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/*************************************************************************
** Opacity.hpp **
** **
** This file is part of dvisvgm -- a fast DVI to SVG converter **
** Copyright (C) 2005-2022 Martin Gieseking <martin.gieseking@uos.de> **
** **
** 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 3 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, see <http://www.gnu.org/licenses/>. **
*************************************************************************/
#ifndef OPACITY_HPP
#define OPACITY_HPP
#include <string>
class OpacityAlpha {
public:
OpacityAlpha () =default;
OpacityAlpha (double constalpha, double shapealpha) : _constalpha(constalpha), _shapealpha(shapealpha) {}
void setConstAlpha (double alpha) { _constalpha = alpha;}
void setShapeAlpha (double shapealpha) {_shapealpha = shapealpha;}
double value () const {return _constalpha * _shapealpha;}
bool operator == (const OpacityAlpha &alpha) const {return alpha._constalpha == _constalpha && alpha._shapealpha == _shapealpha;}
bool operator != (const OpacityAlpha &alpha) const {return alpha._constalpha != _constalpha || alpha._shapealpha != _shapealpha;}
bool isOpaque () const {return _constalpha == 1.0 && _shapealpha == 1.0;}
private:
double _constalpha=1.0;
double _shapealpha=1.0;
};
class Opacity {
public:
enum BlendMode {
BM_NORMAL, BM_MULTIPLY, BM_SCREEN, BM_OVERLAY,
BM_SOFTLIGHT, BM_HARDLIGHT, BM_COLORDODGE, BM_COLORBURN,
BM_DARKEN, BM_LIGHTEN, BM_DIFFERENCE, BM_EXCLUSION,
BM_HUE, BM_SATURATION, BM_COLOR, BM_LUMINOSITY
};
public:
Opacity () =default;
Opacity (OpacityAlpha fillalpha, OpacityAlpha strokealpha, BlendMode bm) : _fillalpha(fillalpha), _strokealpha(strokealpha), _blendMode(bm) {}
Opacity (OpacityAlpha fillalpha, OpacityAlpha strokealpha) : Opacity(fillalpha, strokealpha, BM_NORMAL) {}
explicit Opacity (BlendMode bm) : _blendMode(bm) {}
OpacityAlpha& fillalpha () {return _fillalpha;}
OpacityAlpha& strokealpha () {return _strokealpha;}
const OpacityAlpha& fillalpha () const {return _fillalpha;}
const OpacityAlpha& strokealpha () const {return _strokealpha;}
BlendMode blendMode () const {return _blendMode;}
void setBlendMode (BlendMode mode) {_blendMode = mode;}
std::string cssBlendMode () const {return cssBlendMode(_blendMode);}
static std::string cssBlendMode (BlendMode bm);
bool isFillDefault () const {return _fillalpha.isOpaque() && _blendMode == BM_NORMAL;}
bool isStrokeDefault () const {return _strokealpha.isOpaque() && _blendMode == BM_NORMAL;}
bool operator == (const Opacity &opacity) const;
bool operator != (const Opacity &opacity) const;
private:
OpacityAlpha _fillalpha;
OpacityAlpha _strokealpha;
BlendMode _blendMode=BM_NORMAL;
};
#endif
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