src/glut/glx/glut_ext.c

   1
   2 /* Copyright (c) Mark J. Kilgard, 1994, 1997. */
   3
   4 /* This program is freely distributable without licensing fees
   5    and is provided without guarantee or warrantee expressed or
   6    implied. This program is -not- in the public domain. */
   7
   8 #include <stdlib.h>
   9 #include <string.h>
  10
  11 #include "glutint.h"
  12
  13 /* CENTRY */
  14 int APIENTRY
  15 glutExtensionSupported(const char *extension)
  16 {
  17   static const GLubyte *extensions = NULL;
  18   const GLubyte *start;
  19   GLubyte *where, *terminator;
  20
  21   /* Extension names should not have spaces. */
  22   where = (GLubyte *) strchr(extension, ' ');
  23   if (where || *extension == '\0')
  24     return 0;
  25
  26   if (!extensions) {
  27     extensions = glGetString(GL_EXTENSIONS);
  28   }
  29   /* It takes a bit of care to be fool-proof about parsing the
  30      OpenGL extensions string.  Don't be fooled by sub-strings,
  31      etc. */
  32   start = extensions;
  33   for (;;) {
  34     /* If your application crashes in the strstr routine below,
  35        you are probably calling glutExtensionSupported without
  36        having a current window.  Calling glGetString without
  37        a current OpenGL context has unpredictable results.
  38        Please fix your program. */
  39     where = (GLubyte *) strstr((const char *) start, extension);
  40     if (!where)
  41       break;
  42     terminator = where + strlen(extension);
  43     if (where == start || *(where - 1) == ' ') {
  44       if (*terminator == ' ' || *terminator == '\0') {
  45         return 1;
  46       }
  47     }
  48     start = terminator;
  49   }
  50   return 0;
  51 }
  52
  53
  54 /* XXX This isn't an official GLUT function, yet */
  55 void * APIENTRY
  56 glutGetProcAddress(const char *procName)
  57 {
  58 #if defined(_WIN32)
  59   return (void *) wglGetProcAddress((LPCSTR) procName);
  60 #elif defined(GLX_ARB_get_proc_address)
  61   return (void *) glXGetProcAddressARB((const GLubyte *) procName);
  62 #else
  63   return NULL;
  64 #endif
  65 }
  66
  67
  68 /* ENDCENTRY */