/* -*- C++ -*-
 * Copyright ©2004 Hugo Mills <hugo@carfax.org.uk>
 *
 * This software is distributed under the terms of the GNU GPL v3
 * For more information on the GPL, see the file COPYING or 
 * visit http://www.gnu.org/
 *
 * This software is distributed without warranty
 */

#include "crossing.h"

bool Crossing::operator==(const Crossing& c) const
{
	if(_isc != c._isc) return false;
	if(_isc)
		return _pos == c._pos;
	else
	{
		Crossing tmp = c.opp();
		return (_pos == c._pos && _d == c._d)
			|| (_pos == tmp._pos && _d == tmp._d);
	}	
}

std::ostream& operator<<(std::ostream& o, const Crossing& c)
{
	o << c.pos();
	if(!c._isc)
		o << " " << c._d;
	return o;
}

Crossing operator+(const Crossing& c, const Diff& d)
{
	if(d.isc())
		return Crossing(c._pos.x + d.x(),
						c._pos.y + d.y());
	else
		return Crossing(c._pos.x + d.x(),
						c._pos.y + d.y(),
						d.d());
}

const Diff offset_opp[4] = {
	Diff(-1, 0, 2),
	Diff(0, -1, 3),
	Diff(1, 0, 0),
	Diff(0, 1, 1)
};

Crossing Crossing::opp(void) const
{
	if(_isc)
		return *this;
	else
		return *this + offset_opp[_d];
}

const Diff endpos_offset[] = {
	Diff(-1, 0), Diff(0, -1), Diff(1, 0), Diff(0, 1)
};

iCoordinate Crossing::end(void) const
{
	if(_isc)
		return _pos;
	else
	{
		Crossing tmp = _pos + endpos_offset[_d];
		return tmp.pos();
	}
}