rect.h

/*
 * rect.h - D2<Interval> specialization to Rect
 *
 * Copyright 2007 Michael Sloan <mgsloan@gmail.com>
 *
 * 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, output to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 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.
 *
 */

/* Authors of original rect class:
 *   Lauris Kaplinski <lauris@kaplinski.com>
 *   Nathan Hurst <njh@mail.csse.monash.edu.au>
 *   bulia byak <buliabyak@users.sf.net>
 *   MenTaLguY <mental@rydia.net>
 */

#ifdef _2GEOM_D2  /*This is intentional: we don't actually want anyone to
                    include this, other than D2.h.  If somone else tries, D2
                    won't be defined.  If it is, this will already be included. */
#ifndef _2GEOM_RECT
#define _2GEOM_RECT

#include "matrix.h"
#include <boost/optional/optional.hpp>

namespace Geom {

typedef D2<Interval> Rect;

Rect unify(const Rect &, const Rect &);

template<>
class D2<Interval> {
  private:
    Interval f[2];
  public:
    D2<Interval>() { f[X] = f[Y] = Interval(0, 0); }
    
    D2<Interval>(Interval const &a, Interval const &b) {
        f[X] = a;
        f[Y] = b;
    }

    D2<Interval>(Point const & a, Point const & b) {
        f[X] = Interval(a[X], b[X]);
        f[Y] = Interval(a[Y], b[Y]);
    }

    inline Interval& operator[](unsigned i)              { return f[i]; }
    inline Interval const & operator[](unsigned i) const { return f[i]; }

    inline Point min() const { return Point(f[X].min(), f[Y].min()); }
    inline Point max() const { return Point(f[X].max(), f[Y].max()); }

    Point corner(unsigned i) const {
        switch(i % 4) {
            case 0:  return Point(f[X].min(), f[Y].min());
            case 1:  return Point(f[X].max(), f[Y].min());
            case 2:  return Point(f[X].max(), f[Y].max());
            default: return Point(f[X].min(), f[Y].max());
        }
    }
        
    //We should probably remove these - they're coord sys gnostic
    inline double top() const { return f[Y].min(); }
    inline double bottom() const { return f[Y].max(); }
    inline double left() const { return f[X].min(); }
    inline double right() const { return f[X].max(); }
    
    inline double width() const { return f[X].extent(); }
    inline double height() const { return f[Y].extent(); }

    inline Point dimensions() const { return Point(f[X].extent(), f[Y].extent()); }
    inline Point midpoint() const { return Point(f[X].middle(), f[Y].middle()); }

    inline double area() const { return f[X].extent() * f[Y].extent(); }
    inline double maxExtent() const { return std::max(f[X].extent(), f[Y].extent()); }

    inline bool isEmpty()                 const { 
    return f[X].isEmpty()        && f[Y].isEmpty(); 
    }
    inline bool intersects(Rect const &r) const { 
    return f[X].intersects(r[X]) && f[Y].intersects(r[Y]); 
    }
    inline bool contains(Rect const &r)   const { 
    return f[X].contains(r[X]) && f[Y].contains(r[Y]); 
    }
    inline bool contains(Point const &p)  const {
    return f[X].contains(p[X]) && f[Y].contains(p[Y]);
    }

    inline void expandTo(Point p)        { 
    f[X].extendTo(p[X]);  f[Y].extendTo(p[Y]); 
    }
    inline void unionWith(Rect const &b) { 
    f[X].unionWith(b[X]); f[Y].unionWith(b[Y]); 
    }

    inline void expandBy(double amnt)    { 
    f[X].expandBy(amnt);  f[Y].expandBy(amnt); 
    }
    inline void expandBy(Point const p)  { 
    f[X].expandBy(p[X]);  f[Y].expandBy(p[Y]); 
    }

    inline Rect operator*(Matrix const m) const { 
        return unify(Rect(corner(0) * m, corner(2) * m),
                     Rect(corner(1) * m, corner(3) * m));
    }
};

inline Rect unify(Rect const & a, Rect const & b) {
    return Rect(unify(a[X], b[X]), unify(a[Y], b[Y]));
}

inline Rect union_list(std::vector<Rect> const &r) {
    if(r.empty()) return Rect(Interval(0,0), Interval(0,0));
    Rect ret = r[0];
    for(unsigned i = 1; i < r.size(); i++)
        ret.unionWith(r[i]);
    return ret;
}

inline boost::optional<Rect> intersect(Rect const & a, Rect const & b) {
    boost::optional<Interval> x = intersect(a[X], b[X]);
    boost::optional<Interval> y = intersect(a[Y], b[Y]);
    return x && y ? boost::optional<Rect>(Rect(*x, *y)) : boost::optional<Rect>();
}

}

#endif //_2GEOM_RECT
#endif //_2GEOM_D2
/*
  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:
*/
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