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Diffstat (limited to 'src/3rdparty/2geom/include/2geom/linear.h')
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1 files changed, 167 insertions, 0 deletions
diff --git a/src/3rdparty/2geom/include/2geom/linear.h b/src/3rdparty/2geom/include/2geom/linear.h new file mode 100644 index 0000000..75c6e01 --- /dev/null +++ b/src/3rdparty/2geom/include/2geom/linear.h @@ -0,0 +1,167 @@ +/** + * \file + * \brief Linear fragment function class + *//* + * Authors: + * Nathan Hurst <njh@mail.csse.monash.edu.au> + * Michael Sloan <mgsloan@gmail.com> + * Krzysztof Kosiński <tweenk.pl@gmail.com> + * + * Copyright (C) 2006-2015 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_LINEAR_H +#define LIB2GEOM_SEEN_LINEAR_H + +#include <2geom/interval.h> +#include <2geom/math-utils.h> + +namespace Geom { + +class SBasis; + +/** + * @brief Function that interpolates linearly between two values. + * @ingroup Fragments + */ +class Linear + : boost::additive< Linear + , boost::arithmetic< Linear, Coord + , boost::equality_comparable< Linear + > > > +{ +public: + Coord a[2]; + Linear() {a[0]=0; a[1]=0;} + Linear(Coord aa, Coord b) {a[0] = aa; a[1] = b;} + Linear(Coord aa) {a[0] = aa; a[1] = aa;} + + Coord operator[](unsigned i) const { + assert(i < 2); + return a[i]; + } + Coord &operator[](unsigned i) { + assert(i < 2); + return a[i]; + } + + //IMPL: FragmentConcept + typedef Coord output_type; + bool isZero(Coord eps=EPSILON) const { return are_near(a[0], 0., eps) && are_near(a[1], 0., eps); } + bool isConstant(Coord eps=EPSILON) const { return are_near(a[0], a[1], eps); } + bool isFinite() const { return std::isfinite(a[0]) && std::isfinite(a[1]); } + + Coord at0() const { return a[0]; } + Coord &at0() { return a[0]; } + Coord at1() const { return a[1]; } + Coord &at1() { return a[1]; } + + Coord valueAt(Coord t) const { return lerp(t, a[0], a[1]); } + Coord operator()(Coord t) const { return valueAt(t); } + + // not very useful, but required for FragmentConcept + std::vector<Coord> valueAndDerivatives(Coord t, unsigned n) { + std::vector<Coord> result(n+1, 0.0); + result[0] = valueAt(t); + if (n >= 1) { + result[1] = a[1] - a[0]; + } + return result; + } + + //defined in sbasis.h + inline SBasis toSBasis() const; + + OptInterval bounds_exact() const { return Interval(a[0], a[1]); } + OptInterval bounds_fast() const { return bounds_exact(); } + OptInterval bounds_local(double u, double v) const { return Interval(valueAt(u), valueAt(v)); } + + double tri() const { + return a[1] - a[0]; + } + double hat() const { + return (a[1] + a[0])/2; + } + + // addition of other Linears + Linear &operator+=(Linear const &other) { + a[0] += other.a[0]; + a[1] += other.a[1]; + return *this; + } + Linear &operator-=(Linear const &other) { + a[0] -= other.a[0]; + a[1] -= other.a[1]; + return *this; + } + + // + Linear &operator+=(Coord x) { + a[0] += x; a[1] += x; + return *this; + } + Linear &operator-=(Coord x) { + a[0] -= x; a[1] -= x; + return *this; + } + Linear &operator*=(Coord x) { + a[0] *= x; a[1] *= x; + return *this; + } + Linear &operator/=(Coord x) { + a[0] /= x; a[1] /= x; + return *this; + } + Linear operator-() const { + Linear ret(-a[0], -a[1]); + return ret; + } + + bool operator==(Linear const &other) const { + return a[0] == other.a[0] && a[1] == other.a[1]; + } +}; + +inline Linear reverse(Linear const &a) { return Linear(a[1], a[0]); } +inline Linear portion(Linear const &a, Coord from, Coord to) { + Linear result(a.valueAt(from), a.valueAt(to)); + return result; +} + +} // end namespace Geom + +#endif //LIB2GEOM_SEEN_LINEAR_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 : |