第五个OpenGL程序，vector 向量 （矩阵变换之 旋转，缩放）后续 绘制多个 图形
效果：
代码 main.cpp
#include <iostream> #include <glad/glad.h> #include <glfw3.h> #include "Shader.h" #define STB_IMAGE_IMPLEMENTATION #include <stb_image.h> #include <glm/glm.hpp> #include <glm/gtc/matrix_transform.hpp> #include <glm/gtc/type_ptr.hpp> #include <chrono> #include <thread> using namespace std; // 回调函数，每当窗口改变大小，视口大小也跟随改变 void framebuffer_size_callback(GLFWwindow* window,int width,int height) { glViewport(0,0,width,height); } // 输入 在GLFW中实现一些输入控制 void processInput(GLFWwindow *window) { if(glfwGetKey(window,GLFW_KEY_ESCAPE) == GLFW_PRESS) // 是否按下了返回键(Esc) { glfwSetWindowShouldClose(window,true); // 把WindowShouldClose属性设置为 true来关闭GLFW } } // ************** opengl 具体实现 ************ // 顶点数据 float vertices[] = { // ---- 位置 ---- - 纹理坐标 - 0.5f, 0.5f, 0.0f, 1.0f, 1.0f, // 右上 0.5f, -0.5f, 0.0f, 1.0f, 0.0f, // 右下 -0.5f, -0.5f, 0.0f, 0.0f, 0.0f, // 左下 -0.5f, 0.5f, 0.0f, 0.0f, 1.0f // 左上 }; // 纹理索引 unsigned int indices[] = { // 注意索引从0开始! // 此例的索引(0,1,2,3)就是顶点数组vertices的下标， // 这样可以由下标代表顶点组合成矩形 0, 1, 3, // 第一个三角形 1, 2, 3 // 第二个三角形 }; //****************************************** int main() { cout << "纹理" << endl; // GLFW (窗口) glfwInit(); // 初始化GLFW glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR,3); // 主版本号 glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR,3); // 次版本号 glfwWindowHint(GLFW_OPENGL_PROFILE,GLFW_OPENGL_CORE_PROFILE); // 使用核心模式 //glfwWindowHint(GLFW_OPENGL_FORWARD_COMPAT, GL_TRUE); Mac OS X系统 // 创建一个GLFW窗口对象 GLFWwindow* window = glfwCreateWindow(800,600,"texture",NULL,NULL); if(window == NULL) { std::cout<< "Failed to create GLFW window"<<std::endl; glfwTerminate(); return -1; } glfwMakeContextCurrent(window); // 窗口的上下文设置为当前线程的主上下文 // GLAD if(!gladLoadGLLoader((GLADloadproc)glfwGetProcAddress)) // 初始化GLAD(初始化OpenGL函数指针) { std::cout<<"Failed to initialize GLAD"<<std::endl; return -1; } //*********** opengl 具体实现 ****************** // 着色器类 Shader shader("E:\\Project\\openglstudy2\\05_OpenglVector\\05_OpenglVector\\vertexSourceCode.vert", "E:\\Project\\openglstudy2\\05_OpenglVector\\05_OpenglVector\\fragmentSourceCode.frag"); // 顶点数组对象 VAO unsigned int VAO; glGenVertexArrays(1,&VAO); // 创建顶点数组对象 glBindVertexArray(VAO); // 绑定顶点数组对象 // 顶点缓冲对象 VBO unsigned int VBO; glGenBuffers(1,&VBO); glBindBuffer(GL_ARRAY_BUFFER,VBO); // 绑定顶点缓冲对象 glBufferData(GL_ARRAY_BUFFER,sizeof(vertices),vertices,GL_STATIC_DRAW); // 把之前定义的顶点数据复制到缓冲的内存中 // 索引缓存对象 EBO unsigned int EBO; glGenBuffers(1,&EBO); glBindBuffer(GL_ELEMENT_ARRAY_BUFFER,EBO); // 绑定索引缓冲对象 glBufferData(GL_ELEMENT_ARRAY_BUFFER,sizeof(indices),indices,GL_STATIC_DRAW); // 把之前定义的索引数据复制到索引缓冲的内存中 // 链接顶点属性 （告诉 gpu 如何解析内存中的顶点数据） // 0 位置坐标 glVertexAttribPointer(0,3,GL_FLOAT,GL_FALSE,5 * sizeof(float),(void*)0); glEnableVertexAttribArray(0); // 1 纹理坐标 glVertexAttribPointer(1,2,GL_FLOAT,GL_FALSE,5 * sizeof(float),(void*)(3*sizeof(float))); glEnableVertexAttribArray(1); unsigned int texture1,texture2; // 纹理对象1 texture1 glGenTextures(1,&texture1); glBindTexture(GL_TEXTURE_2D,texture1); // 设置纹理图像环绕方式 glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT); glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT); // 设置纹理过滤 glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR); glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR); // 加载图片 int width,height,nrChannels; unsigned char *data = stbi_load("E:\\Project\\openglstudy2\\resources\\textures\\container.jpg", &width,&height,&nrChannels,0); if(data) { glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB, width, height, 0, GL_RGB, GL_UNSIGNED_BYTE, data); glGenerateMipmap(GL_TEXTURE_2D); } else { std::cout << "Failed to load texture" << std::endl; } // 释放掉图像数据 stbi_image_free(data); shader.use(); // 纹理对象2 texture2 glGenTextures(1,&texture2); glBindTexture(GL_TEXTURE_2D,texture2); // 设置纹理图像环绕方式 glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT); glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT); // 重复 // 设置纹理过滤 glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR); glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR); // 加载图片 stbi_set_flip_vertically_on_load(true); data = stbi_load("E:\\Project\\openglstudy2\\resources\\textures\\awesomeface.png", &width,&height,&nrChannels,0); if(data) { glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, width, height, 0, GL_RGBA, GL_UNSIGNED_BYTE, data); glGenerateMipmap(GL_TEXTURE_2D); } else { std::cout << "Failed to load texture" << std::endl; } // 释放掉图像数据 stbi_image_free(data); // 设置采样器对应的纹理单元（unform） shader.use(); shader.setInt("texture1",0); shader.setInt("texture2",1); // 变换 float scal = 0.1; bool flag = true; unsigned int transformLoc = glGetUniformLocation(shader.ID,"transform"); //************************** // 视口 glViewport(0,0,800,600); // 视口跟随窗口大小改变 glfwSetFramebufferSizeCallback(window,framebuffer_size_callback); // 渲染循环 while(!glfwWindowShouldClose(window)) // 检查GLFW是否被要求退出 { // 输入 （用户） processInput(window); // 输入控制（自定义） //************** 渲染指令 （用户）********** glClearColor(0.2f, 0.3f, 0.3f, 1.0f); glClear(GL_COLOR_BUFFER_BIT); glActiveTexture(GL_TEXTURE0); glBindTexture(GL_TEXTURE_2D, texture1); glActiveTexture(GL_TEXTURE1); glBindTexture(GL_TEXTURE_2D, texture2); glBindVertexArray(VAO); // create transformations glm::mat4 transform; // make sure to initialize matrix to identity matrix first transform = glm::translate(transform, glm::vec3(0.5f, 0.5f, 0.0f)); auto gltime = (float)glfwGetTime(); transform = glm::rotate(transform, gltime*2, glm::vec3(0.0f, 0.0f, 1.0f)); transform = glm::scale(transform, glm::vec3(scal, scal, scal)); if(scal >= 1.0) // 自己实现的缩放效果 { flag = false; } else if(scal <= 0.1) { flag = true; } if(flag) { scal +=0.1; } else { scal -= 0.1; } // get matrix's uniform location and set matrix shader.use(); unsigned int transformLoc = glGetUniformLocation(shader.ID, "transform"); glUniformMatrix4fv(transformLoc, 1, GL_FALSE, glm::value_ptr(transform)); glDrawElements(GL_TRIANGLES,6,GL_UNSIGNED_INT,0); // create transformations glm::mat4 transform2; // make sure to initialize matrix to identity matrix first transform2 = glm::translate(transform2, glm::vec3(0.5f, -0.5f, 0.0f)); transform2 = glm::rotate(transform2, (float)glfwGetTime()*4, glm::vec3(0.0f, 0.0f, 1.0f)); float scaleAmount = static_cast<float>(sin(glfwGetTime())); transform2 = glm::scale(transform2, glm::vec3(scaleAmount, scaleAmount, scaleAmount)); // get matrix's uniform location and set matrix shader.use(); unsigned int transformLoc2 = glGetUniformLocation(shader.ID, "transform"); glUniformMatrix4fv(transformLoc2, 1, GL_FALSE, glm::value_ptr(transform2)); glDrawElements(GL_TRIANGLES,6,GL_UNSIGNED_INT,0); // create transformations glm::mat4 transform3; // make sure to initialize matrix to identity matrix first transform3 = glm::translate(transform3, glm::vec3(-0.5f, 0.5f, 0.0f)); transform3 = glm::rotate(transform3, (float)glfwGetTime()*6, glm::vec3(0.0f, 0.0f, 1.0f)); transform3 = glm::scale(transform3, glm::vec3(scaleAmount, scaleAmount, scaleAmount)); // get matrix's uniform location and set matrix shader.use(); unsigned int transformLoc3 = glGetUniformLocation(shader.ID, "transform"); glUniformMatrix4fv(transformLoc3, 1, GL_FALSE, glm::value_ptr(transform3)); glDrawElements(GL_TRIANGLES,6,GL_UNSIGNED_INT,0); // create transformations glm::mat4 transform4; // make sure to initialize matrix to identity matrix first transform4 = glm::translate(transform4, glm::vec3(-0.5f, -0.5f, 0.0f)); transform4 = glm::rotate(transform4, (float)glfwGetTime()*8, glm::vec3(0.0f, 0.0f, 1.0f)); transform4 = glm::scale(transform4, glm::vec3(scaleAmount, scaleAmount, scaleAmount)); // get matrix's uniform location and set matrix shader.use(); unsigned int transformLoc4 = glGetUniformLocation(shader.ID, "transform"); glUniformMatrix4fv(transformLoc4, 1, GL_FALSE, glm::value_ptr(transform4)); glDrawElements(GL_TRIANGLES,6,GL_UNSIGNED_INT,0); //*************************************** // 检查并调用事件，交换缓冲 （默认操作） glfwSwapBuffers(window); // 交换颜色缓冲（它是一个储存着GLFW窗口每一个像素颜色值的大缓冲），它在这一迭代中被用来绘制，并且将会作为输出显示在屏幕上。 glfwPollEvents(); // 有没有触发什么事件（比如键盘输入、鼠标移动等）、更新窗口状态 } // 解绑 VAO VBO 着色器程序对象 glDeleteVertexArrays(1, &VAO); glDeleteBuffers(1, &VBO); // 当渲染循环结束后我们需要正确释放/删除之前的分配的所有资源 glfwTerminate(); return 0; }
着色器代码：
顶点着色器：
#version 330 core layout (location = 0) in vec3 aPos; layout (location = 1) in vec2 aTexCoord; out vec2 TexCoord; uniform mat4 transform; void main() { gl_Position = transform * vec4(aPos,1.0) ; TexCoord = vec2(aTexCoord.x, 1-aTexCoord.y); }
片段着色器：
#version 330 core out vec4 FragColor; in vec3 ourColor; in vec2 TexCoord; // 定义一个全局的2D纹理采样器 uniform sampler2D texture1; uniform sampler2D texture2; void main() { // GLSL内建的mix函数需要接受两个值作为参数，并对它们根据第三个参数进行线性插值。 FragColor = mix(texture(texture1, TexCoord), texture(texture2, vec2(-TexCoord.x,TexCoord.y)), 0.2); }
