Package arc.math.geom

Class ConvexHull

java.lang.Object

arc.math.geom.ConvexHull

public class ConvexHull
extends Object

Computes the convex hull of a set of points using the monotone chain convex hull algorithm (aka Andrew's algorithm).

Constructor Summary

Constructors

Constructor	Description
ConvexHull()

Method Summary

Modifier and Type	Method	Description
IntSeq	computeIndices(float[] polygon, boolean sorted, boolean yDown)
IntSeq	computeIndices(float[] points, int offset, int count, boolean sorted, boolean yDown)	Computes a hull the same as computePolygon(float[], int, int, boolean) but returns indices of the specified points.
IntSeq	computeIndices(FloatSeq points, boolean sorted, boolean yDown)
FloatSeq	computePolygon(float[] polygon, boolean sorted)
FloatSeq	computePolygon(float[] points, int offset, int count, boolean sorted)	Returns the convex hull polygon for the given point cloud.
FloatSeq	computePolygon(FloatSeq points, boolean sorted)

Methods inherited from class java.lang.Object

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

Constructor Details

ConvexHull

public ConvexHull()

Method Details

computePolygon

public FloatSeq computePolygon(FloatSeq points,
 boolean sorted)

See Also:

• computePolygon(float[], int, int, boolean)

computePolygon

public FloatSeq computePolygon(float[] polygon,
 boolean sorted)

See Also:

• computePolygon(float[], int, int, boolean)

computePolygon

public FloatSeq computePolygon(float[] points,
 int offset,
 int count,
 boolean sorted)

Returns the convex hull polygon for the given point cloud.

Parameters:

points - x,y pairs describing points. Duplicate points will result in undefined behavior.

sorted - If false, the points will be sorted by the x coordinate then the y coordinate, which is required by the convex hull algorithm. If sorting is done the input array is not modified and count additional working memory is needed.

Returns:

pairs of coordinates that describe the convex hull polygon in counterclockwise order. Note the returned array is reused for later calls to the same method.

computeIndices

public IntSeq computeIndices(FloatSeq points,
 boolean sorted,
 boolean yDown)

See Also:

• computeIndices(float[], int, int, boolean, boolean)

computeIndices

public IntSeq computeIndices(float[] polygon,
 boolean sorted,
 boolean yDown)

See Also:

• computeIndices(float[], int, int, boolean, boolean)

computeIndices

public IntSeq computeIndices(float[] points,
 int offset,
 int count,
 boolean sorted,
 boolean yDown)

Computes a hull the same as computePolygon(float[], int, int, boolean) but returns indices of the specified points.