[Johann Baudy]

Thanks AaronP, I've just tried with glXSwapIntervalSGI() or glXSwapIntervalEXT().

Unfortunately, graphic results are the same:
- Tearing ... flickering .. for ACER GD245HQ
- Perfect with Samsung SyncMaster 2233RZ

With glXSwapIntervalEXT or glXSwapIntervalSGI or glXWaitVideoSyncSGI(), buffer swap seems to not be done during vertical blanking interval with ACER GD245HQ.

Below my GL code:

Init after window creation:
glXSwapIntervalSGI(1);

Idle:
glClearColor(0.0, 0.0, 0.0, 1.0);
glClear(GL_COLOR_BUFFER_BIT);

glBegin(GL_QUADS);
if (i_current) {
glVertex2f(-1.0, -1.0);
glVertex2f(-0.1, -1.0);
glVertex2f(-0.1, 1.0);
glVertex2f(-1.0, 1.0);
} else {
glVertex2f( 0.1, -1.0);
glVertex2f( 1.0, -1.0);
glVertex2f( 1.0, 1.0);
glVertex2f( 0.1, 1.0);
}
glEnd();

glutSwapBuffers();