT || pname == GL_SPOT_CUTOFF || pname == GL_CONSTANT_ATTENUATION || pname == GL_LINEAR_ATTENUATION || pname == GL_QUADRATIC_ATTENUATION), GL_INVALID_ENUM);
  
      if (type == GL_FLOAT)
          get_light_param<GLfloat>(light, pname, static_cast<GLfloat*>(params));
      else if (type == GL_INT)
          get_light_param<GLint>(light, pname, static_cast<GLint*>(params));
      else
          VERIFY_NOT_REACHED();
  }
  
  template<typename T>
  void GLContext::get_light_param(GLenum light, GLenum pname, T* params)
  {
      auto const& light_state = m_light_states[light - GL_LIGHT0];
      switch (pname) {
      case GL_AMBIENT:
          params[0] = light_state.ambient_intensity.x();
          params[1] = light_state.ambient_intensity.y();
          params[2] = light_state.ambient_intensity.z();
          params[3] = light_state.ambient_intensity.w();
          break;
      case GL_DIFFUSE:
          params[0] = light_state.diffuse_intensity.x();
          params[1] = light_state.diffuse_intensity.y();
          params[2] = light_state.diffuse_intensity.z();
          params[3] = light_state.diffuse_intensity.w();
          break;
      case GL_SPECULAR:
          params[0] = light_state.specular_intensity.x();
          params[1] = light_state.specular_intensity.y();
          params[2] = light_state.specular_intensity.z();
          params[3] = light_state.specular_intensity.w();
          break;
      case GL_SPOT_DIRECTION:
          params[0] = light_state.spotlight_direction.x();
          params[1] = light_state.spotlight_direction.y();
          params[2] = light_state.spotlight_direction.z();
          break;
      case GL_SPOT_EXPONENT:
          *params = light_state.spotlight_exponent;
          break;
      case GL_SPOT_CUTOFF:
          *params = light_state.spotlight_cutoff_angle;
          break;
      case GL_CONSTANT_ATTENUATION:
          *params = light_state.constant_attenuation;
          break;
      case GL_LINEAR_ATTENUATION:
          *params = light_state.linear_attenuation;
          break;
      case GL_QUADRATIC_ATTENUATION:
          *params = light_state.quadratic_attenuation;
          break;
      }
  }
  
  void GLContext::gl_get_material(GLenum face, GLenum pname, void* params, GLenum type)
  {
      APPEND_TO_CALL_LIST_AND_RETURN_IF_NEEDED(gl_get_material, face, pname, params, type);
      RETURN_WITH_ERROR_IF(m_in_draw_state, GL_INVALID_OPERATION);
      RETURN_WITH_ERROR_IF(!(pname == GL_AMBIENT || pname == GL_DIFFUSE || pname == GL_SPECULAR || pname == GL_EMISSION), GL_INVALID_ENUM);
      RETURN_WITH_ERROR_IF(!(face == GL_FRONT || face == GL_BACK), GL_INVALID_ENUM);
  
      Face material_face = Front;
      switch (face) {
      case GL_FRONT:
          material_face = Front;
          break;
      case GL_BACK:
          material_face = Back;
          break;
      }
  
      if (type == GL_FLOAT)
          get_material_param<GLfloat>(material_face, pname, static_cast<GLfloat*>(params));
      else if (type == GL_INT)
          get_material_param<GLint>(material_face, pname, static_cast<GLint*>(params));
      else
          VERIFY_NOT_REACHED();
  }
  
  template<typename T>
  void GLContext::get_material_param(Face face, GLenum pname, T* params)
  {
      auto const& material = m_material_states[face];
      switch (pname) {
      case GL_AMBIENT:
          params[0] = static_cast<T>(material.ambient.x());
          params[1] = static_cast<T>(material.ambient.y());
          params[2] = static_cast<T>(material.ambient.z());
          params[3] = static_cast<T>(material.ambient.w());
          break;
      case GL_DIFFUSE:
          params[0] = static_cast<T>(material.diffuse.x());
          params[1] = static_cast<T>(material.diffuse.y());
          params[2] = static_cast<T>(material.diffuse.z());
          params[3] = static_cast<T>(material.diffuse.w());
          break;
      case GL_SPECULAR:
          params[0] = static_cast<T>(material.specular.x());
          params[1] = static_cast<T>(material.specular.y());
          params[2] = static_cast<T>(material.specular.z());
          params[3] = static_cast<T>(material.specular.w());
          break;
      case GL_EMISSION:
          params[0] = static_cast<T>(material.emissive.x());
          params[1] = static_cast<T>(material.emissive.y());
          params[2] = static_cast<T>(material.emissive.z());
          params[3] = static_cast<T>(material.emissive.w());
          break;
      case GL_SHININESS:
          *params = material.shininess;
          break;
      }
  }
  
  NonnullOwnPtr<GLContext> create_context(Gfx::Bitmap& bitmap)
  {
      auto context = make<GLContext>(bitmap);
      dbgln_if(GL_DEBUG, "GL::create_context({}) -> {:p}", bitmap.size(), context.ptr());
  
      if (!g_gl_context)
          make_context_current(context);
  
      return context;
  }
  
  void make_context_current(GLContext* context)
  {
      if (g_gl_context == context)
          return;
  
      dbgln_if(GL_DEBUG, "GL::make_context_current({:p})", context);
      g_gl_context = context;
  }
  
  void present_context(GLContext* context)
  {
      context->present();
  }
  
  }
  