make afterburner work

src/lindbergh/graphics.c

@@ -242,3 +242,33 @@ Bool XF86VidModeSwitchToMode(Display *display, int screen, XF86VidModeModeInfo *
 {
   return 0;
 }
+
+typedef unsigned int uint;
+
+int glXSwapIntervalSGI(int interval) {
+  return 0;
+}
+
+int glXGetVideoSyncSGI(uint *count) {
+  static unsigned int frameCount = 0;
+  //TODO: Framecount should depend on current system time
+  *count = (frameCount++)/2; // NOTE: Keeps the same frame for 2 calls
+  return 0;
+}
+
+int glXGetRefreshRateSGI(unsigned int * rate) { //TODO: need an actual prototype
+  *rate = 60; //TODO: what does this function return?
+  return 0;
+}
+
+void glGenFencesNV(int n, uint *fences) {
+  static unsigned int curf = 1;
+  while(n--) {
+    *fences++ = curf++;
+  }
+  return;
+}
+
+void glDeleteFencesNV(int a, const uint *b) {
+  return;
+}