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/**
* \file
* \brief Cartesian point / 2D vector with integer coordinates
*//*
* Copyright 2011 Krzysztof Kosiński <tweenk.pl@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, 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_INT_POINT_H
#define LIB2GEOM_SEEN_INT_POINT_H
#include <cassert>
#include <tuple>
#include <boost/functional/hash.hpp>
#include <boost/operators.hpp>
#include <2geom/coord.h>
namespace Geom {
/**
* @brief Two-dimensional point with integer coordinates.
*
* This class is an exact equivalent of Point, except it stores integer coordinates.
* Integer points are useful in contexts related to rasterized graphics, for example
* for bounding boxes when rendering SVG.
*
* @see Point
* @ingroup Primitives */
class IntPoint
: boost::additive< IntPoint
, boost::totally_ordered< IntPoint
, boost::multiplicative< IntPoint, IntCoord
, boost::multiplicative< IntPoint
>>>> // base class chaining, see documentation for Boost.Operator
{
IntCoord _pt[2] = { 0, 0 };
public:
/// @name Create integer points
/// @{
/** Construct a point at the origin. */
constexpr IntPoint() = default;
/** Construct a point from its coordinates. */
constexpr IntPoint(IntCoord x, IntCoord y)
: _pt{ x, y }
{}
/// @}
/// @name Access the coordinates of a point
/// @{
IntCoord operator[](unsigned i) const { assert(i < 2); return _pt[i]; }
IntCoord &operator[](unsigned i) { assert(i < 2); return _pt[i]; }
constexpr IntCoord operator[](Dim2 d) const { return _pt[d]; }
constexpr IntCoord &operator[](Dim2 d) { return _pt[d]; }
constexpr IntCoord x() const noexcept { return _pt[X]; }
constexpr IntCoord &x() noexcept { return _pt[X]; }
constexpr IntCoord y() const noexcept { return _pt[Y]; }
constexpr IntCoord &y() noexcept { return _pt[Y]; }
// Structured binding support
template <size_t I> constexpr IntCoord get() const { static_assert(I < 2); return _pt[I]; }
template <size_t I> constexpr IntCoord &get() { static_assert(I < 2); return _pt[I]; }
/// @}
/// @name Vector-like operations
/// @{
constexpr IntCoord lengthSq() const { return _pt[X] * _pt[X] + _pt[Y] * _pt[Y]; }
/** @brief Return a point like this point but rotated -90 degrees.
* If the y axis grows downwards and the x axis grows to the
* right, then this is 90 degrees counter-clockwise. */
constexpr IntPoint ccw() const {
return IntPoint(_pt[Y], -_pt[X]);
}
/** @brief Return a point like this point but rotated +90 degrees.
* If the y axis grows downwards and the x axis grows to the
* right, then this is 90 degrees clockwise. */
constexpr IntPoint cw() const {
return IntPoint(-_pt[Y], _pt[X]);
}
/// @}
/// @name Vector-like arithmetic operations
/// @{
constexpr IntPoint operator-() const {
return IntPoint(-_pt[X], -_pt[Y]);
}
constexpr IntPoint &operator+=(IntPoint const &o) {
_pt[X] += o._pt[X];
_pt[Y] += o._pt[Y];
return *this;
}
constexpr IntPoint &operator-=(IntPoint const &o) {
_pt[X] -= o._pt[X];
_pt[Y] -= o._pt[Y];
return *this;
}
constexpr IntPoint &operator*=(IntPoint const &o) {
_pt[X] *= o._pt[X];
_pt[Y] *= o._pt[Y];
return *this;
}
constexpr IntPoint &operator*=(IntCoord o) {
_pt[X] *= o;
_pt[Y] *= o;
return *this;
}
constexpr IntPoint &operator/=(IntPoint const &o) {
_pt[X] /= o._pt[X];
_pt[Y] /= o._pt[Y];
return *this;
}
constexpr IntPoint &operator/=(IntCoord o) {
_pt[X] /= o;
_pt[Y] /= o;
return *this;
}
/// @}
/// @name Various utilities
/// @{
/** @brief Equality operator. */
constexpr bool operator==(IntPoint const &p) const {
return _pt[X] == p[X] && _pt[Y] == p[Y];
}
/** @brief Lexicographical ordering for points.
* Y coordinate is regarded as more significant. When sorting according to this
* ordering, the points will be sorted according to the Y coordinate, and within
* points with the same Y coordinate according to the X coordinate. */
constexpr bool operator<(IntPoint const &p) const {
return _pt[Y] < p[Y] || (_pt[Y] == p[Y] && _pt[X] < p[X]);
}
/// @}
/** @brief Lexicographical ordering functor.
* @param d The more significant dimension */
template <Dim2 d> struct LexLess;
/** @brief Lexicographical ordering functor.
* @param d The more significant dimension */
template <Dim2 d> struct LexGreater;
/** @brief Lexicographical ordering functor with runtime dimension. */
struct LexLessRt {
LexLessRt(Dim2 d) : dim(d) {}
inline bool operator()(IntPoint const &a, IntPoint const &b) const;
private:
Dim2 dim;
};
/** @brief Lexicographical ordering functor with runtime dimension. */
struct LexGreaterRt {
LexGreaterRt(Dim2 d) : dim(d) {}
inline bool operator()(IntPoint const &a, IntPoint const &b) const;
private:
Dim2 dim;
};
};
template<> struct IntPoint::LexLess<X> {
bool operator()(IntPoint const &a, IntPoint const &b) const {
return a[X] < b[X] || (a[X] == b[X] && a[Y] < b[Y]);
}
};
template<> struct IntPoint::LexLess<Y> {
bool operator()(IntPoint const &a, IntPoint const &b) const {
return a[Y] < b[Y] || (a[Y] == b[Y] && a[X] < b[X]);
}
};
template<> struct IntPoint::LexGreater<X> {
bool operator()(IntPoint const &a, IntPoint const &b) const {
return a[X] > b[X] || (a[X] == b[X] && a[Y] > b[Y]);
}
};
template<> struct IntPoint::LexGreater<Y> {
bool operator()(IntPoint const &a, IntPoint const &b) const {
return a[Y] > b[Y] || (a[Y] == b[Y] && a[X] > b[X]);
}
};
inline bool IntPoint::LexLessRt::operator()(IntPoint const &a, IntPoint const &b) const {
return dim ? IntPoint::LexLess<Y>()(a, b) : IntPoint::LexLess<X>()(a, b);
}
inline bool IntPoint::LexGreaterRt::operator()(IntPoint const &a, IntPoint const &b) const {
return dim ? IntPoint::LexGreater<Y>()(a, b) : IntPoint::LexGreater<X>()(a, b);
}
} // namespace Geom
// Structured binding support
template <> struct std::tuple_size<Geom::IntPoint> : std::integral_constant<size_t, 2> {};
template <size_t I> struct std::tuple_element<I, Geom::IntPoint> { using type = Geom::IntCoord; };
// Hash support
template <> struct std::hash<Geom::IntPoint>
{
size_t operator()(Geom::IntPoint const &p) const noexcept {
size_t hash = 0;
boost::hash_combine(hash, p.x());
boost::hash_combine(hash, p.y());
return hash;
}
};
#endif // LIB2GEOM_SEEN_INT_POINT_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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