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c++macosopenglsdlosx-mountain-lion

C++ + SDL + OpenGL 3.3 doesn't work on Mac OS X?


I'm starting developing OpenGL 3 (I'm used to 1, so it's quite a change), and I'm using SDL as my windowing/image/sound/event-framework. I have the following code(taken from opengl.org and slightly modified):

#include <stdio.h>
#include <stdlib.h>
/* If using gl3.h */
/* Ensure we are using opengl's core profile only */
#define GL3_PROTOTYPES 1
#include <OpenGL/gl3.h>

#include <SDL2/SDL.h>
#define PROGRAM_NAME "Tutorial1"

/* A simple function that prints a message, the error code returned by SDL,
 * and quits the application */
void sdldie(const char *msg)
{
    printf("%s: %s\n", msg, SDL_GetError());
    SDL_Quit();
    exit(1);
}


void checkSDLError(int line = -1)
{
#ifndef NDEBUG
    const char *error = SDL_GetError();
    if (*error != '\0')
    {
        printf("SDL Error: %s\n", error);
        if (line != -1)
            printf(" + line: %i\n", line);
        SDL_ClearError();
    }
#endif
}

void render(SDL_Window* win){
    glClearColor(1.0,0.0,0.0,1.0);
    glClear ( GL_COLOR_BUFFER_BIT );
    SDL_GL_SwapWindow(win);
}


/* Our program's entry point */
int main(int argc, char *argv[])
{
    SDL_Window *mainwindow; /* Our window handle */
    SDL_GLContext maincontext; /* Our opengl context handle */

    if (SDL_Init(SDL_INIT_VIDEO) < 0) /* Initialize SDL's Video subsystem */
    sdldie("Unable to initialize SDL"); /* Or die on error */

    /* Request opengl 3.2 context.
     * SDL doesn't have the ability to choose which profile at this time of writing,
     * but it should default to the core profile */
    SDL_GL_SetAttribute(SDL_GL_CONTEXT_MAJOR_VERSION, 3);
    SDL_GL_SetAttribute(SDL_GL_CONTEXT_MINOR_VERSION, 2);

    /* Turn on double buffering with a 24bit Z buffer.
     * You may need to change this to 16 or 32 for your system */
    SDL_GL_SetAttribute(SDL_GL_DOUBLEBUFFER, 1);
    SDL_GL_SetAttribute(SDL_GL_DEPTH_SIZE, 24);

    /* Create our window centered at 512x512 resolution */
    mainwindow = SDL_CreateWindow(PROGRAM_NAME, SDL_WINDOWPOS_CENTERED, SDL_WINDOWPOS_CENTERED,
                              512, 512, SDL_WINDOW_OPENGL | SDL_WINDOW_SHOWN);
    if (!mainwindow) /* Die if creation failed */
        sdldie("Unable to create window");

    checkSDLError(__LINE__);

    /* Create our opengl context and attach it to our window */
    maincontext = SDL_GL_CreateContext(mainwindow);
    checkSDLError(__LINE__);


    /* This makes our buffer swap syncronized with the monitor's vertical refresh */
    SDL_GL_SetSwapInterval(1);

    render(mainwindow);
    SDL_Delay(2000);

    /* Delete our opengl context, destroy our window, and shutdown SDL */
    SDL_GL_DeleteContext(maincontext);
    SDL_DestroyWindow(mainwindow);
    SDL_Quit();

    return 0;
}

And this works well. But if I change this line:

SDL_GL_SetAttribute(SDL_GL_CONTEXT_MINOR_VERSION, 2);

To this:

SDL_GL_SetAttribute(SDL_GL_CONTEXT_MINOR_VERSION, 3);

So it uses OpenGL 3.3 instead of 3.2, I get a EXC_BAD_ACCES error on every single OpenGL call. I do want to use OpenGL 3.3. My Computer: MacBook Pro retina late 2012 Mac OS X Mountain Lion Intel i7 2.7 GHz Intel HD 4000 NVidia GeForce G

Anyone knows wether this is a OS X error, a SDL error, or something wrong with my code? (I know the SDL-code may not be the best, but it was originally SDL 1.2 code)


Solution

  • because OSX only have opengl capabilities up to 3.2.

    if you do SDL_GetError, it will tell you what is wrong.

    Edit: OSX Mavericks (10.9) now supports 4.1.