Handle vsync without halving fps

This commit is contained in:
Zach Pomerantz 2016-05-19 13:18:02 -07:00
parent 1cce891f7c
commit 2026226fe2

View file

@ -1822,28 +1822,37 @@ bool Application::event(QEvent* event) {
return false;
}
static bool justPresented = false;
// Presentation/painting logic
// TODO: Decouple presentation and painting loops
static bool isPainting = false;
if ((int)event->type() == (int)Present) {
if (justPresented) {
justPresented = false;
// If presentation is hogging the main thread, repost as low priority to avoid hanging the GUI.
if (isPainting) {
// If painting (triggered by presentation) is hogging the main thread,
// repost as low priority to avoid hanging the GUI.
// This has the effect of allowing presentation to exceed the paint budget by X times and
// only dropping every (1/X) frames, instead of every ceil(X) frames.
// only dropping every (1/X) frames, instead of every ceil(X) frames
// (e.g. at a 60FPS target, painting for 17us would fall to 58.82FPS instead of 30FPS).
removePostedEvents(this, Present);
postEvent(this, new QEvent(static_cast<QEvent::Type>(Present)), Qt::LowEventPriority);
isPainting = false;
return true;
}
idle();
postEvent(this, new QEvent(static_cast<QEvent::Type>(Paint)), Qt::HighEventPriority);
isPainting = true;
return true;
} else if ((int)event->type() == (int)Paint) {
// NOTE: This must be updated as close to painting as possible,
// or AvatarInputs will mysteriously move to the bottom-right
AvatarInputs::getInstance()->update();
justPresented = true;
paintGL();
isPainting = false;
return true;
}
@ -2658,9 +2667,6 @@ void Application::idle() {
// Sync up the _renderedFrameIndex
_renderedFrameIndex = displayPlugin->presentCount();
// Request a paint ASAP
postEvent(this, new QEvent(static_cast<QEvent::Type>(Paint)), Qt::HighEventPriority + 1);
// Update the deadlock watchdog
updateHeartbeat();
@ -2687,8 +2693,6 @@ void Application::idle() {
_keyboardDeviceHasFocus = true;
}
// We're going to execute idle processing, so restart the last idle timer
_lastTimeUpdated.start();