From b9fd1e6d10d1cea78a49a62289fb779d2a565913 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Martin=20Gr=C3=A4=C3=9Flin?= <kde@martin-graesslin.com>
Date: Sun, 30 Nov 2008 13:11:11 +0000
Subject: [PATCH] * Update the snow flakes only once per frame. This fixes the
 problem of faster snow flakes if there are more then one screens. * Disable
 snow effect if there is an active full screen effect as it causes some
 problems. E.g. in desktop grid the snow flakes are painted several times and
 by that look terrible. CCBUG: 176489

svn path=/trunk/KDE/kdebase/workspace/; revision=890836
---
 effects/snow.cpp | 23 ++++++++++++++++++-----
 effects/snow.h   |  1 +
 2 files changed, 19 insertions(+), 5 deletions(-)

diff --git a/effects/snow.cpp b/effects/snow.cpp
index 49fb696b0b..b259b4d809 100644
--- a/effects/snow.cpp
+++ b/effects/snow.cpp
@@ -50,6 +50,7 @@ SnowEffect::SnowEffect()
     , mShader( 0 )
     , mInited( false )
     , mUseShader( true )
+    , hasSnown( false )
     {
     srandom( std::time( NULL ) );
     nextFlakeMillis = 0;
@@ -81,7 +82,7 @@ void SnowEffect::reconfigure( ReconfigureFlags )
 
 void SnowEffect::prePaintScreen( ScreenPrePaintData& data, int time )
     {
-    if ( active )
+    if ( active && effects->activeFullScreenEffect() == NULL )
         {
             // if number of active snowflakes is smaller than maximum number
             // create a random new snowflake
@@ -101,6 +102,7 @@ void SnowEffect::prePaintScreen( ScreenPrePaintData& data, int time )
                 nextFlakeMillis = next;
                 }
         data.mask |= PAINT_SCREEN_TRANSFORMED;
+        hasSnown = false;
         }
     effects->prePaintScreen( data, time );
     }
@@ -116,6 +118,8 @@ void SnowEffect::paintScreen( int mask, QRegion region, ScreenPaintData& data )
 
 void SnowEffect::snowing( QRegion& region )
     {
+    if( effects->activeFullScreenEffect() != NULL )
+        return;
     if(! texture ) loadTexture();
     if( texture )
         {
@@ -136,10 +140,14 @@ void SnowEffect::snowing( QRegion& region )
         for (int i=0; i<flakes.count(); i++)
             {
             SnowFlake& flake = flakes[i];
-            if( flake.addFrame() == 0 )
+            if( !hasSnown )
                 {
-                flakes.removeAt( i-- );
-                continue;
+                // only update during first paint in one frame
+                if( flake.addFrame() == 0 )
+                    {
+                    flakes.removeAt( i-- );
+                    continue;
+                    }
                 }
 
             if( mUseShader )
@@ -156,7 +164,11 @@ void SnowEffect::snowing( QRegion& region )
                 }
             else
                 {
-                flake.updateSpeedAndRotation();
+                if( !hasSnown )
+                    {
+                    // only update during first paint in one frame
+                    flake.updateSpeedAndRotation();
+                    }
                 // no shader
                 // save the matrix
                 glPushMatrix();
@@ -186,6 +198,7 @@ void SnowEffect::snowing( QRegion& region )
         glDisable( GL_BLEND );
         texture->unbind();
         glPopAttrib();
+        hasSnown = true;
         }
     }
 
diff --git a/effects/snow.h b/effects/snow.h
index 4c4ebdc933..d11bc60e3d 100644
--- a/effects/snow.h
+++ b/effects/snow.h
@@ -98,6 +98,7 @@ class SnowEffect
         bool mInited;
         bool mUseShader;
         QRegion repaintRegion;
+        bool hasSnown;
     };
 
 } // namespace