kolourpaint/imagelib/effects/kpEffectEmboss.cpp

   1
   2 /*
   3    Copyright (c) 2003-2007 Clarence Dang <dang@kde.org>
   4    All rights reserved.
   5
   6    Redistribution and use in source and binary forms, with or without
   7    modification, are permitted provided that the following conditions
   8    are met:
   9
  10    1. Redistributions of source code must retain the above copyright
  11       notice, this list of conditions and the following disclaimer.
  12    2. Redistributions in binary form must reproduce the above copyright
  13       notice, this list of conditions and the following disclaimer in the
  14       documentation and/or other materials provided with the distribution.
  15
  16    THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  17    IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  18    OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  19    IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
  20    INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  21    NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  22    DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  23    THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  24    (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  25    THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  26 */
  27
  28
  29 #define DEBUG_KP_EFFECT_EMBOSS 0
  30
  31
  32 #include <kpEffectEmboss.h>
  33
  34 #include <qimageblitz.h>
  35
  36 #include <qimage.h>
  37
  38 #include <kdebug.h>
  39
  40 #include <kpPixmapFX.h>
  41
  42
  43 static QImage EmbossQImage (const QImage &qimage_, int strength)
  44 {
  45     QImage qimage = qimage_;
  46     if (strength == 0)
  47         return qimage;
  48
  49
  50     // The numbers that follow were picked by experimentation to try to get
  51     // an effect linearly proportional to <strength> and at the same time,
  52     // be fast enough.
  53     //
  54     // I still have no idea what "radius" and "sigma" mean.
  55
  56     const double radius = 0;
  57
  58 #if 0
  59     const double SigmaMin = 1;
  60     const double SigmaMax = 1.2;
  61
  62     return SigmaMin +
  63         (kpEffectEmboss::MaxStrength - strength) *
  64         (SigmaMax - SigmaMin) /
  65         (kpEffectEmboss::MaxStrength - 1);
  66 #endif
  67     const double sigma = 1;
  68
  69     const int repeat = 1;
  70
  71
  72     for (int i = 0; i < repeat; i++)
  73     {
  74         qimage = Blitz::emboss (qimage, radius, sigma);
  75     }
  76
  77
  78     return qimage;
  79 }
  80
  81
  82 // public static
  83 kpImage kpEffectEmboss::applyEffect (const kpImage &image, int strength)
  84 {
  85 #if DEBUG_KP_EFFECT_EMBOSS
  86     kDebug () << "kpEffectEmboss::applyEffect(strength=" << strength << ")"
  87                << endl;
  88 #endif
  89
  90     Q_ASSERT (strength >= MinStrength && strength <= MaxStrength);
  91
  92
  93     QImage qimage = kpPixmapFX::convertToQImage (image);
  94
  95     qimage = ::EmbossQImage (qimage, strength);
  96
  97     kpImage retImage = kpPixmapFX::convertToPixmap (qimage);
  98
  99
 100 #if DEBUG_KP_EFFECT_EMBOSS
 101     kDebug () << "\thave masks: input=" << image.hasAlpha ()
 102               << " output=" << retImage.hasAlpha ()
 103               << endl;
 104 #endif
 105
 106     return retImage;
 107 }
 108