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Diffstat (limited to 'include/2geom/nearest-time.h')
-rw-r--r-- | include/2geom/nearest-time.h | 141 |
1 files changed, 141 insertions, 0 deletions
diff --git a/include/2geom/nearest-time.h b/include/2geom/nearest-time.h new file mode 100644 index 0000000..007cd27 --- /dev/null +++ b/include/2geom/nearest-time.h @@ -0,0 +1,141 @@ +/** @file + * @brief Nearest time routines for D2<SBasis> and Piecewise<D2<SBasis>> + *//* + * Authors: + * 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 LIB2GEOM_SEEN_NEAREST_TIME_H +#define LIB2GEOM_SEEN_NEAREST_TIME_H + + +#include <vector> + +#include <2geom/d2.h> +#include <2geom/piecewise.h> +#include <2geom/exception.h> +#include <2geom/bezier.h> + + +namespace Geom +{ + +/* + * Given a line L specified by a point A and direction vector v, + * return the point on L nearest to p. Note that the returned value + * is with respect to the _normalized_ direction of v! + */ +inline double nearest_time(Point const &p, Point const &A, Point const &v) +{ + Point d(p - A); + return d[0] * v[0] + d[1] * v[1]; +} + +Coord nearest_time(Point const &p, D2<Bezier> const &bez, Coord from = 0, Coord to = 1); + +//////////////////////////////////////////////////////////////////////////////// +// D2<SBasis> versions + +/* + * Return the parameter t of a nearest point on the portion of the curve "c", + * related to the interval [from, to], to the point "p". + * The needed curve derivative "deriv" is passed as parameter. + * The function return the first nearest point to "p" that is found. + */ +double nearest_time(Point const &p, + D2<SBasis> const &c, D2<SBasis> const &deriv, + double from = 0, double to = 1); + +inline +double nearest_time(Point const &p, + D2<SBasis> const &c, + double from = 0, double to = 1 ) +{ + return nearest_time(p, c, Geom::derivative(c), from, to); +} + +/* + * Return the parameters t of all the nearest times on the portion of + * the curve "c", related to the interval [from, to], to the point "p". + * The needed curve derivative "dc" is passed as parameter. + */ +std::vector<double> +all_nearest_times(Point const& p, + D2<SBasis> const& c, D2<SBasis> const& dc, + double from = 0, double to = 1 ); + +inline +std::vector<double> +all_nearest_times(Point const &p, + D2<SBasis> const &c, + double from = 0, double to = 1) +{ + return all_nearest_times(p, c, Geom::derivative(c), from, to); +} + + +//////////////////////////////////////////////////////////////////////////////// +// Piecewise< D2<SBasis> > versions + +double nearest_time(Point const &p, + Piecewise< D2<SBasis> > const &c, + double from, double to); + +inline +double nearest_time(Point const& p, Piecewise< D2<SBasis> > const &c) +{ + return nearest_time(p, c, c.cuts[0], c.cuts[c.size()]); +} + + +std::vector<double> +all_nearest_times(Point const &p, + Piecewise< D2<SBasis> > const &c, + double from, double to); + +inline +std::vector<double> +all_nearest_times( Point const& p, Piecewise< D2<SBasis> > const& c ) +{ + return all_nearest_times(p, c, c.cuts[0], c.cuts[c.size()]); +} + +} // end namespace Geom + +#endif // LIB2GEOM_SEEN_NEAREST_TIME_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:fileencoding=utf-8:textwidth=99 : |