我已经阅读了一些编写以下代码的教程。唯一的区别是原始教程中使用SDL而不是GLEW。

我不明白这段代码有什么问题。它编译，但我看不到三角形。（教程也没有使用着色器）

#include <iostream>
#include <GL/glew.h>
#include <GL/gl.h>
#include <GLFW/glfw3.h>

GLFWwindow* window;

int main(int argc, const char * argv[])
{
    if (!glfwInit())
    {
        return -1;
    }
    glfwWindowHint(GLFW_SAMPLES, 4);
    glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 3);
    glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 3);

    window = glfwCreateWindow(640, 480, "Test", NULL, NULL);
    if (window==NULL)
    {
        return -1;
    }
    glfwMakeContextCurrent(window);

    glewExperimental = true;
    if (glewInit() != GLEW_OK)
    {
        return -1;
    }

    glfwSetInputMode(window, GLFW_STICKY_KEYS, GL_TRUE);
    glClearColor(0.0f, 1.0f, 1.0f, 1.0f);

    do
    {
        glfwPollEvents();

        float vertices[] = {-0.5, -0.5,   0.0, 0.5,   0.5, -0.5};
        glClear(GL_COLOR_BUFFER_BIT);
        glVertexAttribPointer(0, 2, GL_FLOAT, GL_FALSE, 0, vertices);
        glEnableVertexAttribArray(0);
        glDrawArrays(GL_TRIANGLES, 0, 3);
        glDisableVertexAttribArray(0);

        glfwSwapBuffers(window);
    }
    while( glfwGetKey(window, GLFW_KEY_ESCAPE ) != GLFW_PRESS && glfwWindowShouldClose(window) == 0 );

    glfwTerminate();

    return 0;
}