/*
    SDL - Simple DirectMedia Layer
    Copyright (C) 1997-2006 Sam Lantinga

    This library is free software; you can redistribute it and/or
    modify it under the terms of the GNU Lesser General Public
    License as published by the Free Software Foundation; either
    version 2.1 of the License, or (at your option) any later version.

    This library is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
    Lesser General Public License for more details.

    You should have received a copy of the GNU Lesser General Public
    License along with this library; if not, write to the Free Software
    Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA

    Sam Lantinga
    slouken@libsdl.org
*/
#include "SDL_config.h"

/* AGL implementation of SDL OpenGL support */

#include "SDL_lowvideo.h"
#include "SDL_macgl_c.h"
#include "SDL_loadso.h"


/* krat: adding OpenGL support */
int
Mac_GL_Init (_THIS)
{
#if SDL_VIDEO_OPENGL
    AGLPixelFormat format;
    int i = 0;
    GLint attributes[26];       /* 26 is max possible in this setup */
    GLboolean noerr;

    /* load the gl driver from a default path */
    if (!this->gl_config.driver_loaded) {
        /* no driver has been loaded, use default (ourselves) */
        if (Mac_GL_LoadLibrary (this, NULL) < 0) {
            return (-1);
        }
    }

    attributes[i++] = AGL_RGBA;
    if (this->gl_config.red_size != 0 &&
        this->gl_config.blue_size != 0 && this->gl_config.green_size != 0) {
        attributes[i++] = AGL_RED_SIZE;
        attributes[i++] = this->gl_config.red_size;
        attributes[i++] = AGL_GREEN_SIZE;
        attributes[i++] = this->gl_config.green_size;
        attributes[i++] = AGL_BLUE_SIZE;
        attributes[i++] = this->gl_config.blue_size;
        attributes[i++] = AGL_ALPHA_SIZE;
        attributes[i++] = this->gl_config.alpha_size;
    }
    if (this->gl_config.double_buffer) {
        attributes[i++] = AGL_DOUBLEBUFFER;
    }
    if (this->gl_config.depth_size != 0) {
        attributes[i++] = AGL_DEPTH_SIZE;
        attributes[i++] = this->gl_config.depth_size;
    }
    if (this->gl_config.stencil_size != 0) {
        attributes[i++] = AGL_STENCIL_SIZE;
        attributes[i++] = this->gl_config.stencil_size;
    }
    if (this->gl_config.accum_red_size != 0 &&
        this->gl_config.accum_blue_size != 0 &&
        this->gl_config.accum_green_size != 0) {

        attributes[i++] = AGL_ACCUM_RED_SIZE;
        attributes[i++] = this->gl_config.accum_red_size;
        attributes[i++] = AGL_ACCUM_GREEN_SIZE;
        attributes[i++] = this->gl_config.accum_green_size;
        attributes[i++] = AGL_ACCUM_BLUE_SIZE;
        attributes[i++] = this->gl_config.accum_blue_size;
        attributes[i++] = AGL_ACCUM_ALPHA_SIZE;
        attributes[i++] = this->gl_config.accum_alpha_size;
    }
    if (this->gl_config.stereo) {
        attributes[i++] = AGL_STEREO;
    }
#if defined(AGL_SAMPLE_BUFFERS_ARB) && defined(AGL_SAMPLES_ARB)
    if (this->gl_config.multisamplebuffers != 0) {
        attributes[i++] = AGL_SAMPLE_BUFFERS_ARB;
        attributes[i++] = this->gl_config.multisamplebuffers;
    }
    if (this->gl_config.multisamplesamples != 0) {
        attributes[i++] = AGL_SAMPLES_ARB;
        attributes[i++] = this->gl_config.multisamplesamples;
    }
#endif
    if (this->gl_config.accelerated > 0) {
        attributes[i++] = AGL_ACCELERATED;
        attributes[i++] = AGL_NO_RECOVERY;
    }

    attributes[i++] = AGL_ALL_RENDERERS;
    attributes[i] = AGL_NONE;

    format = aglChoosePixelFormat (NULL, 0, attributes);
    if (format == NULL) {
        SDL_SetError ("Couldn't match OpenGL desired format");
        return (-1);
    }

    glContext = aglCreateContext (format, NULL);
    if (glContext == NULL) {
        SDL_SetError ("Couldn't create OpenGL context");
        return (-1);
    }
    aglDestroyPixelFormat (format);

#if  TARGET_API_MAC_CARBON
    noerr = aglSetDrawable (glContext, GetWindowPort (SDL_Window));
#else
    noerr = aglSetDrawable (glContext, (AGLDrawable) SDL_Window);
#endif

    if (!noerr) {
        SDL_SetError ("Unable to bind GL context to window");
        return (-1);
    }
    return (0);
#else
    SDL_SetError ("OpenGL support not configured");
    return (-1);
#endif
}

void
Mac_GL_Quit (_THIS)
{
#if SDL_VIDEO_OPENGL
    if (glContext != NULL) {
        aglSetCurrentContext (NULL);
        aglSetDrawable (glContext, NULL);
        aglDestroyContext (glContext);
        glContext = NULL;
    }
#endif
}

#if SDL_VIDEO_OPENGL

/* Make the current context active */
int
Mac_GL_MakeCurrent (_THIS)
{
    int retval;

    retval = 0;
    if (!aglSetCurrentContext (glContext)) {
        SDL_SetError ("Unable to make GL context current");
        retval = -1;
    }
    return (retval);
}

void
Mac_GL_SwapBuffers (_THIS)
{
    aglSwapBuffers (glContext);
}

int
Mac_GL_LoadLibrary (_THIS, const char *location)
{
    if (location == NULL)
#if __MACH__
        location = "/System/Library/Frameworks/OpenGL.framework/OpenGL";
#else
        location = "OpenGLLibrary";
#endif

    this->hidden->libraryHandle = SDL_LoadObject (location);

    this->gl_config.driver_loaded = 1;
    return (this->hidden->libraryHandle != NULL) ? 0 : -1;
}

void
Mac_GL_UnloadLibrary (_THIS)
{
    SDL_UnloadObject (this->hidden->libraryHandle);

    this->hidden->libraryHandle = NULL;
    this->gl_config.driver_loaded = 0;
}

void *
Mac_GL_GetProcAddress (_THIS, const char *proc)
{
    return SDL_LoadFunction (this->hidden->libraryHandle, proc);
}

#endif /* SDL_VIDEO_OPENGL */
/* vi: set ts=4 sw=4 expandtab: */