跟着cherno手搓游戏引擎【20】混合（blend）

抽象：

Renderer.h:

#pragma once
#include"RenderCommand.h"
#include "OrthographicCamera.h"
#include"Shader.h"
namespace YOTO {class Renderer {public:static void Init();static void BeginScene(OrthographicCamera& camera);static void EndScene();static void Submit(const Ref<Shader>& shader, const Ref<VertexArray>& vertexArray,const glm::mat4&transform = glm::mat4(1.0f));inline static RendererAPI::API GetAPI() {return RendererAPI::GetAPI();}private:struct SceneData {glm::mat4 ViewProjectionMatrix;};static SceneData* m_SceneData;};}

Renderer.cpp:

#include"ytpch.h"
#include"Renderer.h"
#include <Platform/OpenGL/OpenGLShader.h>
namespace YOTO {Renderer::SceneData* Renderer::m_SceneData = new	Renderer::SceneData;void Renderer::Init(){RenderCommand::Init();}void Renderer::BeginScene(OrthographicCamera& camera){m_SceneData->ViewProjectionMatrix = camera.GetViewProjectionMatrix();}void Renderer::EndScene(){}void Renderer::Submit(const Ref<Shader>& shader, const Ref<VertexArray>& vertexArray, const glm::mat4& transform){shader->Bind();std::dynamic_pointer_cast<OpenGLShader>(shader)->UploadUniformMat4("u_ViewProjection", m_SceneData->ViewProjectionMatrix);std::dynamic_pointer_cast<OpenGLShader>(shader)->UploadUniformMat4("u_Transform", transform);/*	mi.Bind();*/vertexArray->Bind();RenderCommand::DrawIndexed(vertexArray);}
}

 RenderCommand.h:

#pragma once
#include"RendererAPI.h"
namespace YOTO {class RenderCommand{public:inline static void Init() {s_RendererAPI->Init();}inline static void SetClearColor(const glm::vec4& color) {s_RendererAPI->SetClearColor(color);}inline static void Clear() {s_RendererAPI->Clear();}inline static void DrawIndexed(const Ref<VertexArray>& vertexArray) {s_RendererAPI->DrawIndexed(vertexArray);}private:static RendererAPI* s_RendererAPI;};}

 RendererAPI.h:

#pragma once
#include<glm/glm.hpp>
#include "VertexArray.h"
namespace YOTO {class RendererAPI{public:enum class API {None = 0,OpenGL = 1};public:virtual void Init() = 0;virtual void SetClearColor(const glm::vec4& color)=0;virtual void Clear() = 0;virtual void DrawIndexed(const Ref<VertexArray>& vertexArray)=0;inline static API GetAPI() { return s_API; }private:static API s_API;};
}

实现：

OpenGLRendererAPI.h

#pragma once
#include"YOTO/Renderer/RendererAPI.h"
namespace YOTO {class OpenGLRendererAPI:public RendererAPI{public:virtual void Init()override;virtual void SetClearColor(const glm::vec4& color)override;virtual void Clear()override;virtual void DrawIndexed(const Ref<VertexArray>& vertexArray) override;};
}

 OpenGLRendererAPI.h

#include "ytpch.h"
#include "OpenGLTexture.h"
#include<glad/glad.h>
#include"stb_image.h"
namespace YOTO {OpenGLTexture2D::OpenGLTexture2D(const std::string path):m_Path(path){int width, height, channels;stbi_set_flip_vertically_on_load(1);//翻转stbi_uc*data=stbi_load(path.c_str(),&width,&height,&channels,0);YT_CORE_ASSERT(data, "图片加载错误");m_Width = width;m_Height = height;GLenum internalFormat = 0,dataFormat=0;if (channels == 4) {internalFormat = GL_RGBA8;dataFormat = GL_RGBA;}else if (channels==3) {internalFormat = GL_RGB8;dataFormat = GL_RGB;}YT_CORE_ASSERT(internalFormat& dataFormat,"OpenGLTexture2D：不支持的颜色格式")//创建纹理glCreateTextures(GL_TEXTURE_2D, 1, &m_RendererID);///告诉OpenGLm_RendererID的纹理存储的是rbg8位，宽高的缓冲区glTextureStorage2D(m_RendererID, 1, internalFormat,m_Width,m_Height);//配置参数:纹理放大时用周围颜色的平均值过滤glTextureParameteri(m_RendererID,GL_TEXTURE_MIN_FILTER,GL_LINEAR);glTextureParameteri(m_RendererID, GL_TEXTURE_MAG_FILTER, GL_NEAREST);glTextureSubImage2D(m_RendererID, 0, 0, 0, m_Width, m_Height, dataFormat,GL_UNSIGNED_BYTE,data);stbi_image_free(data);}OpenGLTexture2D::~OpenGLTexture2D(){glDeleteTextures(1,&m_RendererID);}void OpenGLTexture2D::Bind(uint32_t slot) const{glBindTextureUnit(slot, m_RendererID);}
}

  OpenGLRendererAPI.cpp

#include "ytpch.h"
#include "OpenGLRendererAPI.h"
#include <glad/glad.h>
namespace YOTO {void OpenGLRendererAPI::Init(){//启用混合glEnable(GL_BLEND);//设置混合函数glBlendFunc(GL_SRC_ALPHA,GL_ONE_MINUS_SRC_ALPHA);}void OpenGLRendererAPI::SetClearColor(const glm::vec4& color){glClearColor(color.r, color.g, color.b, color.a);}void OpenGLRendererAPI::Clear(){glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);}void OpenGLRendererAPI::DrawIndexed(const Ref<VertexArray>& vertexArray){glDrawElements(GL_TRIANGLES, vertexArray->GetIndexBuffer()->GetCount(), GL_UNSIGNED_INT, nullptr);}
}

调用：

Application.cpp:

#include"ytpch.h"
#include "Application.h"#include"Log.h"
#include "YOTO/Renderer/Renderer.h"
#include"Input.h"
#include <GLFW/glfw3.h>namespace YOTO {
#define BIND_EVENT_FN(x) std::bind(&x, this, std::placeholders::_1)Application* Application::s_Instance = nullptr;Application::Application(){YT_CORE_ASSERT(!s_Instance, "Application需要为空！")s_Instance = this;//智能指针m_Window = std::unique_ptr<Window>(Window::Creat());//设置回调函数m_Window->SetEventCallback(BIND_EVENT_FN(Application::OnEvent));m_Window->SetVSync(false);Renderer::Init();//new一个Layer，放在最后层进行渲染m_ImGuiLayer = new ImGuiLayer();PushOverlay(m_ImGuiLayer);	}Application::~Application() {}/// <summary>/// 所有的Window事件都会在这触发，作为参数e/// </summary>/// <param name="e"></param>void Application::OnEvent(Event& e) {//根据事件类型绑定对应事件EventDispatcher dispatcher(e);dispatcher.Dispatch<WindowCloseEvent>(BIND_EVENT_FN(Application::OnWindowClosed));//输出事件信息YT_CORE_INFO("Application：{0}", e);for (auto it = m_LayerStack.end(); it != m_LayerStack.begin();) {(*--it)->OnEvent(e);if (e.m_Handled)break;}}bool Application::OnWindowClosed(WindowCloseEvent& e) {m_Running = false;return true;}void Application::Run() {WindowResizeEvent e(1280, 720);if (e.IsInCategory(EventCategoryApplication)) {YT_CORE_TRACE(e);}if (e.IsInCategory(EventCategoryInput)) {YT_CORE_ERROR(e);}while (m_Running){float time = (float)glfwGetTime();//window平台Timestep timestep = time - m_LastFrameTime;m_LastFrameTime = time;for (Layer* layer : m_LayerStack) {layer->OnUpdate(timestep);}//将ImGui的刷新放到APP中，与Update分开m_ImGuiLayer->Begin();for (Layer* layer : m_LayerStack) {layer->OnImGuiRender();}m_ImGuiLayer->End();m_Window->OnUpdate();}}void Application::PushLayer(Layer* layer) {m_LayerStack.PushLayer(layer);layer->OnAttach();}void Application::PushOverlay(Layer* layer) {m_LayerStack.PushOverlay(layer);layer->OnAttach();}
}

SandboxApp.cpp:

#include<YOTO.h>
#include "imgui/imgui.h"
#include<stdio.h>
#include <glm/gtc/matrix_transform.hpp>
#include <Platform/OpenGL/OpenGLShader.h>
#include <glm/gtc/type_ptr.hpp>
class ExampleLayer:public YOTO::Layer
{
public:ExampleLayer():Layer("Example"),  m_Camera(-2.0f, 2.0f, -2.0f, 2.0f), m_CameraPosition(0){uint32_t indices[3] = { 0,1,2 };float vertices[3 * 7] = {-0.5f,-0.5f,0.0f, 0.8f,0.2f,0.8f,1.0f,0.5f,-0.5f,0.0f,  0.2f,0.3f,0.8f,1.0f,0.0f,0.5f,0.0f,   0.8f,0.8f,0.2f,1.0f,};m_VertexArray.reset(YOTO::VertexArray::Create());YOTO::Ref<YOTO::VertexBuffer> m_VertexBuffer;m_VertexBuffer.reset(YOTO::VertexBuffer::Create(vertices, sizeof(vertices)));{YOTO::BufferLayout setlayout = {{YOTO::ShaderDataType::Float3,"a_Position"},{YOTO::ShaderDataType::Float4,"a_Color"}};m_VertexBuffer->SetLayout(setlayout);}m_VertexArray->AddVertexBuffer(m_VertexBuffer);YOTO::Ref<YOTO::IndexBuffer>m_IndexBuffer;m_IndexBuffer.reset(YOTO::IndexBuffer::Create(indices, sizeof(indices) / sizeof(uint32_t)));m_VertexArray->AddIndexBuffer(m_IndexBuffer);std::string vertexSource = R"(#version 330 corelayout(location = 0) in vec3 a_Position;layout(location = 1) in vec4 a_Color;uniform mat4 u_ViewProjection;uniform mat4 u_Transform;out vec3 v_Position;out vec4 v_Color;void main(){v_Position=a_Position;v_Color=a_Color;gl_Position =u_ViewProjection *u_Transform* vec4( a_Position,1.0);})";//绘制颜色std::string fragmentSource = R"(#version 330 corelayout(location = 0) out vec4 color;in vec3 v_Position;in vec4 v_Color;void main(){color=vec4(v_Color);})";m_Shader.reset(YOTO::Shader::Create(vertexSource, fragmentSource));///测试/m_SquareVA.reset(YOTO::VertexArray::Create());float squareVertices[5 * 4] = {-0.5f,-0.5f,0.0f, 0.0f,0.0f,0.5f,-0.5f,0.0f,  1.0f,0.0f,0.5f,0.5f,0.0f,   1.0f,1.0f,-0.5f,0.5f,0.0f,  0.0f,1.0f,};YOTO::Ref<YOTO::VertexBuffer> squareVB;squareVB.reset(YOTO::VertexBuffer::Create(squareVertices, sizeof(squareVertices)));squareVB->SetLayout({{YOTO::ShaderDataType::Float3,"a_Position"},{YOTO::ShaderDataType::Float2,"a_TexCoord"}});m_SquareVA->AddVertexBuffer(squareVB);uint32_t squareIndices[6] = { 0,1,2,2,3,0 };YOTO::Ref<YOTO::IndexBuffer> squareIB;squareIB.reset((YOTO::IndexBuffer::Create(squareIndices, sizeof(squareIndices) / sizeof(uint32_t))));m_SquareVA->AddIndexBuffer(squareIB);//测试：std::string BlueShaderVertexSource = R"(#version 330 corelayout(location = 0) in vec3 a_Position;uniform mat4 u_ViewProjection;uniform mat4 u_Transform;out vec3 v_Position;void main(){v_Position=a_Position;gl_Position =u_ViewProjection*u_Transform*vec4( a_Position,1.0);})";//绘制颜色std::string BlueShaderFragmentSource = R"(#version 330 corelayout(location = 0) out vec4 color;in vec3 v_Position;uniform vec3 u_Color;void main(){color=vec4(u_Color,1.0);})";m_BlueShader.reset(YOTO::Shader::Create(BlueShaderVertexSource, BlueShaderFragmentSource));std::string textureVertexSource = R"(#version 330 corelayout(location = 0) in vec3 a_Position;layout(location = 1) in vec2 a_TexCoord;uniform mat4 u_ViewProjection;uniform mat4 u_Transform;out vec2 v_TexCoord;out vec3 v_Position;void main(){v_TexCoord=a_TexCoord;v_Position=a_Position;gl_Position =u_ViewProjection*u_Transform*vec4( a_Position,1.0);})";//绘制颜色std::string textureFragmentSource = R"(#version 330 corelayout(location = 0) out vec4 color;in vec3 v_Position;in vec2 v_TexCoord;uniform sampler2D u_Texture ;void main(){color = texture(u_Texture, v_TexCoord);	//	color = vec4(v_TexCoord, 0.0f, 1.0f);	})";m_TextureShader.reset(YOTO::Shader::Create(textureVertexSource, textureFragmentSource));m_Texture=YOTO::Texture2D::Create("assets/textures/Checkerboard.png");m_ChernoLogo= YOTO::Texture2D::Create("assets/textures/ChernoLogo.png");std::dynamic_pointer_cast<YOTO::OpenGLShader>(m_TextureShader)->Bind();std::dynamic_pointer_cast<YOTO::OpenGLShader>(m_TextureShader)->UploadUniformInt("u_Texture", 0);}void OnImGuiRender() override {ImGui::Begin("设置");ImGui::ColorEdit3("正方形颜色", glm::value_ptr(m_SquareColor));ImGui::End();}void OnUpdate(YOTO::Timestep ts)override {//YT_CLIENT_TRACE("delta time {0}s ({1}ms)", ts.GetSeconds(), ts.GetMilliseconds());if (YOTO::Input::IsKeyPressed(YT_KEY_LEFT)) {m_CameraPosition.x -= m_CameraMoveSpeed* ts;}else if (YOTO::Input::IsKeyPressed(YT_KEY_RIGHT)) {m_CameraPosition.x += m_CameraMoveSpeed * ts;}if (YOTO::Input::IsKeyPressed(YT_KEY_DOWN)) {m_CameraPosition.y -= m_CameraMoveSpeed * ts;}else if (YOTO::Input::IsKeyPressed(YT_KEY_UP)) {m_CameraPosition.y += m_CameraMoveSpeed * ts;}if (YOTO::Input::IsKeyPressed(YT_KEY_A)) {m_CameraRotation += m_CameraRotationSpeed * ts;}else if (YOTO::Input::IsKeyPressed(YT_KEY_D)) {m_CameraRotation -= m_CameraRotationSpeed * ts;}YOTO::RenderCommand::SetClearColor({ 0.2f, 0.2f, 0.2f, 1.0f });YOTO::RenderCommand::Clear();m_Camera.SetPosition(m_CameraPosition);m_Camera.SetRotation(m_CameraRotation);YOTO::Renderer::BeginScene(m_Camera);{static glm::mat4 scale = glm::scale(glm::mat4(1.0f), glm::vec3(0.1f)); glm::vec4  redColor(0.8f, 0.3f, 0.3f, 1.0f);glm::vec4  blueColor(0.2f, 0.3f, 0.8f, 1.0f);/*		YOTO::MaterialRef material = new YOTO::MaterialRef(m_FlatColorShader);YOTO::MaterialInstaceRef mi = new YOTO::MaterialInstaceRef(material);mi.setValue("u_Color",redColor);mi.setTexture("u_AlbedoMap", texture);squreMesh->SetMaterial(mi);*/std::dynamic_pointer_cast<YOTO::OpenGLShader>(m_BlueShader)->Bind();std::dynamic_pointer_cast<YOTO::OpenGLShader>(m_BlueShader)->UploadUniformFloat3("u_Color",m_SquareColor);for (int y = 0; y < 20; y++) {for (int x = 0; x <20; x++){glm::vec3 pos(x * 0.105f,y* 0.105f, 0.0);glm::mat4 transform = glm::translate(glm::mat4(1.0f), pos) * scale;/*if (x % 2 == 0) {m_BlueShader->UploadUniformFloat4("u_Color", redColor);}else {m_BlueShader->UploadUniformFloat4("u_Color", blueColor);}*/YOTO::Renderer::Submit(m_BlueShader, m_SquareVA, transform);}}m_Texture->Bind();YOTO::Renderer::Submit(m_TextureShader, m_SquareVA, glm::scale(glm::mat4(1.0f), glm::vec3(1.5f)));m_ChernoLogo->Bind();YOTO::Renderer::Submit(m_TextureShader, m_SquareVA, glm::scale(glm::mat4(1.0f), glm::vec3(1.5f)));//YOTO::Renderer::Submit(m_Shader, m_VertexArray);YOTO::Renderer::EndScene();}}void OnEvent(YOTO::Event& event)override {/*if (event.GetEventType() == YOTO::EventType::KeyPressed) {YOTO:: KeyPressedEvent& e = (YOTO::KeyPressedEvent&)event;YT_CLIENT_TRACE("ExampleLayer:{0}",(char)e.GetKeyCode());if (e.GetKeyCode()==YT_KEY_TAB) {YT_CLIENT_INFO("ExampleLayerOnEvent:TAB按下了");}}*///YT_CLIENT_TRACE("SandBoxApp:测试event{0}", event);}private:YOTO::Ref<YOTO::Shader> m_Shader;YOTO::Ref<YOTO::VertexArray> m_VertexArray;YOTO::Ref<YOTO::Shader> m_BlueShader,m_TextureShader;YOTO::Ref<YOTO::VertexArray> m_SquareVA;YOTO::Ref<YOTO::Texture2D> m_Texture,m_ChernoLogo;YOTO::OrthographicCamera m_Camera;glm::vec3 m_CameraPosition;float m_CameraMoveSpeed = 5.0f;float m_CameraRotation = 0;float m_CameraRotationSpeed = 180.0f;glm::vec3 m_SquareColor = { 0.2f,0.3f,0.7f };};class Sandbox:public YOTO::Application
{
public:Sandbox(){PushLayer(new ExampleLayer());//PushLayer(new YOTO::ImGuiLayer());}~Sandbox() {}private:};YOTO::Application* YOTO::CreateApplication() {printf("helloworld");return new Sandbox();
}

加了个init涉及了好几个类，小改动，为了方便观察，我把整个类都复制下来了。