Simple triangle using OpenGL and GLFW [duplicate]

Question

This question already has an answer here:

• How do I create an OpenGL 3.3 context in GLFW 3 1 answer

I wrote a small program to display a simple triangle using vertex buffer. For the windowing i'm using glfw, my environment is Mac 10.9, XCode 5.

The window appears black but the triangle isn't paint.

Here the code:

#include <GLFW/glfw3.h>
#include <OpenGL/gl.h>
#include <iostream>

int main(int argc, const char * argv[])
{
    GLFWwindow* window;
    if (!glfwInit())
    {
        return -1;
    }

    glfwWindowHint (GLFW_CONTEXT_VERSION_MAJOR, 4);
    glfwWindowHint (GLFW_CONTEXT_VERSION_MINOR, 1);
    glfwWindowHint (GLFW_OPENGL_FORWARD_COMPAT, GL_TRUE);
    glfwWindowHint (GLFW_OPENGL_PROFILE, GLFW_OPENGL_CORE_PROFILE);

    window = glfwCreateWindow(640, 480, "Hello Triangle", NULL, NULL);
    if (!window) 
    {
        glfwTerminate();
        return -1;
    }

    glfwMakeContextCurrent(window);

    GLfloat verts[] =
    {
        0.0f,  0.5f,  0.0f,
        0.5f, -0.5f,  0.0f,
        -0.5f, -0.5f,  0.0f
    };

    //Generate a buffer id
    GLuint vboID;

    //Create a buffer on GPU memory
    glGenBuffers(1, &vboID);

    //Bind an arraybuffer to the ID
    glBindBuffer(GL_ARRAY_BUFFER, vboID);

    // Fill that buffer with the client vertex
    glBufferData(GL_ARRAY_BUFFER, sizeof(verts), verts, GL_STATIC_DRAW);

    //Enable attributes
    glEnableVertexAttribArray(0);

    // Setup a pointer to the attributes
    glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 0, 0);
    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

    while (!glfwWindowShouldClose(window))
    {
        glDrawArrays(GL_TRIANGLES, 0, 3);

        glfwPollEvents();
        glfwSwapBuffers(window);
    }

    glfwTerminate();
    return 0;
}

Answer 1

You're choosing the OpenGL Core Profile for your rendering:

glfwWindowHint(GLFW_OPENGL_FORWARD_COMPAT, GL_TRUE);
glfwWindowHint(GLFW_OPENGL_PROFILE, GLFW_OPENGL_CORE_PROFILE);

Your code is missing a number of things to be Core Profile compliant:

• You need to implement shader programs. The Core Profile does not support the old fixed pipeline anymore, and requires you to implement your own shaders in GLSL. Explaining how to do this in detail is beyond the scope of an answer, but you will be using calls like glCreateProgram, glCreateShader, glShaderSource, glCompileShader, glAttachShader, glLinkProgram. You should be able to find material online and in books.
• You need to use Vertex Array Objects (VAO). Look up glGenVertexArrays and glBindVertexArray.