com.seisw.util.geom
Interface Poly

All Known Implementing Classes:

PolyDefault, PolySimple

public interface Poly

Poly is an interface to a complex polygon. Poly polygons can consist of multiple "inner" polygons that can be disjoint and can be considered holes.

Currently, this interface supports two concepts:

• a set of inner polygons
• a set of points of a polygon

Refactoring. This would be a good place for some refactoring to create a ComplexPoly and an InnerPoly or something so that these two concepts are broken out. One might also consider changing from an interface to an abstract class, so the methods isContributing() and setContributing() could have an access of package only. Or, the Clip algorithm could not store this information in the Poly.

Assumptions. The methods that access the polygon as though it were a set of points assume it is accessing the first polygon in the list of inner polygons. It is also assumed that inner polygons do not have more inner polygons.

Author:

Dan Bridenbecker, Solution Engineering, Inc.

Method Summary

void	add(double x, double y) Add a point to the first inner polygon.
void	add(java.awt.geom.Point2D p) Add a point to the first inner polygon.
void	add(Poly p) Add an inner polygon to this polygon - assumes that adding polygon does not have any inner polygons.
void	clear() Remove all of the points.
double	getArea() Return the area of the polygon in square units.
java.awt.geom.Rectangle2D	getBounds() Returns the bounding rectangle of this polygon.
Poly	getInnerPoly(int polyIndex) Returns the polygon at this index.
int	getNumInnerPoly() Returns the number of inner polygons - inner polygons are assumed to return one here.
int	getNumPoints() Return the number points of the first inner polygon
double	getX(int index) Return the X value of the point at the index in the first inner polygon
double	getY(int index) Return the Y value of the point at the index in the first inner polygon
Poly	intersection(Poly p) Return a Poly that is the intersection of this polygon with the given polygon.
boolean	isContributing(int polyIndex) Return true if the given inner polygon is contributing to the set operation.
boolean	isEmpty() Return true if the polygon is empty
boolean	isHole() Return true if this polygon is a hole.
void	setContributing(int polyIndex, boolean contributes) Set whether or not this inner polygon is constributing to the set operation.
void	setIsHole(boolean isHole) Set whether or not this polygon is a hole.
Poly	union(Poly p) Return a Poly that is the union of this polygon with the given polygon.
Poly	xor(Poly p) Return a Poly that is the exclusive-or of this polygon with the given polygon.

Method Detail

clear

public void clear()

Remove all of the points. Creates an empty polygon.

add

public void add(double x,
                double y)

Add a point to the first inner polygon.

add

public void add(java.awt.geom.Point2D p)

Add a point to the first inner polygon.

add

public void add(Poly p)

Add an inner polygon to this polygon - assumes that adding polygon does not have any inner polygons.

isEmpty

public boolean isEmpty()

Return true if the polygon is empty

getBounds

public java.awt.geom.Rectangle2D getBounds()

Returns the bounding rectangle of this polygon.

getInnerPoly

public Poly getInnerPoly(int polyIndex)

Returns the polygon at this index.

getNumInnerPoly

public int getNumInnerPoly()

Returns the number of inner polygons - inner polygons are assumed to return one here.

getNumPoints

public int getNumPoints()

Return the number points of the first inner polygon

getX

public double getX(int index)

Return the X value of the point at the index in the first inner polygon

getY

public double getY(int index)

Return the Y value of the point at the index in the first inner polygon

isHole

public boolean isHole()

Return true if this polygon is a hole. Holes are assumed to be inner polygons of a more complex polygon.

Throws:

java.lang.IllegalStateException - if called on a complex polygon.

setIsHole

public void setIsHole(boolean isHole)

Set whether or not this polygon is a hole. Cannot be called on a complex polygon.

Throws:

java.lang.IllegalStateException - if called on a complex polygon.

isContributing

public boolean isContributing(int polyIndex)

Return true if the given inner polygon is contributing to the set operation. This method should NOT be used outside the Clip algorithm.

setContributing

public void setContributing(int polyIndex,
                            boolean contributes)

Set whether or not this inner polygon is constributing to the set operation. This method should NOT be used outside the Clip algorithm.

intersection

public Poly intersection(Poly p)

Return a Poly that is the intersection of this polygon with the given polygon. The returned polygon could be complex.

union

public Poly union(Poly p)

Return a Poly that is the union of this polygon with the given polygon. The returned polygon could be complex.

xor

public Poly xor(Poly p)

Return a Poly that is the exclusive-or of this polygon with the given polygon. The returned polygon could be complex.

getArea

public double getArea()

Return the area of the polygon in square units.