/**
 *  \file
 *  \brief Defines the Coord "real" type with sufficient precision for coordinates.
 *//*
 * 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 <boost/operators.hpp>
#include <2geom/forward.h>

namespace Geom {

/** @brief 2D axis enumeration (X or Y). */
enum Dim2 { X=0, Y=1 };

/**
 * @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; }

template <typename C>
struct CoordTraits {};

// 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;
};

} // 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 :