org.tinfour.contour

Class ContourRegion

java.lang.Object

org.tinfour.contour.ContourRegion

public class ContourRegion
extends Object

Provides a elements and access methods for a region created through a contour-building process.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	ContourRegion.ContourRegionType An enumeration that indicates the type of a contour region.

Method Summary

Modifier and Type	Method and Description
double	getAbsoluteArea() Gets the absolute value of the overall area of the region.
double	getAdjustedArea() Get the area for the region excluding that of any enclosed regions.
double	getArea() Gets the signed area of the region.
ContourRegion.ContourRegionType	getContourRegionType() Gets an enumerated value indicating what kind of contour region this instance represents.
List<ContourRegion>	getEnclosedRegions() Gets a list of regions that are enclosed by this region.
Path2D	getPath2D(AffineTransform transform) Gets a Path2D suitable for rendering purposes including both the outer polygon and any internal (nested child) polygons.
Path2D	getPath2DWithoutNesting(AffineTransform transform) Gets a Path2D suitable for rendering purposes.
int	getRegionIndex() Gets the index of the region.
Point2D	getTestPoint() Gets a point lying on one of the segments in the region to support testing for polygon enclosures.
double[]	getXY() Get the XY coordinates for the contour region.
boolean	isPointInsideRegion(double[] xy, double x, double y) Indicates whether the specified point is inside a closed polygon.
boolean	isPointInsideRegion(double x, double y) Indicates whether the specified point is inside the region
String	toString()

Methods inherited from class java.lang.Object

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

Method Detail

getXY

public double[] getXY()

Get the XY coordinates for the contour region. Coordinates are stored in a one-dimensional array of doubles in the order:

 { (x0,y0), (x1,y1), (x2,y2), etc. }.

Returns:

a safe copy of the geometry of the contour region.

isPointInsideRegion

public boolean isPointInsideRegion(double x,
                                   double y)

Indicates whether the specified point is inside the region

Parameters:

x - the Cartesian coordinate for the point of interest

y - the Cartesian coordinate for the point of interest

Returns:

true if the point is inside the contour; otherwise, fakse

isPointInsideRegion

public boolean isPointInsideRegion(double[] xy,
                                   double x,
                                   double y)

Indicates whether the specified point is inside a closed polygon.

Parameters:

xy - an array giving the Cartesian coordinates of the closed, simple polygon for the region to be tested.

x - the Cartesian coordinate for the point of interest

y - the Cartesian coordinate for the point of interest

Returns:

true if the point is inside the contour; otherwise, fakse

getAbsoluteArea

public double getAbsoluteArea()

Gets the absolute value of the overall area of the region. No adjustment is made for enclosed regions.

Returns:

a positive value.

getAdjustedArea

public double getAdjustedArea()

Get the area for the region excluding that of any enclosed regions. The enclosed regions are not, strictly speaking, part of this region and, so, are not included in the adjusted area.

Returns:

a positive value.

getArea

public double getArea()

Gets the signed area of the region. If the points that specify the region are given in a counter-clockwise order, the region will have a positive area. If the points are given in a clockwise order, the region will have a negative area.

Returns:

a signed real value.

getRegionIndex

public int getRegionIndex()

Gets the index of the region. The indexing scheme is based on the original values of the zContour array used when the contour regions were built. The minimum proper region index is zero.

At this time, regions are not constructed for areas of null data. In future implementations, null-data regions will be indicated by a region index of -1.

Returns:

a positive integer value, or -1 for null-data regions.

getPath2DWithoutNesting

public Path2D getPath2DWithoutNesting(AffineTransform transform)

Gets a Path2D suitable for rendering purposes. The path includes only the outer polygon for the region and does not include the internal (nested) polygons. Because the contour builder class sorts polygons by descending area, this method will general attain the same effect as the conventional getPath2D() call when rendering the full set of regions. However, this method is not suitable in cases where interior regions are to be omitted or filled with a semi-transparent color.

Parameters:

transform - a valid AffineTransform, typically specified to map the Cartesian coordinates of the contour to pixel coordinate.

Returns:

a valid instance

getPath2D

public Path2D getPath2D(AffineTransform transform)

Gets a Path2D suitable for rendering purposes including both the outer polygon and any internal (nested child) polygons. In used for fill operations, regions that include nested child regions will be rendered with "holes" where the child polygons are indicated.

Parameters:

transform - a valid AffineTransform, typically specified to map the Cartesian coordinates of the contour to pixel coordinate.

Returns:

a valid instance

getTestPoint

public Point2D getTestPoint()

Gets a point lying on one of the segments in the region to support testing for polygon enclosures. Note that the test point is never one of the vertices of the segment.

Returns:

a valid instance of a Point2D object

getEnclosedRegions

public List<ContourRegion> getEnclosedRegions()

Gets a list of regions that are enclosed by this region. This list includes only those regions that are immediately enclosed by this region, but does not include any that may be "nested" within the enclosed regions.

Returns:

a valid, potentially empty, list.

getContourRegionType

public ContourRegion.ContourRegionType getContourRegionType()

Gets an enumerated value indicating what kind of contour region this instance represents.

Returns:

a valid enumeration.

toString

public String toString()

Overrides:

toString in class Object