File indexing completed on 2024-05-05 08:25:41
0001 // vim: set tabstop=4 shiftwidth=4 expandtab: 0002 /* 0003 Gwenview: an image viewer 0004 Copyright 2008 Aurélien Gâteau <agateau@kde.org> 0005 0006 This program is free software; you can redistribute it and/or 0007 modify it under the terms of the GNU General Public License 0008 as published by the Free Software Foundation; either version 2 0009 of the License, or (at your option) any later version. 0010 0011 This program is distributed in the hope that it will be useful, 0012 but WITHOUT ANY WARRANTY; without even the implied warranty of 0013 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 0014 GNU General Public License for more details. 0015 0016 You should have received a copy of the GNU General Public License 0017 along with this program; if not, write to the Free Software 0018 Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. 0019 0020 */ 0021 #ifndef RAMP_H 0022 #define RAMP_H 0023 0024 namespace Gwenview 0025 { 0026 /** 0027 * This class maps values on a linear ramp. 0028 * It's useful to do mappings like this: 0029 * 0030 * x | -oo x1 x2 +oo 0031 * --+-------------------------------------- 0032 * y | y1 y1 (linear ramp) y2 y2 0033 * 0034 * Note that y1 can be greater than y2 if necessary 0035 */ 0036 class Ramp 0037 { 0038 public: 0039 Ramp(qreal x1, qreal x2, qreal y1, qreal y2) 0040 : mX1(x1) 0041 , mX2(x2) 0042 , mY1(y1) 0043 , mY2(y2) 0044 { 0045 mK = (y2 - y1) / (x2 - x1); 0046 } 0047 0048 qreal operator()(qreal x) const 0049 { 0050 if (x < mX1) { 0051 return mY1; 0052 } 0053 if (x > mX2) { 0054 return mY2; 0055 } 0056 return mY1 + (x - mX1) * mK; 0057 } 0058 0059 private: 0060 qreal mX1, mX2, mY1, mY2, mK; 0061 }; 0062 0063 } // namespace 0064 0065 #endif /* RAMP_H */