From c1c69abf7bc964b6e2c1c5d5c1ba7f1542dcecc4 Mon Sep 17 00:00:00 2001
From: David Robillard <d@drobilla.net>
Date: Sun, 2 Feb 2020 14:55:16 +0100
Subject: Only resize backend when necessary

This avoids resizing the backend when the window is only moved, which fixes
flicker with Cairo where resizing is expensive.
---
 pugl/detail/win.c | 23 ++++++++++++++---------
 pugl/detail/x11.c | 20 ++++++++++++--------
 2 files changed, 26 insertions(+), 17 deletions(-)

diff --git a/pugl/detail/win.c b/pugl/detail/win.c
index 9debb6d..6ef9255 100644
--- a/pugl/detail/win.c
+++ b/pugl/detail/win.c
@@ -435,20 +435,25 @@ handleConfigure(PuglView* view, PuglEvent* event)
 	                (LPPOINT)&rect,
 	                2);
 
-	view->frame.x      = rect.left;
-	view->frame.y      = rect.top;
-	view->frame.width  = rect.right - rect.left;
-	view->frame.height = rect.bottom - rect.top;
+	const LONG width  = rect.right - rect.left;
+	const LONG height = rect.bottom - rect.top;
+
+	view->frame.x = rect.left;
+	view->frame.y = rect.top;
 
 	event->configure.type   = PUGL_CONFIGURE;
 	event->configure.x      = view->frame.x;
 	event->configure.y      = view->frame.y;
-	event->configure.width  = view->frame.width;
-	event->configure.height = view->frame.height;
+	event->configure.width  = width;
+	event->configure.height = height;
+
+	if (view->frame.width != width || view->frame.height != height) {
+		view->frame.width  = width;
+		view->frame.height = height;
+
+		view->backend->resize(view, width, height);
+	}
 
-	view->backend->resize(view,
-	                      rect.right - rect.left,
-	                      rect.bottom - rect.top);
 	return rect;
 }
 
diff --git a/pugl/detail/x11.c b/pugl/detail/x11.c
index 49c843b..4099553 100644
--- a/pugl/detail/x11.c
+++ b/pugl/detail/x11.c
@@ -648,14 +648,18 @@ flushPendingConfigure(PuglView* view)
 	PuglEvent* const configure = &view->impl->pendingConfigure;
 
 	if (configure->type) {
-		view->frame.x      = configure->configure.x;
-		view->frame.y      = configure->configure.y;
-		view->frame.width  = configure->configure.width;
-		view->frame.height = configure->configure.height;
-
-		view->backend->resize(view,
-		                      (int)view->frame.width,
-		                      (int)view->frame.height);
+		view->frame.x = configure->configure.x;
+		view->frame.y = configure->configure.y;
+
+		if (configure->configure.width != view->frame.width ||
+		    configure->configure.height != view->frame.height) {
+			view->frame.width  = configure->configure.width;
+			view->frame.height = configure->configure.height;
+
+			view->backend->resize(view,
+			                      (int)view->frame.width,
+			                      (int)view->frame.height);
+		}
 
 		view->eventFunc(view, configure);
 		configure->type = 0;
-- 
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