nkeynes@635: /**
nkeynes@636:  * $Id$
nkeynes@635:  *
nkeynes@635:  * GL-based support functions 
nkeynes@635:  *
nkeynes@635:  * Copyright (c) 2005 Nathan Keynes.
nkeynes@635:  *
nkeynes@635:  * This program is free software; you can redistribute it and/or modify
nkeynes@635:  * it under the terms of the GNU General Public License as published by
nkeynes@635:  * the Free Software Foundation; either version 2 of the License, or
nkeynes@635:  * (at your option) any later version.
nkeynes@635:  *
nkeynes@635:  * This program is distributed in the hope that it will be useful,
nkeynes@635:  * but WITHOUT ANY WARRANTY; without even the implied warranty of
nkeynes@635:  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
nkeynes@635:  * GNU General Public License for more details.
nkeynes@635:  */
nkeynes@645: #include <string.h>
nkeynes@635: #include "pvr2/glutil.h"
nkeynes@635: 
nkeynes@635: /**
nkeynes@635:  * Test if a specific extension is supported. From opengl.org
nkeynes@635:  * @param extension extension name to check for
nkeynes@635:  * @return TRUE if supported, otherwise FALSE.
nkeynes@635:  */
nkeynes@635: gboolean isGLExtensionSupported( const char *extension )
nkeynes@635: {
nkeynes@635:     const GLubyte *extensions = NULL;
nkeynes@635:     const GLubyte *start;
nkeynes@635:     GLubyte *where, *terminator;
nkeynes@635: 
nkeynes@635:     /* Extension names should not have spaces. */
nkeynes@635:     where = (GLubyte *) strchr(extension, ' ');
nkeynes@635:     if (where || *extension == '\0')
nkeynes@635: 	return 0;
nkeynes@635:     extensions = glGetString(GL_EXTENSIONS);
nkeynes@645:     if( extensions == NULL ) {
nkeynes@645: 	/* No GL available, so we're pretty sure the extension isn't
nkeynes@645: 	 * available either. */
nkeynes@645: 	return FALSE;
nkeynes@645:     }
nkeynes@635:     /* It takes a bit of care to be fool-proof about parsing the
nkeynes@635:        OpenGL extensions string. Don't be fooled by sub-strings,
nkeynes@635:        etc. */
nkeynes@635:     start = extensions;
nkeynes@635:     for (;;) {
nkeynes@635: 	where = (GLubyte *) strstr((const char *) start, extension);
nkeynes@635: 	if (!where)
nkeynes@635: 	    break;
nkeynes@635: 	terminator = where + strlen(extension);
nkeynes@635: 	if (where == start || *(where - 1) == ' ')
nkeynes@635: 	    if (*terminator == ' ' || *terminator == '\0')
nkeynes@635: 		return TRUE;
nkeynes@635: 	start = terminator;
nkeynes@635:     }
nkeynes@635:     return FALSE;
nkeynes@635: }