From 32d0e4c15fb33f80db194087850466664a43516a Mon Sep 17 00:00:00 2001
From: Johannes Schickel
Date: Sat, 19 Feb 2011 20:44:06 +0100
Subject: OPENGLSDL: Avoid warping in warpMouse when the logical coordinates
 did not change.

This fixes a slight move of the mouse cursor when the hardware mouse position
is at a subpixel from the logical coordinates.
---
 backends/graphics/openglsdl/openglsdl-graphics.cpp | 12 ++++++++++++
 1 file changed, 12 insertions(+)

(limited to 'backends/graphics/openglsdl')

diff --git a/backends/graphics/openglsdl/openglsdl-graphics.cpp b/backends/graphics/openglsdl/openglsdl-graphics.cpp
index b10c94b03f..c7ce0aa7de 100644
--- a/backends/graphics/openglsdl/openglsdl-graphics.cpp
+++ b/backends/graphics/openglsdl/openglsdl-graphics.cpp
@@ -195,6 +195,18 @@ void OpenGLSdlGraphicsManager::warpMouse(int x, int y) {
 	int scaledX = x;
 	int scaledY = y;
 
+	int16 currentX = _cursorState.x;
+	int16 currentY = _cursorState.y;
+
+	adjustMousePosition(currentX, currentY);
+
+	// Do not adjust the real screen position, when the current game / overlay
+	// coordinates match the requested coordinates. This avoids a slight
+	// movement which might occur otherwise when the mouse is at a subpixel
+	// position.
+	if (x == currentX && y == currentY)
+		return;
+
 	if (_videoMode.mode == OpenGL::GFX_NORMAL) {
 		if (_videoMode.hardwareWidth != _videoMode.overlayWidth)
 			scaledX = scaledX * _videoMode.hardwareWidth / _videoMode.overlayWidth;
-- 
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