这篇文章主要讲解了“怎么使用C++的OpenGL绘制三角形”，文中的讲解内容简单清晰，易于学习与理解，下面请大家跟着小编的思路慢慢深入，一起来研究和学习“怎么使用C++的OpenGL绘制三角形”吧！
一、绘制三角形
1、初始化
（1）初始化GLFW
//初始化GLFW glfwInit();//初始化GLFW glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 3);//设置主版本号 glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 3);//设置次版本号 glfwWindowHint(GLFW_OPENGL_PROFILE, GLFW_OPENGL_CORE_PROFILE);//设置核心模式 //glfwWindowHint(GLFW_OPENGL_FORWARD_COMPAT, GL_TRUE);//MAC OS glfwWindowHint(GLFW_RESIZABLE, false);//关闭可调节窗口大小（2）创建一个窗口
//创建窗口(宽、高、窗口名) auto window = glfwCreateWindow(screen_width, screen_hight, "Triangle", nullptr, nullptr); if (window == nullptr) { std::cout << "Failed to Create OpenGL Context" << std::endl; glfwTerminate(); return -1; } glfwMakeContextCurrent(window);（3）初始化GLAD
//初始化GLAD if (!gladLoadGLLoader((GLADloadproc)glfwGetProcAddress)) { std::cout << "Failed to initialize GLAD" << std::endl; return -1; }（4）创建一个视口
//创建视口 glViewport(0, 0, screen_width, screen_hight);初始化代码（全）：
#include <glad/glad.h> #include <GLFW/glfw3.h>#include <iostream>const int screen_width = 800;const int screen_hight = 600;int main() {//初始化GLFWglfwInit();//初始化GLFWglfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 3);//设置主版本号glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 3);//设置次版本号glfwWindowHint(GLFW_OPENGL_PROFILE, GLFW_OPENGL_CORE_PROFILE);//设置核心模式//glfwWindowHint(GLFW_OPENGL_FORWARD_COMPAT, GL_TRUE);//MAC OSglfwWindowHint(GLFW_RESIZABLE, false);//关闭可调节窗口大小//创建窗口(宽、高、窗口名)auto window = glfwCreateWindow(screen_width, screen_hight, "Triangle", nullptr, nullptr);if (window == nullptr) {std::cout << "Failed to Create OpenGL Context" << std::endl;glfwTerminate();return -1;}glfwMakeContextCurrent(window);//初始化GLADif (!gladLoadGLLoader((GLADloadproc)glfwGetProcAddress)){std::cout << "Failed to initialize GLAD" << std::endl;return -1;}//创建视口glViewport(0, 0, screen_width, screen_hight);return 0;}2、顶点输入
坐标系规定
顶点坐标代码
//三角形的顶点数据const float triangle[] = { //--位置--// -0.5f,-0.5f,0.0f,//左下 0.5f,-0.5f,0.0f,//右下 0.0f,0.5f,0.0f,//正上};
3、数据处理
（1）VBO、VAO
//生成并绑定VBO GLuint vertex_buffer_object; glGenBuffers(1, &vertex_buffer_object); glBindBuffer(GL_ARRAY_BUFFER, vertex_buffer_object); //将顶点数据绑定至默认的缓冲中 glBufferData(GL_ARRAY_BUFFER, sizeof(triangle), triangle, GL_STATIC_DRAW);
//生成并绑定VAO GLuint vertex_array_object; glGenVertexArrays(1, &vertex_array_object); glBindVertexArray(vertex_array_object);
（2）顶点属性
//设置顶点属性指针 glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 3 * sizeof(float),(void*)0); glEnableVertexAttribArray(0);
（3）解绑代码
//设置完成之后就可以解绑VBO、VAO了 glBindVertexArray(0); glBindBuffer(GL_ARRAY_BUFFER, 0);4、顶点着色器和片段着色器
//顶点着色器源码 const char* vertex_shader_source = "#version 330 core\n" "layout (location = 0) in vec3 aPos;\n" "void main()\n" "{\n" " gl_Position = vec4(aPos,1.0);\n" "}\n\0";
//片段着色器源码 const char* fragment_shader_source = "#version 330 core\n" "out vec4 FragColor;\n" "void main()\n" "{\n" " FragColor = vec4(1.0f,0.5f,0.2f,1.0f);\n" "}\n\0";
//生成并编译着色器 //顶点着色器 int vertex_shader = glCreateShader(GL_VERTEX_SHADER); glShaderSource(vertex_shader, 1, &vertex_shader_source, NULL); glCompileShader(vertex_shader); int success; char info_log[512]; // 检查着色器是否成功编译，如果编译失败，打印错误信息 glGetShaderiv(vertex_shader, GL_COMPILE_STATUS, &success); if (!success) { glGetShaderInfoLog(vertex_shader, 512, NULL, info_log); std::cout << "ERROR::SHADER::VERTEX::COMPILATION_FAILED\n" << info_log << std::endl; } // 片段着色器 int fragment_shader = glCreateShader(GL_FRAGMENT_SHADER); glShaderSource(fragment_shader, 1, &fragment_shader_source, NULL); glCompileShader(fragment_shader); // 检查着色器是否成功编译，如果编译失败，打印错误信息 glGetShaderiv(fragment_shader, GL_COMPILE_STATUS, &success); if (!success) { glGetShaderInfoLog(fragment_shader, 512, NULL, info_log); std::cout << "ERROR::SHADER::FRAGMENT::COMPILATION_FAILED\n" << info_log << std::endl; }
// 链接顶点和片段着色器至一个着色器程序 int shader_program = glCreateProgram(); glAttachShader(shader_program, vertex_shader); glAttachShader(shader_program, fragment_shader); glLinkProgram(shader_program); // 检查着色器是否成功链接，如果链接失败，打印错误信息 glGetProgramiv(shader_program, GL_LINK_STATUS, &success); if (!success) { glGetProgramInfoLog(shader_program, 512, NULL, info_log); std::cout << "ERROR::SHADER::PROGRAM::LINKING_FAILED\n" << info_log << std::endl; } // 删除着色器 glDeleteShader(vertex_shader); glDeleteShader(fragment_shader);// 线框模式 //glPolygonMode(GL_FRONT_AND_BACK, GL_LINE);5、渲染
//渲染循环while (!glfwWindowShouldClose(window)) {// 清空颜色缓冲glClearColor(0.0f, 0.34f, 0.57f, 1.0f);glClear(GL_COLOR_BUFFER_BIT);// 使用着色器程序glUseProgram(shader_program);// 绘制三角形glBindVertexArray(vertex_array_object); // 绑定VAOglDrawArrays(GL_TRIANGLES, 0, 3); // 绘制三角形glBindVertexArray(0); // 解除绑定// 交换缓冲并且检查是否有触发事件(比如键盘输入、鼠标移动等）glfwSwapBuffers(window);glfwPollEvents();} // 删除VAO和VBO glDeleteVertexArrays(1, &vertex_array_object); glDeleteBuffers(1, &vertex_buffer_object);二、完整代码
代码
#include <glad/glad.h> #include <GLFW/glfw3.h>#include <iostream>const int screen_width = 800;const int screen_hight = 600;//三角形的顶点数据const float triangle[] = {//--位置--//-0.5f,-0.5f,0.0f,//左下0.5f,-0.5f,0.0f,//右下0.0f,0.5f,0.0f,//正上};int main() {//初始化GLFWglfwInit();//初始化GLFWglfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 3);//设置主版本号glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 3);//设置次版本号glfwWindowHint(GLFW_OPENGL_PROFILE, GLFW_OPENGL_CORE_PROFILE);//设置核心模式//glfwWindowHint(GLFW_OPENGL_FORWARD_COMPAT, GL_TRUE);//MAC OSglfwWindowHint(GLFW_RESIZABLE, false);//关闭可调节窗口大小//创建窗口(宽、高、窗口名)auto window = glfwCreateWindow(screen_width, screen_hight, "Triangle", nullptr, nullptr);if (window == nullptr) {std::cout << "Failed to Create OpenGL Context" << std::endl;glfwTerminate();return -1;}glfwMakeContextCurrent(window);//初始化GLADif (!gladLoadGLLoader((GLADloadproc)glfwGetProcAddress)){std::cout << "Failed to initialize GLAD" << std::endl;return -1;}//创建视口glViewport(0, 0, screen_width, screen_hight);//生成并绑定VBOGLuint vertex_buffer_object;glGenBuffers(1, &vertex_buffer_object);glBindBuffer(GL_ARRAY_BUFFER, vertex_buffer_object);//将顶点数据绑定至默认的缓冲中glBufferData(GL_ARRAY_BUFFER, sizeof(triangle), triangle, GL_STATIC_DRAW);//生成并绑定VAOGLuint vertex_array_object;glGenVertexArrays(1, &vertex_array_object);glBindVertexArray(vertex_array_object);//设置顶点属性指针glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 3 * sizeof(float), (void*)0);//参数：顶点着色器位置值，分量，顶点数据类型，是否标准化，步长、数据偏移量glEnableVertexAttribArray(0);//开启0通道//设置完成之后就可以解绑VBO、VAO了glBindVertexArray(0);glBindBuffer(GL_ARRAY_BUFFER, 0);//顶点着色器源码const char* vertex_shader_source ="#version 330 core\n""layout (location = 0) in vec3 aPos;\n""void main()\n""{\n""gl_Position = vec4(aPos,1.0);\n""}\n\0";//片段着色器源码const char* fragment_shader_source ="#version 330 core\n""out vec4 FragColor;\n""void main()\n""{\n""FragColor = vec4(1.0f,0.1f,0.1f,1.0f);\n""}\n\0";//生成并编译着色器//顶点着色器int vertex_shader = glCreateShader(GL_VERTEX_SHADER);glShaderSource(vertex_shader, 1, &vertex_shader_source, NULL);glCompileShader(vertex_shader);int success;char info_log[512];// 检查着色器是否成功编译，如果编译失败，打印错误信息glGetShaderiv(vertex_shader, GL_COMPILE_STATUS, &success);if (!success){glGetShaderInfoLog(vertex_shader, 512, NULL, info_log);std::cout << "ERROR::SHADER::VERTEX::COMPILATION_FAILED\n" << info_log << std::endl;}// 片段着色器int fragment_shader = glCreateShader(GL_FRAGMENT_SHADER);glShaderSource(fragment_shader, 1, &fragment_shader_source, NULL);glCompileShader(fragment_shader);// 检查着色器是否成功编译，如果编译失败，打印错误信息glGetShaderiv(fragment_shader, GL_COMPILE_STATUS, &success);if (!success){glGetShaderInfoLog(fragment_shader, 512, NULL, info_log);std::cout << "ERROR::SHADER::FRAGMENT::COMPILATION_FAILED\n" << info_log << std::endl;}// 链接顶点和片段着色器至一个着色器程序int shader_program = glCreateProgram();glAttachShader(shader_program, vertex_shader);glAttachShader(shader_program, fragment_shader);glLinkProgram(shader_program);// 检查着色器是否成功链接，如果链接失败，打印错误信息glGetProgramiv(shader_program, GL_LINK_STATUS, &success);if (!success) {glGetProgramInfoLog(shader_program, 512, NULL, info_log);std::cout << "ERROR::SHADER::PROGRAM::LINKING_FAILED\n" << info_log << std::endl;}// 删除着色器glDeleteShader(vertex_shader);glDeleteShader(fragment_shader);// 线框模式//glPolygonMode(GL_FRONT_AND_BACK, GL_LINE);//渲染循环while (!glfwWindowShouldClose(window)) {// 清空颜色缓冲glClearColor(0.0f, 0.0f, 0.0f, 1.0f);glClear(GL_COLOR_BUFFER_BIT);// 使用着色器程序glUseProgram(shader_program);// 绘制三角形glBindVertexArray(vertex_array_object); // 绑定VAOglDrawArrays(GL_TRIANGLES, 0, 3); // 绘制三角形glBindVertexArray(0); // 解除绑定// 交换缓冲并且检查是否有触发事件(比如键盘输入、鼠标移动等）glfwSwapBuffers(window);glfwPollEvents();}// 删除VAO和VBOglDeleteVertexArrays(1, &vertex_array_object);glDeleteBuffers(1, &vertex_buffer_object);// 清理所有的资源并正确退出程序glfwTerminate();return 0;}输出
修改尺寸
修改三角形颜色
修改背景颜色
线框模式
输出
感谢各位的阅读，以上就是“怎么使用C++的OpenGL绘制三角形”的内容了，经过本文的学习后，相信大家对怎么使用C++的OpenGL绘制三角形这一问题有了更深刻的体会，具体使用情况还需要大家实践验证。这里是编程网，小编将为大家推送更多相关知识点的文章，欢迎关注！
