javax.microedition.m3d
Class TriangleStripArray

java.lang.Object
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  +--javax.microedition.m3d.Object3D
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        +--javax.microedition.m3d.IndexBuffer
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              +--javax.microedition.m3d.TriangleStripArray

public class TriangleStripArray

extends IndexBuffer

TriangleStripArray defines a set of triangle strips. In a triangle strip, the first three vertex indices define the first triangle. Each subsequent index defines a new triangle, along with the two previous indices. For example, the strip S = (2, 0, 1, 4) defines two triangles: (2, 0, 1) and (0, 1, 4).

Triangle strip indices may be explicitly defined, as in the example above, or they may be implicit. In an implicit TriangleStripArray, only the first index of the first strip is specified. All subsequent indices are one greater than their predecessor. For example, if there are two strips with lengths 3 and 4, and the initial index is 10, the strips are formed as follows: S₁ = (10, 11, 12) and S₂ = (13, 14, 15, 16).

Explicit triangle strips may contain so-called degenerate triangles, that have the same index specified for two or three vertices. Degenerate triangles often result from merging multiple strips into one at content authoring stage. Degenerate triangles are not rendered.

See Also:

Binary format

Field Summary

Fields inherited from class javax.microedition.m3d.Object3D

userObject

Constructor Summary

TriangleStripArray(int[] indices, int[] stripLengths)
Constructs a triangle strip array with explicit indices.

TriangleStripArray(int firstIndex, int[] stripLengths)
Constructs a triangle strip array with implicit indices.

Methods inherited from class javax.microedition.m3d.Object3D

addAnimationTrack, animate, clone, find, getAnimationTrack, getAnimationTrackCount, getReferences, getUserID, removeAnimationTrack, setUserID

Methods inherited from class java.lang.Object

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

Constructor Detail

TriangleStripArray

public TriangleStripArray(int firstIndex,
                          int[] stripLengths)

Constructs a triangle strip array with implicit indices. The first index of the first strip is specified, along with the lengths of the individual strips.

Parameters:

firstIndex - index of the initial vertex of the first strip

stripLengths - array of per-strip vertex counts to be copied in

Throws:

java.lang.IllegalArgumentException - if stripLengths is empty

java.lang.IllegalArgumentException - if any element in stripLengths is less than 3

TriangleStripArray

public TriangleStripArray(int[] indices,
                          int[] stripLengths)

Constructs a triangle strip array with explicit indices. An array of indices is specified, along with the lengths of the individual strips. The combined length of the strips must not exceed the number of elements in the index array. The contents of both arrays are copied in.

Parameters:

indices - array of indices to be copied in

stripLengths - array of per-strip index counts to be copied in

Throws:

java.lang.IllegalArgumentException - if stripLengths is empty

java.lang.IllegalArgumentException - if any element in stripLengths is less than 3

java.lang.IllegalArgumentException - if any element in indices is negative

java.lang.IllegalArgumentException - if indices.length < sum(stripLengths)