com.mapinfo.midev.geometry

Interface IRing

All Superinterfaces:

IGeometry, Iterable<ICurveSegment>, Serializable

public interface IRing
extends IGeometry, Iterable<ICurveSegment>

An IRing is a list of consecutively connected ICurveSegments where the last position is exactly equal to the first position.

By policy, instances of classes that implement this interface cannot be empty, must be closed and must contain at least one ICurveSegment.

Method Summary

Modifier and Type	Method and Description
ILineString	asLineString() Returns an ILineString that approximates this IRing.
ILineString	asLineString(Length maxSpacing, Length maxOffset) Returns a linear approximation of this IRing as a single ILineString.
IRing	getCopy() Get a (permanent) copy of this IGeometry.
IRing	getCopy(CoordSys crs) Get a (permanent) copy of this IGeometry transformed to the given coordinate system.
ICurveSegment	getCurveSegment(int i) Returns the ICurveSegment at the specified index.
int	getCurveSegmentCount() Returns the number of ICurveSegments that this IRing contains.
Length	getEndDistance(ComputationType ct) Returns the distance corresponding to the last direct position of this IRing.
com.mapinfo.midev.geometry.DirectPosition	getEndPosition() Return the last position of the IRing.
com.mapinfo.midev.geometry.DirectPosition	getPointForDistance(Length len) Returns the DirectPosition that lies at the specified distance along this IRing.
Length	getStartDistance(ComputationType ct) Returns the distance corresponding to the first direct position of this IRing.
com.mapinfo.midev.geometry.DirectPosition	getStartPosition() Return the first position of the IRing.
boolean	isLinear() Return true if this IRing is linear; false if not.
IRing	reverse() Returns a new IRing that has the opposite orientation of this IRing.

Methods inherited from interface com.mapinfo.midev.geometry.IGeometry

contains, getArea, getCoordSys, getDimension, getEnvelope, getPerimeter, getSpatialInfo, getType, isEmpty, isTransient, mAllSet, mSet, zAllSet, zSet

Methods inherited from interface java.lang.Iterable

forEach, iterator, spliterator

Method Detail

getStartPosition

com.mapinfo.midev.geometry.DirectPosition getStartPosition()

Return the first position of the IRing.

Returns:

the first position of the IRing.

getEndPosition

com.mapinfo.midev.geometry.DirectPosition getEndPosition()

Return the last position of the IRing.

Returns:

the last position of the IRing.

isLinear

boolean isLinear()

Return true if this IRing is linear; false if not. An IRing is linear if all the contained ICurveSegments are of type CurveInterpolationType.LINEAR.

Returns:

true if this IRing is linear; false if not.

getStartDistance

Length getStartDistance(ComputationType ct)

Returns the distance corresponding to the first direct position of this IRing.

The start distance for any IRing is always 0.0. However, the start distance for any ICurveSegment contained in an IRing is always the distance along that IRing where it's first direct position lies. The start distance for a stand alone ICurveSegment that is not part of an IRing is always 0.0.

For any IRing:

   pointForDistance(startDistance(ct)) == first direct position
   endDistance(ct) - startDistance(ct) == getLength() or getPerimeter()
 

Parameters:

ct - ComputationType to use for the distance calculation

Returns:

the distance corresponding to the first direct position of this IRing.

getEndDistance

Length getEndDistance(ComputationType ct)

Returns the distance corresponding to the last direct position of this IRing.

The end distance for any IRing is always the same value as that returned by IGeometry.getPerimeter(ComputationType) respectively. However, the end distance for any ICurveSegment contained in an IRing is always the distance along that IRing where it's last direct position lies. The end distance for a stand alone ICurveSegment that is not part of an IRing is always the same as it's length.

For any IGenericCurve:

   pointForDistance(endDistance(ct)) == last direct position
   endDistance(ct) - startDistance(ct) == getLength() or getPerimeter()
 

Parameters:

ct - ComputationType to use for the distance calculation

Returns:

the end distance of the last direct position of this generic curve

Throws:

InvalidComputationTypeException - if the given computation type is incompatible with the coordinate system of this geometry

getPointForDistance

com.mapinfo.midev.geometry.DirectPosition getPointForDistance(Length len)

Returns the DirectPosition that lies at the specified distance along this IRing.

Parameters:

len - length along this IRing to return the point. Value must be inclusively between the values returned by IRing.getStartDistance(ComputationType) and IRing.getEndDistance(ComputationType)

Returns:

the DirectPosition that lies at the specified distance along this IRing.

Throws:

InvalidComputationTypeException - if the computation type of the length is incompatible with the coordinate system of the geometry or if the value of len is not inclusively between the values returned by IRing.getStartDistance(ComputationType) and IRing.getEndDistance(ComputationType)

getCurveSegmentCount

int getCurveSegmentCount()

Returns the number of ICurveSegments that this IRing contains.

Returns:

the number of ICurveSegments that this IRing contains.

getCurveSegment

ICurveSegment getCurveSegment(int i)

Returns the ICurveSegment at the specified index.

Parameters:

i - zero-based index of ICurveSegment to return.

Returns:

A new copy of the ith segment.

getCopy

IRing getCopy(CoordSys crs)

Description copied from interface: IGeometry

Get a (permanent) copy of this IGeometry transformed to the given coordinate system.

Specified by:

getCopy in interface IGeometry

Parameters:

crs - coordinate system of the returned copy

Returns:

copy of this IGeometry in the given coordinate system

See Also:

IGeometry.isTransient()

getCopy

IRing getCopy()

Description copied from interface: IGeometry

Get a (permanent) copy of this IGeometry.

Specified by:

getCopy in interface IGeometry

Returns:

permanent copy of this IGeometry.

See Also:

IGeometry.getCopy(CoordSys), IGeometry.isTransient()

reverse

IRing reverse()

Returns a new IRing that has the opposite orientation of this IRing.

Returns:

a new IRing that has the opposite orientation of this IRing.

asLineString

ILineString asLineString()

Returns an ILineString that approximates this IRing.

Returns:

an ILineString that approximates this IRing.

asLineString

ILineString asLineString(Length maxSpacing,
                         Length maxOffset)

Returns a linear approximation of this IRing as a single ILineString. The first position of the second and subsequent segments of this curve are omitted because they would be x/y equal to the end position of the previous segment.

Regardless of parameters, the control points of all the curve segments are always included (except the first position of all but the first segment, as explained above). If both parameters are zero, then only the control points are returned.

Parameters:

maxSpacing - the maximum distance between points in the constructed ILineString. A maxSpacing of zero means "no limit".

maxOffset - the maximum deviation of the constructed ILineString from this curve. A maxOffset of zero means "no limit".

Returns:

a linear approximation of this IRing as a single ILineString.