1.1 --- /dev/null	Thu Jan 01 00:00:00 1970 +0000
     1.2 +++ b/src/pvr2/glutil.c	Fri Mar 28 12:32:25 2008 +0000
     1.3 @@ -0,0 +1,57 @@
     1.4 +/**
     1.5 + * $Id$
     1.6 + *
     1.7 + * GL-based support functions 
     1.8 + *
     1.9 + * Copyright (c) 2005 Nathan Keynes.
    1.10 + *
    1.11 + * This program is free software; you can redistribute it and/or modify
    1.12 + * it under the terms of the GNU General Public License as published by
    1.13 + * the Free Software Foundation; either version 2 of the License, or
    1.14 + * (at your option) any later version.
    1.15 + *
    1.16 + * This program is distributed in the hope that it will be useful,
    1.17 + * but WITHOUT ANY WARRANTY; without even the implied warranty of
    1.18 + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    1.19 + * GNU General Public License for more details.
    1.20 + */
    1.21 +#include <string.h>
    1.22 +#include "pvr2/glutil.h"
    1.23 +
    1.24 +/**
    1.25 + * Test if a specific extension is supported. From opengl.org
    1.26 + * @param extension extension name to check for
    1.27 + * @return TRUE if supported, otherwise FALSE.
    1.28 + */
    1.29 +gboolean isGLExtensionSupported( const char *extension )
    1.30 +{
    1.31 +    const GLubyte *extensions = NULL;
    1.32 +    const GLubyte *start;
    1.33 +    GLubyte *where, *terminator;
    1.34 +
    1.35 +    /* Extension names should not have spaces. */
    1.36 +    where = (GLubyte *) strchr(extension, ' ');
    1.37 +    if (where || *extension == '\0')
    1.38 +	return 0;
    1.39 +    extensions = glGetString(GL_EXTENSIONS);
    1.40 +    if( extensions == NULL ) {
    1.41 +	/* No GL available, so we're pretty sure the extension isn't
    1.42 +	 * available either. */
    1.43 +	return FALSE;
    1.44 +    }
    1.45 +    /* It takes a bit of care to be fool-proof about parsing the
    1.46 +       OpenGL extensions string. Don't be fooled by sub-strings,
    1.47 +       etc. */
    1.48 +    start = extensions;
    1.49 +    for (;;) {
    1.50 +	where = (GLubyte *) strstr((const char *) start, extension);
    1.51 +	if (!where)
    1.52 +	    break;
    1.53 +	terminator = where + strlen(extension);
    1.54 +	if (where == start || *(where - 1) == ' ')
    1.55 +	    if (*terminator == ' ' || *terminator == '\0')
    1.56 +		return TRUE;
    1.57 +	start = terminator;
    1.58 +    }
    1.59 +    return FALSE;
    1.60 +}