From 82c451774cbdd25566cd417adf60d5de47a7b039 Mon Sep 17 00:00:00 2001
From: Torbjörn Andersson
Date: Mon, 1 Mar 2004 08:04:10 +0000
Subject: When scrolling, force a full redraw not only when the scroll offset
 changes but also on the first frame where it doesn't. This is necessary
 because parallax layers may be drawn on the *old* scroll offset (for reasons
 unknown to me).

To see the bug, walk right from the first screen until you reach the tree.
Notice how the part of the tree you walk behind gets redrawn slightly to
the left.

svn-id: r13120
---
 sword1/screen.cpp | 5 +++++
 1 file changed, 5 insertions(+)

(limited to 'sword1/screen.cpp')

diff --git a/sword1/screen.cpp b/sword1/screen.cpp
index c037b1ae72..cc422bcd6c 100644
--- a/sword1/screen.cpp
+++ b/sword1/screen.cpp
@@ -70,6 +70,11 @@ void Screen::setScrolling(int16 offsetX, int16 offsetY) {
 		Logic::_scriptVars[SCROLL_FLAG] = 1;
 		_fullRefresh = true;
 	} else if (Logic::_scriptVars[SCROLL_FLAG] == 1) {
+		// Because parallax layers may be drawn on the old scroll offset, we
+		// want a full refresh not only when the scroll offset changes, but
+		// also on the frame where they become the same.
+		if (_oldScrollX != Logic::_scriptVars[SCROLL_OFFSET_X] || _oldScrollY != Logic::_scriptVars[SCROLL_OFFSET_Y])
+			_fullRefresh = true;
 		_oldScrollX = Logic::_scriptVars[SCROLL_OFFSET_X];
 		_oldScrollY = Logic::_scriptVars[SCROLL_OFFSET_Y];
 		int32 distX = inRange(-MAX_SCROLL_DISTANCE, _oldScrollX - offsetX, MAX_SCROLL_DISTANCE);
-- 
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