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C语言使用glfw3与opengl在vs2022中开发窗口程序

1.准备开发环境

  1. 使用vkpkg安装glfw3.
  2. 使用vkpkg安装glad

2.使用glfw创建一个窗口程序

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#include <GLFW/glfw3.h>   
#include <stdio.h>
int main()
{
    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(800, 600, "LearnOpenGL", NULL, NULL);
    if (window == NULL)
    {
        printf("Failed to create GLFW window");
        glfwTerminate();
        return -1;
    }
    glfwMakeContextCurrent(window);
    while (!glfwWindowShouldClose(window))
    {
        // glfw: swap buffers and poll IO events (keys pressed/released, mouse moved etc.)
        // -------------------------------------------------------------------------------
        glfwSwapBuffers(window);
        glfwPollEvents();
    }

    return 0;
}

3.在窗口程序中接收键盘消息

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#include <GLFW/glfw3.h>   
#include <stdio.h>

void key_callback(GLFWwindow* window, int key, int scancode, int action, int mode)
{
    if (key == GLFW_KEY_ESCAPE && action == GLFW_PRESS)//按下esc退出程序
    {
        glfwSetWindowShouldClose(window, GL_TRUE);
    }
    else if (key == GLFW_KEY_LEFT && action == GLFW_PRESS)
    {
        printf("key left press\n");
    }
    else if (key == GLFW_KEY_RIGHT && action == GLFW_RELEASE)
    {
        printf("key right release\n");
    }
    else if (key == GLFW_KEY_UP)
    {
        if (action == GLFW_PRESS|| action == GLFW_RELEASE) {
            printf("key up\n");
        }
    }
    else if (key == GLFW_KEY_DOWN)
    {
        printf("key dwon\n");
    }
}
int main()
{
    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(800, 600, "LearnOpenGL", NULL, NULL);
    if (window == NULL)
    {
        printf("Failed to create GLFW window");
        glfwTerminate();
        return -1;
    }
    glfwMakeContextCurrent(window);
    glfwSetKeyCallback(window, key_callback);
    while (!glfwWindowShouldClose(window))
    {
        // glfw: swap buffers and poll IO events (keys pressed/released, mouse moved etc.)
        // -------------------------------------------------------------------------------
        glfwSwapBuffers(window);
        glfwPollEvents();
    }

    return 0;
}

4.使用glad与glfw3创建窗口并更换窗口背景色

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#include <GLAD/glad.h>
#include <GLFW/glfw3.h>
#include <stdio.h>


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);

#ifdef __APPLE__
    glfwWindowHint(GLFW_OPENGL_FORWARD_COMPAT, GL_TRUE);
#endif

    // glfw window creation
    // --------------------
    GLFWwindow* window = glfwCreateWindow(SCR_WIDTH, SCR_HEIGHT, "LearnOpenGL", NULL, NULL);
    if (window == NULL)
    {
        printf("Failed to create GLFW window" );
        glfwTerminate();
        return -1;
    }
    glfwMakeContextCurrent(window);
    glfwSetFramebufferSizeCallback(window, framebuffer_size_callback);

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

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

        // render
        // ------
        glClearColor(0.2f, 0.3f, 0.3f, 1.0f);
        glClear(GL_COLOR_BUFFER_BIT);

        // glfw: swap buffers and poll IO events (keys pressed/released, mouse moved etc.)
        // -------------------------------------------------------------------------------
        glfwSwapBuffers(window);
        glfwPollEvents();
    }

    // glfw: terminate, clearing all previously allocated GLFW resources.
    // ------------------------------------------------------------------
    glfwTerminate();
    return 0;
}

// process all input: query GLFW whether relevant keys are pressed/released this frame and react accordingly
// ---------------------------------------------------------------------------------------------------------
void processInput(GLFWwindow* window)
{
    if (glfwGetKey(window, GLFW_KEY_ESCAPE) == GLFW_PRESS)
        glfwSetWindowShouldClose(window, 1);
}

// glfw: whenever the window size changed (by OS or user resize) this callback function executes
// ---------------------------------------------------------------------------------------------
void framebuffer_size_callback(GLFWwindow* window, int width, int height)
{
    // make sure the viewport matches the new window dimensions; note that width and 
    // height will be significantly larger than specified on retina displays.
    glViewport(0, 0, width, height);
}

5..使用glad与glfw3创建窗口并画一个矩形

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#include <glad\glad.h>   //这个必须放在GLFW之前
#include <GLFW\glfw3.h>

#include <stdio.h>

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;

const char *vertexShaderSource = "#version 330 core\n"
"layout (location = 0) in vec3 aPos;\n"
"void main()\n"
"{\n"
"   gl_Position = vec4(aPos.x, aPos.y, aPos.z, 1.0);\n"
"}\0";
const char *fragmentShaderSource = "#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";

int main() {
	// glfw: initialize and configure
	// ------------------------------
	glfwInit(); //glfw 初始化
	//设置OpenGL版本等信息
	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); // uncomment this statement to fix compilation on OS X
#endif

	// glfw window creation
	// --------------------
	//创建GLFW窗口
	GLFWwindow* window = glfwCreateWindow(SCR_WIDTH, SCR_HEIGHT, "LearnOpenGL", NULL, NULL);
	if(window == NULL) {
		printf("Failed to create GLFW window");
		glfwTerminate();
		return -1;
	}
	//设置当前上下文
	glfwMakeContextCurrent(window);
	glfwSetFramebufferSizeCallback(window, framebuffer_size_callback);

	// glad: load all OpenGL function pointers
	// ---------------------------------------
	//把OpenGL的函数指针导入给GLAD
	if(!gladLoadGLLoader((GLADloadproc)glfwGetProcAddress)) {
		printf("Failed to initialize GLAD");
		return -1;
	}

	// build and compile our shader program
	// ------------------------------------
	// vertex shader
	int vertexShader = glCreateShader(GL_VERTEX_SHADER);
	glShaderSource(vertexShader, 1, &vertexShaderSource, NULL);
	glCompileShader(vertexShader);
	// check for shader compile errors
	int success;
	char infoLog[512];
	glGetShaderiv(vertexShader, GL_COMPILE_STATUS, &success);
	if(!success) {
		glGetShaderInfoLog(vertexShader, 512, NULL, infoLog);
		printf("ERROR::SHADER::VERTEX::COMPILATION_FAILED\n%s\n", infoLog);
	}
	// fragment shader
	int fragmentShader = glCreateShader(GL_FRAGMENT_SHADER);
	glShaderSource(fragmentShader, 1, &fragmentShaderSource, NULL);
	glCompileShader(fragmentShader);
	// check for shader compile errors
	glGetShaderiv(fragmentShader, GL_COMPILE_STATUS, &success);
	if(!success) {
		glGetShaderInfoLog(fragmentShader, 512, NULL, infoLog);
		printf("ERROR::SHADER::FRAGMENT::COMPILATION_FAILED\n%s\n", infoLog);
	}
	// link shaders
	int shaderProgram = glCreateProgram();
	glAttachShader(shaderProgram, vertexShader);
	glAttachShader(shaderProgram, fragmentShader);
	glLinkProgram(shaderProgram);
	// check for linking errors
	glGetProgramiv(shaderProgram, GL_LINK_STATUS, &success);
	if(!success) {
		glGetProgramInfoLog(shaderProgram, 512, NULL, infoLog);
		printf("ERROR::SHADER::PROGRAM::LINKING_FAILED\n%s\n", infoLog);
	}
	glDeleteShader(vertexShader);
	glDeleteShader(fragmentShader);

	// set up vertex data (and buffer(s)) and configure vertex attributes
	// ------------------------------------------------------------------
	float vertices[] ={
		0.5f, 0.5f, 0.0f,  // top right
		0.5f, -0.5f, 0.0f,  // bottom right
		-0.5f, -0.5f, 0.0f,  // bottom left
		-0.5f, 0.5f, 0.0f   // top left 
	};
	unsigned int indices[] ={  // note that we start from 0!
		0, 1, 3,  // first Triangle
		1, 2, 3   // second Triangle
	};
	unsigned int VBO, VAO, EBO;
	glGenVertexArrays(1, &VAO);
	glGenBuffers(1, &VBO);
	glGenBuffers(1, &EBO);
	// bind the Vertex Array Object first, then bind and set vertex buffer(s), and then configure vertex attributes(s).
	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);

	glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 3 * sizeof(float), (void*)0);
	glEnableVertexAttribArray(0);

	// note that this is allowed, the call to glVertexAttribPointer registered VBO as the vertex attribute's bound vertex buffer object so afterwards we can safely unbind
	glBindBuffer(GL_ARRAY_BUFFER, 0);

	// remember: do NOT unbind the EBO while a VAO is active as the bound element buffer object IS stored in the VAO; keep the EBO bound.
	//glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, 0);

	// You can unbind the VAO afterwards so other VAO calls won't accidentally modify this VAO, but this rarely happens. Modifying other
	// VAOs requires a call to glBindVertexArray anyways so we generally don't unbind VAOs (nor VBOs) when it's not directly necessary.
	glBindVertexArray(0);

	// uncomment this call to draw in wireframe polygons.
	//glPolygonMode(GL_FRONT_AND_BACK, GL_LINE);

	// render loop
	// -----------
	//循环渲染
	while(!glfwWindowShouldClose(window)) {
		// input
		// -----
		processInput(window);

		// render
		// ------
		glClearColor(0.2f, 0.3f, 0.3f, 1.0f);
		glClear(GL_COLOR_BUFFER_BIT);

		// draw our first triangle
		glUseProgram(shaderProgram);
		glBindVertexArray(VAO); // seeing as we only have a single VAO there's no need to bind it every time, but we'll do so to keep things a bit more organized
		//glDrawArrays(GL_TRIANGLES, 0, 6);
		glDrawElements(GL_TRIANGLES, 6, GL_UNSIGNED_INT, 0);
		// glBindVertexArray(0); // no need to unbind it every time 

		// glfw: swap buffers and poll IO events (keys pressed/released, mouse moved etc.)
		// -------------------------------------------------------------------------------
		//交换缓存
		glfwSwapBuffers(window);
		//事件处理
		glfwPollEvents();
	}

	// optional: de-allocate all resources once they've outlived their purpose:
	// ------------------------------------------------------------------------
	glDeleteVertexArrays(1, &VAO);
	glDeleteBuffers(1, &VBO);
	glDeleteBuffers(1, &EBO);

	// glfw: terminate, clearing all previously allocated GLFW resources.
	// ------------------------------------------------------------------
	//停止
	glfwTerminate();
	return 0;
}

// process all input: query GLFW whether relevant keys are pressed/released this frame and react accordingly
// ---------------------------------------------------------------------------------------------------------
//输入处理函数
void processInput(GLFWwindow *window) {
	if(glfwGetKey(window, GLFW_KEY_ESCAPE) == GLFW_PRESS)
		glfwSetWindowShouldClose(window, 1);
}

// glfw: whenever the window size changed (by OS or user resize) this callback function executes
//窗口大小设置回调函数
// ---------------------------------------------------------------------------------------------
void framebuffer_size_callback(GLFWwindow* window, int width, int height) {
	// make sure the viewport matches the new window dimensions; note that width and 
	// height will be significantly larger than specified on retina displays.
	glViewport(0, 0, width, height);
}

5.设置键盘消息的回调函数，响应上下左右键，实现线条在窗口中的上下左右的移动

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#include <stdio.h>
#include <Windows.h>

// GLEW    
#include <GL/glew.h>    

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

GLuint WIDTH = 400, HEIGHT = 400;
GLfloat gX = 0, gY = 0;

void key_callback(GLFWwindow* window, int key, int scancode, int action, int mode);

//opengl在glfw中显示规则：
//1.画布中间坐标为0,0。长宽个1.0f个单位，超过1.0f的部分不会被绘制出来
void DrawLine()
{
	glColor4b(99, 38, 13, 90);

	glBegin(GL_LINES);

	glVertex2f(-1 + gX * 4, 1 + gY * 4);//指定第一个点
	glVertex2f(-0.8 + gX * 4, gY * 4 + 0.8);//指定第二个点

	glEnd();//结束
}

void render(GLFWwindow* window)
{
	glClearColor(1.0f, 0.8f, 1.0f, 1.0f);
	glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
	glEnable(GL_DEPTH_TEST);

	DrawLine();
}

void initWindow(GLFWwindow* window)
{
	glfwMakeContextCurrent(window);

	//设置按键回调
	glfwSetKeyCallback(window, key_callback);
}

void initParam()
{
	//显示规则：窗口左下角坐标为0，0；所以下行代码表示在窗口左下角向右向上的400个像素单位作为画布
	glViewport(0, 0, WIDTH, HEIGHT);//设置显示区域400*400，但是可以拖动改变窗口大小
	glLineWidth(3.0);//设置线条宽度，3个像素
}

int main()
{
	glfwInit();

	GLFWwindow* window = glfwCreateWindow(WIDTH, HEIGHT, "OpenGL", 0, 0);
	if (window == 0)
	{
		printf("Failed to create GLFW window");
		glfwTerminate();
		return -1;
	}

	initWindow(window);

	if (glewInit() != GLEW_OK)
	{
		printf("Failed to initialize GLEW");
		return -1;
	}

	initParam();

	// Game loop    
	while (!glfwWindowShouldClose(window))
	{
		glfwPollEvents();

		render(window);

		glfwSwapBuffers(window);
	}

	// Terminate GLFW, clearing any resources allocated by GLFW.    
	glfwTerminate();
	return 0;
}

void key_callback(GLFWwindow* window, int key, int scancode, int action, int mode)
{
	if (key == GLFW_KEY_ESCAPE && action == GLFW_PRESS)//按下esc退出程序
	{
		glfwSetWindowShouldClose(window, GL_TRUE);
	}
	else if (key == GLFW_KEY_LEFT)
	{
		gX -= 0.01;
	}
	else if (key == GLFW_KEY_RIGHT)
	{
		gX += 0.01;
	}
	else if (key == GLFW_KEY_UP)
	{
		gY += 0.01;
	}
	else if (key == GLFW_KEY_DOWN)
	{
		gY -= 0.01;
	}
}