src/glut/glx/glut_swap.c

   1
   2 /* Copyright (c) Mark J. Kilgard, 1994, 1997.  */
   3
   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. */
   7
   8 #include "glutint.h"
   9
  10 /* CENTRY */
  11 void APIENTRY
  12 glutSwapBuffers(void)
  13 {
  14   GLUTwindow *window = __glutCurrentWindow;
  15
  16   if (window->renderWin == window->win) {
  17     if (__glutCurrentWindow->treatAsSingle) {
  18       /* Pretend the double buffered window is single buffered,
  19          so treat glutSwapBuffers as a no-op. */
  20       return;
  21     }
  22   } else {
  23     if (__glutCurrentWindow->overlay->treatAsSingle) {
  24       /* Pretend the double buffered overlay is single
  25          buffered, so treat glutSwapBuffers as a no-op. */
  26       return;
  27     }
  28   }
  29
  30   /* For the MESA_SWAP_HACK. */
  31   window->usedSwapBuffers = 1;
  32
  33   SWAP_BUFFERS_LAYER(__glutCurrentWindow);
  34
  35   /* I considered putting the window being swapped on the
  36      GLUT_FINISH_WORK work list because you could call
  37      glutSwapBuffers from an idle callback which doesn't call
  38      __glutSetWindow which normally adds indirect rendering
  39      windows to the GLUT_FINISH_WORK work list.  Not being put
  40      on the list could lead to the buffering up of multiple
  41      redisplays and buffer swaps and hamper interactivity.  I
  42      consider this an application bug due to not using
  43      glutPostRedisplay to trigger redraws.  If
  44      glutPostRedisplay were used, __glutSetWindow would be
  45      called and a glFinish to throttle buffering would occur. */
  46 }
  47 /* ENDCENTRY */