+/**
+ * Identical to gluCheckExtension, which is not part of GLU on Windows.
+ */
+static GLboolean
+checkExtension(const char *extName, const GLubyte *extString)
+{
+ const char *p = (const char *)extString;
+ const char *q = extName;
+ char c;
+ do {
+ c = *p++;
+ if (c == '\0' || c == ' ') {
+ if (q && *q == '\0') {
+ return GL_TRUE;
+ } else {
+ q = extName;
+ }
+ } else {
+ if (q && *q == c) {
+ ++q;
+ } else {
+ q = 0;
+ }
+ }
+ } while (c);
+ return GL_FALSE;
+}
+
+