Package org.locationtech.jts.operation.buffer.validate

Class BufferResultValidator

java.lang.Object

org.locationtech.jts.operation.buffer.validate.BufferResultValidator

public class BufferResultValidator
extends Object

Validates that the result of a buffer operation is geometrically correct, within a computed tolerance.

This is a heuristic test, and may return false positive results (I.e. it may fail to detect an invalid result.) It should never return a false negative result, however (I.e. it should never report a valid result as invalid.)

This test may be (much) more expensive than the original buffer computation.

Field Summary

Fields

Modifier and Type	Field	Description
private double	distance
private Geometry	errorIndicator
private Coordinate	errorLocation
private String	errorMsg
private Geometry	input
private boolean	isValid
private static final double	MAX_ENV_DIFF_FRAC	Maximum allowable fraction of buffer distance the actual distance can differ by.
private Geometry	result
private static boolean	VERBOSE

Constructor Summary

Constructors

Constructor	Description
BufferResultValidator(Geometry input, double distance, Geometry result)

Method Summary

Modifier and Type	Method	Description
private void	checkArea()
private void	checkDistance()
private void	checkEnvelope()
private void	checkExpectedEmpty()
private void	checkPolygonal()
Geometry	getErrorIndicator()	Gets a geometry which indicates the location and nature of a validation failure.
Coordinate	getErrorLocation()
String	getErrorMessage()
boolean	isValid()
static boolean	isValid(Geometry g, double distance, Geometry result)
static String	isValidMsg(Geometry g, double distance, Geometry result)	Checks whether the geometry buffer is valid, and returns an error message if not.
private void	report(String checkName)

Methods inherited from class java.lang.Object

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

Field Details

VERBOSE

private static boolean VERBOSE

MAX_ENV_DIFF_FRAC

private static final double MAX_ENV_DIFF_FRAC

Maximum allowable fraction of buffer distance the actual distance can differ by. 1% sometimes causes an error - 1.2% should be safe.

See Also:

• Constant Field Values

input

private Geometry input

distance

private double distance

result

private Geometry result

isValid

private boolean isValid

errorMsg

private String errorMsg

errorLocation

private Coordinate errorLocation

errorIndicator

private Geometry errorIndicator

Constructor Details

BufferResultValidator

public BufferResultValidator(Geometry input,
 double distance,
 Geometry result)

Method Details

isValid

public static boolean isValid(Geometry g,
 double distance,
 Geometry result)

isValidMsg

public static String isValidMsg(Geometry g,
 double distance,
 Geometry result)

Checks whether the geometry buffer is valid, and returns an error message if not.

Parameters:

g -

distance -

result -

Returns:

an appropriate error message or null if the buffer is valid

isValid

public boolean isValid()

getErrorMessage

public String getErrorMessage()

getErrorLocation

public Coordinate getErrorLocation()

getErrorIndicator

public Geometry getErrorIndicator()

Gets a geometry which indicates the location and nature of a validation failure.

If the failure is due to the buffer curve being too far or too close to the input, the indicator is a line segment showing the location and size of the discrepancy.

Returns:

a geometric error indicator or null if no error was found

report

private void report(String checkName)

checkPolygonal

private void checkPolygonal()

checkExpectedEmpty

private void checkExpectedEmpty()

checkEnvelope

private void checkEnvelope()

checkArea

private void checkArea()

checkDistance

private void checkDistance()