From 2c9dd370d999cbd9f697da41370769dfa3cd4636 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Lubo=C5=A1=20Lu=C5=88=C3=A1k?= <l.lunak@kde.org>
Date: Tue, 21 Nov 2006 22:22:48 +0000
Subject: [PATCH] Do not try to paint outside of the screen.

svn path=/branches/work/kwin_composite/; revision=606822
---
 scene.cpp        | 8 ++++++--
 scene_opengl.cpp | 4 +++-
 scene_opengl.h   | 2 +-
 3 files changed, 10 insertions(+), 4 deletions(-)

diff --git a/scene.cpp b/scene.cpp
index 28282ea5cd..a9b8bd438a 100644
--- a/scene.cpp
+++ b/scene.cpp
@@ -111,8 +111,12 @@ void Scene::paintScreen( int* mask, QRegion* region )
         *mask &= ~PAINT_SCREEN_REGION;
         *region = infiniteRegion();
         }
-    else if(( *mask & PAINT_SCREEN_REGION ) == 0 )
-        { // force region to be full
+    else if(  *mask & PAINT_SCREEN_REGION )
+        { // make sure not to go outside visible screen
+        *region &= QRegion( 0, 0, displayWidth(), displayHeight());
+        }
+    else
+        { // whole screen, not transformed, force region to be full
         *region = QRegion( 0, 0, displayWidth(), displayHeight());
         }
     ScreenPaintData data;
diff --git a/scene_opengl.cpp b/scene_opengl.cpp
index 8850f85ac5..2fcea9a23c 100644
--- a/scene_opengl.cpp
+++ b/scene_opengl.cpp
@@ -467,8 +467,10 @@ void SceneOpenGL::waitSync()
     }
 
 // actually paint to the screen (double-buffer swap or copy from pixmap buffer)
-void SceneOpenGL::flushBuffer( int mask, const QRegion& damage )
+void SceneOpenGL::flushBuffer( int mask, QRegion damage )
     {
+    if( mask & PAINT_SCREEN_REGION )//    make sure not to go outside visible screen
+        damage &= QRegion( 0, 0, displayWidth(), displayHeight());
     if( db )
         {
         if( mask & PAINT_SCREEN_REGION )
diff --git a/scene_opengl.h b/scene_opengl.h
index e21b9352e5..8644ab84ea 100644
--- a/scene_opengl.h
+++ b/scene_opengl.h
@@ -45,7 +45,7 @@ class SceneOpenGL
         void initRenderingContext();
         bool findConfig( const int* attrs, GLXFBConfig* config, VisualID visual = None );
         void waitSync();
-        void flushBuffer( int mask, const QRegion& damage );
+        void flushBuffer( int mask, QRegion damage );
         typedef GLuint Texture;
         GC gcroot;
         Drawable buffer;