/*
 * This file is part of libgim.
 *
 * libgim is free software: you can redistribute it and/or modify it under the
 * terms of the GNU General Public License as published by the Free Software
 * Foundation, either version 3 of the License, or (at your option) any later
 * version.
 *
 * libgim is distributed in the hope that it will be useful, but WITHOUT ANY
 * WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
 * FOR A PARTICULAR PURPOSE.  See the GNU General Public License for more
 * details.
 *
 * You should have received a copy of the GNU General Public License
 * along with libgim.  If not, see <http://www.gnu.org/licenses/>.
 *
 * Copyright 2010 Danny Robson <danny@blubinc.net>
 */


#include "region.hpp"

#include "enable_if.hpp"
#include "debug.hpp"

#include <type_traits>

using namespace util;

/*
 * Rect
 */
template <typename T>
extent<T>::extent (const T  _width, const T  _height):
        width (_width),
        height (_height)
    { ; }


template <typename T>
T
extent<T>::area (void) const
    { return width * height; }


template <typename T>
bool
extent<T>::empty (void) const
    { return almost_equal (area(), 0); }


template <typename T>
bool
extent<T>::operator ==(const extent& rhs) const {
    return almost_equal (width,  rhs.width) &&
           almost_equal (height, rhs.height);
}


template <typename T>
void
extent<T>::sanity (void) const
    { check (width >= 0 && height >= 0); }


namespace util {
    template <>
    void
    extent<unsigned int>::sanity (void) const
        { return; }
}

template struct extent<unsigned int>;
template struct extent<double>;

/*
 * Region
 */

template <typename T>
region<T>::region (T _x, T _y, T _width, T _height):
    x      (_x),
    y      (_y),
    width  (_width),
    height (_height)
{ ; }


template <typename T>
T 
region<T>::area (void) const
    { return width * height; }


template <typename T>
bool 
region<T>::empty (void) const
    { return almost_equal (area (), 0); }


template <typename T>
point
region<T>::centre (void) const {
    double cx = x + static_cast<T>(width  / 2.0),
           cy = y + static_cast<T>(height / 2.0);

    return { cx, cy, 0.0 };
}


template <typename T>
bool
region<T>::includes (const point &p) const {
    return p.x >= x &&
           p.y >= y &&
           p.x <= x + width &&
           p.y <= y + height;
}


template <typename T>
bool
region<T>::contains (const point& p) const {
    return p.x > x &&
           p.y > y &&
           p.x < x + width &&
           p.y < y + height;
}


template <typename T>
bool
region<T>::overlaps (const region<T> &rhs) const {
    return x < rhs.x + rhs.width && 
           x + width > rhs.x &&
           y < rhs.y + rhs.height &&
           y + height > rhs.y;
}

template <typename T>
bool
region<T>::operator ==(const region& rhs) const
    { return almost_equal (x,      rhs.x)     &&
             almost_equal (y,      rhs.y)     &&
             almost_equal (width,  rhs.width) &&
             almost_equal (height, rhs.height); }


template <typename T>
void region<T>::sanity (void) const
    { check (width >= 0 && height >= 0); }


namespace util {
    template <>
    void region<unsigned int>::sanity (void) const
        { return; }
}


template struct region<unsigned int>;
template struct region<double>;