de.grogra.imp3d

Class PolygonArray

java.lang.Object

de.grogra.imp3d.VertexArray

de.grogra.imp3d.PolygonArray

All Implemented Interfaces:

Mesh

public class PolygonArray
extends VertexArray
implements Mesh

This class represents a list of polygons.

Author:

Ole Kniemeyer

Field Summary

Fields

Modifier and Type	Field and Description
boolean	closed Indicates whether this polygon is a closed surface or not.
int	edgeCount Defines the number of edges of the polygons in this list.
ByteList	normals This list contains the (unnormalized) normal vectors.
boolean	planar Flag indicating whether the polygons are planar.
IntList	polygonNormals Specifies the normal indices of polygons if usePolygonNormals is true.
IntList	polygons Specifies the polygons.
boolean	usePolygonNormals Indicates whether normal indices are specified separately by polygonNormals or just like the other indices by polygons.
FloatList	uv This list contains the uv coordinates.
int	visibleSides Enumeration value indicating the visible polygon sides.

Fields inherited from class de.grogra.imp3d.VertexArray

dimension, userObject, vertices

Constructor Summary

Constructors

Constructor and Description
PolygonArray()

Method Summary

Methods

Modifier and Type	Method and Description
void	computeNormals() Compute normal vector for every vertex.
void	copyNormal(int from, int to) Copies a vector in the list of normal vectors.
void	freeArrays()
int	getMaxEdgeCount() Returns the maximum number of edges of a single polygon of the mesh.
void	getNormal(float[] out, int index) Reads the value of the normal vector at index and places it in out.
void	getNormal(int index, Tuple3d out) Gets the normal vector of normal index.
int	getNormalCount() Returns the number of normals of the mesh.
int	getPolygon(int index, int[] indicesOut, int[] normalsOut) Writes the vertex indices of polygon index to indicesOut and the normal indices to normalsOut and returns the number of vertices of the polygon.
int	getPolygonCount() Returns the number of polygons of the mesh.
void	getUV(int index, Tuple2d out) Gets the uv coordinates of vertex index.
void	getVertex(int index, Tuple3d out) Gets the spatial vertex coordinates of vertex index.
int	getVertexCount() Returns the number of vertices of the mesh.
boolean	isClosed() Indicates whether this mesh is a closed surface or not.
boolean	isPolygonPlanar(int index) Returns true iff the polygon number index is planar.
void	setNormal(int index, float x, float y, float z) Sets a normal vector.

Methods inherited from class de.grogra.imp3d.VertexArray

addVertex, addVertex, addVertex, computeNormal, init, wasCleared

Methods inherited from class java.lang.Object

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

Field Detail

closed

public boolean closed

Indicates whether this polygon is a closed surface or not. If it is closed, normal vectors have to point to the exterior.

edgeCount

public int edgeCount

Defines the number of edges of the polygons in this list. All polygons have the same number of edges. edgeCount may only be 3 (triangles) or 4 (quadrilaterals).

normals

public ByteList normals

This list contains the (unnormalized) normal vectors. The components are contained contiguously, with three byte-values for each vertex. Each byte-value c is to be interpreted as a floating-point vector component f in the range [-1, 1] using the formula f = (2 c + 1) / 255

planar

public boolean planar

Flag indicating whether the polygons are planar. In the case of triangles, this is always the case. In the case of quadrilaterals, it is guaranteed that each quadrilateral will be planar (all vertices lie on a plane) if planar is true.

polygonNormals

public IntList polygonNormals

Specifies the normal indices of polygons if usePolygonNormals is true. For each entry in polygons, i.e., a vertex, a corresponding entry has to be present which defines the index into normals.

polygons

public IntList polygons

Specifies the polygons. Each polygon is represented by a contiguous sequence of edgeCount indices into the other arrays (however note that if usePolygonNormals is true, normal indices are specified by polygonNormals). The polygons are placed one after another without space inbetween.

usePolygonNormals

public boolean usePolygonNormals

Indicates whether normal indices are specified separately by polygonNormals or just like the other indices by polygons.

uv

public FloatList uv

This list contains the uv coordinates. The coordinates are contained contiguously, with two float-values for each vertex.

visibleSides

public int visibleSides

Enumeration value indicating the visible polygon sides. If this value is Attributes.VISIBLE_SIDES_FRONT, only front sides (as defined by the counter-clockwise order of vertices) are visible. If this is Attributes.VISIBLE_SIDES_BACK, only back sides are visible. For Attributes.VISIBLE_SIDES_BOTH, both sides are visible.

Constructor Detail

PolygonArray

public PolygonArray()

Method Detail

computeNormals

public void computeNormals()

Compute normal vector for every vertex.

copyNormal

public void copyNormal(int from,
              int to)

Copies a vector in the list of normal vectors.

Parameters:

from - the source index

to - the target index

freeArrays

public void freeArrays()

Overrides:

freeArrays in class VertexArray

getMaxEdgeCount

public int getMaxEdgeCount()

Description copied from interface: Mesh

Returns the maximum number of edges of a single polygon of the mesh.

Specified by:

getMaxEdgeCount in interface Mesh

Returns:

maximum number of edges

getNormal

public void getNormal(float[] out,
             int index)

Reads the value of the normal vector at index and places it in out.

Parameters:

out - the result will be placed in here

index - the index of the normal vector (note that the actual index into normals is 3 * index)

getNormal

public void getNormal(int index,
             Tuple3d out)

Description copied from interface: Mesh

Gets the normal vector of normal index. The normal vector is not necessarily normalized.

Specified by:

getNormal in interface Mesh

Parameters:

index - normal number

out - normal vector will be placed in here

getNormalCount

public int getNormalCount()

Description copied from interface: Mesh

Returns the number of normals of the mesh.

Specified by:

getNormalCount in interface Mesh

Returns:

number of normals

getPolygon

public int getPolygon(int index,
             int[] indicesOut,
             int[] normalsOut)

Description copied from interface: Mesh

Writes the vertex indices of polygon index to indicesOut and the normal indices to normalsOut and returns the number of vertices of the polygon. If the mesh is closed (see Mesh.isClosed()), inside and outside are determined by the ordering of the vertices: when seen from the outside, vertices have to be oriented in a counter-clockwise manner. Then also the normal vectors have to point to the outside.

Specified by:

getPolygon in interface Mesh

Parameters:

index - polygon number

indicesOut - the vertex indices will be placed in here

normalsOut - the normal indices will be placed in here

Returns:

number of vertex indices of polygon

getPolygonCount

public int getPolygonCount()

Description copied from interface: Mesh

Returns the number of polygons of the mesh.

Specified by:

getPolygonCount in interface Mesh

Returns:

number of polygons

getUV

public void getUV(int index,
         Tuple2d out)

Description copied from interface: Mesh

Gets the uv coordinates of vertex index.

Specified by:

getUV in interface Mesh

Parameters:

index - vertex number

out - uv coordinates will be placed in here

getVertex

public void getVertex(int index,
             Tuple3d out)

Description copied from interface: Mesh

Gets the spatial vertex coordinates of vertex index.

Specified by:

getVertex in interface Mesh

Parameters:

index - vertex number

out - vertex coordinates will be placed in here

getVertexCount

public int getVertexCount()

Description copied from interface: Mesh

Returns the number of vertices of the mesh.

Specified by:

getVertexCount in interface Mesh

Returns:

number of vertices

isClosed

public boolean isClosed()

Description copied from interface: Mesh

Indicates whether this mesh is a closed surface or not. If it is closed, normal vectors have to point to the exterior.

Specified by:

isClosed in interface Mesh

Returns:

is surface closed?

isPolygonPlanar

public boolean isPolygonPlanar(int index)

Description copied from interface: Mesh

Returns true iff the polygon number index is planar.

Specified by:

isPolygonPlanar in interface Mesh

Parameters:

index - polygon number

Returns:

is polygon planar?

setNormal

public void setNormal(int index,
             float x,
             float y,
             float z)

Sets a normal vector. The vector is rescaled so that the maximum of the absolute values of its components is one.

Parameters:

index - the index of the normal vector (note that the actual index into normals is 3 * index)

x - the x-component

y - the y-component

z - the z-component