在OpenGL中打印一个红色三角形

，如果您想要的是GL 2.1：

• 通过GLFW_OPENGL_PROFILE，GLFW_CONTEXT_VERSION_MAJOR和GLFW_CONTEXT_VERSION_MINOR请求版本的核心上下文；它应该满足或超过您在着色器中指定的#version
• 特别是对于MacOS，您需要一个前兼派的上下文；将GLFW_OPENGL_FORWARD_COMPAT设置为GL_TRUE
• 核心上下文需要一个顶点数组对象（VAO）才能绘制 notings ;对于简单的东西，您可以摆脱创建一个单个的东西，然后将其绑定到

一起：

#include <GL/glew.h>
#include <GLFW/glfw3.h>
#include <vector>
#include <iostream>
#include <cstdarg>
struct Program
{
    static GLuint Load( const char* shader, ... )
    {
        GLuint prog = glCreateProgram();
        va_list args;
        va_start( args, shader );
        while( shader )
        {
            const GLenum type = va_arg( args, GLenum );
            AttachShader( prog, type, shader );
            shader = va_arg( args, const char* );
        }
        va_end( args );
        glLinkProgram( prog );
        CheckStatus( prog );
        return prog;
    }
private:
    static void CheckStatus( GLuint obj )
    {
        GLint status = GL_FALSE;
        if( glIsShader(obj) ) glGetShaderiv( obj, GL_COMPILE_STATUS, &status );
        if( glIsProgram(obj) ) glGetProgramiv( obj, GL_LINK_STATUS, &status );
        if( status == GL_TRUE ) return;
        GLchar log[ 1 << 15 ] = { 0 };
        if( glIsShader(obj) ) glGetShaderInfoLog( obj, sizeof(log), NULL, log );
        if( glIsProgram(obj) ) glGetProgramInfoLog( obj, sizeof(log), NULL, log );
        std::cerr << log << std::endl;
        std::exit( EXIT_FAILURE );
    }
    static void AttachShader( GLuint program, GLenum type, const char* src )
    {
        GLuint shader = glCreateShader( type );
        glShaderSource( shader, 1, &src, NULL );
        glCompileShader( shader );
        CheckStatus( shader );
        glAttachShader( program, shader );
        glDeleteShader( shader );
    }
};
const char* vert = 1 + R"GLSL(
#version 330 core
layout(location = 0) in vec4 position;
void main()
{
    gl_Position = position;
};
)GLSL";
const char* frag = 1 + R"GLSL(
#version 330 core
layout(location = 0) out vec4 color;
void main()
{
    color = vec4(1.0, 0.0, 0.0, 1.0);
}
)GLSL";
int main(void)
{
    /* Initialize the library */
    if (!glfwInit())
        return -1;
    /* Create a windowed mode window and its OpenGL context */
    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 );
    GLFWwindow* window = glfwCreateWindow(640, 480, "Hello World", NULL, NULL);
    if (!window)
    {
        glfwTerminate();
        return -1;
    }
    /* Make the window's context current */
    glfwMakeContextCurrent(window);
    if (glewInit() != GLEW_OK)
        std::cout << "Error!" << std::endl;
    GLuint vao = 0;
    glGenVertexArrays( 1, &vao );
    glBindVertexArray( vao );
    float positions[6] =
    {
        -0.5f, -0.5f,
         0.0f,  0.5f,
         0.5f, -0.5f
    };
    unsigned int buffer;
    glGenBuffers(1, &buffer);
    glBindBuffer(GL_ARRAY_BUFFER, buffer);
    glBufferData(GL_ARRAY_BUFFER, 6 * sizeof(float), positions, GL_STATIC_DRAW);
    glEnableVertexAttribArray(0);
    glVertexAttribPointer(0, 2, GL_FLOAT, GL_FALSE, 2 * sizeof(float), 0);
    GLuint shader = Program::Load( vert, GL_VERTEX_SHADER, frag, GL_FRAGMENT_SHADER, NULL );
    glUseProgram(shader);
    glBindBuffer(GL_ARRAY_BUFFER, 0);
    /* Loop until the user closes the window */
    while (!glfwWindowShouldClose(window))
    {
        /* Render here */
        glClear(GL_COLOR_BUFFER_BIT);
        glDrawArrays(GL_TRIANGLES, 0, 3);
        /* Swap front and back buffers */
        glfwSwapBuffers(window);
        /* Poll for and process events */
        glfwPollEvents();
    }
    glDeleteProgram(shader);
    glfwTerminate();
    return 0;
}

您的问题可能是在顶点着色器中在这里，您定义了VEC4，但是您正在从Glvertexattribpointer（）函数中发送VEC2。尝试发送VEC4或在Vertex着色器

std::string vertexShader =
"#version 330 coren"
"n"
"layout(location = 0) in vec2 position;n"
"n"
"void main()n"
"{n"
"   gl_Position = vec4(position, 0, 1);n"
"}n";