完整的GLFW应用程序示例

/** 完整的GLFW应用程序示例* 包含窗口创建、输入处理、渲染循环等所有主要功能* 每行代码都有详细注释，便于学习GLFW的使用*/#include <GLFW/glfw3.h>  // GLFW主头文件
#include <iostream>      // 用于控制台输出
#include <cmath>         // 用于数学计算// 全局变量定义
GLFWwindow* g_window = nullptr;  // 全局窗口指针
int g_windowWidth = 800;         // 窗口宽度
int g_windowHeight = 600;        // 窗口高度
float g_backgroundColor[3] = {0.2f, 0.3f, 0.3f};  // 背景颜色(RGB)
bool g_wireframeMode = false;    // 线框模式标志/** 错误回调函数* 当GLFW发生错误时自动调用*/
void errorCallback(int error, const char* description) {std::cerr << "GLFW错误 " << error << ": " << description << std::endl;
}/** 窗口大小改变回调函数* 当用户调整窗口大小时自动调用*/
void framebufferSizeCallback(GLFWwindow* window, int width, int height) {g_windowWidth = width;g_windowHeight = height;// 设置视口大小，匹配窗口大小glViewport(0, 0, width, height);std::cout << "窗口大小改变: " << width << " x " << height << std::endl;
}/** 键盘按键回调函数* 当用户按下或释放键盘按键时调用*/
void keyCallback(GLFWwindow* window, int key, int scancode, int action, int mods) {// 只处理按键按下事件，忽略重复和释放事件if (action == GLFW_PRESS) {switch (key) {case GLFW_KEY_ESCAPE:// ESC键：关闭窗口std::cout << "ESC键按下，关闭窗口" << std::endl;glfwSetWindowShouldClose(window, true);break;case GLFW_KEY_SPACE:// 空格键：切换背景颜色g_backgroundColor[0] = static_cast<float>(rand()) / RAND_MAX;g_backgroundColor[1] = static_cast<float>(rand()) / RAND_MAX;g_backgroundColor[2] = static_cast<float>(rand()) / RAND_MAX;std::cout << "空格键按下，切换背景颜色" << std::endl;break;case GLFW_KEY_W:// W键：切换线框模式g_wireframeMode = !g_wireframeMode;if (g_wireframeMode) {glPolygonMode(GL_FRONT_AND_BACK, GL_LINE);std::cout << "线框模式: 开启" << std::endl;} else {glPolygonMode(GL_FRONT_AND_BACK, GL_FILL);std::cout << "线框模式: 关闭" << std::endl;}break;case GLFW_KEY_F:// F键：切换全屏/窗口模式static bool fullscreen = false;fullscreen = !fullscreen;if (fullscreen) {// 获取主显示器模式GLFWmonitor* monitor = glfwGetPrimaryMonitor();const GLFWvidmode* mode = glfwGetVideoMode(monitor);// 切换到全屏模式glfwSetWindowMonitor(window, monitor, 0, 0, mode->width, mode->height, mode->refreshRate);std::cout << "切换到全屏模式" << std::endl;} else {// 切换到窗口模式glfwSetWindowMonitor(window, nullptr, 100, 100, g_windowWidth, g_windowHeight, 0);std::cout << "切换到窗口模式" << std::endl;}break;case GLFW_KEY_P:// P键：打印窗口信息int x, y;glfwGetWindowPos(window, &x, &y);std::cout << "窗口位置: (" << x << ", " << y << ")" << std::endl;std::cout << "窗口大小: " << g_windowWidth << " x " << g_windowHeight << std::endl;break;}}
}/** 鼠标移动回调函数* 当鼠标移动时调用*/
void cursorPosCallback(GLFWwindow* window, double xpos, double ypos) {// 可以在这里处理鼠标移动逻辑// 示例：每100次调用打印一次位置（避免过于频繁的输出）static int callCount = 0;if (callCount++ % 100 == 0) {std::cout << "鼠标位置: (" << xpos << ", " << ypos << ")" << std::endl;}
}/** 鼠标按钮回调函数* 当鼠标按钮按下或释放时调用*/
void mouseButtonCallback(GLFWwindow* window, int button, int action, int mods) {if (action == GLFW_PRESS) {double xpos, ypos;glfwGetCursorPos(window, &xpos, &ypos);switch (button) {case GLFW_MOUSE_BUTTON_LEFT:std::cout << "左键点击位置: (" << xpos << ", " << ypos << ")" << std::endl;break;case GLFW_MOUSE_BUTTON_RIGHT:std::cout << "右键点击位置: (" << xpos << ", " << ypos << ")" << std::endl;break;case GLFW_MOUSE_BUTTON_MIDDLE:std::cout << "中键点击位置: (" << xpos << ", " << ypos << ")" << std::endl;break;}}
}/** 鼠标滚轮回调函数* 当鼠标滚轮滚动时调用*/
void scrollCallback(GLFWwindow* window, double xoffset, double yoffset) {std::cout << "鼠标滚轮: X=" << xoffset << ", Y=" << yoffset << std::endl;
}/** 窗口焦点回调函数* 当窗口获得或失去焦点时调用*/
void windowFocusCallback(GLFWwindow* window, int focused) {if (focused) {std::cout << "窗口获得焦点" << std::endl;} else {std::cout << "窗口失去焦点" << std::endl;}
}/** 窗口图标化回调函数* 当窗口被最小化或恢复时调用*/
void windowIconifyCallback(GLFWwindow* window, int iconified) {if (iconified) {std::cout << "窗口被最小化" << std::endl;} else {std::cout << "窗口恢复" << std::endl;}
}/** 初始化GLFW和创建窗口* 返回true表示成功，false表示失败*/
bool initializeGLFW() {// 设置错误回调函数glfwSetErrorCallback(errorCallback);// 初始化GLFW库if (!glfwInit()) {std::cerr << "GLFW初始化失败!" << std::endl;return false;}// 配置GLFW窗口属性glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 3);  // OpenGL主版本号glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 3);  // OpenGL次版本号glfwWindowHint(GLFW_OPENGL_PROFILE, GLFW_OPENGL_CORE_PROFILE);  // 使用核心模式glfwWindowHint(GLFW_RESIZABLE, GLFW_TRUE);      // 窗口可调整大小glfwWindowHint(GLFW_SAMPLES, 4);                // 4倍多重采样抗锯齿#ifdef __APPLE__// macOS需要额外的配置glfwWindowHint(GLFW_OPENGL_FORWARD_COMPAT, GL_TRUE);
#endif// 创建窗口和OpenGL上下文g_window = glfwCreateWindow(g_windowWidth, g_windowHeight, "GLFW完整示例 - 学习OpenGL", nullptr, nullptr);if (!g_window) {std::cerr << "创建GLFW窗口失败!" << std::endl;glfwTerminate();return false;}// 将窗口的上下文设置为当前线程的主上下文glfwMakeContextCurrent(g_window);// 设置垂直同步（1表示开启，0表示关闭）glfwSwapInterval(1);// 设置各种回调函数glfwSetFramebufferSizeCallback(g_window, framebufferSizeCallback);glfwSetKeyCallback(g_window, keyCallback);glfwSetCursorPosCallback(g_window, cursorPosCallback);glfwSetMouseButtonCallback(g_window, mouseButtonCallback);glfwSetScrollCallback(g_window, scrollCallback);glfwSetWindowFocusCallback(g_window, windowFocusCallback);glfwSetWindowIconifyCallback(g_window, windowIconifyCallback);// 设置输入模式glfwSetInputMode(g_window, GLFW_STICKY_KEYS, GLFW_TRUE);  // 启用粘性键glfwSetInputMode(g_window, GLFW_CURSOR, GLFW_CURSOR_NORMAL);  // 正常光标模式std::cout << "GLFW初始化成功!" << std::endl;std::cout << "控制说明:" << std::endl;std::cout << "  ESC - 退出程序" << std::endl;std::cout << "  空格 - 随机改变背景颜色" << std::endl;std::cout << "  W - 切换线框模式" << std::endl;std::cout << "  F - 切换全屏/窗口模式" << std::endl;std::cout << "  P - 打印窗口信息" << std::endl;return true;
}/** 渲染一个简单的旋转三角形*/
void renderTriangle(float time) {// 开始绘制三角形glBegin(GL_TRIANGLES);// 计算旋转角度（随时间变化）float angle = time * 50.0f;  // 每秒旋转50度// 第一个顶点（红色）glColor3f(1.0f, 0.0f, 0.0f);  // 红色glVertex2f(0.0f * cos(angle) - 0.5f * sin(angle), 0.0f * sin(angle) + 0.5f * cos(angle));// 第二个顶点（绿色）glColor3f(0.0f, 1.0f, 0.0f);  // 绿色glVertex2f(-0.5f * cos(angle) - (-0.5f) * sin(angle), -0.5f * sin(angle) + (-0.5f) * cos(angle));// 第三个顶点（蓝色）glColor3f(0.0f, 0.0f, 1.0f);  // 蓝色glVertex2f(0.5f * cos(angle) - (-0.5f) * sin(angle), 0.5f * sin(angle) + (-0.5f) * cos(angle));glEnd();
}/** 渲染场景*/
void renderScene(float time) {// 清除颜色缓冲区glClear(GL_COLOR_BUFFER_BIT);// 设置投影矩阵为正交投影glMatrixMode(GL_PROJECTION);glLoadIdentity();glOrtho(-1.0, 1.0, -1.0, 1.0, -1.0, 1.0);// 设置模型视图矩阵glMatrixMode(GL_MODELVIEW);glLoadIdentity();// 渲染旋转三角形renderTriangle(time);
}/** 主函数 - 程序入口点*/
int main() {std::cout << "启动GLFW应用程序..." << std::endl;// 初始化GLFWif (!initializeGLFW()) {return -1;}// 设置初始视口glViewport(0, 0, g_windowWidth, g_windowHeight);// 获取时间基准double lastTime = glfwGetTime();int frameCount = 0;// 主渲染循环while (!glfwWindowShouldClose(g_window)) {// 计算帧率double currentTime = glfwGetTime();frameCount++;// 每秒更新一次帧率显示if (currentTime - lastTime >= 1.0) {std::string title = "GLFW示例 - FPS: " + std::to_string(frameCount);glfwSetWindowTitle(g_window, title.c_str());frameCount = 0;lastTime = currentTime;}// 设置清除颜色（背景色）glClearColor(g_backgroundColor[0], g_backgroundColor[1], g_backgroundColor[2], 1.0f);// 渲染场景renderScene(static_cast<float>(currentTime));// 交换前后缓冲区（双缓冲技术）glfwSwapBuffers(g_window);// 处理事件（输入、窗口事件等）glfwPollEvents();// 检查某些特定按键状态（持续按下的处理）if (glfwGetKey(g_window, GLFW_KEY_R) == GLFW_PRESS) {// R键持续按下时重置背景颜色g_backgroundColor[0] = 0.2f;g_backgroundColor[1] = 0.3f;g_backgroundColor[2] = 0.3f;}}// 清理资源glfwDestroyWindow(g_window);glfwTerminate();std::cout << "程序正常退出" << std::endl;return 0;
}