Hazel Game Engine (117) maintenance project

If there are errors in the code, terminology, etc. in the text, please correct me

foreword

• of this program

  Where maintenance items are to be perfected and repaired

Some important improvements

• Solve the problem that the physical calculation of the bounding box offset position of the box is incorrect

  Original pull request link

  void Scene::OnPhysics2DStart(){
        
        
      //boxShape.SetAsBox(bc2d.Size.x * transform.Scale.x, bc2d.Size.y * transform.Scale.y);
      // 包围盒的计算范围跟随物体的size、偏移位置而变化
      boxShape.SetAsBox(bc2d.Size.x * transform.Scale.x, bc2d.Size.y * transform.Scale.y,
                        b2Vec2(bc2d.Offset.x, bc2d.Offset.y), 0);
  

  void EditorLayer::OnOverlayRender(){
        
        	
  for (auto entity : view) {
        
        
      auto [tc, bc2d] = view.get<TransformComponent, BoxCollider2DComponent>(entity);
      // 0.001fZ轴偏移量
      glm::vec3 translation = tc.Translation + glm::vec3(bc2d.Offset, 0.001f);
      glm::vec3 scale = tc.Scale * glm::vec3(bc2d.Size * 2.0f, 1.0f); // 注意bc2d.Size需乘以2，以免缩小一半
  
      // 若将偏移位置先和物体的位置相加后再与旋转相乘，会导致包围盒的位置很奇怪，所以不正确!!!!
      //glm::mat4 transform = glm::translate(glm::mat4(1.0f), translation)
      //	* rotation
      //	* glm::scale(glm::mat4(1.0f), scale);
  
      // 应该先物体的位置乘以旋转再乘偏移量才正确
      glm::mat4 transform = glm::translate(glm::mat4(1.0f), tc.Translation)
          * rotation
          * glm::translate(glm::mat4(1.0f), glm::vec3(bc2d.Offset, 0.001f))// 包围盒的位置还需要算上偏移位置
          * glm::scale(glm::mat4(1.0f), scale);
  
      Renderer2D::DrawRect(transform, glm::vec4(0, 1, 0, 1));// 绿色的包围盒
  }
  

  For detailed explanation, refer to Section 112

• Click on the object in the scene viewport, the frame of the clicked object can be displayed to mark the distinction

  void EditorLayer::OnOverlayRender(){
        
        	
      ......
  	// 绘画选择实体的轮廓
      if (Entity selectEntity = m_SceneHierarchyPanel.GetSelectedEntity()) {
        
        
          const TransformComponent& transform = selectEntity.GetComponent<TransformComponent>();
  
          Renderer2D::DrawRect(transform.GetTransform(), glm::vec4(1, 0.5, 0, 1));
      }
  

• Set up the structure to initialize the project

  • reason

    An error will be reported when starting the old Sandbox project, because imgui has set the font, but there is no font file in the current directory of the sandbox, and the font file is in hazelnut (visual editor project).

  • Solutions

    I don’t want two project paths for font files to exist, so I need to set the Sandbox current directory as the working directory of hazelnut , so that the font files in hazelnut can be read.

    This setting needs to be set separately according to the two different projects of sandbox and hazelnut, and there is also the name of the running window, so they are fused together into a structure to initialize the project runner.

  struct ApplicationCommandLineArgs {
        
        
      int Count = 0;
      char** Args = nullptr;
  
      const char* operator[](int index) const
      {
        
        
          HZ_CORE_ASSERT(index < Count);
          return Args[index];
      }
     /*
      int main(int argc, char** argv)
      属性Count对应argc
      属性Args对应argv
     */
  };
  struct ApplicationSpecification {
        
        
      std::string Name = "Game Engine Application"; // 默认运行程序名称
      std::string WorkingDirectory;				// 工作目录
      ApplicationCommandLineArgs CommandLineArgs;
  
  };
  class HAZEL_API Application
  	{
        
        
  	public:
  		//Application(const std::string& name = "Game Engine", ApplicationCommandLineArgs args = ApplicationCommandLineArgs());
  		Application(const ApplicationSpecification& specification);
  		virtual ~Application();
  

  class GameEngineEditor : public Application {
        
        
      public:
      //GameEngineEditor(ApplicationCommandLineArgs args)
      //	: Application("GameEngine Editor", args)
      GameEngineEditor(const ApplicationSpecification& spec)
          : Application(spec)// 将结构体传给父类
          {
        
        
              PushLayer(new EditorLayer());
          }
      ~GameEngineEditor() {
        
        
      }
  
  };
  // 定义entryPoint的main函数
  Application* CreateApplication(ApplicationCommandLineArgs args) {
        
        
      ApplicationSpecification spec;
      spec.Name = "GameEngine Editor";// 运行窗口名称
      spec.CommandLineArgs = args;
  
      return new GameEngineEditor(spec);
  }
  

  class Sandbox : public Hazel::Application {
        
        
  public:
  	Sandbox(const Hazel::ApplicationSpecification& specification)
  		: Hazel::Application(specification) // 将结构体传给父类
  	{
        
        
  		PushLayer(new Sandbox2D());
  	}
  	~Sandbox() {
        
        
  	}
  
  };
  Hazel::Application* Hazel::CreateApplication(ApplicationCommandLineArgs args) {
        
        
  	ApplicationSpecification spec;
  	spec.Name = "Sandbox";	// 运行窗口名称
  	spec.WorkingDirectory = "../GameEngine-Editor";// 工作目录
  	spec.CommandLineArgs = args;
  	return new Sandbox(spec);
  }
  

  Application::Application(const ApplicationSpecification& specification)
      : m_Specification(specification)
      {
        
        
          HZ_PROFILE_FUNCTION();
          //HZ_CORE_ASSERT(!s_Instance, "Application already exists!");
          s_Instance = this;
  
          // 设置工作目录
          if (!m_Specification.WorkingDirectory.empty()) {
        
        
              std::filesystem::current_path(m_Specification.WorkingDirectory);
          }
          // 创建窗口
          m_Window = Window::Create(WindowProps(m_Specification.Name));
          m_Window->SetEventCallback(BIND_EVENT_FN(OnEvent));
  

• The pixels in the area surrounded by the Quad texture image are 0, which will also prevent the mouse from clicking on the object behind it.

  So it needs to be detected in the fragment stage of the shader like rendering a circle, and if the alpha is 0, it will be discarded

  if (texColor.a == 0.0)
      discard;
  

• Serialization needs to save the texture path of the entity in the scene, and the texture should be loaded according to the texture path when parsing

  // 保存
  if (entity.HasComponent<SpriteRendererComponent>()) {
        
        
      out << YAML::Key << "SpriteRendererComponent";
      out << YAML::BeginMap;
  
      auto& spriteRendererComponent = entity.GetComponent<SpriteRendererComponent>();
      out << YAML::Key << "Color" << YAML::Value << spriteRendererComponent.Color;
      // 存储纹理路径
      if (spriteRendererComponent.Texture) {
        
        
          out << YAML::Key << "TexturePath" << YAML::Value << spriteRendererComponent.Texture->GetPath();
      }
      out << YAML::Key << "TilingFactor" << YAML::Value << spriteRendererComponent.TilingFactor;
      out << YAML::EndMap;
  }
  

  // 解析
  auto spriteRendererComponent = entity["SpriteRendererComponent"];
  if (spriteRendererComponent) {
        
        
      auto& src = deserializedEntity.AddComponent<SpriteRendererComponent>();
      src.Color = spriteRendererComponent["Color"].as<glm::vec4>();
      if (spriteRendererComponent["TexturePath"]) {
        
        
          /
          // 加载纹理//
          src.Texture = Texture2D::Create(spriteRendererComponent["TexturePath"].as<std::string>());
      }
      if (spriteRendererComponent["TilingFactor"]) {
        
        
          src.TilingFactor = spriteRendererComponent["TilingFactor"].as<float>();
      }
  }
  

• Add entity to rendering Rect

  DrawLine(p0, p1, color, entityID);
  DrawLine(p1, p2, color, entityID);
  DrawLine(p2, p3, color, entityID);
  DrawLine(p3, p0, color, entityID);