l2j_mobius/trunk/java/com/l2jserver/gameserver/util/LinePointIterator.java
2015-01-02 15:09:44 +00:00

116 lines
2.1 KiB
Java

/*
* Copyright (C) 2004-2015 L2J Server
*
* This file is part of L2J Server.
*
* L2J Server 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.
*
* L2J Server 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 this program. If not, see <http://www.gnu.org/licenses/>.
*/
package com.l2jserver.gameserver.util;
/**
* @author HorridoJoho
*/
public final class LinePointIterator
{
// src is moved towards dst in next()
private int _srcX;
private int _srcY;
private final int _dstX;
private final int _dstY;
private final long _dx;
private final long _dy;
private final long _sx;
private final long _sy;
private long _error;
private boolean _first;
public LinePointIterator(int srcX, int srcY, int dstX, int dstY)
{
_srcX = srcX;
_srcY = srcY;
_dstX = dstX;
_dstY = dstY;
_dx = Math.abs((long) dstX - srcX);
_dy = Math.abs((long) dstY - srcY);
_sx = srcX < dstX ? 1 : -1;
_sy = srcY < dstY ? 1 : -1;
if (_dx >= _dy)
{
_error = _dx / 2;
}
else
{
_error = _dy / 2;
}
_first = true;
}
public boolean next()
{
if (_first)
{
_first = false;
return true;
}
else if (_dx >= _dy)
{
if (_srcX != _dstX)
{
_srcX += _sx;
_error += _dy;
if (_error >= _dx)
{
_srcY += _sy;
_error -= _dx;
}
return true;
}
}
else
{
if (_srcY != _dstY)
{
_srcY += _sy;
_error += _dx;
if (_error >= _dy)
{
_srcX += _sx;
_error -= _dy;
}
return true;
}
}
return false;
}
public int x()
{
return _srcX;
}
public int y()
{
return _srcY;
}
}