From fca9bcdd7f0ff730a70ddc3efbc181731c1c9c05 Mon Sep 17 00:00:00 2001
From: Arseniy Lartsev <3534650+ars3niy@users.noreply.github.com>
Date: Sun, 3 May 2020 00:26:30 +0200
Subject: [PATCH] Fixed possible freezes while dragging visible area on minimap
 (#638)

---
 client/gui/CGuiHandler.cpp | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/client/gui/CGuiHandler.cpp b/client/gui/CGuiHandler.cpp
index 9af279bb7..b915f0cab 100644
--- a/client/gui/CGuiHandler.cpp
+++ b/client/gui/CGuiHandler.cpp
@@ -194,6 +194,14 @@ void CGuiHandler::handleEvents()
 		SDL_Event ev = events.front();
 		current = &ev;
 		events.pop();
+
+		// In a sequence of mouse motion events, skip all but the last one.
+		// This prevents freezes when every motion event takes longer to handle than interval at which
+		// the events arrive (like dragging on the minimap in world view, with redraw at every event)
+		// so that the events would start piling up faster than they can be processed.
+		if ((ev.type == SDL_MOUSEMOTION) && !events.empty() && (events.front().type == SDL_MOUSEMOTION))
+			continue;
+
 		handleCurrentEvent();
 	}
 }