workspace/kwin/effects/snow.cpp

   1 /********************************************************************
   2  KWin - the KDE window manager
   3  This file is part of the KDE project.
   4
   5  Copyright (C) 2007 Martin Gräßlin <ubuntu@martin-graesslin.com
   6
   7 This program is free software; you can redistribute it and/or modify
   8 it under the terms of the GNU General Public License as published by
   9 the Free Software Foundation; either version 2 of the License, or
  10 (at your option) any later version.
  11
  12 This program is distributed in the hope that it will be useful,
  13 but WITHOUT ANY WARRANTY; without even the implied warranty of
  14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15 GNU General Public License for more details.
  16
  17 You should have received a copy of the GNU General Public License
  18 along with this program.  If not, see <http://www.gnu.org/licenses/>.
  19 *********************************************************************/
  20
  21 #include "snow.h"
  22
  23 #include <kwinconfig.h>
  24
  25 #include <kaction.h>
  26 #include <kactioncollection.h>
  27 #include <kconfiggroup.h>
  28 #include <kglobal.h>
  29 #include <klocale.h>
  30 #include <kstandarddirs.h>
  31
  32 #include <kdebug.h>
  33 #include <QApplication>
  34 #include <QDesktopWidget>
  35
  36 #include <ctime>
  37
  38 #ifdef KWIN_HAVE_OPENGL_COMPOSITING
  39 #include <GL/gl.h>
  40 #endif
  41
  42
  43 namespace KWin
  44 {
  45
  46 KWIN_EFFECT( snow, SnowEffect )
  47
  48 SnowEffect::SnowEffect()
  49     : texture( NULL )
  50     , flakes( NULL )
  51     , active( false)
  52     {
  53     srandom( std::time( NULL ) );
  54     lastFlakeTime = QTime::currentTime();
  55     nextFlakeMillis = 0;
  56     KConfigGroup conf = effects->effectConfig("Snow");
  57     mNumberFlakes = conf.readEntry("Number", 50);
  58     mMinFlakeSize = conf.readEntry("MinFlakes", 10);
  59     mMaxFlakeSize = conf.readEntry("MaxFlakes", 50);
  60
  61     KActionCollection* actionCollection = new KActionCollection( this );
  62     KAction* a = static_cast< KAction* >( actionCollection->addAction( "Snow" ));
  63     a->setText( i18n("Snow" ));
  64     a->setGlobalShortcut( KShortcut( Qt::CTRL + Qt::META + Qt::Key_F12 ));
  65     connect( a, SIGNAL( triggered( bool )), this, SLOT( toggle()));
  66     }
  67
  68 SnowEffect::~SnowEffect()
  69     {
  70     delete texture;
  71     delete flakes;
  72     }
  73
  74 void SnowEffect::prePaintScreen( ScreenPrePaintData& data, int time )
  75     {
  76     if ( active )
  77         {
  78         if (! flakes )
  79             {
  80             flakes = new QList<QRect>();
  81             lastFlakeTime.start();
  82             }
  83         int count = flakes->count();
  84         for (int i=0; i<count; i++)
  85             {
  86             // move flake to bottom. Therefore pop the flake, change y and push
  87             // flake back to QVector
  88             QRect flake = flakes->first();
  89             flakes->pop_front();
  90             int size = flake.height();
  91             int y = flake.y();
  92             // if flake has reached bottom, don't push it back
  93             if ( y >= QApplication::desktop()->geometry().bottom() )
  94                 {
  95                 continue;
  96                 }
  97             int speed;
  98             float factor = (float)(size-mMinFlakeSize) / (float)(mMaxFlakeSize-mMinFlakeSize);
  99             if (factor >= 0.5) speed = 2;
 100             else speed = 1;
 101             flake.setY(y + speed);
 102             flake.setHeight(size);
 103             flakes->append(flake);
 104             }
 105             // if number of active snowflakes is smaller than maximum number
 106             // create a random new snowflake
 107             if ( ( lastFlakeTime.elapsed() >= nextFlakeMillis ) && flakes->count() < mNumberFlakes)
 108                 {
 109                 int size = 0;
 110                 while ( size < mMinFlakeSize )
 111                     size = random() % mMaxFlakeSize;
 112                 QRect flake = QRect( random() % (QApplication::desktop()->geometry().right() - size), -1 * size, size, size );
 113                 flakes->append( flake );
 114
 115                 // calculation of next time of snowflake
 116                 // depends on the time the flow needs to get to the bottom (screen size)
 117                 // and the fps
 118                 int speed;
 119                 float factor = (float)(size-mMinFlakeSize) / (float)(mMaxFlakeSize-mMinFlakeSize);
 120                 if (factor >= 0.5) speed = 4;
 121                 else speed = 2;
 122                 long next = ((1000/(time+5))*(Effect::displayHeight()/speed))/mNumberFlakes;
 123                 nextFlakeMillis = next;
 124                 lastFlakeTime.restart();
 125                 }
 126         }
 127     effects->prePaintScreen( data, time );
 128     }
 129
 130 void SnowEffect::paintScreen( int mask, QRegion region, ScreenPaintData& data )
 131     {
 132     effects->paintScreen( mask, region, data ); // paint normal screen
 133 #ifdef KWIN_HAVE_OPENGL_COMPOSITING
 134     if( active )
 135         {
 136         if(! texture ) loadTexture();
 137         if( texture )
 138             {
 139             glPushAttrib( GL_CURRENT_BIT | GL_ENABLE_BIT );
 140             texture->bind();
 141             glEnable( GL_BLEND );
 142             glBlendFunc( GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA );
 143             for (int i=0; i<flakes->count(); i++)
 144                 {
 145                 texture->render( region, flakes->at(i));
 146                 }
 147             texture->unbind();
 148             glPopAttrib();
 149             }
 150         }
 151 #endif
 152     }
 153
 154 void SnowEffect::postPaintScreen()
 155     {
 156     if( active )
 157         {
 158         effects->addRepaintFull();
 159         }
 160     effects->postPaintScreen();
 161     }
 162
 163 void SnowEffect::toggle()
 164     {
 165     active = !active;
 166     if (!active) flakes->clear();
 167     effects->addRepaintFull();
 168     }
 169
 170 void SnowEffect::loadTexture()
 171     {
 172 #ifdef KWIN_HAVE_OPENGL_COMPOSITING
 173     QString file = KGlobal::dirs()->findResource( "appdata", "snowflake.png" );
 174     if( file.isEmpty())
 175         return;
 176     texture = new GLTexture( file );
 177 #endif
 178     }
 179
 180
 181 } // namespace