跟着cherno手搓游戏引擎【18】抽象Shader、项目小修改

抽象：

Shader.h:

#pragma once
#include <string>namespace YOTO {class Shader {public:virtual~Shader()=default;virtual void Bind()const=0;virtual void UnBind()const=0;static Shader* Create(const std::string& vertexSrc, const std::string& fragmentSrc);};
}

Shader.cpp:

#include "ytpch.h"
#include "Shader.h"
#include"Renderer.h"
#include "Platform/OpenGL/OpenGLShader.h"
namespace YOTO {Shader* Shader::Create(const std::string& vertexSrc, const std::string& fragmentSrc){switch (Renderer::GetAPI()){case RendererAPI::API::None:YT_CORE_ASSERT(false, "Buffer：API为None不支持");return nullptr;case RendererAPI::API::OpenGL:return new OpenGLShader(vertexSrc, fragmentSrc);}YT_CORE_ASSERT(false, "Buffer：未知API");return nullptr;}
}

实现：

新建OpenGLShader类：

OpenGLShader.h

#pragma once
#include <string>
#include "YOTO/Renderer/Shader.h"
#include <glm/glm.hpp>
namespace YOTO {class OpenGLShader:public Shader {public:OpenGLShader(const std::string& vertexSrc, const std::string& fragmentSrc);~OpenGLShader();void Bind()const override;void UnBind()const override;void UploadUniformMat4(const std::string& name, const glm::mat4& matrix);void UploadUniformMat3(const std::string& name, const glm::mat3& matrix);void UploadUniformFloat4(const std::string& name, const glm::vec4& values);void UploadUniformFloat3(const std::string& name, const glm::vec3& values);void UploadUniformFloat2(const std::string& name, const glm::vec2& values);void UploadUniformFloat(const std::string& name, float values);void UploadUniformInt(const std::string& name, int values);private:uint32_t m_RendererID;};
} 

 OpenGLShader.cpp

#include "ytpch.h"
#include "OpenGLShader.h"#include <glad/glad.h>
#include <YOTO/Log.h>
#include<glm/gtc/type_ptr.hpp>
namespace YOTO {OpenGLShader::OpenGLShader(const std::string& vertexSrc, const std::string& fragmentSrc){// 1.1.创建顶点着色器对象GLuint vertexShader = glCreateShader(GL_VERTEX_SHADER);// Send the vertex shader source code to GL// Note that std::string's .c_str is NULL character terminated.// 1.2.附加顶点着色器源码到顶点着色器对象中const GLchar* source = vertexSrc.c_str();glShaderSource(vertexShader, 1, &source, 0);// 1.3.编译顶点着色器对象glCompileShader(vertexShader);// 1.4.检查是否编译成功GLint isCompiled = 0;glGetShaderiv(vertexShader, GL_COMPILE_STATUS, &isCompiled);if (isCompiled == GL_FALSE) {// 1.4.2编译失败可以打印报错信息GLint maxLength = 0;glGetShaderiv(vertexShader, GL_INFO_LOG_LENGTH, &maxLength);// The maxLength includes the NULL characterstd::vector<GLchar> infoLog(maxLength);glGetShaderInfoLog(vertexShader, maxLength, &maxLength, &infoLog[0]);// We don't need the shader anymore.glDeleteShader(vertexShader);YT_CORE_ERROR("{0}", infoLog.data());YT_CORE_ASSERT(false, "Vertex shader compilation failure!");return;}// 片段着色器一样// 2.1.创建片段着色器对象GLuint fragmentShader = glCreateShader(GL_FRAGMENT_SHADER);// Send the fragment shader source code to GL// Note that std::string's .c_str is NULL character terminated.// 2.2.附加片段着色器源码到片段着色器对象中source = fragmentSrc.c_str();glShaderSource(fragmentShader, 1, &source, 0);// 2.3.编译片段着色器对象glCompileShader(fragmentShader);// 2.4.检查是否编译成功glGetShaderiv(fragmentShader, GL_COMPILE_STATUS, &isCompiled);if (isCompiled == GL_FALSE) {// 2.4.2编译失败可以打印报错信息GLint maxLength = 0;glGetShaderiv(fragmentShader, GL_INFO_LOG_LENGTH, &maxLength);// The maxLength includes the NULL characterstd::vector<GLchar> infoLog(maxLength);glGetShaderInfoLog(fragmentShader, maxLength, &maxLength, &infoLog[0]);// We don't need the shader anymore.glDeleteShader(fragmentShader);// Either of them. Don't leak shaders.glDeleteShader(vertexShader);YT_CORE_ERROR("{0}", infoLog.data());YT_CORE_ASSERT(false, "Fragment shader compilation failure!");return;}// Vertex and fragment shaders are successfully compiled.// Now time to link them together into a program.// Get a program object.// 3.1创建着色器程序对象m_RendererID = glCreateProgram();GLuint program = m_RendererID;// 3.2附加着色器对象给着色器程序对象glAttachShader(program, vertexShader);glAttachShader(program, fragmentShader);// 3.3链接着色器程序对象glLinkProgram(program);// 3.4可以检查链接是否成功// Note the different functions here: glGetProgram* instead of glGetShader*.GLint isLinked = 0;glGetProgramiv(program, GL_LINK_STATUS, (int*)&isLinked);if (isLinked == GL_FALSE) {GLint maxLength = 0;glGetProgramiv(program, GL_INFO_LOG_LENGTH, &maxLength);// The maxLength includes the NULL characterstd::vector<GLchar> infoLog(maxLength);glGetProgramInfoLog(program, maxLength, &maxLength, &infoLog[0]);// We don't need the program anymore.glDeleteProgram(program);// Don't leak shaders either.glDeleteShader(vertexShader);glDeleteShader(fragmentShader);YT_CORE_ERROR("{0}", infoLog.data());YT_CORE_ASSERT(false, "Shader link failure!");return;}// 4.删除着色器对象// Always detach shaders after a successful link.glDetachShader(program, vertexShader);glDetachShader(program, fragmentShader);}OpenGLShader::~OpenGLShader(){glDeleteProgram(m_RendererID);}void OpenGLShader::Bind() const{glUseProgram(m_RendererID);}void OpenGLShader::UnBind() const{glUseProgram(0);}void OpenGLShader::UploadUniformMat4(const std::string& name, const glm::mat4& matrix){GLint loacation = glGetUniformLocation(m_RendererID, name.c_str());glUniformMatrix4fv(loacation, 1, GL_FALSE, glm::value_ptr(matrix));}void OpenGLShader::UploadUniformMat3(const std::string& name, const glm::mat3& matrix){GLint loacation = glGetUniformLocation(m_RendererID, name.c_str());glUniformMatrix3fv(loacation, 1, GL_FALSE, glm::value_ptr(matrix)); }void OpenGLShader::UploadUniformFloat4(const std::string& name, const glm::vec4& values){GLint loacation = glGetUniformLocation(m_RendererID, name.c_str());glUniform4f(loacation, values.x, values.y, values.z, values.w);}void OpenGLShader::UploadUniformFloat3(const std::string& name, const glm::vec3& values){GLint loacation = glGetUniformLocation(m_RendererID, name.c_str());glUniform3f(loacation, values.x, values.y, values.z);}void OpenGLShader::UploadUniformFloat2(const std::string& name, const glm::vec2& values){GLint loacation = glGetUniformLocation(m_RendererID, name.c_str());glUniform2f(loacation, values.x, values.y);}void OpenGLShader::UploadUniformFloat(const std::string& name, float values){GLint loacation = glGetUniformLocation(m_RendererID, name.c_str());glUniform1f(loacation, values);}void OpenGLShader::UploadUniformInt(const std::string& name, int values){GLint loacation = glGetUniformLocation(m_RendererID, name.c_str());glUniform1i(loacation, values);}
}

测试：

#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());std::shared_ptr<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);std::shared_ptr<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[3 * 4] = {-0.5f,-0.5f,0.0f,0.5f,-0.5f,0.0f,0.5f,0.5f,0.0f,-0.5f,0.5f,0.0f};std::shared_ptr<YOTO::VertexBuffer> squareVB;squareVB.reset(YOTO::VertexBuffer::Create(squareVertices, sizeof(squareVertices)));squareVB->SetLayout({{YOTO::ShaderDataType::Float3,"a_Position"}});m_SquareVA->AddVertexBuffer(squareVB);uint32_t squareIndices[6] = { 0,1,2,2,3,0 };std::shared_ptr<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));}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 * 0.11f,y* 0.11f, 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);}}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:std::shared_ptr<YOTO::Shader> m_Shader;std::shared_ptr<YOTO::VertexArray> m_VertexArray;std::shared_ptr<YOTO::Shader> m_BlueShader;std::shared_ptr<YOTO::VertexArray> m_SquareVA;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();
}

 cool！

小修改：

Core.h:

#pragma once
#include<memory>
//用于dll的宏
#ifdef YT_PLATFORM_WINDOWS
#if YT_DYNAMIC_LINK#ifdef YT_BUILD_DLL#define YOTO_API __declspec(dllexport) #else#define YOTO_API __declspec(dllimport) #endif // DEBUG
#else#define YOTO_API
#endif
#else
#error YOTO_ONLY_SUPPORT_WINDOWS
#endif // YOTO_PLATFORM_WINDOWS#ifdef YT_DEBUG
#define YT_ENABLE_ASSERTS
#endif#ifdef YT_ENABLE_ASSERTS
#define YT_CLIENT_ASSERT(x,...) {if(!(x)){YT_CLIENT_ERROR("断言错误：{0}",__VA_ARGS__);__debugbreak();}}
#define YT_CORE_ASSERT(x,...) {if(!(x)){YT_CORE_ERROR("断言错误：{0}",__VA_ARGS__);__debugbreak();}}
#else
#define YT_CLIENT_ASSERT(x,...)
#define YT_CORE_ASSERT(x,...)#endif // YT_ENABLE_ASSERTS#define BIT(x)(1<<x)
//绑定事件定义
#define YT_BIND_EVENT_FN(fn) std::bind(&fn, this, std::placeholders::_1)namespace YOTO {template<typename T>using  Scope = std::unique_ptr<T>;template<typename T>using  Ref = std::shared_ptr<T>;
}

之后把所有share_ptr的地方改成Ref就好了。