OpenGL教程2_创建窗口
预备知识
OpenGL:
开放图形库，或者说是一个图形标准。
GLFW：
Graphics Library For Windows 目的是实现 创建，管理窗口，增加交互性（鼠标，键盘，和其他设备），和其他是操作系统打交道的事情，由GLUT、FreeGLUT发展而来
GLAD
GL ADdress,获取OpenGL拓展函数的地址，并绑定到对应的函数指针上，方便对函数的调用
GLSL
OpenGL的着色器语言，绘制图像纹理时会用到
1、导入相关的库
GLFW用于窗口的绘制和交互，GLAD用于加载GLFW函数指针地址
#include <glad/glad.h> #include <GLFW/glfw3.h> #include <iostream> 复制代码
2、初使化glfw
glfwInit初使化，版本为3.3，模式为核心模式，Mac额外配置
glfwInit(); glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 3); glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 3); glfwWindowHint(GLFW_OPENGL_PROFILE, GLFW_OPENGL_CORE_PROFILE); #ifdef __APPLE__ glfwWindowHint(GLFW_OPENGL_FORWARD_COMPAT, GL_TRUE); #endif 复制代码
3、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); 复制代码4、初使化glad
加载GLFW函数指针地址
if (!gladLoadGLLoader((GLADloadproc)glfwGetProcAddress)) { std::cout << "Failed to initialize GLAD" << std::endl; return -1; } 复制代码5、设置视图
framebuffer_size_callback是窗口大小变化时的回调函数,随时修改窗口显示
glfwSetFramebufferSizeCallback(window, framebuffer_size_callback); void framebuffer_size_callback(GLFWwindow* window, int width, int height) { glViewport(0, 0, width, height); } 复制代码6、持续渲染，以免渲染一次后就退出
while (!glfwWindowShouldClose(window)) { glfwSwapBuffers(window); glfwPollEvents(); } 复制代码7、设置背景颜色
glClearColor(0.2f, 0.3f, 0.3f, 1.0f); glClear(GL_COLOR_BUFFER_BIT); 复制代码
附加功能
点击esc按键，退出界面
processInput(window); void processInput(GLFWwindow *window) { if(glfwGetKey(window, GLFW_KEY_ESCAPE) == GLFW_PRESS) glfwSetWindowShouldClose(window, true); } 复制代码释放/删除之前的分配的所有资源
glfwTerminate(); 复制代码
完整代码
#include <glad/glad.h> #include <GLFW/glfw3.h> #include <iostream> void framebuffer_size_callback(GLFWwindow* window, int width, int height); void processInput(GLFWwindow *window); const unsigned int SCR_WIDTH = 800; const unsigned int SCR_HEIGHT = 600; int main() { // glfw: initialize and configure // ------------------------------ glfwInit(); glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 3); glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 3); glfwWindowHint(GLFW_OPENGL_PROFILE, GLFW_OPENGL_CORE_PROFILE); #ifdef __APPLE__ glfwWindowHint(GLFW_OPENGL_FORWARD_COMPAT, GL_TRUE); #endif 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); if (!gladLoadGLLoader((GLADloadproc)glfwGetProcAddress)) { std::cout << "Failed to initialize GLAD" << std::endl; return -1; } while (!glfwWindowShouldClose(window)) { processInput(window); glClearColor(0.2f, 0.3f, 0.3f, 1.0f); glClear(GL_COLOR_BUFFER_BIT); glfwSwapBuffers(window); glfwPollEvents(); } glfwTerminate(); return 0; } void processInput(GLFWwindow *window) { if(glfwGetKey(window, GLFW_KEY_ESCAPE) == GLFW_PRESS) glfwSetWindowShouldClose(window, true); } void framebuffer_size_callback(GLFWwindow* window, int width, int height) { glViewport(0, 0, width, height); }
作者：KO
链接：https://juejin.cn/post/7040748736942702623