libGDX 1.14.2 · com.badlogic.gdx.math.EarClippingTriangulator

A simple implementation of the ear cutting algorithm to triangulate simple polygons without holes. For more information:

If the input polygon is not simple (self-intersects), there will be output but it is of unspecified quality (garbage in, garbage out).

If the polygon vertices are very large or very close together then GeometryUtils#isClockwise(float[], int, int) may not be able to properly assess the winding (because it uses floats). In that case the vertices should be adjusted, eg by finding the smallest X and Y values and subtracting that from each vertex.

Field Summary

Modifier and Type	Field and Description
private static final int	CONCAVE
private static final int	CONVEX
private short[]	indices
private final ShortArray	indicesArray
private final ShortArray	triangles
private int	vertexCount
private final IntArray	vertexTypes
private float[]	vertices

Constructor Summary

Access	Constructor and Description
public	EarClippingTriangulator()

Method Summary

Modifier and Type	Method and Description
private int	classifyVertex(int index) Returns: `CONCAVE` or `CONVEX`
private static int	computeSpannedAreaSign(float p1x, float p1y, float p2x, float p2y, float p3x, float p3y)
public ShortArray	computeTriangles(FloatArray vertices)
public ShortArray	computeTriangles(float[] vertices)
public ShortArray	Returns: triples of triangle indices in clockwise order. Note the returned array is reused for later calls to the same method. computeTriangles(float[] pairs describing vertices of the polygon, in either clockwise or counterclockwise order. vertices, int offset, int count) Triangulates the given (convex or concave) simple polygon to a list of triangle vertices.
private void	cutEarTip(int earTipIndex)
private int	findEarTip()
private boolean	isEarTip(int earTipIndex)
private int	nextIndex(int index)
private int	previousIndex(int index)
private void	triangulate()

Inherited from java.lang.Object:: clone equals finalize getClass hashCode notify notifyAll toString wait wait wait

Field Detail

CONCAVE	back to summary
private static final int CONCAVE

CONVEX	back to summary
private static final int CONVEX

indices	back to summary
private short[] indices

indicesArray	back to summary
private final ShortArray indicesArray

triangles	back to summary
private final ShortArray triangles

vertexCount	back to summary
private int vertexCount

vertexTypes	back to summary
private final IntArray vertexTypes

vertices	back to summary
private float[] vertices

Constructor Detail

EarClippingTriangulator	back to summary
public EarClippingTriangulator()

Method Detail

classifyVertex	back to summary
private int classifyVertex(int index) Returns:int `CONCAVE` or `CONVEX`

computeSpannedAreaSign	back to summary
private static int computeSpannedAreaSign(float p1x, float p1y, float p2x, float p2y, float p3x, float p3y)

computeTriangles	back to summary
public ShortArray computeTriangles(FloatArray vertices) See Also `computeTriangles(float[], int, int)`

computeTriangles	back to summary
public ShortArray computeTriangles(float[] vertices) See Also `computeTriangles(float[], int, int)`

computeTriangles	back to summary
public ShortArray computeTriangles(float[] vertices, int offset, int count) Triangulates the given (convex or concave) simple polygon to a list of triangle vertices. Parameters vertices:float[] pairs describing vertices of the polygon, in either clockwise or counterclockwise order. Returns:ShortArray triples of triangle indices in clockwise order. Note the returned array is reused for later calls to the same method.

computeTriangles

back to summary

public ShortArray computeTriangles(float[] vertices, int offset, int count)

Triangulates the given (convex or concave) simple polygon to a list of triangle vertices.

Parameters

vertices:float[]: pairs describing vertices of the polygon, in either clockwise or counterclockwise order.

Returns:ShortArray

triples of triangle indices in clockwise order. Note the returned array is reused for later calls to the same method.

cutEarTip	back to summary
private void cutEarTip(int earTipIndex)

findEarTip	back to summary
private int findEarTip()

isEarTip	back to summary
private boolean isEarTip(int earTipIndex)

nextIndex	back to summary
private int nextIndex(int index)

previousIndex	back to summary
private int previousIndex(int index)

triangulate	back to summary
private void triangulate()