libsdl-1.2 support for OpenGL 3.2

Ale

This week we take a break from the C++ saga to talk a little about OpenGL. I’ve forked libsdl-1.2 and added support for creating OpenGL 3.2 forward-compatible contexts. This is something that could be deemed helpful until libsdl 2.0 is released.

You can find the source code on my GitHub page, at: github.com/alesegovia. In so far, only the Mac platform is supported, as it’s the only Operating System I currently have access to. I’ll hopefully be able to add Linux support as soon as I can get hold of a Linux box with a suitable video card.

Creating an OpenGL 3.2 compatible context is very simple. Once you have downloaded, compiled and installed libsdl-1.2-gl, you just need to create your window using the new SDL_OPENGLCORE flag.

This sample program creates an OpenGL 3.2 context, displays the OpenGL version number and exits:

#include <SDL.h>
#include <stdio.h>
#include <OpenGL/gl.h>

int main(int argc, char* argv[])
{
    SDL_Init(SDL_INIT_VIDEO);

    SDL_Surface* pSurface = SDL_SetVideoMode(600, 600, 32, SDL_OPENGL|SDL_OPENGLCORE);

    printf("GL Version:%s\n", glGetString(GL_VERSION));

    SDL_Quit();

    return 0;
}

You need to be running Mac OS X Lion or higher in order to be able to create OpenGL 3.2 contexts. If you are running Snow Leopard or your video card does not support OpenGL 3.2, you might get a Compatibility profile and your OpenGL version might be stuck on 2.1.

Also note that Mac OS X reports the OpenGL version to be 2.1 unless you specifically create forward-compatible OpenGL contexts, so if you need to know whether your Mac supports OpenGL 3.2, you can look your system configuration up in this great table maintained by Apple.

If you find this useful, let me know in the comments. Enjoy!