de.grogra.vecmath.geom
Class CSGUnion

java.lang.Object
  de.grogra.vecmath.geom.VolumeBase
      de.grogra.vecmath.geom.CompoundVolume
          de.grogra.vecmath.geom.UnionBase
              de.grogra.vecmath.geom.CSGUnion

All Implemented Interfaces:

Volume

public class CSGUnion
extends UnionBase

An instance of this class represents the union of a list of volumes as defined by Constructive Solid Geometry.

Author:

Ole Kniemeyer

Field Summary

Fields inherited from class de.grogra.vecmath.geom.CompoundVolume

volumes

Constructor Summary

CSGUnion()
Creates a new CSGUnion whose list of volumes is empty.

CSGUnion(Volume a, Volume b)
Creates a new CSGUnion whose list of volumes is set to [a, b].

Method Summary

boolean	computeIntersections(Line line, int which, IntersectionList list, Intersection excludeStart, Intersection excludeEnd) Computes intersections between the boundary surface of this object and the specified line.
Volume	operator$or(Volume v) This operator method creates the union of this volume and v.

Methods inherited from class de.grogra.vecmath.geom.UnionBase

contains, getExtent

Methods inherited from class de.grogra.vecmath.geom.CompoundVolume

boxContainsBoundary, computeNormal, computeTangents, computeUV

Methods inherited from class de.grogra.vecmath.geom.VolumeBase

addConvexIntersections, getId, operator$and, operator$com, operator$sub, setId

Methods inherited from class java.lang.Object

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

Constructor Detail

CSGUnion

public CSGUnion()

Creates a new CSGUnion whose list of volumes is empty.

CSGUnion

public CSGUnion(Volume a,
                Volume b)

Creates a new CSGUnion whose list of volumes is set to [a, b].

Method Detail

computeIntersections

public boolean computeIntersections(Line line,
                                    int which,
                                    IntersectionList list,
                                    Intersection excludeStart,
                                    Intersection excludeEnd)

Description copied from interface: Volume

Computes intersections between the boundary surface of this object and the specified line. The intersections are added to list in ascending order of distance (i.e., of Intersection.parameter), where the parameter has to lie between line.start and line.end. Implementations of this method must not clear or modify the existing intersections in list.

The parameter which has to be one of Intersection.ALL, Intersection.CLOSEST, Intersection.ANY. It determines if all intersections have to be added to the list, only the closest (minimal value of Intersection.parameter), or an arbitrary of the set of all intersections. Only in case of ALL, the return value of this method is precise.

If specific intersection points should be excluded from the list of computed intersections, they have to be specified in excludeStart and excludeEnd. The intersection point of excludeStart has to be the starting point of line, the intersection point of excludeEnd has to be the end point of line. The exclusion of intersections is a useful feature for ray-tracing, e.g., when a ray is re-emitted at an intersection point in another direction.

Parameters:

line - a line

which - one of Intersection.ALL, Intersection.CLOSEST, Intersection.ANY, this determines which intersections have to be added to list

list - the intersections are added to this list

excludeStart - intersection at start point which shall be excluded, or null

excludeEnd - intersection at end point which shall be excluded, or null

Returns:

true iff the beginning of the line lies within the volume (i.e., if the line starts within the volume or enters the volume at the starting point); however note that the returned value is valid only if which == Intersection.ALL

operator$or

public Volume operator$or(Volume v)

Description copied from interface: Volume

This operator method creates the union of this volume and v.

Specified by:

operator$or in interface Volume

Overrides:

operator$or in class VolumeBase

Parameters:

v - a volume

Returns:

the union of this volume and v

See Also:

CSGUnion