2 /* Copyright (c) Mark J. Kilgard, 1994, 1997. */
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. */
12 GLint __glutSwapCount
= 0;
13 GLint __glutSwapTime
= 0;
19 GLUTwindow
*window
= __glutCurrentWindow
;
25 if (window
->renderWin
== window
->win
) {
26 if (__glutCurrentWindow
->treatAsSingle
) {
27 /* Pretend the double buffered window is single buffered,
28 so treat glutSwapBuffers as a no-op. */
32 if (__glutCurrentWindow
->overlay
->treatAsSingle
) {
33 /* Pretend the double buffered overlay is single
34 buffered, so treat glutSwapBuffers as a no-op. */
39 /* For the MESA_SWAP_HACK. */
40 window
->usedSwapBuffers
= 1;
42 SWAP_BUFFERS_LAYER(__glutCurrentWindow
);
44 /* I considered putting the window being swapped on the
45 GLUT_FINISH_WORK work list because you could call
46 glutSwapBuffers from an idle callback which doesn't call
47 __glutSetWindow which normally adds indirect rendering
48 windows to the GLUT_FINISH_WORK work list. Not being put
49 on the list could lead to the buffering up of multiple
50 redisplays and buffer swaps and hamper interactivity. I
51 consider this an application bug due to not using
52 glutPostRedisplay to trigger redraws. If
53 glutPostRedisplay were used, __glutSetWindow would be
54 called and a glFinish to throttle buffering would occur. */
57 GLint t
= glutGet(GLUT_ELAPSED_TIME
);
59 if (__glutSwapTime
== 0)
61 else if (t
- __glutSwapTime
> __glutFPS
) {
62 float time
= 0.001 * (t
- __glutSwapTime
);
63 float fps
= (float) __glutSwapCount
/ time
;
64 fprintf(stderr
, "GLUT: %d frames in %.2f seconds = %.2f FPS\n",
65 __glutSwapCount
, time
, fps
);