============================================ gl3w: Simple OpenGL 3/4 core profile loading

Introduction

gl3w_ is the easiest way to get your hands on the functionality offered by OpenGL 3/4 core profile specification.

Its main part is a simple gl3w_gen.py_ Python 2.6 script that downloads the Khronos_ supported glcorearb.h_ header and generates gl3w.h and gl3w.c from it. Those files can then be added and linked (statically or dynamically) into your project.

Example

Here is a simple example of using gl3w_ with glut. Note that GL/gl3w.h must be included before any other OpenGL related headers::

#include <stdio.h>
#include <GL/gl3w.h>
#include <GL/glut.h>

// ...

int main(int argc, char **argv)
{
        glutInit(&argc, argv);
        glutInitDisplayMode(GLUT_RGBA | GLUT_DEPTH | GLUT_DOUBLE);
        glutInitWindowSize(width, height);
        glutCreateWindow("cookie");

        glutReshapeFunc(reshape);
        glutDisplayFunc(display);
        glutKeyboardFunc(keyboard);
        glutSpecialFunc(special);
        glutMouseFunc(mouse);
        glutMotionFunc(motion);

        if (gl3wInit()) {
                fprintf(stderr, "failed to initialize OpenGL\n");
                return -1;
        }
        if (!gl3wIsSupported(3, 2)) {
                fprintf(stderr, "OpenGL 3.2 not supported\n");
                return -1;
        }
        printf("OpenGL %s, GLSL %s\n", glGetString(GL_VERSION),
               glGetString(GL_SHADING_LANGUAGE_VERSION));

        // ...

        glutMainLoop();
        return 0;
}

API Reference

The gl3w_ API consist of just three functions:

int gl3wInit(void)

Initializes the library. Should be called once after an OpenGL context has
been created. Returns ``0`` when gl3w_ was initialized successfully,
``-1`` if there was an error.

int gl3wIsSupported(int major, int minor)

Returns ``1`` when OpenGL core profile version *major.minor* is available,
and ``0`` otherwise.

void *gl3wGetProcAddress(const char *proc)

Returns the address of an OpenGL extension function. Generally, you won't
need to use it since gl3w_ loads all the functions defined in the OpenGL
core profile on initialization. It allows you to load OpenGL extensions
outside of the core profile.

License

gl3w_ is in the public domain.

Credits

Slavomir Kaslev slavomir.kaslev@gmail.com Initial implementation

Kelvin McDowell Mac OS X support

Sjors Gielen Mac OS X support

Rommel160 [github.com/Rommel160] Code contributions

Copyright

OpenGL_ is a registered trademark of SGI_.

.. _gl3w: https://github.com/skaslev/gl3w .. _gl3w_gen.py: https://github.com/skaslev/gl3w/blob/master/gl3w_gen.py .. _glcorearb.h: http://www.opengl.org/registry/api/glcorearb.h .. _OpenGL: http://www.opengl.org/ .. _Khronos: http://www.khronos.org/ .. _SGI: http://www.sgi.com/