trunk/java/com/l2jserver/gameserver/util/LinePointIterator.java

@@ -0,0 +1,115 @@
+/*
+ * Copyright (C) 2004-2014 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;
+	}
+}