org.apache.lucene.document

Class ShapeField

java.lang.Object

org.apache.lucene.document.ShapeField

public final class ShapeField
extends Object

A base shape utility class used for both LatLon (spherical) and XY (cartesian) shape fields.

Polygon's and Line's are decomposed into a triangular mesh using the Tessellator utility class. Each ShapeField.Triangle is encoded by this base class and indexed as a seven dimension multi-value field.

Finding all shapes that intersect a range (e.g., bounding box), or target shape, at search time is efficient.

This class defines the static methods for encoding the three vertices of a tessellated triangles as a seven dimension point. The coordinates are converted from double precision values into 32 bit integers so they are sortable at index time.

WARNING: This API is experimental and might change in incompatible ways in the next release.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	ShapeField.DecodedTriangle Represents a encoded triangle using decodeTriangle(byte[], DecodedTriangle).
static class	ShapeField.QueryRelation Query Relation Types
static class	ShapeField.Triangle polygons are decomposed into tessellated triangles using Tessellator these triangles are encoded and inserted as separate indexed POINT fields

Field Summary

Fields

Modifier and Type	Field and Description
protected static FieldType	TYPE tessellated triangles are seven dimensions; the first four are the bounding box index dimensions

Method Summary

Modifier and Type	Method and Description
static void	decodeTriangle(byte[] t, ShapeField.DecodedTriangle triangle) Decode a triangle encoded by encodeTriangle(byte[], int, int, boolean, int, int, boolean, int, int, boolean).
static void	encodeTriangle(byte[] bytes, int aLat, int aLon, boolean abFromShape, int bLat, int bLon, boolean bcFromShape, int cLat, int cLon, boolean caFromShape) A triangle is encoded using 6 points and an extra point with encoded information in three bits of how to reconstruct it.

Methods inherited from class java.lang.Object

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

Field Detail

TYPE

protected static final FieldType TYPE

tessellated triangles are seven dimensions; the first four are the bounding box index dimensions

Method Detail

encodeTriangle

public static void encodeTriangle(byte[] bytes,
                                  int aLat,
                                  int aLon,
                                  boolean abFromShape,
                                  int bLat,
                                  int bLon,
                                  boolean bcFromShape,
                                  int cLat,
                                  int cLon,
                                  boolean caFromShape)

A triangle is encoded using 6 points and an extra point with encoded information in three bits of how to reconstruct it. Triangles are encoded with CCW orientation and might be rotated to limit the number of possible reconstructions to 2^3. Reconstruction always happens from west to east.

decodeTriangle

public static void decodeTriangle(byte[] t,
                                  ShapeField.DecodedTriangle triangle)

Decode a triangle encoded by encodeTriangle(byte[], int, int, boolean, int, int, boolean, int, int, boolean).