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/**
* \file angle.h
* \brief Various trigoniometric helper functions
*
* Authors:
* Johan Engelen <goejendaagh@zonnet.nl>
*
* Copyright (C) 2007 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 LIB2GEOM_SEEN_ANGLE_H
#define LIB2GEOM_SEEN_ANGLE_H
namespace Geom {
#ifndef M_PI
# define M_PI 3.14159265358979323846
#endif
inline double deg_to_rad(double deg) { return deg*M_PI/180.0;}
inline double rad_to_deg(double rad) { return rad*180.0/M_PI;}
/*
* start_angle and angle must belong to [0, 2PI[
* and angle must belong to the cirsular arc defined by
* start_angle, end_angle and with rotation direction cw
*/
inline
double map_circular_arc_on_unit_interval( double angle, double start_angle, double end_angle, bool cw = true )
{
double d = end_angle - start_angle;
double t = angle - start_angle;
if ( !cw )
{
d = -d;
t = -t;
}
d = std::fmod(d, 2*M_PI);
t = std::fmod(t, 2*M_PI);
if ( d < 0 ) d += 2*M_PI;
if ( t < 0 ) t += 2*M_PI;
return t / d;
}
inline
Coord map_unit_interval_on_circular_arc(Coord t, double start_angle, double end_angle, bool cw = true)
{
double sweep_angle = end_angle - start_angle;
if ( !cw ) sweep_angle = -sweep_angle;
sweep_angle = std::fmod(sweep_angle, 2*M_PI);
if ( sweep_angle < 0 ) sweep_angle += 2*M_PI;
Coord angle = start_angle;
if ( cw )
{
angle += sweep_angle * t;
}
else
{
angle -= sweep_angle * t;
}
angle = std::fmod(angle, 2*M_PI);
if (angle < 0) angle += 2*M_PI;
return angle;
}
}
#endif
/*
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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