From 763d9d8c6f129cb1e19861b8072d2e7d05661712 Mon Sep 17 00:00:00 2001
From: Lucas Murray <lmurray@undefinedfire.com>
Date: Sun, 14 Dec 2008 12:43:16 +0000
Subject: [PATCH] Previous shadow damage commit didn't catch 100% of the
 events. Lets just do it the old way but taking into account the decoration
 shadow sizes.

svn path=/trunk/KDE/kdebase/workspace/; revision=896765
---
 effects/shadow.cpp | 39 ++++++++++++++++++---------------------
 effects/shadow.h   |  2 +-
 2 files changed, 19 insertions(+), 22 deletions(-)

diff --git a/effects/shadow.cpp b/effects/shadow.cpp
index 8954991d77..c391abad51 100644
--- a/effects/shadow.cpp
+++ b/effects/shadow.cpp
@@ -192,12 +192,13 @@ void ShadowEffect::updateShadowColor()
     shadowColor = conf.readEntry( "Color",  schemeShadowColor() );
     }
 
-QRect ShadowEffect::shadowRectangle( EffectWindow* w ) const
+QRect ShadowEffect::shadowRectangle( EffectWindow* w, const QRect& windowRectangle ) const
     {
     QRectF shadowRect;
     bool shadowDefined = false;
     if( effects->hasDecorationShadows() )
-        {
+        { // TODO: This function is called for EVERY damage, we need to cache this
+          //       (But how? Decoration shadow can change shape if it wanted to)
         if( w->hasDecoration() && !forceDecorated )
             { // Decorated windows must be normal windows
             foreach( const QRect &r, w->shadowQuads( ShadowBorderedActive ))
@@ -225,17 +226,16 @@ QRect ShadowEffect::shadowRectangle( EffectWindow* w ) const
         }
     if( !shadowDefined )
         {
-        int width = qMax( shadowFuzzyness * 2, w->width() + 2 * shadowSize );
-        int height = qMax( shadowFuzzyness * 2, w->height() + 2 * shadowSize );
-        int x1, y1, x2, y2;
-        // top-left
-        x1 = shadowXOffset - shadowSize + 0 - shadowFuzzyness;
-        y1 = shadowYOffset - shadowSize + 0 - shadowFuzzyness;
-        x2 = shadowXOffset - shadowSize + width + shadowFuzzyness;
-        y2 = shadowYOffset - shadowSize + height + shadowFuzzyness;
-        return QRect( x1 + w->x(), y1 + w->y(), x2 - x1, y2 - y1 );
+        int shadowGrow = shadowFuzzyness + shadowSize;
+        return windowRectangle.adjusted( shadowXOffset - shadowGrow, shadowYOffset - shadowGrow,
+                shadowXOffset + shadowGrow, shadowYOffset + shadowGrow);
         }
-    return shadowRect.toRect().translated( w->x(), w->y() );
+    return windowRectangle.adjusted(
+        qMin( shadowRect.x(), 0.0 ),
+        qMin( shadowRect.y(), 0.0 ),
+        qMax( shadowRect.x() + shadowRect.width() - w->width(), 0.0 ),
+        qMax( shadowRect.y() + shadowRect.height() - w->height(), 0.0 )
+        );
     }
 
 #ifdef KWIN_HAVE_XRENDER_COMPOSITING
@@ -264,12 +264,8 @@ void ShadowEffect::paintScreen( int mask, QRegion region, ScreenPaintData& data
 
 void ShadowEffect::prePaintWindow( EffectWindow* w, WindowPrePaintData& data, int time )
     {
-    // Add the shadow area to the repaint if we are repainting the entire window
-    // This occurs when the active window is changed for example
-    // TODO: This only works if there are no animations in the shadows
-    QRect overlap = ( data.paint & w->geometry() ).boundingRect();
-    if( useShadow( w ) && !overlap.isEmpty() && overlap != data.paint.boundingRect() )
-        data.paint |= shadowRectangle( w );
+    if( useShadow( w ))
+        data.paint |= shadowRectangle( w, data.paint.boundingRect() );
     effects->prePaintWindow( w, data, time );
     }
 
@@ -300,7 +296,8 @@ void ShadowEffect::drawWindow( EffectWindow* w, int mask, QRegion region, Window
             if( !shadowDatas.isEmpty())
                 d.clip |= shadowDatas.last().clip;
             d.mask = mask;
-            d.region |= shadowRectangle( w );
+            foreach( const QRect &r, region.rects() )
+                d.region |= shadowRectangle( w, r );
             d.region &= region;
             shadowDatas.append(d);
             }
@@ -476,13 +473,13 @@ QRect ShadowEffect::transformWindowDamage( EffectWindow* w, const QRect& r )
     {
     if( !useShadow( w ))
         return effects->transformWindowDamage( w, r );
-    QRect r2 = r | shadowRectangle( w );
+    QRect r2 = r | shadowRectangle( w, r );
     return effects->transformWindowDamage( w, r2 );
     }
 
 void ShadowEffect::windowClosed( EffectWindow* c )
     {
-    effects->addRepaint( shadowRectangle( c ));
+    effects->addRepaint( shadowRectangle( c, c->geometry() ));
     }
 
 bool ShadowEffect::useShadow( EffectWindow* w ) const
diff --git a/effects/shadow.h b/effects/shadow.h
index ef2fc2ac3e..eafa1cdb45 100644
--- a/effects/shadow.h
+++ b/effects/shadow.h
@@ -61,7 +61,7 @@ class ShadowEffect
         void drawShadow( EffectWindow* w, int mask, QRegion region, const WindowPaintData& data );
         void addQuadVertices(QVector<float>& verts, float x1, float y1, float x2, float y2) const;
         // transforms window rect -> shadow rect
-        QRect shadowRectangle( EffectWindow* w ) const;
+        QRect shadowRectangle( EffectWindow* w, const QRect& windowRectangle ) const;
         bool useShadow( EffectWindow* w ) const;
         void drawQueuedShadows( EffectWindow* behindWindow );