1 files changed, 67 insertions, 0 deletions
diff --git a/src/glut/os2/glut_swap.cpp b/src/glut/os2/glut_swap.cpp
new file mode 100644
index 0000000000..210a7fc37e
--- /dev/null
+++ b/src/glut/os2/glut_swap.cpp
@@ -0,0 +1,67 @@
+
+/* 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 <stdio.h>
+#include "glutint.h"
+
+GLint __glutFPS = 0;
+GLint __glutSwapCount = 0;
+GLint __glutSwapTime = 0;
+
+/* CENTRY */
+void GLUTAPIENTRY
+glutSwapBuffers(void)
+{
+  GLUTwindow *window = __glutCurrentWindow;
+
+  if (window->renderWin == window->win) {
+    if (__glutCurrentWindow->treatAsSingle) {
+      /* Pretend the double buffered window is single buffered,
+         so treat glutSwapBuffers as a no-op. */
+      return;
+    }
+  } else {
+    if (__glutCurrentWindow->overlay->treatAsSingle) {
+      /* Pretend the double buffered overlay is single
+         buffered, so treat glutSwapBuffers as a no-op. */
+      return;
+    }
+  }
+
+  /* For the MESA_SWAP_HACK. */
+  window->usedSwapBuffers = 1;
+
+  SWAP_BUFFERS_LAYER(__glutCurrentWindow);
+
+  /* I considered putting the window being swapped on the
+     GLUT_FINISH_WORK work list because you could call
+     glutSwapBuffers from an idle callback which doesn't call
+     __glutSetWindow which normally adds indirect rendering
+     windows to the GLUT_FINISH_WORK work list.  Not being put
+     on the list could lead to the buffering up of multiple
+     redisplays and buffer swaps and hamper interactivity.  I
+     consider this an application bug due to not using
+     glutPostRedisplay to trigger redraws.  If
+     glutPostRedisplay were used, __glutSetWindow would be
+     called and a glFinish to throttle buffering would occur. */
+
+  if (__glutFPS) {
+     GLint t = glutGet(GLUT_ELAPSED_TIME);
+     __glutSwapCount++;
+     if (__glutSwapTime == 0)
+        __glutSwapTime = t;
+     else if (t - __glutSwapTime > __glutFPS) {
+        float time = 0.001 * (t - __glutSwapTime);
+        float fps = (float) __glutSwapCount / time;
+        fprintf(stderr, "GLUT: %d frames in %.2f seconds = %.2f FPS\n",
+                __glutSwapCount, time, fps);
+        __glutSwapTime = t;
+        __glutSwapCount = 0;
+     }
+  }
+}
+/* ENDCENTRY */