Home | History | Annotate | Download | only in svg 
      1 /*
      2  * Copyright (C) 2007 Eric Seidel <eric (at) 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 #include "core/svg/ColorDistance.h"
     22 
     23 #include "core/platform/graphics/Color.h"
     24 #include "wtf/MathExtras.h"
     25 
     26 namespace WebCore {
     27 
     28 ColorDistance::ColorDistance()
     29     : m_redDiff(0)
     30     , m_greenDiff(0)
     31     , m_blueDiff(0)
     32 {
     33 }
     34 
     35 ColorDistance::ColorDistance(const Color& fromColor, const Color& toColor)
     36     : m_redDiff(toColor.red() - fromColor.red())
     37     , m_greenDiff(toColor.green() - fromColor.green())
     38     , m_blueDiff(toColor.blue() - fromColor.blue())
     39 {
     40 }
     41 
     42 ColorDistance::ColorDistance(int redDiff, int greenDiff, int blueDiff)
     43     : m_redDiff(redDiff)
     44     , m_greenDiff(greenDiff)
     45     , m_blueDiff(blueDiff)
     46 {
     47 }
     48 
     49 static inline int clampColorValue(int v)
     50 {
     51     if (v > 255)
     52         v = 255;
     53     else if (v < 0)
     54         v = 0;
     55     return v;
     56 }
     57 
     58 ColorDistance ColorDistance::scaledDistance(float scaleFactor) const
     59 {
     60     return ColorDistance(static_cast<int>(scaleFactor * m_redDiff),
     61                          static_cast<int>(scaleFactor * m_greenDiff),
     62                          static_cast<int>(scaleFactor * m_blueDiff));
     63 }
     64 
     65 Color ColorDistance::clampColor(int red, int green, int blue, int alpha)
     66 {
     67     return Color(clampColorValue(red), clampColorValue(green), clampColorValue(blue), clampColorValue(alpha));
     68 }
     69 
     70 Color ColorDistance::addColors(const Color& first, const Color& second)
     71 {
     72     return Color(first.red() + second.red(), first.green() + second.green(), first.blue() + second.blue());
     73 }
     74 
     75 Color ColorDistance::addToColor(const Color& color) const
     76 {
     77     return Color(color.red() + m_redDiff, color.green() + m_greenDiff, 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