code.vuplus.com Git - vuplus_webkit/blob - Source/WebCore/svg/ColorDistance.cpp

   1 /*
   2  * Copyright (C) 2007 Eric Seidel <eric@webkit.org>
   3  *
   4  * This library is free software; you can redistribute it and/or
   5  * modify it under the terms of the GNU Library General Public
   6  * License as published by the Free Software Foundation; either
   7  * version 2 of the License, or (at your option) any later version.
   8  *
   9  * This library is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12  * Library General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU Library General Public License
  15  * along with this library; see the file COPYING.LIB.  If not, write to
  16  * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
  17  * Boston, MA 02110-1301, USA.
  18  */
  19
  20 #include "config.h"
  21 #if ENABLE(SVG)
  22 #include "ColorDistance.h"
  23
  24 #include "Color.h"
  25 #include <wtf/MathExtras.h>
  26
  27 namespace WebCore {
  28
  29 ColorDistance::ColorDistance()
  30     : m_redDiff(0)
  31     , m_greenDiff(0)
  32     , m_blueDiff(0)
  33 {
  34 }
  35
  36 ColorDistance::ColorDistance(const Color& fromColor, const Color& toColor)
  37     : m_redDiff(toColor.red() - fromColor.red())
  38     , m_greenDiff(toColor.green() - fromColor.green())
  39     , m_blueDiff(toColor.blue() - fromColor.blue())
  40 {
  41 }
  42
  43 ColorDistance::ColorDistance(int redDiff, int greenDiff, int blueDiff)
  44     : m_redDiff(redDiff)
  45     , m_greenDiff(greenDiff)
  46     , m_blueDiff(blueDiff)
  47 {
  48 }
  49
  50 static inline int clampColorValue(int v)
  51 {
  52     if (v > 255)
  53         v = 255;
  54     else if (v < 0)
  55         v = 0;
  56     return v;
  57 }
  58
  59 ColorDistance ColorDistance::scaledDistance(float scaleFactor) const
  60 {
  61     return ColorDistance(static_cast<int>(scaleFactor * m_redDiff),
  62                          static_cast<int>(scaleFactor * m_greenDiff),
  63                          static_cast<int>(scaleFactor * m_blueDiff));
  64 }
  65
  66 Color ColorDistance::addColorsAndClamp(const Color& first, const Color& second)
  67 {
  68     return Color(clampColorValue(first.red() + second.red()),
  69                  clampColorValue(first.green() + second.green()),
  70                  clampColorValue(first.blue() + second.blue()));
  71 }
  72
  73 Color ColorDistance::addToColorAndClamp(const Color& color) const
  74 {
  75     return Color(clampColorValue(color.red() + m_redDiff),
  76                  clampColorValue(color.green() + m_greenDiff),
  77                  clampColorValue(color.blue() + m_blueDiff));
  78 }
  79
  80 bool ColorDistance::isZero() const
  81 {
  82     return !m_redDiff && !m_blueDiff && !m_greenDiff;
  83 }
  84
  85 float ColorDistance::distance() const
  86 {
  87     // This is just a simple distance calculation, not respecting color spaces
  88     return sqrtf(m_redDiff * m_redDiff + m_blueDiff * m_blueDiff + m_greenDiff * m_greenDiff);
  89 }
  90
  91 }
  92
  93 #endif