+ drawFps(vmem_back);
+ if((next = page_flip(opt.vsync ? FLIP_VBLANK_WAIT : FLIP_NOW))) {
+ assert(next == vmem_back);
+ vmem_back = vmem_front;
+ vmem_front = next;
+ } else {
+ /* failed to page flip, assume we drew in the front buffer then
+ * and just wait for vsync if necessary
+ */
+ if(opt.vsync) {
+ wait_vsync();
+ }