com.askgeo.flt.base
Class PolygonData

java.lang.Object
  com.askgeo.flt.base.PolygonData

public class PolygonData
extends java.lang.Object

Represents the raw polygonal data of a geographic shape on a map. The PolygonData is the only form of geographic data that can be queried from the subclasses of GeneralMap, so if you are wanting to work with the raw shapes, this is the class that you will be interfacing with.

Geographic shapes in AskGeo are described as complex polygons. By this, we mean the union of multiple closed polygonal chains of latitude and longitude vertexes. Counter-clockwise polygonal chains count as positive area, adding to the shape. Clockwise polygonal chains count as negative area, subtracting from positive areas to create cut-outs.

PolygonData objects are not intended to be created by the user. Rather, they are created by a Multigon as an internal operation in constructing a subclass of ResultBase. So to access a PolygonData object, you should query a map with findResult(), which will return a subclass of ResultBase, which has an accessor getPolygonData that will return the corresponding shape's PolygonData.

The subclasses of GeneralMap also expose the method getAllResults(), which returns a Vector of all the possible results. If you wish to iterate over the shapes in a map, that is the method you will want to use.

Constructor Summary

PolygonData(float[][] shapeLatsArr, float[][] shapeLonsArr, float[] bbox)
Constructs a new PolygonData object from latitude and longitude arrays, the shape's bounding box, and the shapes area.

Method Summary

float	computeAreaSqKm() Computes the area in square kilometers.
float	getMaxLatitudeDeg() Returns the upper bound latitude in degrees from the bounding box.
float	getMaxLongitudeDeg() Returns the upper bound longitude in degrees from the bounding box.
float	getMinLatitudeDeg() Returns the lower bound latitude in degrees from the bounding box.
float	getMinLongitudeDeg() Returns the lower bound longitude in degrees from the bounding box.
int	getNumNodes() Returns a count of the total number of nodes (vertexes) in this shape.
int	getNumParts() Returns the number of parts in the polygon data.
int	getNumVertexes(int partIndex) Returns the number of vertexes in the given part.
float	getVertexLatitudeDeg(int partIndex, int vertexIndex) Returns the latitude in degrees of the given vertex.
float	getVertexLongitudeDeg(int partIndex, int vertexIndex) Returns the longitude in degrees of the given vertex.

Methods inherited from class java.lang.Object

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

Constructor Detail

PolygonData

public PolygonData(float[][] shapeLatsArr,
                   float[][] shapeLonsArr,
                   float[] bbox)

Constructs a new PolygonData object from latitude and longitude arrays, the shape's bounding box, and the shapes area. Even though the last two are computable from the first two, they are passed in because the object that uses this constructor already has that information on hand.

Parameters:

shapeLatsArr - the array of latitude values, in radians.

shapeLonsArr - the array of longitude values, in radians.

bbox - the bounding box of the shape.

Method Detail

getNumNodes

public int getNumNodes()

Returns a count of the total number of nodes (vertexes) in this shape.

Returns:

the number of nodes (vertexes) in this shape.

getMinLatitudeDeg

public float getMinLatitudeDeg()

Returns the lower bound latitude in degrees from the bounding box.

Returns:

the lower bound latitude in degrees from the bounding box.

getMaxLatitudeDeg

public float getMaxLatitudeDeg()

Returns the upper bound latitude in degrees from the bounding box.

Returns:

the upper bound latitude in degrees from the bounding box.

getMinLongitudeDeg

public float getMinLongitudeDeg()

Returns the lower bound longitude in degrees from the bounding box.

Returns:

the lower bound longitude in degrees from the bounding box.

getMaxLongitudeDeg

public float getMaxLongitudeDeg()

Returns the upper bound longitude in degrees from the bounding box.

Returns:

the upper bound longitude in degrees from the bounding box.

getNumParts

public int getNumParts()

Returns the number of parts in the polygon data. Each part is one of the closed polygonal chains that define the shape.

Returns:

the number of rings in the shape.

getNumVertexes

public int getNumVertexes(int partIndex)

Returns the number of vertexes in the given part.

Parameters:

partIndex - the index of the part.

Returns:

the number of vertexes in the given part.

getVertexLatitudeDeg

public float getVertexLatitudeDeg(int partIndex,
                                  int vertexIndex)

Returns the latitude in degrees of the given vertex.

Parameters:

partIndex - the part index.

vertexIndex - the vertex index within that part.

Returns:

the latitude in degrees of the given vertex.

getVertexLongitudeDeg

public float getVertexLongitudeDeg(int partIndex,
                                   int vertexIndex)

Returns the longitude in degrees of the given vertex.

Parameters:

partIndex - the part index.

vertexIndex - the vertex index within that part.

Returns:

the longitude in degrees of the given vertex.

computeAreaSqKm

public float computeAreaSqKm()

Computes the area in square kilometers.