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/** @file
* @brief Integral and real coordinate types and some basic utilities
*//*
* Copyright 2006 Nathan Hurst <njh@mail.csse.monash.edu.au>
*
* 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_COORD_H
#define LIB2GEOM_SEEN_COORD_H
#include <cmath>
#include <limits>
#include <string>
#include <functional>
#include <boost/operators.hpp>
#include <2geom/forward.h>
namespace Geom {
/// 2D axis enumeration (X or Y).
enum Dim2 { X=0, Y=1 };
/// Get the other (perpendicular) dimension.
inline Dim2 other_dimension(Dim2 d) { return d == Y ? X : Y; }
// TODO: make a smarter implementation with C++11
template <typename T>
struct D2Traits {
typedef typename T::D1Value D1Value;
typedef typename T::D1Reference D1Reference;
typedef typename T::D1ConstReference D1ConstReference;
};
// for use with things such as transform_iterator
template <typename T>
struct GetX {
typedef typename D2Traits<T>::D1Value result_type;
typedef T argument_type;
typename D2Traits<T>::D1Value operator()(T const &a) const {
return a[X];
}
};
template <typename T>
struct GetY {
typedef typename D2Traits<T>::D1Value result_type;
typedef T argument_type;
typename D2Traits<T>::D1Value operator()(T const &a) const {
return a[Y];
}
};
/**
* @brief Floating point type used to store coordinates.
*
* You may safely assume that double (or even float) provides enough precision for storing
* on-canvas points, and hence that double provides enough precision for dot products of
* differences of on-canvas points.
*/
typedef double Coord;
typedef int IntCoord;
const Coord EPSILON = 1e-5; //1e-18;
inline Coord infinity() { return std::numeric_limits<Coord>::infinity(); }
//IMPL: NearConcept
inline bool are_near(Coord a, Coord b, double eps=EPSILON) { return a-b <= eps && a-b >= -eps; }
inline bool rel_error_bound(Coord a, Coord b, double eps=EPSILON) { return a <= eps*b && a >= -eps*b; }
/// Numerically stable linear interpolation.
inline Coord lerp(Coord t, Coord a, Coord b) {
return (1 - t) * a + t * b;
}
template <typename C>
struct CoordTraits {
typedef D2<C> PointType;
typedef GenericInterval<C> IntervalType;
typedef GenericOptInterval<C> OptIntervalType;
typedef GenericRect<C> RectType;
typedef GenericOptRect<C> OptRectType;
typedef
boost::equality_comparable< IntervalType
, boost::orable< IntervalType
> >
IntervalOps;
typedef
boost::equality_comparable< RectType
, boost::orable< RectType
, boost::orable< RectType, OptRectType
> > >
RectOps;
};
// NOTE: operator helpers for Rect and Interval are defined here.
// This is to avoid increasing their size through multiple inheritance.
template<>
struct CoordTraits<IntCoord> {
typedef IntPoint PointType;
typedef IntInterval IntervalType;
typedef OptIntInterval OptIntervalType;
typedef IntRect RectType;
typedef OptIntRect OptRectType;
typedef
boost::equality_comparable< IntInterval
, boost::additive< IntInterval
, boost::additive< IntInterval, IntCoord
, boost::orable< IntInterval
> > > >
IntervalOps;
typedef
boost::equality_comparable< IntRect
, boost::orable< IntRect
, boost::orable< IntRect, OptIntRect
, boost::additive< IntRect, IntPoint
> > > >
RectOps;
};
template<>
struct CoordTraits<Coord> {
typedef Point PointType;
typedef Interval IntervalType;
typedef OptInterval OptIntervalType;
typedef Rect RectType;
typedef OptRect OptRectType;
typedef
boost::equality_comparable< Interval
, boost::equality_comparable< Interval, IntInterval
, boost::additive< Interval
, boost::multipliable< Interval
, boost::orable< Interval
, boost::arithmetic< Interval, Coord
> > > > > >
IntervalOps;
typedef
boost::equality_comparable< Rect
, boost::equality_comparable< Rect, IntRect
, boost::orable< Rect
, boost::orable< Rect, OptRect
, boost::additive< Rect, Point
, boost::multipliable< Rect, Affine
> > > > > >
RectOps;
};
/** @brief Convert coordinate to shortest possible string
* @return The shortest string that parses back to the original value. */
std::string format_coord_shortest(Coord x);
/** @brief Convert coordinate to human-readable string
* Unlike format_coord_shortest, this function will not omit a leading zero
* before a decimal point or use small negative exponents. The output format
* is similar to Javascript functions. */
std::string format_coord_nice(Coord x);
/** @brief Parse coordinate string
* When using this function in conjunction with format_coord_shortest()
* or format_coord_nice(), the value is guaranteed to be preserved exactly. */
Coord parse_coord(std::string const &s);
} // end namespace Geom
#endif // LIB2GEOM_SEEN_COORD_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 :
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