kolourpaint/imagelib/effects/kpEffectHSV.cpp

   1
   2 /*
   3    Copyright (c) 2007 Mike Gashler <gashlerm@yahoo.com>
   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 // TODO: Clarence's code review
  29
  30 #include <kpEffectHSV.h>
  31
  32 #include <math.h>
  33
  34 #include <qbitmap.h>
  35 #include <qimage.h>
  36
  37 #include <kdebug.h>
  38
  39 #include <kpPixmapFX.h>
  40
  41
  42 static void ColorToHSV(unsigned int c, float* pHue, float* pSaturation, float* pValue)
  43 {
  44     int r = qRed(c);
  45     int g = qGreen(c);
  46     int b = qBlue(c);
  47     int min;
  48     if(b >= g && b >= r)
  49     {
  50         // Blue
  51         min = qMin(r, g);
  52         if(b != min)
  53         {
  54             *pHue = (float)(r - g) / ((b - min) * 6) + (float)2 / 3;
  55             *pSaturation = (float)1 - (float)min / (float)b;
  56         }
  57         else
  58         {
  59             *pHue = 0;
  60             *pSaturation = 0;
  61         }
  62         *pValue = (float)b / 255;
  63     }
  64     else if(g >= r)
  65     {
  66         // Green
  67         min = qMin(b, r);
  68         if(g != min)
  69         {
  70             *pHue = (float)(b - r) / ((g - min) * 6) + (float)1 / 3;
  71             *pSaturation = (float)1 - (float)min / (float)g;
  72         }
  73         else
  74         {
  75             *pHue = 0;
  76             *pSaturation = 0;
  77         }
  78         *pValue = (float)g / 255;
  79     }
  80     else
  81     {
  82         // Red
  83         min = qMin(g, b);
  84         if(r != min)
  85         {
  86             *pHue = (float)(g - b) / ((r - min) * 6);
  87             if(*pHue < 0)
  88                 (*pHue) += (float)1;
  89             *pSaturation = (float)1 - (float)min / (float)r;
  90         }
  91         else
  92         {
  93             *pHue = 0;
  94             *pSaturation = 0;
  95         }
  96         *pValue = (float)r / 255;
  97     }
  98 }
  99
 100 static unsigned int HSVToColor(int alpha, float hue, float saturation, float value)
 101 {
 102     //Q_ASSERT (hue >= 0 && hue <= 1 && saturation >= 0 && saturation <= 1 && value >= 0 && value <= 1);
 103
 104     hue *= (float)5.999999;
 105     int h = (int)hue;
 106     float f = hue - h;
 107     float p = value * ((float)1 - saturation);
 108     float q = value * ((float)1 - ((h & 1) == 0 ? (float)1 - f : f) * saturation);
 109     switch(h)
 110     {
 111         case 0: return qRgba((int)(value * 255.999999), (int)(q * 255.999999), (int)(p * 255.999999), alpha);
 112         case 1: return qRgba((int)(q * 255.999999), (int)(value * 255.999999), (int)(p * 255.999999), alpha);
 113         case 2: return qRgba((int)(p * 255.999999), (int)(value * 255.999999), (int)(q * 255.999999), alpha);
 114         case 3: return qRgba((int)(p * 255.999999), (int)(q * 255.999999), (int)(value * 255.999999), alpha);
 115         case 4: return qRgba((int)(q * 255.999999), (int)(p * 255.999999), (int)(value * 255.999999), alpha);
 116         case 5: return qRgba((int)(value * 255.999999), (int)(p * 255.999999), (int)(q * 255.999999), alpha);
 117     }
 118     return qRgba(0, 0, 0, alpha);
 119 }
 120
 121 static QRgb AdjustHSVInternal (QRgb pix, double hueDiv360, double saturation, double value)
 122 {
 123     float h, s, v;
 124     ::ColorToHSV(pix, &h, &s, &v);
 125
 126     const int alpha = qAlpha(pix);
 127
 128     h += (float)hueDiv360;
 129     h -= floor(h);
 130
 131     s = qMax((float)0, qMin((float)1, s + (float)saturation));
 132
 133     v = qMax((float)0, qMin((float)1, v + (float)value));
 134
 135     return ::HSVToColor(alpha, h, s, v);
 136 }
 137
 138 static void AdjustHSV (QImage* pImage, double hue, double saturation, double value)
 139 {
 140     hue /= 360;
 141
 142     if (pImage->depth () > 8)
 143     {
 144         for (int y = 0; y < pImage->height (); y++)
 145         {
 146             for (int x = 0; x < pImage->width (); x++)
 147             {
 148                 QRgb pix = pImage->pixel (x, y);
 149                 pix = ::AdjustHSVInternal (pix, hue, saturation, value);
 150                 pImage->setPixel (x, y, pix);
 151             }
 152         }
 153     }
 154     else
 155     {
 156         for (int i = 0; i < pImage->numColors (); i++)
 157         {
 158             QRgb pix = pImage->color (i);
 159             pix = ::AdjustHSVInternal (pix, hue, saturation, value);
 160             pImage->setColor (i, pix);
 161         }
 162     }
 163 }
 164
 165 // public static
 166 kpImage kpEffectHSV::applyEffect (const kpImage &image,
 167                                           double hue, double saturation, double value)
 168 {
 169     QImage qimage = kpPixmapFX::convertToQImage (image);
 170
 171     ::AdjustHSV (&qimage, hue, saturation, value);
 172
 173     QPixmap retPixmap = kpPixmapFX::convertToPixmap (qimage);
 174
 175     return retPixmap;
 176 }
 177