现代OpenGL自学----坐标变换

来源：互联网发布：zcash 挖矿 linux 编辑：程序博客网时间：2024/05/29 13:23
#include <iostream>#include <glad\glad.h>#include <GLFW\glfw3.h>#include <glm\glm\glm.hpp>#include <glm\glm\gtc\matrix_transform.hpp>#include <glm\glm\gtc\type_ptr.hpp>#define STB_IMAGE_IMPLEMENTATION#include "stb_image.h"#include <shader.h>using namespace glm;void framebuffer_size_callback(GLFWwindow* window, int width, int height);void processInput(GLFWwindow *window);// settingsconst unsigned int SCR_WIDTH = 800;const unsigned int SCR_HEIGHT = 600;int main(){    // ------------------------------    glfwInit();//必须要初始化    glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 3);    glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 3);    glfwWindowHint(GLFW_OPENGL_PROFILE, GLFW_OPENGL_CORE_PROFILE);    // 创建窗口    // --------------------    GLFWwindow* window = glfwCreateWindow(SCR_WIDTH, SCR_HEIGHT, "LearnOpenGL", NULL, NULL);    if (window == NULL)    {        std::cout << "Failed to create GLFW window" << std::endl;        glfwTerminate();        return -1;    }    glfwMakeContextCurrent(window);    glfwSetFramebufferSizeCallback(window, framebuffer_size_callback);    // glad: 加载所有的OpenGL函数指针    // ---------------------------------------    if (!gladLoadGLLoader((GLADloadproc)glfwGetProcAddress))    {        std::cout << "Failed to initialize GLAD" << std::endl;        return -1;    }    // 创建连接着色器    // ------------------------------------    Shader ourShader("1.txt", "2.txt");    //设置顶点数据和缓冲，并配置顶点属性    // ------------------------------------------------------------------    float vertices[] = {        // 顶点坐标       // 纹理坐标        0.5f, 0.5f, 0.0f, 1.0f, 1.0f, // top right        0.5f, -0.5f, 0.0f, 1.0f, 0.0f, // bottom right        -0.5f, -0.5f, 0.0f, 0.0f, 0.0f, // bottom left        -0.5f, 0.5f, 0.0f, 0.0f, 1.0f  // top left     };    unsigned int indices[] = {        0, 1, 3, // 第一个三角形        1, 2, 3  // 第二个三角形    };    unsigned int VBO, VAO, EBO;    glGenVertexArrays(1, &VAO);    glGenBuffers(1, &VBO);    glGenBuffers(1, &EBO);    glBindVertexArray(VAO);    glBindBuffer(GL_ARRAY_BUFFER, VBO);    glBufferData(GL_ARRAY_BUFFER, sizeof(vertices), vertices, GL_STATIC_DRAW);    glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, EBO);    glBufferData(GL_ELEMENT_ARRAY_BUFFER, sizeof(indices), indices, GL_STATIC_DRAW);    //顶点位置属性    glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 5 * sizeof(float), (void*)0);    glEnableVertexAttribArray(0);    //纹理坐标属性    glVertexAttribPointer(1, 2, GL_FLOAT, GL_FALSE, 5 * sizeof(float), (void*)(3 * sizeof(float)));    glEnableVertexAttribArray(1);    // 加载并创建纹理    // -------------------------    unsigned int texture1, texture2;    // 纹理1    // ---------    glGenTextures(1, &texture1);    glBindTexture(GL_TEXTURE_2D, texture1);    // 设置纹理的环绕方式    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT);    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT);    // 设置纹理的过滤方式    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);    // 加载图片创建纹理生成mipmap    int width, height, nrChannels;    stbi_set_flip_vertically_on_load(true); // 翻转图片, 因为stb的y轴和屏幕的y是相反的    unsigned char *data = stbi_load("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;    }    stbi_image_free(data);    // 纹理 2    // ---------    glGenTextures(1, &texture2);    glBindTexture(GL_TEXTURE_2D, texture2);    // 设置纹理的环绕方式    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT);    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT);    // 设置纹理的过滤方式    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);    // 加载图片创建纹理生成mipmap    data = stbi_load("awesomeface.png", &width, &height, &nrChannels, 0);    if (data)    {        // 注意下面的图片是RGBA的格式        glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB, width, height, 0, GL_RGBA, GL_UNSIGNED_BYTE, data);        glGenerateMipmap(GL_TEXTURE_2D);    }    else    {        std::cout << "Failed to load texture" << std::endl;    }    stbi_image_free(data);    // 告诉opengl每个采样器所属的纹理单元（只需要做一次）    // -------------------------------------------------------------------------------------------    ourShader.use();    ourShader.setInt("texture1", 0);    ourShader.setInt("texture2", 1);    // 渲染循环    // -----------    while (!glfwWindowShouldClose(window))    {        // 输入        // -----        processInput(window);        // 渲染        // ------        glClearColor(0.2f, 0.3f, 0.3f, 1.0f);        glClear(GL_COLOR_BUFFER_BIT);        // 在相应的纹理单元上绑定纹理        glActiveTexture(GL_TEXTURE0);        glBindTexture(GL_TEXTURE_2D, texture1);        glActiveTexture(GL_TEXTURE1);        glBindTexture(GL_TEXTURE_2D, texture2);        // 创建变换        mat4 transform;        transform = translate(transform, vec3(0.15f, 0.22f, 0.0f));        for (int i = 0; i < 3; i++)        {            GLfloat a = sin(i) * glfwGetTime();            transform = rotate(transform, a, vec3(0.0f, 0.0f, 1.0f));        }        // 得到矩阵的全局位置并设置矩阵        ourShader.use();        unsigned int transformLoc = glGetUniformLocation(ourShader.ID, "transform");        glUniformMatrix4fv(transformLoc, 1, GL_FALSE, value_ptr(transform));        // 渲染container        glBindVertexArray(VAO);        glDrawElements(GL_TRIANGLES, 6, GL_UNSIGNED_INT, 0);        // glfw: 交换缓冲区域和IO事件(比如按下键和鼠标)        // -------------------------------------------------------------------------------        glfwSwapBuffers(window);        glfwPollEvents();    }    // 可选：一旦他们的用途失效，就取消分配所有的资源：    // ------------------------------------------------------------------------    glDeleteVertexArrays(1, &VAO);    glDeleteBuffers(1, &VBO);    glDeleteBuffers(1, &EBO);    // glfw: 终止，清除所有以前分配的GLFW资源。    // ------------------------------------------------------------------    glfwTerminate();    return 0;}// 处理所有输入：查询GLFW相关键是否被按下/释放这个帧，并作出相应的反应// ---------------------------------------------------------------------------------------------------------void processInput(GLFWwindow *window){    if (glfwGetKey(window, GLFW_KEY_ESCAPE) == GLFW_PRESS)        glfwSetWindowShouldClose(window, true);}// glfw: 每当窗口大小改变（通过操作系统或用户调整大小）这个回调函数执行// ---------------------------------------------------------------------------------------------void framebuffer_size_callback(GLFWwindow* window, int width, int height){    // 确保视口符合新的窗口尺寸; 请注意，宽度和高度将显着大于视网膜显示器上指定的宽度和高度。    glViewport(0, 0, width, height);}
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