Code cleanup

src/demo/enemy.cc

@@ -420,7 +420,7 @@ void Enemy::StopAllEnemyUnits(bool chromatic_aberration_effect) {
       continue;
 
     if (chromatic_aberration_effect) {
-      e.sprite.SetCustomShader(chromatic_aberration_);
+      e.sprite.SetCustomShader(chromatic_aberration_.get());
       e.chromatic_aberration_active_ = true;
     }
 

src/demo/enemy.h

@@ -106,7 +106,7 @@ class Enemy {
     eng::SoundPlayer hit;
   };
 
-  std::shared_ptr<eng::Shader> chromatic_aberration_;
+  std::unique_ptr<eng::Shader> chromatic_aberration_;
   float chromatic_aberration_offset_ = 0;
 
   eng::ImageQuad boss_;

src/engine/engine.cc

@@ -37,13 +37,10 @@ Engine::Engine(Platform* platform, Renderer* renderer, Audio* audio)
   solid_shader_ = CreateRenderResource<Shader>();
 
   stats_ = std::make_unique<ImageQuad>();
-  stats_->SetZOrder(std::numeric_limits<int>::max());
 }
 
 Engine::~Engine() {
-  game_.reset();
   stats_.reset();
-
   singleton = nullptr;
 }
 
@@ -91,6 +88,7 @@ bool Engine::Initialize() {
     return false;
 
   SetImageSource("stats_tex", std::bind(&Engine::PrintStats, this));
+  stats_->SetZOrder(std::numeric_limits<int>::max());
 
   game_ = GameFactoryBase::CreateGame("");
   if (!game_) {
@@ -108,6 +106,9 @@ bool Engine::Initialize() {
 
 void Engine::Shutdown() {
   LOG << "Shutting down engine.";
+  game_.reset();
+  stats_->Destory();
+  textures_.clear();
 }
 
 void Engine::Update(float delta_time) {
@@ -119,12 +120,6 @@ void Engine::Update(float delta_time) {
 
   game_->Update(delta_time);
 
-  // Destroy unused textures.
-  for (auto& t : textures_) {
-    if (!t.second.persistent && t.second.texture.use_count() == 1)
-      t.second.texture->Destroy();
-  }
-
   fps_seconds_ += delta_time;
   if (fps_seconds_ >= 1) {
     fps_ = renderer_->GetAndResetFPS();
@@ -227,15 +222,16 @@ void Engine::SetImageSource(const std::string& asset_name,
 void Engine::SetImageSource(const std::string& asset_name,
                             CreateImageCB create_image,
                             bool persistent) {
-  std::shared_ptr<Texture> texture;
+  Texture* texture;
   auto it = textures_.find(asset_name);
   if (it != textures_.end()) {
-    texture = it->second.texture;
+    texture = it->second.texture.get();
     it->second.create_image = create_image;
     it->second.persistent = persistent;
   } else {
-    texture = CreateRenderResource<Texture>();
-    textures_[asset_name] = {texture, create_image, persistent};
+    auto& t = textures_[asset_name] = {CreateRenderResource<Texture>(),
+                                       create_image, persistent, 0};
+    texture = t.texture.get();
   }
 
   if (persistent) {
@@ -259,18 +255,33 @@ void Engine::RefreshImage(const std::string& asset_name) {
     it->second.texture->Destroy();
 }
 
-std::shared_ptr<Texture> Engine::GetTexture(const std::string& asset_name) {
+Texture* Engine::AcquireTexture(const std::string& asset_name) {
   auto it = textures_.find(asset_name);
   if (it != textures_.end()) {
     if (!it->second.texture->IsValid())
       RefreshImage(it->first);
-    return it->second.texture;
+    it->second.use_count++;
+    return it->second.texture.get();
   }
 
-  std::shared_ptr<Texture> texture = CreateRenderResource<Texture>();
-  textures_[asset_name] = {texture};
+  auto& t = textures_[asset_name] = {CreateRenderResource<Texture>(), nullptr,
+                                     false, 1};
+  return t.texture.get();
+}
 
-  return texture;
+void Engine::ReleaseTexture(const std::string& asset_name) {
+  auto it = textures_.find(asset_name);
+  if (it == textures_.end())
+    return;
+
+  if (it->second.use_count == 0) {
+    DCHECK(!it->second.texture->IsValid());
+    return;
+  }
+
+  it->second.use_count--;
+  if (!it->second.persistent && it->second.use_count == 0)
+    it->second.texture->Destroy();
 }
 
 void Engine::AddInputEvent(std::unique_ptr<InputEvent> event) {

src/engine/engine.h

@@ -76,7 +76,8 @@ class Engine {
 
   void RefreshImage(const std::string& asset_name);
 
-  std::shared_ptr<Texture> GetTexture(const std::string& asset_name);
+  Texture* AcquireTexture(const std::string& asset_name);
+  void ReleaseTexture(const std::string& asset_name);
 
   void AddInputEvent(std::unique_ptr<InputEvent> event);
   std::unique_ptr<InputEvent> GetNextInputEvent();
@@ -151,9 +152,10 @@ class Engine {
   // Class holding information about texture resources managed by engine.
   // Texture is created from the image returned by create_image callback.
   struct TextureResource {
-    std::shared_ptr<Texture> texture;
+    std::unique_ptr<Texture> texture;
     CreateImageCB create_image;
     bool persistent = false;
+    size_t use_count = 0;
   };
 
   static Engine* singleton;

src/engine/image_quad.cc

@@ -10,11 +10,17 @@ using namespace base;
 
 namespace eng {
 
+ImageQuad::ImageQuad() = default;
+
+ImageQuad::~ImageQuad() {
+  Destory();
+}
+
 void ImageQuad::Create(const std::string& asset_name,
                        std::array<int, 2> num_frames,
                        int frame_width,
                        int frame_height) {
-  texture_ = Engine::Get().GetTexture(asset_name);
+  texture_ = Engine::Get().AcquireTexture(asset_name);
 
   num_frames_ = std::move(num_frames);
   frame_width_ = frame_width;
@@ -27,7 +33,8 @@ void ImageQuad::Create(const std::string& asset_name,
 }
 
 void ImageQuad::Destory() {
-  texture_.reset();
+  Engine::Get().ReleaseTexture(asset_name_);
+  texture_ = nullptr;
 }
 
 void ImageQuad::AutoScale() {
@@ -40,7 +47,7 @@ void ImageQuad::AutoScale() {
   SetSize(size);
 }
 
-void ImageQuad::SetCustomShader(std::shared_ptr<Shader> shader) {
+void ImageQuad::SetCustomShader(Shader* shader) {
   custom_shader_ = shader;
   custom_uniforms_.clear();
 }
@@ -66,8 +73,8 @@ void ImageQuad::Draw(float frame_frac) {
   Vector2f tex_scale = {GetFrameWidth() / texture_->GetWidth(),
                         GetFrameHeight() / texture_->GetHeight()};
 
-  Shader* shader = custom_shader_ ? custom_shader_.get()
-                                  : Engine::Get().GetPassThroughShader();
+  Shader* shader =
+      custom_shader_ ? custom_shader_ : Engine::Get().GetPassThroughShader();
 
   shader->Activate();
   shader->SetUniform("offset", position_);

src/engine/image_quad.h

@@ -2,7 +2,6 @@
 #define ENGINE_IMAGE_QUAD_H
 
 #include <array>
-#include <memory>
 #include <string>
 #include <unordered_map>
 #include <variant>
@@ -17,8 +16,8 @@ class Texture;
 
 class ImageQuad : public Animatable {
  public:
-  ImageQuad() = default;
-  ~ImageQuad() override = default;
+  ImageQuad();
+  ~ImageQuad() override;
 
   void Create(const std::string& asset_name,
               std::array<int, 2> num_frames = {1, 1},
@@ -29,7 +28,7 @@ class ImageQuad : public Animatable {
 
   void AutoScale();
 
-  void SetCustomShader(std::shared_ptr<Shader> shader);
+  void SetCustomShader(Shader* shader);
 
   template <typename T>
   void SetCustomUniform(const std::string& name, T value) {
@@ -54,9 +53,9 @@ class ImageQuad : public Animatable {
                                     float,
                                     int>;
 
-  std::shared_ptr<Texture> texture_;
+  Texture* texture_ = nullptr;
 
-  std::shared_ptr<Shader> custom_shader_;
+  Shader* custom_shader_ = nullptr;
   std::unordered_map<std::string, UniformValue> custom_uniforms_;
 
   size_t current_frame_ = 0;

src/engine/renderer/texture.cc

@@ -22,9 +22,9 @@ void Texture::Update(std::unique_ptr<Image> image) {
 
 void Texture::Destroy() {
   if (IsValid()) {
+    DLOG << "Texture destroyed. resource_id: " << resource_id_;
     renderer_->DestroyTexture(resource_id_);
     resource_id_ = 0;
-    DLOG << "Texture destroyed. resource_id: " << resource_id_;
   }
 }