File indexing completed on 2024-04-28 04:18:52

 // vim: set tabstop=4 shiftwidth=4 expandtab:
 /*
 Gwenview: an image viewer
 Copyright 2008 Aurélien Gâteau <agateau@kde.org>
 
 This program is free software; you can redistribute it and/or
 modify it under the terms of the GNU General Public License
 as published by the Free Software Foundation; either version 2
 of the License, or (at your option) any later version.
 
 This program is distributed in the hope that it will be useful,
 but WITHOUT ANY WARRANTY; without even the implied warranty of
 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 GNU General Public License for more details.
 
 You should have received a copy of the GNU General Public License
 along with this program; if not, write to the Free Software
 Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
 
 */
 #ifndef RAMP_H
 #define RAMP_H
 
 namespace Gwenview
 {
 /**
  * This class maps values on a linear ramp.
  * It's useful to do mappings like this:
  *
  * x | -oo       x1               x2     +oo
  * --+--------------------------------------
  * y |  y1       y1 (linear ramp) y2      y2
  *
  * Note that y1 can be greater than y2 if necessary
  */
 class Ramp
 {
 public:
     Ramp(qreal x1, qreal x2, qreal y1, qreal y2)
         : mX1(x1)
         , mX2(x2)
         , mY1(y1)
         , mY2(y2)
     {
         mK = (y2 - y1) / (x2 - x1);
     }
 
     qreal operator()(qreal x) const
     {
         if (x < mX1) {
             return mY1;
         }
         if (x > mX2) {
             return mY2;
         }
         return mY1 + (x - mX1) * mK;
     }
 
 private:
     qreal mX1, mX2, mY1, mY2, mK;
 };
 
 } // namespace
 
 #endif /* RAMP_H */