elliptical-arc.h revision 76addc201c409e81eaaa73fe27cc0f79c4db097c
/**
* \file
* \brief Elliptical arc curve
*
*//*
* Authors:
* MenTaLguY <mental@rydia.net>
* Marco Cecchetti <mrcekets at gmail.com>
* Krzysztof Kosiński <tweenk.pl@gmail.com>
*
* Copyright 2007-2009 Authors
*
* 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
*
* 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 LIB2GEOM_SEEN_ELLIPTICAL_ARC_H
#define LIB2GEOM_SEEN_ELLIPTICAL_ARC_H
#include <algorithm>
{
{
/** @brief Creates an arc with all variables set to zero, and both flags to true. */
: AngleInterval(0, 0, true)
, _initial_point(0,0)
, _final_point(0,0)
, _rays(0,0)
, _center(0,0)
, _rot_angle(0)
, _large_arc(true)
{}
/** @brief Create a new elliptical arc.
* @param ip Initial point of the arc
* @param rx First ray of the ellipse
* @param ry Second ray of the ellipse
* @param rot Angle of rotation of the X axis of the ellipse in radians
* @param large If true, the large arc is chosen (always >= 180 degrees), otherwise
* the smaller arc is chosen
* @param sweep If true, the clockwise arc is chosen, otherwise the counter-clockwise
* arc is chosen
* @param fp Final point of the arc */
)
: AngleInterval(0,0,sweep)
, _initial_point(ip)
, _final_point(fp)
{
_updateCenterAndAngles(false);
}
// methods new to EllipticalArc go here
/// @name Retrieve and modify parameters
/// @{
/** @brief Get the interval of angles the arc contains
* @return The interval between the final and initial angles of the arc */
/** @brief Get a coordinate of the elliptical arc's center.
* @param d The dimension to retrieve
* @return The selected coordinate of the center */
/** @brief Get the defining ellipse's rotation
* @return Angle between the +X ray of the ellipse and the +X axis */
Angle rotationAngle() const {
return _rot_angle;
}
/** @brief Get one of the ellipse's rays
* @param d Dimension to retrieve
* @return The selected ray of the ellipse */
/** @brief Get both rays as a point
* @return Point with X equal to the X ray and Y to Y ray */
/** @brief Whether the arc is larger than half an ellipse.
* @return True if the arc is larger than \f$\pi\f$, false otherwise */
bool largeArc() const { return _large_arc; }
/** @brief Whether the arc turns clockwise
* @return True if the arc makes a clockwise turn when going from initial to final
* point, false otherwise */
/** @brief Get the line segment connecting the arc's endpoints.
* @return A linear segment with initial and final point correspoding to those of the arc. */
/** @brief Change the arc's parameters. */
)
{
_initial_point = ip;
_final_point = fp;
}
/** @brief Change the initial and final point in one operation.
* This method exists because modifying any of the endpoints causes rather costly
* recalculations of the center and extreme angles.
* @param ip New initial point
* @param fp New final point */
_initial_point = ip;
_final_point = fp;
}
/// @}
/// @name Access computed parameters of the arc
/// @{
/** @brief Get the arc's center
* @return The arc's center, situated on the intersection of the ellipse's rays */
/** @brief Get the extent of the arc
* @return The angle between the initial and final point, in arc's angular coordinates */
Coord sweepAngle() const {
return extent();
}
/// @}
/// @name Angular evaluation
/// @{
/** Check whether the arc contains the given angle
* @param t The angle to check
* @return True if the arc contains the angle, false otherwise */
/** @brief Evaluate the arc at the specified angular coordinate
* @param t Angle
* @return Point corresponding to the given angle */
/** @brief Evaluate one of the arc's coordinates at the specified angle
* @param t Angle
* @param d The dimension to retrieve
* @return Selected coordinate of the arc at the specified angle */
/** @brief Retrieve the unit circle transform.
* Each ellipse can be interpreted as a translated, scaled and rotate unit circle.
* This function returns the transform that maps the unit circle to the arc's ellipse.
* @return Transform from unit circle to the arc's ellipse */
Affine unitCircleTransform() const;
/// @}
/** @brief Check whether the arc adheres to SVG 1.1 implementation guidelines */
virtual bool isSVGCompliant() const { return false; }
/// Check whether both rays are nonzero
bool isChord() const {
}
return arc_pair;
}
// implementation of overloads goes here
_initial_point = p;
}
_final_point = p;
}
virtual bool isDegenerate() const {
return _initial_point == _final_point;
}
return boundsExact();
}
// TODO: native implementation of the following methods
}
#ifdef HAVE_GSL
virtual std::vector<double> allNearestTimes( Point const& p, double from = 0, double to = 1 ) const;
#endif
return from;
}
}
_initial_point += m.vector();
_final_point += m.vector();
return *this;
}
/**
* The size of the returned vector equals n+1.
*/
return valueAtAngle(angleAt(t), d);
}
return pointAtAngle(angleAt(t));
}
void _updateCenterAndAngles(bool svg);
bool _large_arc;
}; // end class EllipticalArc
} // end namespace Geom
#endif // LIB2GEOM_SEEN_ELLIPTICAL_ARC_H
/*
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End:
*/
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