Move custom shader from ImageQuad to Drawable

src/engine/drawable.cc

@@ -1,6 +1,7 @@
 #include "engine/drawable.h"
 
 #include "engine/engine.h"
+#include "engine/renderer/shader.h"
 
 namespace eng {
 
@@ -12,4 +13,17 @@ Drawable::~Drawable() {
   Engine::Get().RemoveDrawable(this);
 }
 
+void Drawable::SetCustomShader(const std::string& asset_name) {
+  custom_shader_ = Engine::Get().GetShader(asset_name);
+  custom_uniforms_.clear();
+}
+
+void Drawable::DoSetCustomUniforms() {
+  if (custom_shader_) {
+    for (auto& cu : custom_uniforms_)
+      std::visit([&](auto&& arg) { custom_shader_->SetUniform(cu.first, arg); },
+                 cu.second);
+  }
+}
+
 }  // namespace eng

src/engine/drawable.h

@@ -1,10 +1,16 @@
 #ifndef ENGINE_DRAWABLE_H
 #define ENGINE_DRAWABLE_H
 
+#include <string>
+#include <unordered_map>
+#include <variant>
+
 #include "base/vecmath.h"
 
 namespace eng {
 
+class Shader;
+
 class Drawable {
  public:
   Drawable();
@@ -21,9 +27,30 @@ class Drawable {
   int GetZOrder() const { return z_order_; }
   bool IsVisible() const { return visible_; }
 
+  void SetCustomShader(const std::string& asset_name);
+
+  template <typename T>
+  void SetCustomUniform(const std::string& name, T value) {
+    custom_uniforms_[name] = UniformValue(value);
+  }
+
+ protected:
+  Shader* GetCustomShader() { return custom_shader_; }
+  void DoSetCustomUniforms();
+
  private:
+  using UniformValue = std::variant<base::Vector2f,
+                                    base::Vector3f,
+                                    base::Vector4f,
+                                    base::Matrix4f,
+                                    float,
+                                    int>;
+
   bool visible_ = false;
   int z_order_ = 0;
+
+  Shader* custom_shader_ = nullptr;
+  std::unordered_map<std::string, UniformValue> custom_uniforms_;
 };
 
 }  // namespace eng

src/engine/image_quad.cc

@@ -40,11 +40,6 @@ void ImageQuad::Destroy() {
   }
 }
 
-void ImageQuad::SetCustomShader(const std::string& asset_name) {
-  custom_shader_ = Engine::Get().GetShader(asset_name);
-  custom_uniforms_.clear();
-}
-
 void ImageQuad::SetFrame(size_t frame) {
   DCHECK(frame < GetNumFrames())
       << "asset: " << asset_name_ << " frame: " << frame;
@@ -66,8 +61,9 @@ void ImageQuad::Draw(float frame_frac) {
   Vector2f tex_scale = {GetFrameWidth() / texture_->GetWidth(),
                         GetFrameHeight() / texture_->GetHeight()};
 
-  Shader* shader =
-      custom_shader_ ? custom_shader_ : Engine::Get().GetPassThroughShader();
+  Shader* shader = GetCustomShader();
+  if (!shader)
+    shader = Engine::Get().GetPassThroughShader();
 
   shader->Activate();
   shader->SetUniform("offset", position_);
@@ -78,12 +74,7 @@ void ImageQuad::Draw(float frame_frac) {
   shader->SetUniform("projection", Engine::Get().GetProjectionMatrix());
   shader->SetUniform("color", color_);
   shader->SetUniform("texture_0", 0);
-  if (custom_shader_) {
-    for (auto& cu : custom_uniforms_)
-      std::visit(
-          [shader, &cu](auto&& arg) { shader->SetUniform(cu.first, arg); },
-          cu.second);
-  }
+  DoSetCustomUniforms();
   shader->UploadUniforms();
 
   Engine::Get().GetQuad()->Draw();

src/engine/image_quad.h

@@ -3,15 +3,12 @@
 
 #include <array>
 #include <string>
-#include <unordered_map>
-#include <variant>
 
 #include "base/vecmath.h"
 #include "engine/animatable.h"
 
 namespace eng {
 
-class Shader;
 class Texture;
 
 class ImageQuad final : public Animatable {
@@ -26,13 +23,6 @@ class ImageQuad final : public Animatable {
 
   void Destroy();
 
-  void SetCustomShader(const std::string& asset_name);
-
-  template <typename T>
-  void SetCustomUniform(const std::string& name, T value) {
-    custom_uniforms_[name] = UniformValue(value);
-  }
-
   // Animatable interface.
   void SetFrame(size_t frame) final;
   size_t GetFrame() const final { return current_frame_; }
@@ -44,18 +34,8 @@ class ImageQuad final : public Animatable {
   void Draw(float frame_frac) final;
 
  private:
-  using UniformValue = std::variant<base::Vector2f,
-                                    base::Vector3f,
-                                    base::Vector4f,
-                                    base::Matrix4f,
-                                    float,
-                                    int>;
-
   Texture* texture_ = nullptr;
 
-  Shader* custom_shader_ = nullptr;
-  std::unordered_map<std::string, UniformValue> custom_uniforms_;
-
   size_t current_frame_ = 0;
   std::array<int, 2> num_frames_ = {1, 1};  // horizontal, vertical
   int frame_width_ = 0;

src/engine/solid_quad.cc

@@ -12,7 +12,9 @@ namespace eng {
 void SolidQuad::Draw(float frame_frac) {
   DCHECK(IsVisible());
 
-  Shader* shader = Engine::Get().GetSolidShader();
+  Shader* shader = GetCustomShader();
+  if (!shader)
+    shader = Engine::Get().GetSolidShader();
 
   shader->Activate();
   shader->SetUniform("offset", position_);
@@ -20,6 +22,7 @@ void SolidQuad::Draw(float frame_frac) {
   shader->SetUniform("rotation", rotation_);
   shader->SetUniform("projection", Engine::Get().GetProjectionMatrix());
   shader->SetUniform("color", color_);
+  DoSetCustomUniforms();
   shader->UploadUniforms();
 
   Engine::Get().GetQuad()->Draw();