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/**
* \file
* \brief Elliptical Arc - implementation of the svg elliptical arc path element
*
* Authors:
* MenTaLguY <mental@rydia.net>
* Marco Cecchetti <mrcekets at gmail.com>
*
* Copyright 2007-2008 authors
*
* This library is free software; you can redistribute it and/or
* modify it either under the terms of the GNU Lesser General Public
* License version 2.1 as published by the Free Software Foundation
* (the "LGPL") or, at your option, under the terms of the Mozilla
* Public License Version 1.1 (the "MPL"). If you do not alter this
* notice, a recipient may use your version of this file under either
* the MPL or the LGPL.
*
* You should have received a copy of the LGPL along with this library
* in the file COPYING-LGPL-2.1; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
* You should have received a copy of the MPL along with this library
* in the file COPYING-MPL-1.1
*
* The contents of this file are subject to the Mozilla Public License
* Version 1.1 (the "License"); you may not use this file except in
* compliance with the License. You may obtain a copy of the License at
* http://www.mozilla.org/MPL/
*
* This software is distributed on an "AS IS" basis, WITHOUT WARRANTY
* OF ANY KIND, either express or implied. See the LGPL or the MPL for
* the specific language governing rights and limitations.
*/
#ifndef _2GEOM_ELLIPTICAL_ARC_H_
#define _2GEOM_ELLIPTICAL_ARC_H_
#include <2geom/curve.h>
#include <2geom/angle.h>
#include <2geom/utils.h>
#include <2geom/sbasis-curve.h> // for non-native methods
#include <algorithm>
namespace Geom
{
class EllipticalArc : public Curve
{
public:
EllipticalArc()
: m_initial_point(Point(0,0)), m_final_point(Point(0,0)),
m_rx(0), m_ry(0), m_rot_angle(0),
m_large_arc(true), m_sweep(true)
{
m_start_angle = m_end_angle = 0;
m_center = Point(0,0);
}
EllipticalArc( Point _initial_point, double _rx, double _ry,
double _rot_angle, bool _large_arc, bool _sweep,
Point _final_point
)
: m_initial_point(_initial_point), m_final_point(_final_point),
m_rx(_rx), m_ry(_ry), m_rot_angle(_rot_angle),
m_large_arc(_large_arc), m_sweep(_sweep)
{
calculate_center_and_extreme_angles();
}
void set( Point _initial_point, double _rx, double _ry,
double _rot_angle, bool _large_arc, bool _sweep,
Point _final_point
)
{
m_initial_point = _initial_point;
m_final_point = _final_point;
m_rx = _rx;
m_ry = _ry;
m_rot_angle = _rot_angle;
m_large_arc = _large_arc;
m_sweep = _sweep;
calculate_center_and_extreme_angles();
}
Curve* duplicate() const
{
return new EllipticalArc(*this);
}
double center(unsigned int i) const
{
return m_center[i];
}
Point center() const
{
return m_center;
}
Point initialPoint() const
{
return m_initial_point;
}
Point finalPoint() const
{
return m_final_point;
}
double start_angle() const
{
return m_start_angle;
}
double end_angle() const
{
return m_end_angle;
}
double ray(unsigned int i) const
{
return (i == 0) ? m_rx : m_ry;
}
bool large_arc_flag() const
{
return m_large_arc;
}
bool sweep_flag() const
{
return m_sweep;
}
double rotation_angle() const
{
return m_rot_angle;
}
void setInitial( const Point _point)
{
m_initial_point = _point;
calculate_center_and_extreme_angles();
}
void setFinal( const Point _point)
{
m_final_point = _point;
calculate_center_and_extreme_angles();
}
void setExtremes( const Point& _initial_point, const Point& _final_point )
{
m_initial_point = _initial_point;
m_final_point = _final_point;
calculate_center_and_extreme_angles();
}
bool isDegenerate() const
{
return ( are_near(ray(X), 0) || are_near(ray(Y), 0) );
}
virtual OptRect boundsFast() const
{
return boundsExact();
}
virtual OptRect boundsExact() const;
// TODO: native implementation of the following methods
virtual OptRect boundsLocal(OptInterval i, unsigned int deg) const
{
return SBasisCurve(toSBasis()).boundsLocal(i, deg);
}
std::vector<double> roots(double v, Dim2 d) const;
std::vector<double>
allNearestPoints( Point const& p, double from = 0, double to = 1 ) const;
double nearestPoint( Point const& p, double from = 0, double to = 1 ) const
{
if ( are_near(ray(X), ray(Y)) && are_near(center(), p) )
{
return from;
}
return allNearestPoints(p, from, to).front();
}
// TODO: native implementation of the following methods
int winding(Point p) const
{
return SBasisCurve(toSBasis()).winding(p);
}
int degreesOfFreedom() const { return 7;}
Curve *derivative() const;
// TODO: native implementation of the following methods
Curve *transformed(Matrix const &m) const
{
return SBasisCurve(toSBasis()).transformed(m);
}
std::vector<Point> pointAndDerivatives(Coord t, unsigned int n) const;
D2<SBasis> toSBasis() const;
bool containsAngle(Coord angle) const;
double valueAtAngle(Coord t, Dim2 d) const;
Point pointAtAngle(Coord t) const
{
double sin_rot_angle = std::sin(rotation_angle());
double cos_rot_angle = std::cos(rotation_angle());
Matrix m( ray(X) * cos_rot_angle, ray(X) * sin_rot_angle,
-ray(Y) * sin_rot_angle, ray(Y) * cos_rot_angle,
center(X), center(Y) );
Point p( std::cos(t), std::sin(t) );
return p * m;
}
double valueAt(Coord t, Dim2 d) const
{
Coord tt = map_to_02PI(t);
return valueAtAngle(tt, d);
}
Point pointAt(Coord t) const
{
Coord tt = map_to_02PI(t);
return pointAtAngle(tt);
}
std::pair<EllipticalArc, EllipticalArc>
subdivide(Coord t) const
{
EllipticalArc* arc1 = static_cast<EllipticalArc*>(portion(0, t));
EllipticalArc* arc2 = static_cast<EllipticalArc*>(portion(t, 1));
assert( arc1 != NULL && arc2 != NULL);
std::pair<EllipticalArc, EllipticalArc> arc_pair(*arc1, *arc2);
delete arc1;
delete arc2;
return arc_pair;
}
Curve* portion(double f, double t) const;
// the arc is the same but traversed in the opposite direction
Curve* reverse() const
{
EllipticalArc* rarc = new EllipticalArc( *this );
rarc->m_sweep = !m_sweep;
rarc->m_initial_point = m_final_point;
rarc->m_final_point = m_initial_point;
rarc->m_start_angle = m_end_angle;
rarc->m_end_angle = m_start_angle;
return rarc;
}
double sweep_angle() const
{
Coord d = end_angle() - start_angle();
if ( !sweep_flag() ) d = -d;
if ( d < 0 )
d += 2*M_PI;
return d;
}
private:
Coord map_to_02PI(Coord t) const;
Coord map_to_01(Coord angle) const;
void calculate_center_and_extreme_angles();
private:
Point m_initial_point, m_final_point;
double m_rx, m_ry, m_rot_angle;
bool m_large_arc, m_sweep;
double m_start_angle, m_end_angle;
Point m_center;
}; // end class EllipticalArc
} // end namespace Geom
#endif // _2GEOM_ELLIPTICAL_ARC_H_
/*
Local Variables:
mode:c++
c-file-style:"stroustrup"
c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
indent-tabs-mode:nil
fill-column:99
End:
*/
// vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:encoding=utf-8:textwidth=99 :
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