Package org.apache.commons.math3.geometry.euclidean.twod

Class NestedLoops

java.lang.Object

org.apache.commons.math3.geometry.euclidean.twod.NestedLoops

class NestedLoops
extends java.lang.Object

This class represent a tree of nested 2D boundary loops.

This class is used for piecewise polygons construction. Polygons are built using the outline edges as representative of boundaries, the orientation of these lines are meaningful. However, we want to allow the user to specify its outline loops without having to take care of this orientation. This class is devoted to correct mis-oriented loops.

Orientation is computed assuming the piecewise polygon is finite, i.e. the outermost loops have their exterior side facing points at infinity, and hence are oriented counter-clockwise. The orientation of internal loops is computed as the reverse of the orientation of their immediate surrounding loop.

Since:

3.0

Field Summary

Fields

Modifier and Type	Field	Description
private Vector2D[]	loop	Boundary loop.
private boolean	originalIsClockwise	Indicator for original loop orientation.
private Region<Euclidean2D>	polygon	Polygon enclosing a finite region.
private java.util.List<NestedLoops>	surrounded	Surrounded loops.
private double	tolerance	Tolerance below which points are considered identical.

Constructor Summary

Constructors

Modifier	Constructor	Description
(package private)	NestedLoops(double tolerance)	Simple Constructor.
private	NestedLoops(Vector2D[] loop, double tolerance)	Constructor.

Method Summary

Modifier and Type	Method	Description
private void	add(NestedLoops node)	Add a loop in a tree.
void	add(Vector2D[] bLoop)	Add a loop in a tree.
void	correctOrientation()	Correct the orientation of the loops contained in the tree.
private void	setClockWise(boolean clockwise)	Set the loop orientation.

Methods inherited from class java.lang.Object

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

Field Detail

loop

private Vector2D[] loop

Boundary loop.

surrounded

private java.util.List<NestedLoops> surrounded

Surrounded loops.

polygon

private Region<Euclidean2D> polygon

Polygon enclosing a finite region.

originalIsClockwise

private boolean originalIsClockwise

Indicator for original loop orientation.

tolerance

private final double tolerance

Tolerance below which points are considered identical.

Constructor Detail

NestedLoops

NestedLoops(double tolerance)

Simple Constructor.

Build an empty tree of nested loops. This instance will become the root node of a complete tree, it is not associated with any loop by itself, the outermost loops are in the root tree child nodes.

Parameters:

tolerance - tolerance below which points are considered identical

Since:

3.3

NestedLoops

private NestedLoops(Vector2D[] loop,
                    double tolerance)
             throws MathIllegalArgumentException

Constructor.

Build a tree node with neither parent nor children

Parameters:

loop - boundary loop (will be reversed in place if needed)

tolerance - tolerance below which points are considered identical

Throws:

MathIllegalArgumentException - if an outline has an open boundary loop

Since:

3.3

Method Detail

add

public void add(Vector2D[] bLoop)
         throws MathIllegalArgumentException

Add a loop in a tree.

Parameters:

bLoop - boundary loop (will be reversed in place if needed)

Throws:

MathIllegalArgumentException - if an outline has crossing boundary loops or open boundary loops

add

private void add(NestedLoops node)
          throws MathIllegalArgumentException

Add a loop in a tree.

Parameters:

node - boundary loop (will be reversed in place if needed)

Throws:

MathIllegalArgumentException - if an outline has boundary loops that cross each other

correctOrientation

public void correctOrientation()

Correct the orientation of the loops contained in the tree.

This is this method that really inverts the loops that where provided through the add method if they are mis-oriented

setClockWise

private void setClockWise(boolean clockwise)

Set the loop orientation.

Parameters:

clockwise - if true, the loop should be set to clockwise orientation