com.sun.j3d.utils.geometry.compression

Class GeneralizedStrip

java.lang.Object

com.sun.j3d.utils.geometry.compression.GeneralizedStrip

 class GeneralizedStrip
extends java.lang.Object

This class provides static methods to support topological transformations on generalized strips. This is used by the GeometryDecompressor. These methods only need to look at the vertex replacement flags to determine how the vertices in the strip are connected. The connections are rearranged in different ways to transform generalized strips to GeometryArray representations.

See Also:

GeneralizedStripFlags, GeneralizedVertexList, GeometryDecompressor

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
(package private) static class	GeneralizedStrip.IntList The IntList is like an ArrayList, but avoids the Integer object wrapper and accessor overhead for simple lists of ints.
(package private) static class	GeneralizedStrip.StripArray The StripArray class is used as the output of some conversion methods in the GeneralizedStrip class.

Field Summary

Fields

Modifier and Type	Field and Description
private static int	CCW
private static int	CW
private static boolean	debug
private static int	REPLACE_MIDDLE
private static int	REPLACE_OLDEST
private static int	RESTART_CCW
private static int	RESTART_CW

Constructor Summary

Constructors

Constructor and Description
GeneralizedStrip()

Method Summary

Methods

Modifier and Type	Method and Description
private static void	addFan(GeneralizedStrip.IntList fanVerts, GeneralizedStrip.IntList fanCounts, int start, int length, int frontFace, int winding, boolean transition)
private static void	addStrip(GeneralizedStrip.IntList stripVerts, GeneralizedStrip.IntList stripCounts, int start, int length, int frontFace, int winding)
(package private) static int[]	fansToTriangles(int[] stripCounts) Breaks up triangle fans into separate triangles.
private static int	fansToTriangles(int tstart, int[] tbuff, int vstart, int[] vertices, int stripStart, int[] stripCounts, int stripCount)
(package private) static GeneralizedStrip.StripArray	fanToStrips(int v, int length, int[] fans, boolean convexPlanar) Takes a fan and converts it to one or more strips.
private static void	fanToStrips(int v, int length, int[] fans, GeneralizedStrip.IntList stripVerts, GeneralizedStrip.IntList stripCounts, boolean convexPlanar)
(package private) static int	getLineCount(int[] stripCounts) Counts the number of lines defined by arrays of line strips.
(package private) static int	getTriangleCount(GeneralizedStrip.IntList stripCounts) Counts the number of triangles defined by arrays of triangle strips or fans.
(package private) static int	getTriangleCount(int[] stripCounts) Counts the number of triangles defined by arrays of triangle strips or fans.
(package private) static int[]	stripsToTriangles(int[] stripCounts) Breaks up triangle strips into separate triangles.
private static int	stripsToTriangles(int tstart, int[] tbuff, int vstart, int[] vertices, int stripStart, int[] stripCounts, int stripCount)
(package private) static GeneralizedStrip.StripArray	toLineStrips(GeneralizedStripFlags vertices) Interprets the vertex flags associated with a class implementing GeneralizedStripFlags, constructing and returning a StripArray.
(package private) static GeneralizedStrip.StripArray[]	toStripsAndFans(GeneralizedStripFlags vertices, int frontFace) Interprets the vertex flags associated with a class implementing GeneralizedStripFlags, constructing and returning a 2-element array of StripArray objects.
private static void	toStripsAndFans(GeneralizedStripFlags vertices, int frontFace, GeneralizedStrip.IntList stripVerts, GeneralizedStrip.IntList stripCounts, GeneralizedStrip.IntList fanVerts, GeneralizedStrip.IntList fanCounts)
(package private) static GeneralizedStrip.StripArray[]	toStripsAndTriangles(GeneralizedStripFlags vertices, int frontFace, int shortStripSize, int maxShortStrips) Interprets the vertex flags associated with a class implementing GeneralizedStripFlags, constructing and returning a 2-element array of StripArray objects.
(package private) static int[]	toTriangles(GeneralizedStripFlags vertices, int frontFace) Interprets the vertex flags associated with a class implementing GeneralizedStripFlags, constructing and returning an array of vertex references representing the original generalized strip as individual triangles.
(package private) static GeneralizedStrip.StripArray	toTriangleStrips(GeneralizedStripFlags vertices, int frontFace) Interprets the vertex flags associated with a class implementing GeneralizedStripFlags, constructing and returning a StripArray containing exclusively strips.

Methods inherited from class java.lang.Object

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

Field Detail

debug

private static final boolean debug

See Also:

Constant Field Values

CW

private static final int CW

See Also:

Constant Field Values

CCW

private static final int CCW

See Also:

Constant Field Values

RESTART_CW

private static final int RESTART_CW

See Also:

Constant Field Values

RESTART_CCW

private static final int RESTART_CCW

See Also:

Constant Field Values

REPLACE_MIDDLE

private static final int REPLACE_MIDDLE

See Also:

Constant Field Values

REPLACE_OLDEST

private static final int REPLACE_OLDEST

See Also:

Constant Field Values

Constructor Detail

GeneralizedStrip

GeneralizedStrip()

Method Detail

toStripsAndFans

static GeneralizedStrip.StripArray[] toStripsAndFans(GeneralizedStripFlags vertices,
                                            int frontFace)

Interprets the vertex flags associated with a class implementing GeneralizedStripFlags, constructing and returning a 2-element array of StripArray objects. The first StripArray will contain triangle strips and the second will contain triangle fans.

Parameters:

vertices - an object implementing GeneralizedStripFlags

frontFace - a flag, either GeneralizedStripFlags.FRONTFACE_CW or GeneralizedStripFlags.FRONTFACE_CCW, indicating front face winding

Returns:

a 2-element array containing strips in 0 and fans in 1

toStripsAndFans

private static void toStripsAndFans(GeneralizedStripFlags vertices,
                   int frontFace,
                   GeneralizedStrip.IntList stripVerts,
                   GeneralizedStrip.IntList stripCounts,
                   GeneralizedStrip.IntList fanVerts,
                   GeneralizedStrip.IntList fanCounts)

addStrip

private static void addStrip(GeneralizedStrip.IntList stripVerts,
            GeneralizedStrip.IntList stripCounts,
            int start,
            int length,
            int frontFace,
            int winding)

addFan

private static void addFan(GeneralizedStrip.IntList fanVerts,
          GeneralizedStrip.IntList fanCounts,
          int start,
          int length,
          int frontFace,
          int winding,
          boolean transition)

toTriangleStrips

static GeneralizedStrip.StripArray toTriangleStrips(GeneralizedStripFlags vertices,
                                           int frontFace)

Interprets the vertex flags associated with a class implementing GeneralizedStripFlags, constructing and returning a StripArray containing exclusively strips.

Parameters:

vertices - an object implementing GeneralizedStripFlags

frontFace - a flag, either GeneralizedStripFlags.FRONTFACE_CW or GeneralizedStripFlags.FRONTFACE_CCW, indicating front face winding

Returns:

a StripArray containing the converted strips

fanToStrips

private static void fanToStrips(int v,
               int length,
               int[] fans,
               GeneralizedStrip.IntList stripVerts,
               GeneralizedStrip.IntList stripCounts,
               boolean convexPlanar)

toTriangles

static int[] toTriangles(GeneralizedStripFlags vertices,
                int frontFace)

Interprets the vertex flags associated with a class implementing GeneralizedStripFlags, constructing and returning an array of vertex references representing the original generalized strip as individual triangles. Each sequence of three consecutive vertex references in the output defines a single triangle.

Parameters:

vertices - an object implementing GeneralizedStripFlags

frontFace - a flag, either GeneralizedStripFlags.FRONTFACE_CW or GeneralizedStripFlags.FRONTFACE_CCW, indicating front face winding

Returns:

an array of indices into the original vertex array

stripsToTriangles

private static int stripsToTriangles(int tstart,
                    int[] tbuff,
                    int vstart,
                    int[] vertices,
                    int stripStart,
                    int[] stripCounts,
                    int stripCount)

fansToTriangles

private static int fansToTriangles(int tstart,
                  int[] tbuff,
                  int vstart,
                  int[] vertices,
                  int stripStart,
                  int[] stripCounts,
                  int stripCount)

toStripsAndTriangles

static GeneralizedStrip.StripArray[] toStripsAndTriangles(GeneralizedStripFlags vertices,
                                                 int frontFace,
                                                 int shortStripSize,
                                                 int maxShortStrips)

Interprets the vertex flags associated with a class implementing GeneralizedStripFlags, constructing and returning a 2-element array of StripArray objects. The first StripArray will contain triangle strips and the second will contain individual triangles in the vertices field. Short strips will be converted to individual triangles.

Parameters:

vertices - an object implementing GeneralizedStripFlags

frontFace - a flag, either GeneralizedStripFlags.FRONTFACE_CW or GeneralizedStripFlags.FRONTFACE_CCW, indicating front face winding

shortStripSize - strips this size or less will be converted to individual triangles if there are more than maxShortStrips of them

maxShortStrips - maximum number of short strips allowed before creating individual triangles

Returns:

a 2-element array containing strips in 0 and triangles in 1

toLineStrips

static GeneralizedStrip.StripArray toLineStrips(GeneralizedStripFlags vertices)

Interprets the vertex flags associated with a class implementing GeneralizedStripFlags, constructing and returning a StripArray. RESTART_CW and RESTART_CCW are treated as equivalent, as are REPLACE_MIDDLE and REPLACE_OLDEST.

Parameters:

vertices - an object implementing GeneralizedStripFlags

Returns:

a StripArray representing an array of line strips

getLineCount

static int getLineCount(int[] stripCounts)

Counts the number of lines defined by arrays of line strips.

Parameters:

stripCounts - array of strip counts, as used by the GeometryStripArray object

Returns:

number of lines in the strips

getTriangleCount

static int getTriangleCount(int[] stripCounts)

Counts the number of triangles defined by arrays of triangle strips or fans.

Parameters:

stripCounts - array of strip counts, as used by the GeometryStripArray object

Returns:

number of triangles in the strips or fans

getTriangleCount

static int getTriangleCount(GeneralizedStrip.IntList stripCounts)

Counts the number of triangles defined by arrays of triangle strips or fans.

Parameters:

stripCounts - IntList of strip counts

Returns:

number of triangles in the strips or fans

stripsToTriangles

static int[] stripsToTriangles(int[] stripCounts)

Breaks up triangle strips into separate triangles.

Parameters:

stripCounts - array of strip counts, as used by the GeometryStripArray object

Returns:

array of ints which index into the original vertex array; each set of three consecutive vertex indices defines a single triangle

fansToTriangles

static int[] fansToTriangles(int[] stripCounts)

Breaks up triangle fans into separate triangles.

Parameters:

stripCounts - array of strip counts, as used by the GeometryStripArray object

Returns:

array of ints which index into the original vertex array; each set of three consecutive vertex indices defines a single triangle

fanToStrips

static GeneralizedStrip.StripArray fanToStrips(int v,
                                      int length,
                                      int[] fans,
                                      boolean convexPlanar)

Takes a fan and converts it to one or more strips.

Parameters:

v - index into the fans array of the first vertex in the fan

length - number of vertices in the fan

fans - array of vertex indices representing one or more fans

convexPlanar - if true indicates that the fan is convex and planar; such fans will always be converted into a single strip

Returns:

a StripArray containing the converted strips