text: /*
      SDL - Simple DirectMedia Layer
      Copyright (C) 1997-2012 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 */
  
  