/*
* Copyright 2010, 2011, 2012 mapsforge.org
*
* This program is free software: you can redistribute it and/or modify it under the
* terms of the GNU Lesser General Public License as published by the Free Software
* Foundation, either version 3 of the License, or (at your option) any later version.
*
* This program 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 Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public License along with
* this program. If not, see <http://www.gnu.org/licenses/>.
*/
package org.mapsforge.map.writer.model;
import java.util.ArrayList;
import java.util.List;
/**
* Represents a coordinate in the tile space.
*
* @author bross
*/
public class TileCoordinate {
private final int x;
private final int y;
private final byte zoomlevel;
/**
* Constructor.
*
* @param x
* the x value of the tile on the given zoom level
* @param y
* the y value of the tile on the given zoom level
* @param zoomlevel
* the zoom level
*/
public TileCoordinate(int x, int y, byte zoomlevel) {
super();
this.x = x;
this.y = y;
this.zoomlevel = zoomlevel;
}
/**
* @return the x
*/
public int getX() {
return this.x;
}
/**
* @return the y
*/
public int getY() {
return this.y;
}
/**
* @return the zoomlevel
*/
public byte getZoomlevel() {
return this.zoomlevel;
}
/**
* Computes which tile on a lower zoom level covers this given tile or which tiles on a higher zoom level together
* cover this tile.
*
* @param zoomlevelNew
* the zoom level
* @return a list of tiles (represented by tile coordinates) which cover this tile
*/
public List<TileCoordinate> translateToZoomLevel(byte zoomlevelNew) {
List<TileCoordinate> tiles = null;
int zoomlevelDistance = zoomlevelNew - this.zoomlevel;
int factor = (int) Math.pow(2, Math.abs(zoomlevelDistance));
if (zoomlevelDistance > 0) {
tiles = new ArrayList<TileCoordinate>((int) Math.pow(4, Math.abs(zoomlevelDistance)));
int tileUpperLeftX = this.x * factor;
int tileUpperLeftY = this.y * factor;
for (int i = 0; i < factor; i++) {
for (int j = 0; j < factor; j++) {
tiles.add(new TileCoordinate(tileUpperLeftX + j, tileUpperLeftY + i, zoomlevelNew));
}
}
} else {
tiles = new ArrayList<TileCoordinate>(1);
tiles.add(new TileCoordinate(this.x / factor, this.y / factor, zoomlevelNew));
}
return tiles;
}
@Override
public int hashCode() {
final int prime = 31;
int result = 1;
result = prime * result + this.x;
result = prime * result + this.y;
result = prime * result + this.zoomlevel;
return result;
}
@Override
public boolean equals(Object obj) {
if (this == obj) {
return true;
}
if (obj == null) {
return false;
}
if (getClass() != obj.getClass()) {
return false;
}
TileCoordinate other = (TileCoordinate) obj;
if (this.x != other.x) {
return false;
}
if (this.y != other.y) {
return false;
}
if (this.zoomlevel != other.zoomlevel) {
return false;
}
return true;
}
@Override
public String toString() {
return "TileCoordinate [x=" + this.x + ", y=" + this.y + ", zoomlevel=" + this.zoomlevel + "]";
}
}