【LearnOpenGL学习笔记】——01.初始窗口的绘制

文章目录

• • 1.绘制过程
  • 2.代码展示
  • 3.运行结果

1.绘制过程

①glfw的初始化与配置
②glfw窗口创建
③glad加载OpenGL的函数指针
④渲染循环（渲染命令在这）
⑤释放资源

2.代码展示

#include <glad/glad.h>
#include <GLFW/glfw3.h>
#include <iostream>

//初始窗口绘制

//Callback Function:窗口大小被调整时调用
void framebuffer_size_callback(GLFWwindow* window, int width, int height);
void processInput(GLFWwindow* window);


//settings
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);
	//glfwWindowHint(GLFW_OPENGL_FORWARD_COMPAT, GL_TRUE);

	// glfw:window creation
	GLFWwindow* window = glfwCreateWindow(800, 800, "LearnOpenGL", NULL, NULL);
	if (window == NULL) {
		std::cout << "Failed to created GLFW window" << std::endl;
		glfwTerminate();
		return -1;
	}
	glfwMakeContextCurrent(window);
	//注册callback函数
	glfwSetFramebufferSizeCallback(window, framebuffer_size_callback);

	// glad: load all OpenGL function pointers
	if (!gladLoadGLLoader((GLADloadproc)glfwGetProcAddress)) {
		std::cout << "Failed to initialize GLAD" << std::endl;
		return -1;
	}

	// render loop
	while (!glfwWindowShouldClose(window)) {
		//input
		processInput(window);

		//渲染指令
		//.....
		glClearColor(0.2f, 0.3f, 0.3f, 1.0f);
		glClear(GL_COLOR_BUFFER_BIT);



		//交换颜色缓冲 用于绘制
		glfwSwapBuffers(window);
		//检查是否触发事件,并调用对应回调函数
		glfwPollEvents();
	}

	//release resource 
	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);
}

3.运行结果