org.mapsforge.map.writer.util

Class GeoUtils

java.lang.Object

org.mapsforge.map.writer.util.GeoUtils

public final class GeoUtils
extends Object

Provides utility functions for the maps preprocessing.

Field Summary

Fields

Modifier and Type	Field and Description
static int	MIN_COORDINATES_POLYGON The minimum amount of coordinates (lat/lon counted separately) required for a valid closed polygon.
static int	MIN_NODES_POLYGON The minimum amount of nodes required for a valid closed polygon.

Method Summary

Methods

Modifier and Type	Method and Description
static com.vividsolutions.jts.geom.Geometry	clipToTile(TDWay way, com.vividsolutions.jts.geom.Geometry geometry, TileCoordinate tileCoordinate, int enlargementInMeters) Clips a geometry to a tile.
static short	computeBitmask(com.vividsolutions.jts.geom.Geometry geometry, TileCoordinate tile, int enlargementInMeter) A tile on zoom level z has exactly 16 sub tiles on zoom level z+2.
static LatLong	computeCentroid(com.vividsolutions.jts.geom.Geometry geometry)
static boolean	coveredByTile(com.vividsolutions.jts.geom.Geometry geometry, TileCoordinate tile, int enlargementInMeter)
static Set<TileCoordinate>	mapWayToTiles(TDWay way, byte baseZoomLevel, int enlargementInMeter) Computes which tiles on the given base zoom level need to include the given way (which may be a polygon).
static boolean	pointInTile(LatLong latLong, TileCoordinate tile)
static com.vividsolutions.jts.geom.Geometry	simplifyGeometry(TDWay way, com.vividsolutions.jts.geom.Geometry geometry, byte zoomlevel, int tileSize, double simplificationFactor) Simplifies a geometry using the Douglas Peucker algorithm.
static List<WayDataBlock>	toWayDataBlockList(com.vividsolutions.jts.geom.Geometry geometry) Convert a JTS Geometry to a WayDataBlock list.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

MIN_COORDINATES_POLYGON

public static final int MIN_COORDINATES_POLYGON

The minimum amount of coordinates (lat/lon counted separately) required for a valid closed polygon.

See Also:

Constant Field Values

MIN_NODES_POLYGON

public static final int MIN_NODES_POLYGON

The minimum amount of nodes required for a valid closed polygon.

See Also:

Constant Field Values

Method Detail

clipToTile

public static com.vividsolutions.jts.geom.Geometry clipToTile(TDWay way,
                                              com.vividsolutions.jts.geom.Geometry geometry,
                                              TileCoordinate tileCoordinate,
                                              int enlargementInMeters)

Clips a geometry to a tile.

Parameters:

way - the way

geometry - the geometry

tileCoordinate - the tile coordinate

enlargementInMeters - the bounding box buffer

Returns:

the clipped geometry

computeBitmask

public static short computeBitmask(com.vividsolutions.jts.geom.Geometry geometry,
                   TileCoordinate tile,
                   int enlargementInMeter)

A tile on zoom level z has exactly 16 sub tiles on zoom level z+2. For each of these 16 sub tiles it is analyzed if the given way needs to be included. The result is represented as a 16 bit short value. Each bit represents one of the 16 sub tiles. A bit is set to 1 if the sub tile needs to include the way. Representation is row-wise.

Parameters:

geometry - the geometry which is analyzed

tile - the tile which is split into 16 sub tiles

enlargementInMeter - amount of pixels that is used to enlarge the bounding box of the way and the tiles in the mapping process

Returns:

a 16 bit short value that represents the information which of the sub tiles needs to include the way

computeCentroid

public static LatLong computeCentroid(com.vividsolutions.jts.geom.Geometry geometry)

Parameters:

geometry - the JTS Geometry object

Returns:

the centroid of the given geometry

coveredByTile

public static boolean coveredByTile(com.vividsolutions.jts.geom.Geometry geometry,
                    TileCoordinate tile,
                    int enlargementInMeter)

Parameters:

geometry - a JTS Geometry object representing the OSM entity

tile - the tile

enlargementInMeter - the enlargement of the tile in meters

Returns:

true, if the geometry is covered completely by this tile

mapWayToTiles

public static Set<TileCoordinate> mapWayToTiles(TDWay way,
                                byte baseZoomLevel,
                                int enlargementInMeter)

Computes which tiles on the given base zoom level need to include the given way (which may be a polygon).

Parameters:

way - the way that is mapped to tiles

baseZoomLevel - the base zoom level which is used in the mapping

enlargementInMeter - amount of pixels that is used to enlarge the bounding box of the way and the tiles in the mapping process

Returns:

all tiles on the given base zoom level that need to include the given way, an empty set if no tiles are matched

pointInTile

public static boolean pointInTile(LatLong latLong,
                  TileCoordinate tile)

Parameters:

latLong - the point

tile - the tile

Returns:

true if the point is located in the given tile

simplifyGeometry

public static com.vividsolutions.jts.geom.Geometry simplifyGeometry(TDWay way,
                                                    com.vividsolutions.jts.geom.Geometry geometry,
                                                    byte zoomlevel,
                                                    int tileSize,
                                                    double simplificationFactor)

Simplifies a geometry using the Douglas Peucker algorithm.

Parameters:

way - the way

geometry - the geometry

zoomlevel - the zoom level

simplificationFactor - the simplification factor

Returns:

the simplified geometry

toWayDataBlockList

public static List<WayDataBlock> toWayDataBlockList(com.vividsolutions.jts.geom.Geometry geometry)

Convert a JTS Geometry to a WayDataBlock list.

Parameters:

geometry - a geometry object which should be converted

Returns:

a list of WayBlocks which you can use to save the way.