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/*************************************************************************
** EllipticalArc.hpp **
** **
** This file is part of dvisvgm -- a fast DVI to SVG converter **
** Copyright (C) 2005-2023 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/>. **
*************************************************************************/
#pragma once
#include "Bezier.hpp"
#include "BoundingBox.hpp"
#include "Matrix.hpp"
#include "Pair.hpp"
class EllipticalArc {
public:
struct CenterParams {
DPair center; ///< absolute coordinates of the center point
double startAngle; ///< angle of start point relative to semi-major axis (in radians)
double deltaAngle; ///< difference between angles of the start and end point (>0 if sweep flag is set)
};
public:
EllipticalArc (const DPair &start, double rx, double ry, double angle, bool laf, bool sweep, const DPair &end);
EllipticalArc (const DPair ¢er, double rx, double ry, double rot, double startAngle, double deltaAngle);
CenterParams getCenterParams () const;
double rx () const {return _rx;}
double ry () const {return _ry;}
bool largeArc () const {return _largeArc;}
bool sweepPositive () const {return _sweepPositive;}
double rotationAngle () const {return _rotationAngle;}
DPair startPoint () const {return _startPoint;}
DPair endPoint () const {return _endPoint;}
bool isStraightLine () const {return _rx < 1e-7 || _ry < 1e-7;}
BoundingBox getBBox () const;
void transform (const Matrix &matrix);
std::vector<CubicBezier> approximate () const;
private:
double _rx, _ry; ///< length of semi-major and semi-minor axes
double _rotationAngle; ///< rotation angle around center (in radians)
bool _largeArc; ///< if true, the longer arc from start to end point is chosen, else the shorter one
bool _sweepPositive; ///< if true, arc is drawn in direction of positive angles, else the opposite direction
DPair _startPoint, _endPoint; ///< absolute coordinates of start and end point
};
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