Method ApplyTextures

libs/drape/render_state.cpp:212–279

uint8_t TextureState::m_usedSlots = 0;

void TextureState::ApplyTextures(ref_ptr<GraphicsContext> context, RenderState const & state,
                                 ref_ptr<GpuProgram> program)
{
  m_usedSlots = 0;
  auto const apiVersion = context->GetApiVersion();
  if (apiVersion == dp::ApiVersion::OpenGLES3)
  {
    ref_ptr<dp::GLGpuProgram> p = program;
    for (auto const & texture : state.GetTextures())
    {
      auto const tex = texture.second;
      int8_t texLoc = -1;
      if (tex != nullptr && (texLoc = p->GetUniformLocation(texture.first)) >= 0)
      {
        GLFunctions::glActiveTexture(gl_const::GLTexture0 + m_usedSlots);
        tex->Bind(context);
        GLFunctions::glUniformValuei(texLoc, m_usedSlots);
        tex->SetFilter(state.GetTextureFilter());
        m_usedSlots++;
      }
    }
  }
  else if (apiVersion == dp::ApiVersion::Metal)
  {
#if defined(OMIM_METAL_AVAILABLE)
    ApplyTexturesForMetal(context, program, state);
#endif
  }
  else if (apiVersion == dp::ApiVersion::Vulkan)
  {
    ref_ptr<dp::vulkan::VulkanBaseContext> vulkanContext = context;
    vulkanContext->ClearParamDescriptors();
    ref_ptr<dp::vulkan::VulkanGpuProgram> p = program;
    auto const & bindings = p->GetTextureBindings();
    for (auto const & texture : state.GetTextures())
    {
      if (texture.second == nullptr)
        continue;

      ref_ptr<dp::vulkan::VulkanTexture> t = texture.second->GetHardwareTexture();
      if (t == nullptr)
      {
        texture.second->UpdateState(context);
        t = texture.second->GetHardwareTexture();
        CHECK(t != nullptr, ());
      }
      t->Bind(context);
      t->SetFilter(state.GetTextureFilter());

      dp::vulkan::ParamDescriptor descriptor;
      descriptor.m_type = dp::vulkan::ParamDescriptor::Type::Texture;
      descriptor.m_imageDescriptor.imageView = t->GetTextureView();
      descriptor.m_imageDescriptor.sampler = vulkanContext->GetSampler(t->GetSamplerKey());
      descriptor.m_imageDescriptor.imageLayout = VK_IMAGE_LAYOUT_SHADER_READ_ONLY_OPTIMAL;

      auto const it = bindings.find(texture.first);
      CHECK(it != bindings.end(), (texture.first, " is not found in the program", p->GetName()));
      descriptor.m_textureSlot = it->second;