/*

    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 */