src/engine/engine.h

@@ -38,7 +38,7 @@ class Engine : public PlatformObserver {
   using CreateImageCB = std::function<std::unique_ptr<Image>()>;
 
   Engine(Platform* platform);
-  ~Engine() noexcept override;
+  ~Engine();
 
   static Engine& Get();
 

src/engine/image_quad.cc

@@ -56,7 +56,7 @@ void ImageQuad::Draw(float frame_frac) {
   if (!texture_ || !texture_->IsValid())
     return;
 
-  texture_->Activate(0);
+  texture_->Activate();
 
   Vector2f tex_scale = {GetFrameWidth() / texture_->GetWidth(),
                         GetFrameHeight() / texture_->GetHeight()};

src/engine/imgui_backend.cc

@@ -106,7 +106,7 @@ void ImguiBackend::Render() {
   ImGui::Render();
 
   ImDrawData* draw_data = ImGui::GetDrawData();
-  if (draw_data->CmdListsCount <= 0)
+  if (draw_data->CmdListsCount < -0)
     return;
 
   float L = draw_data->DisplayPos.x;
@@ -131,7 +131,7 @@ void ImguiBackend::Render() {
 
     for (int cmd_i = 0; cmd_i < cmd_list->CmdBuffer.Size; cmd_i++) {
       const ImDrawCmd* pcmd = &cmd_list->CmdBuffer[cmd_i];
-      reinterpret_cast<Texture*>(pcmd->GetTexID())->Activate(0);
+      reinterpret_cast<Texture*>(pcmd->GetTexID())->Activate();
 
       if (pcmd->ClipRect.z > pcmd->ClipRect.x &&
           pcmd->ClipRect.w > pcmd->ClipRect.y) {

src/engine/platform/platform_observer.h

@@ -7,6 +7,7 @@ class InputEvent;
 
 class PlatformObserver {
  public:
+  PlatformObserver() = default;
   virtual ~PlatformObserver() = default;
 
   virtual void OnWindowCreated() = 0;

src/engine/renderer/opengl/renderer_opengl.cc

@@ -199,7 +199,8 @@ void RendererOpenGL::Draw(uint64_t resource_id,
 uint64_t RendererOpenGL::CreateTexture() {
   GLuint gl_id = 0;
   glGenTextures(1, &gl_id);
-  glBindTexture(GL_TEXTURE_2D, gl_id);
+
+  BindTexture(gl_id);
 
   glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
   glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
@@ -217,7 +218,7 @@ void RendererOpenGL::UpdateTexture(uint64_t resource_id,
   if (it == textures_.end())
     return;
 
-  glBindTexture(GL_TEXTURE_2D, it->second);
+  BindTexture(it->second);
   if (image->IsCompressed()) {
     GLenum format = 0;
     switch (image->GetFormat()) {
@@ -274,23 +275,13 @@ void RendererOpenGL::DestroyTexture(uint64_t resource_id) {
   textures_.erase(it);
 }
 
-void RendererOpenGL::ActivateTexture(uint64_t resource_id,
-                                     uint64_t texture_unit) {
-  if (texture_unit >= kMaxTextureUnits) {
-    DLOG(0) << "Invalid texture unit " << texture_unit;
-    return;
-  }
-
+void RendererOpenGL::ActivateTexture(uint64_t resource_id) {
   auto it = textures_.find(resource_id);
   if (it == textures_.end()) {
     return;
   }
 
-  if (it->second != active_texture_id_[texture_unit]) {
-    glActiveTexture(GL_TEXTURE0 + texture_unit);
-    glBindTexture(GL_TEXTURE_2D, it->second);
-    active_texture_id_[texture_unit] = it->second;
-  }
+  BindTexture(it->second);
 }
 
 uint64_t RendererOpenGL::CreateShader(
@@ -559,6 +550,13 @@ void RendererOpenGL::DestroyAllResources() {
   DCHECK(textures_.size() == 0);
 }
 
+void RendererOpenGL::BindTexture(GLuint id) {
+  if (id != active_texture_id_) {
+    glBindTexture(GL_TEXTURE_2D, id);
+    active_texture_id_ = id;
+  }
+}
+
 bool RendererOpenGL::SetupVertexLayout(
     const VertexDescription& vd,
     GLuint vertex_size,

src/engine/renderer/opengl/renderer_opengl.h

@@ -1,7 +1,6 @@
 #ifndef ENGINE_RENDERER_OPENGL_RENDERER_OPENGL_H
 #define ENGINE_RENDERER_OPENGL_RENDERER_OPENGL_H
 
-#include <array>
 #include <memory>
 #include <string>
 #include <unordered_map>
@@ -44,7 +43,7 @@ class RendererOpenGL final : public Renderer {
   uint64_t CreateTexture() final;
   void UpdateTexture(uint64_t resource_id, std::unique_ptr<Image> image) final;
   void DestroyTexture(uint64_t resource_id) final;
-  void ActivateTexture(uint64_t resource_id, uint64_t texture_unit) final;
+  void ActivateTexture(uint64_t resource_id) final;
 
   uint64_t CreateShader(std::unique_ptr<ShaderSource> source,
                         const VertexDescription& vertex_description,
@@ -114,7 +113,7 @@ class RendererOpenGL final : public Renderer {
   uint64_t last_resource_id_ = 0;
 
   GLuint active_shader_id_ = 0;
-  std::array<GLuint, kMaxTextureUnits> active_texture_id_ = {};
+  GLuint active_texture_id_ = 0;
 
   bool vertex_array_objects_ = false;
   bool npot_ = false;
@@ -145,6 +144,7 @@ class RendererOpenGL final : public Renderer {
   void ContextLost();
   void DestroyAllResources();
 
+  void BindTexture(GLuint id);
   bool SetupVertexLayout(const VertexDescription& vd,
                          GLuint vertex_size,
                          bool use_vao,

src/engine/renderer/opengl/renderer_opengl_android.cc

@@ -57,7 +57,7 @@ void RendererOpenGL::Present() {
   }
   glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
   active_shader_id_ = 0;
-  active_texture_id_ = {};
+  active_texture_id_ = 0;
   fps_++;
 }
 

src/engine/renderer/opengl/renderer_opengl_linux.cc

@@ -50,7 +50,7 @@ void RendererOpenGL::Present() {
   glXSwapBuffers(display_, window_);
   glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
   active_shader_id_ = 0;
-  active_texture_id_ = {};
+  active_texture_id_ = 0;
   fps_++;
 }
 

src/engine/renderer/opengl/renderer_opengl_win.cc

@@ -72,7 +72,7 @@ void RendererOpenGL::Present() {
   SwapBuffers(dc_);
   glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
   active_shader_id_ = 0;
-  active_texture_id_ = {};
+  active_texture_id_ = 0;
   fps_++;
 }
 

src/engine/renderer/renderer.h

@@ -19,8 +19,7 @@ enum class RendererType { kUnknown, kVulkan, kOpenGL };
 
 class Renderer {
  public:
-  static const unsigned kInvalidId = 0;
-  static const unsigned kMaxTextureUnits = 8;
+  const unsigned kInvalidId = 0;
 
   static std::unique_ptr<Renderer> Create(RendererType type,
                                           base::Closure context_lost_cb);
@@ -52,7 +51,7 @@ class Renderer {
   virtual void UpdateTexture(uint64_t resource_id,
                              std::unique_ptr<Image> image) = 0;
   virtual void DestroyTexture(uint64_t resource_id) = 0;
-  virtual void ActivateTexture(uint64_t resource_id, uint64_t texture_unit) = 0;
+  virtual void ActivateTexture(uint64_t resource_id) = 0;
 
   virtual uint64_t CreateShader(std::unique_ptr<ShaderSource> source,
                                 const VertexDescription& vertex_description,

src/engine/renderer/texture.cc

@@ -28,9 +28,9 @@ void Texture::Destroy() {
   }
 }
 
-void Texture::Activate(uint64_t texture_unit) {
+void Texture::Activate() {
   if (IsValid())
-    renderer_->ActivateTexture(resource_id_, texture_unit);
+    renderer_->ActivateTexture(resource_id_);
 }
 
 }  // namespace eng

src/engine/renderer/texture.h

@@ -20,7 +20,7 @@ class Texture : public RenderResource {
 
   void Destroy();
 
-  void Activate(uint64_t texture_unit);
+  void Activate();
 
   int GetWidth() const { return width_; }
   int GetHeight() const { return height_; }

src/engine/renderer/vulkan/renderer_vulkan.cc

@@ -559,24 +559,21 @@ void RendererVulkan::DestroyTexture(uint64_t resource_id) {
   textures_.erase(it);
 }
 
-void RendererVulkan::ActivateTexture(uint64_t resource_id,
-                                     uint64_t texture_unit) {
+void RendererVulkan::ActivateTexture(uint64_t resource_id) {
   auto it = textures_.find(resource_id);
   if (it == textures_.end())
     return;
 
-  if (active_descriptor_sets_[texture_unit] !=
-      std::get<0>(it->second.desc_set)) {
-    active_descriptor_sets_[texture_unit] = std::get<0>(it->second.desc_set);
-    if (active_shader_id_ != kInvalidId) {
+  if (active_descriptor_sets_[/*TODO*/ 0] != std::get<0>(it->second.desc_set)) {
+    active_descriptor_sets_[/*TODO*/ 0] = std::get<0>(it->second.desc_set);
+    if (active_shader_id_ != 0) {
       auto active_shader = shaders_.find(active_shader_id_);
       if (active_shader != shaders_.end() &&
-          active_shader->second.desc_set_count > texture_unit) {
-        vkCmdBindDescriptorSets(
-            frames_[current_frame_].draw_command_buffer,
+          active_shader->second.desc_set_count > 0) {
+        vkCmdBindDescriptorSets(frames_[current_frame_].draw_command_buffer,
                                 VK_PIPELINE_BIND_POINT_GRAPHICS,
-            active_shader->second.pipeline_layout, texture_unit, 1,
-            &active_descriptor_sets_[texture_unit], 0, nullptr);
+                                active_shader->second.pipeline_layout, 0, 1,
+                                &active_descriptor_sets_[0], 0, nullptr);
       }
     }
   }
@@ -791,14 +788,12 @@ void RendererVulkan::ActivateShader(uint64_t resource_id) {
     active_shader_id_ = resource_id;
     vkCmdBindPipeline(frames_[current_frame_].draw_command_buffer,
                       VK_PIPELINE_BIND_POINT_GRAPHICS, it->second.pipeline);
-
-    for (size_t i = 0; i < it->second.desc_set_count; ++i) {
-      if (active_descriptor_sets_[i] != VK_NULL_HANDLE) {
+    if (it->second.desc_set_count > 0 &&
+        active_descriptor_sets_[/*TODO*/ 0] != VK_NULL_HANDLE) {
       vkCmdBindDescriptorSets(frames_[current_frame_].draw_command_buffer,
                               VK_PIPELINE_BIND_POINT_GRAPHICS,
-                                it->second.pipeline_layout, i, 1,
-                                &active_descriptor_sets_[i], 0, nullptr);
-      }
+                              it->second.pipeline_layout, 0, 1,
+                              &active_descriptor_sets_[0], 0, nullptr);
     }
   }
 }
@@ -2058,7 +2053,7 @@ void RendererVulkan::SwapBuffers() {
   context_.SwapBuffers();
   current_frame_ = (current_frame_ + 1) % frames_.size();
 
-  active_shader_id_ = kInvalidId;
+  active_shader_id_ = 0;
   for (auto& ds : active_descriptor_sets_)
     ds = VK_NULL_HANDLE;
 

src/engine/renderer/vulkan/renderer_vulkan.h

@@ -45,7 +45,7 @@ class RendererVulkan final : public Renderer {
   uint64_t CreateTexture() final;
   void UpdateTexture(uint64_t resource_id, std::unique_ptr<Image> image) final;
   void DestroyTexture(uint64_t resource_id) final;
-  void ActivateTexture(uint64_t resource_id, uint64_t texture_unit) final;
+  void ActivateTexture(uint64_t resource_id) final;
 
   uint64_t CreateShader(std::unique_ptr<ShaderSource> source,
                         const VertexDescription& vertex_description,