1 files changed, 53 insertions, 0 deletions
diff --git a/src/glut/glx/glut_ext.c b/src/glut/glx/glut_ext.c
new file mode 100644
index 00000000000..abcb17a911b
--- /dev/null
+++ b/src/glut/glx/glut_ext.c
@@ -0,0 +1,53 @@
+
+/* Copyright (c) Mark J. Kilgard, 1994, 1997. */
+
+/* This program is freely distributable without licensing fees
+   and is provided without guarantee or warrantee expressed or
+   implied. This program is -not- in the public domain. */
+
+#include <stdlib.h>
+#include <string.h>
+
+#include "glutint.h"
+
+/* CENTRY */
+int APIENTRY 
+glutExtensionSupported(const char *extension)
+{
+  static const GLubyte *extensions = NULL;
+  const GLubyte *start;
+  GLubyte *where, *terminator;
+
+  /* Extension names should not have spaces. */
+  where = (GLubyte *) strchr(extension, ' ');
+  if (where || *extension == '\0')
+    return 0;
+
+  if (!extensions) {
+    extensions = glGetString(GL_EXTENSIONS);
+  }
+  /* It takes a bit of care to be fool-proof about parsing the
+     OpenGL extensions string.  Don't be fooled by sub-strings,
+     etc. */
+  start = extensions;
+  for (;;) {
+    /* If your application crashes in the strstr routine below,
+       you are probably calling glutExtensionSupported without
+       having a current window.  Calling glGetString without
+       a current OpenGL context has unpredictable results.
+       Please fix your program. */
+    where = (GLubyte *) strstr((const char *) start, extension);
+    if (!where)
+      break;
+    terminator = where + strlen(extension);
+    if (where == start || *(where - 1) == ' ') {
+      if (*terminator == ' ' || *terminator == '\0') {
+        return 1;
+      }
+    }
+    start = terminator;
+  }
+  return 0;
+}
+
+/* ENDCENTRY */