From fbb7c241c748e7881d2691981686b943041dd7b3 Mon Sep 17 00:00:00 2001
From: Roman Gilg <subdiff@gmail.com>
Date: Thu, 9 Jan 2020 18:06:09 +0100
Subject: [PATCH] Revert "Composite without timer on swap events"

This reverts commit 00bf75d06e678a6b1aa19f8e7da6c5d8b5a2106c.

See: https://mail.kde.org/pipermail/kwin/2020-January/002999.html
---
 composite.cpp | 35 +++++++++++------------------------
 1 file changed, 11 insertions(+), 24 deletions(-)

diff --git a/composite.cpp b/composite.cpp
index 69bb80c142..2fbf3e269c 100644
--- a/composite.cpp
+++ b/composite.cpp
@@ -384,30 +384,8 @@ void Compositor::startupWithWorkspace()
 
 void Compositor::scheduleRepaint()
 {
-    if (m_state != State::On) {
-        return;
-    }
-
-    // Don't repaint if all outputs are disabled
-    if (!kwinApp()->platform()->areOutputsEnabled()) {
-        return;
-    }
-
-    // TODO: Make this distinction not on the question if there is a swap event but if per screen
-    //       rendering? On X we get swap events but they are aligned with the "wrong" screen if
-    //       it the primary/first one is not the one with the highest refresh rate.
-    //       But on the other side Present extension does not allow to sync with another screen
-    //       anyway.
-
-    if (m_scene->hasSwapEvent()) {
-        // TODO: If we don't call it back from the event loop we often crash on Wayland
-        //       in AnimationEffect::postPaintScreen. Why?
-        //       Theory is that effects call addRepaintFull in there and then performCompositing
-        //       is called again while still in the first paint. So queing it here makes sense!
-        QTimer::singleShot(0, this, [this]() { performCompositing(); });
-    } else {
+    if (!compositeTimer.isActive())
         setCompositeTimer();
-    }
 }
 
 void Compositor::stop()
@@ -788,7 +766,16 @@ bool Compositor::windowRepaintsPending() const
 
 void Compositor::setCompositeTimer()
 {
-    if (compositeTimer.isActive()) {
+    if (m_state != State::On) {
+        return;
+    }
+
+    // Don't start the timer if we're waiting for a swap event
+    if (m_bufferSwapPending && m_composeAtSwapCompletion)
+        return;
+
+    // Don't start the timer if all outputs are disabled
+    if (!kwinApp()->platform()->areOutputsEnabled()) {
         return;
     }