source/libs/cairo/cairo-src/src/cairo-gl-info.c

   1 /* cairo - a vector graphics library with display and print output
   2  *
   3  * Copyright © 2010 Linaro Limited
   4  *
   5  * This library is free software; you can redistribute it and/or
   6  * modify it either under the terms of the GNU Lesser General Public
   7  * License version 2.1 as published by the Free Software Foundation
   8  * (the "LGPL") or, at your option, under the terms of the Mozilla
   9  * Public License Version 1.1 (the "MPL"). If you do not alter this
  10  * notice, a recipient may use your version of this file under either
  11  * the MPL or the LGPL.
  12  *
  13  * You should have received a copy of the LGPL along with this library
  14  * in the file COPYING-LGPL-2.1; if not, write to the Free Software
  15  * Foundation, Inc., 51 Franklin Street, Suite 500, Boston, MA 02110-1335, USA
  16  * You should have received a copy of the MPL along with this library
  17  * in the file COPYING-MPL-1.1
  18  *
  19  * The contents of this file are subject to the Mozilla Public License
  20  * Version 1.1 (the "License"); you may not use this file except in
  21  * compliance with the License. You may obtain a copy of the License at
  22  * http://www.mozilla.org/MPL/
  23  *
  24  * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY
  25  * OF ANY KIND, either express or implied. See the LGPL or the MPL for
  26  * the specific language governing rights and limitations.
  27  *
  28  * Contributor(s):
  29  *      Alexandros Frantzis <alexandros.frantzis@linaro.org>
  30  */
  31
  32 #include "cairoint.h"
  33 #include "cairo-gl-private.h"
  34
  35 #include <errno.h>
  36
  37 int
  38 _cairo_gl_get_version (void)
  39 {
  40     int major, minor;
  41     const char *version = (const char *) glGetString (GL_VERSION);
  42     const char *dot = version == NULL ? NULL : strchr (version, '.');
  43     const char *major_start = dot;
  44
  45     /* Sanity check */
  46     if (dot == NULL || dot == version || *(dot + 1) == '\0') {
  47         major = 0;
  48         minor = 0;
  49     } else {
  50         /* Find the start of the major version in the string */
  51         while (major_start > version && *major_start != ' ')
  52             --major_start;
  53         major = strtol (major_start, NULL, 10);
  54         minor = strtol (dot + 1, NULL, 10);
  55     }
  56
  57     return CAIRO_GL_VERSION_ENCODE (major, minor);
  58 }
  59
  60 cairo_gl_flavor_t
  61 _cairo_gl_get_flavor (void)
  62 {
  63     const char *version = (const char *) glGetString (GL_VERSION);
  64     cairo_gl_flavor_t flavor;
  65
  66     if (version == NULL)
  67         flavor = CAIRO_GL_FLAVOR_NONE;
  68     else if (strstr (version, "OpenGL ES") != NULL)
  69         flavor = CAIRO_GL_FLAVOR_ES;
  70     else
  71         flavor = CAIRO_GL_FLAVOR_DESKTOP;
  72
  73     return flavor;
  74 }
  75
  76 unsigned long
  77 _cairo_gl_get_vbo_size (void)
  78 {
  79     unsigned long vbo_size;
  80
  81     const char *env = getenv ("CAIRO_GL_VBO_SIZE");
  82     if (env == NULL) {
  83         vbo_size = CAIRO_GL_VBO_SIZE_DEFAULT;
  84     } else {
  85         errno = 0;
  86         vbo_size = strtol (env, NULL, 10);
  87         assert (errno == 0);
  88         assert (vbo_size > 0);
  89     }
  90
  91     return vbo_size;
  92 }
  93
  94 cairo_bool_t
  95 _cairo_gl_has_extension (const char *ext)
  96 {
  97     const char *extensions = (const char *) glGetString (GL_EXTENSIONS);
  98     size_t len = strlen (ext);
  99     const char *ext_ptr = extensions;
 100
 101     if (unlikely (ext_ptr == NULL))
 102         return 0;
 103
 104     while ((ext_ptr = strstr (ext_ptr, ext)) != NULL) {
 105         if (ext_ptr[len] == ' ' || ext_ptr[len] == '\0')
 106             break;
 107         ext_ptr += len;
 108     }
 109
 110     return (ext_ptr != NULL);
 111 }