1 /* ============================================================
2  *
3  * This file is a part of digiKam project
4  * https://www.digikam.org
5  *
6  * Date        : 2004-12-01
7  * Description : image curves manipulation methods.
8  *
9  * Copyright (C) 2004-2021 by Gilles Caulier <caulier dot gilles at gmail dot com>
10  * Copyright (C) 2010-2012 by Marcel Wiesweg <marcel dot wiesweg at gmx dot de>
11  *
12  * This program is free software; you can redistribute it
13  * and/or modify it under the terms of the GNU General
14  * Public License as published by the Free Software Foundation;
15  * either version 2, or (at your option)
16  * any later version.
17  *
18  * This program is distributed in the hope that it will be useful,
19  * but WITHOUT ANY WARRANTY; without even the implied warranty of
20  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
21  * GNU General Public License for more details.
22  *
23  * ============================================================ */
24 
25 #ifndef DIGIKAM_CURVES_CONTAINER_H
26 #define DIGIKAM_CURVES_CONTAINER_H
27 
28 // Qt includes
29 
30 #include <QPolygon>
31 #include <QString>
32 
33 // Local includes
34 
35 #include "digikam_globals.h"
36 #include "digikam_export.h"
37 
38 namespace Digikam
39 {
40 
41 class FilterAction;
42 
43 class DIGIKAM_EXPORT CurvesContainer
44 {
45 
46 public:
47 
48     /**
49      * Provides a convenient storage for a curve.
50      * Initially, the values are empty.
51      * Call initialize() before adjusting values manually.
52      */
53     CurvesContainer();
54     CurvesContainer(int type, bool sixteenBit);
55 
56     /**
57      * Fills the values with a linear curve suitable for type and sixteenBit parameters.
58      */
59     void initialize();
60 
61     /**
62      * An empty container is interpreted as a linear curve.
63      * A non-empty container can also be linear; test for isLinear()
64      * of the resulting ImageCurves.
65      * Note: If an ImageCurves is linear, it will return an empty container.
66      */
67     bool isEmpty()                                                                      const;
68 
69     bool operator==(const CurvesContainer& other)                                       const;
70 
71     /**
72      * Serialize from and to FilterAction.
73      * isStoredLosslessly returns false if the curve cannot be losslessly stored
74      * in XML because it would be too large (free 16 bit). It is then lossily compressed.
75      */
76     bool isStoredLosslessly()                                                           const;
77     void writeToFilterAction(FilterAction& action, const QString& prefix = QString())   const;
78     static CurvesContainer fromFilterAction(const FilterAction& action, const QString& prefix = QString());
79 
80 public:
81 
82     /**
83      *  Smooth : QPolygon have size of 18 points.
84      *  Free   : QPolygon have size of 255 or 65535 values.
85      */
86     int                     curvesType;
87     QPolygon                values[ColorChannels];
88 
89     bool                    sixteenBit;
90 };
91 
92 } // namespace Digikam
93 
94 #endif // DIGIKAM_CURVES_CONTAINER_H
95