编译opengl编程指南第八版示例代码通过

最近在编译opengl编程指南第八版的示例代码，如下

#include <iostream>
#include "vgl.h"
#include "LoadShaders.h"

using namespace std;


enum VAO_IDs { Triangles, NumVAOs };
enum Buffer_IDs { ArrayBuffer, NumBuffers };
enum Attrib_IDs { vPosition = 0 };
GLuint VAOs[NumVAOs];
GLuint Buffers[NumBuffers];
const GLuint NumVertices = 6;

void
init(void)
{
    glGenVertexArrays(NumVAOs, VAOs);
    glBindVertexArray(VAOs[Triangles]);
    GLfloat vertices[NumVertices][2] = {
        { -0.90, -0.90 }, // Triangle 1
        { 0.85, -0.90 },
        { -0.90, 0.85 },
        { 0.90, -0.85 }, // Triangle 2
        { 0.90, 0.90 },
        { -0.85, 0.90 }
    };
    glGenBuffers(NumBuffers, Buffers);
    glBindBuffer(GL_ARRAY_BUFFER, Buffers[ArrayBuffer]);
    glBufferData(GL_ARRAY_BUFFER, sizeof(vertices),
        vertices, GL_STATIC_DRAW);
    ShaderInfo shaders[] = {
        { GL_VERTEX_SHADER, "triangles.vert" },
        { GL_FRAGMENT_SHADER, "triangles.frag" },
        { GL_NONE, NULL }
    };
    GLuint program = LoadShaders(shaders);
    glUseProgram(program);
    glVertexAttribPointer(vPosition, 2, GL_FLOAT,
        GL_FALSE, 0, BUFFER_OFFSET(0));
    glEnableVertexAttribArray(vPosition);
}

void
display(void)
{
    glClear(GL_COLOR_BUFFER_BIT);
    glBindVertexArray(VAOs[Triangles]);
    glDrawArrays(GL_TRIANGLES, 0, NumVertices);
    glFlush();
}

int
main(int argc, char** argv)
{
    glutInit(&argc, argv);
    glutInitDisplayMode(GLUT_RGBA);
    glutInitWindowSize(512, 512);
    glutInitContextVersion(4, 3);
    glutInitContextProfile(GLUT_CORE_PROFILE);
    glutCreateWindow(argv[0]);
    if (glewInit()) {
        cerr << "Unable to initialize GLEW ... exiting" << endl;
        exit(EXIT_FAILURE);
    }
    init();
    glutDisplayFunc(display);
    glutMainLoop();
}

shader代码如下：

//顶点shader
#version 430 core

layout(location = 0) in vec4 vPosition;

void main(){
    gl_Position = vPosition;
}

//片元shader
#version 430 core

out vec4 fColor;

void main(){
    fColor = vec4(0.0, 0.0, 1.0, 1.0);
}

在编译成功运行的时候老是在glGenVertexArrays和glBindVertexArray两个函数出crash，在stackoverflow上面找到了解决的办法，GLEW has trouble accessing some parts of the opengl core profile by default, so saying "glewExperimental = GL_TRUE;" before your call to glewInit() might help.因此只需要加这么一行代码就可以了

int
main(int argc, char** argv)
{
    glutInit(&argc, argv);
    glutInitDisplayMode(GLUT_RGBA);
    glutInitWindowSize(512, 512);
    glutInitContextVersion(4, 3);
    glutInitContextProfile(GLUT_CORE_PROFILE);
    glutCreateWindow(argv[0]);
    glewExperimental = GL_TRUE;//add
    if (glewInit()) {
        cerr << "Unable to initialize GLEW ... exiting" << endl;
        exit(EXIT_FAILURE);
    }
    init();
    glutDisplayFunc(display);
    glutMainLoop();
}

运行结果如下