org.opentripplanner.common.geometry

Class CompactElevationProfile

java.lang.Object

org.opentripplanner.common.geometry.CompactElevationProfile

All Implemented Interfaces:

Serializable

public final class CompactElevationProfile
extends Object
implements Serializable

Compact elevation profile. To optimize storage, we use the following tricks:

• Store intermediate point in fixed floating points with fixed precision, using delta coding from the previous point, and variable length coding (most of the delta coordinates will thus fits in 1 or 2 bytes).

Performance hit should be low as we do not need the elevation profile itself during a path search.

Author:

laurent

See Also:

Serialized Form

Constructor Summary

Constructors

Constructor and Description
CompactElevationProfile()

Method Summary

Modifier and Type	Method and Description
static byte[]	compactElevationProfile(org.locationtech.jts.geom.CoordinateSequence elevation) Compact an elevation profile onto a var-len int packed form (Dlugosz coding).
static PackedCoordinateSequence	uncompactElevationProfile(byte[] packedCoords) Uncompact an ElevationProfile from a var-len int packed form (Dlugosz coding).

Methods inherited from class java.lang.Object

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

Constructor Detail

CompactElevationProfile

public CompactElevationProfile()

Method Detail

compactElevationProfile

public static byte[] compactElevationProfile(org.locationtech.jts.geom.CoordinateSequence elevation)

Compact an elevation profile onto a var-len int packed form (Dlugosz coding).

Parameters:

profile - The elevation profile to compact

Returns:

The compacted format

uncompactElevationProfile

public static PackedCoordinateSequence uncompactElevationProfile(byte[] packedCoords)

Uncompact an ElevationProfile from a var-len int packed form (Dlugosz coding). TODO relax the returned type to CoordinateSequence

Parameters:

packedCoords - Compacted coordinates

Returns:

The elevation profile