OpenGL入门到入坟：顶点上色

操作系统：Win10

工具：VS2019

环境：GLFW 3.3.0.1、GLEW 1.9.0.1

测试结果

测试代码

#include <iostream>
#include <GL/glew.h>
#include <GLFW/glfw3.h>
using namespace std;

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;

//vertex fragment 着色器编译代码
const char* vertexShaderSource = "#version 330 core\n"
"layout(location = 0) in vec3 Pos;\n"
"layout(location = 1) in vec3 Color;\n "
"out vec3 outColor;\n" 
"void main()\n"
"{\n"
"	gl_Position = vec4(Pos, 1.0);\n"
"	outColor = Color;\n "
"}\n\0";
const char* fragmentShaderSource = "#version 330 core\n"
"out vec4 fragColor;\n"
"in vec3 outColor;\n"
"void main()\n"
"{\n"
"	fragColor = vec4(outColor, 1.0);\n"
"}\n\0";
//窗口消息处理
void processInput(GLFWwindow* window)
{
	if (glfwGetKey(window, GLFW_KEY_ESCAPE) == GLFW_PRESS)
	{
		cout << "Window was closed..." << endl;
		glfwSetWindowShouldClose(window, true);
	}
}
//窗口大小改变回调函数
void framebuffer_size_callback(GLFWwindow* window, int width, int height)
{
	glViewport(0, 0, width, height);
}
int main(int argc, char* argv[])
{
	//初始化glfw，使用3.3版本
	glfwInit();
	glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 3);
	glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 3);
	glfwWindowHint(GLFW_OPENGL_PROFILE, GLFW_OPENGL_CORE_PROFILE);

	//开窗500*500,标题OpenGL

	GLFWwindow* window = glfwCreateWindow(SCR_WIDTH, SCR_HEIGHT, "OpenGL", NULL, NULL);
	//开窗失败
	if (window == NULL)
	{
		cout << "Creating window fail" << endl;
		glfwTerminate();
		return EXIT_FAILURE;
	}

	//设置当前运行的上下文
	glfwMakeContextCurrent(window);
	//窗口大小改变视口
	glfwSetFramebufferSizeCallback(window, framebuffer_size_callback);


	glewExperimental = true;
	if (glewInit() != GLEW_OK)
	{
		cout << "glew init fail" << endl;
		glfwTerminate();
		return EXIT_FAILURE;
	}
	glViewport(0, 0, SCR_WIDTH,SCR_HEIGHT);

	// Create and Compile 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);
		std::cout << "ERROR::SHADER::VERTEX::COMPILATION_FAILED\n" << infoLog << std::endl;
	}
	// Create and Compile 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);
		std::cout << "ERROR::SHADER::FRAGMENT::COMPILATION_FAILED\n" << infoLog << std::endl;
	}
	// Create Program 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);
		std::cout << "ERROR::SHADER::PROGRAM::LINKING_FAILED\n" << infoLog << std::endl;
	}
	glDeleteShader(vertexShader);
	glDeleteShader(fragmentShader);

	
	float vertices[] = {
		// 位置              // 颜色
		 0.5f, -0.5f, 0.0f,  1.0f, 0.0f, 0.0f,   // 右下
		-0.5f, -0.5f, 0.0f,  0.0f, 1.0f, 0.0f,   // 左下
		 0.0f,  0.5f, 0.0f,  0.0f, 0.0f, 1.0f    // 顶部
	};
	unsigned int VBO, VAO;
	glGenVertexArrays(1, &VAO);
	glGenBuffers(1, &VBO);
	glBindVertexArray(VAO);

	glBindBuffer(GL_ARRAY_BUFFER, VBO);
	glBufferData(GL_ARRAY_BUFFER, sizeof(vertices), vertices, GL_STATIC_DRAW);


	// 位置属性
	glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 6 * sizeof(float), (void*)0);
	glEnableVertexAttribArray(0);
	// 颜色属性
	glVertexAttribPointer(1, 3, GL_FLOAT, GL_FALSE, 6 * sizeof(float), (void*)(3 * sizeof(float)));
	glEnableVertexAttribArray(1);

	while (!glfwWindowShouldClose(window))
	{
		
		processInput(window);

		glClearColor(0.2f, 0.5f, 0.8f, 0.0f);
		glClear(GL_COLOR_BUFFER_BIT);

		
		glUseProgram(shaderProgram);

		glDrawArrays(GL_TRIANGLES, 0, 3);
		
		glfwSwapBuffers(window);
		glfwPollEvents();
	}
	glfwTerminate();
	return EXIT_SUCCESS;
}