org.sunflow.math

Class BoundingBox


public class BoundingBox
extends java.lang.Object

3D axis-aligned bounding box. Stores only the minimum and maximum corner points.

Constructor Summary

BoundingBox()
Creates an empty box.
BoundingBox(float size)
Creates a bounding box centered around the origin.
BoundingBox(float x, float y, float z)
Creates a bounding box containing only the specified point.
BoundingBox(BoundingBox b)
Creates a copy of the given box.
BoundingBox(Point3 p)
Creates a bounding box containing only the specified point.

Method Summary

boolean
contains(float x, float y, float z)
Check to see if the specified point is inside the volume defined by this box.
boolean
contains(Point3 p)
Checks to see if the specified pointis inside the volume defined by this box.
void
enlargeUlps()
Enlarge the bounding box by the minimum possible amount to avoid numeric precision related problems.
float
getArea()
Gets the surface area of the box.
float
getBound(int i)
Gets a specific coordinate of the surface's bounding box.
Point3
getCenter()
Gets the center of the box, computed as (min + max) / 2.
Point3
getCorner(int i)
Gets a corner of the bounding box.
Vector3
getExtents()
Gets the extents vector for the box.
Point3
getMaximum()
Gets the maximum corner of the box.
Point3
getMinimum()
Gets the minimum corner of the box.
float
getVolume()
Gets the box's volume
void
include(float x, float y, float z)
Changes the extents of the box as needed to include the given point into this box.
void
include(BoundingBox b)
Changes the extents of the box as needed to include the given box into this box.
void
include(Point3 p)
Changes the extents of the box as needed to include the given pointinto this box.
boolean
intersects(BoundingBox b)
Returns true if the specified bounding box intersects this one.
boolean
isEmpty()
Returns true when the box has just been initialized, and is still empty.
String
toString()

Constructor Details

BoundingBox

public BoundingBox()
Creates an empty box. The minimum point will have all components set to positive infinity, and the maximum will have all components set to negative infinity.

BoundingBox

public BoundingBox(float size)
Creates a bounding box centered around the origin.
Parameters:
size - half edge length of the bounding box

BoundingBox

public BoundingBox(float x,
                   float y,
                   float z)
Creates a bounding box containing only the specified point.
Parameters:
x - x coordinate of the point to include
y - y coordinate of the point to include
z - z coordinate of the point to include

BoundingBox

public BoundingBox(BoundingBox b)
Creates a copy of the given box.
Parameters:
b - bounding box to copy

BoundingBox

public BoundingBox(Point3 p)
Creates a bounding box containing only the specified point.
Parameters:
p - point to include

Method Details

contains

public final boolean contains(float x,
                              float y,
                              float z)
Check to see if the specified point is inside the volume defined by this box.
Parameters:
x - x coordinate of the point to be tested
y - y coordinate of the point to be tested
z - z coordinate of the point to be tested
Returns:
true if the point is inside the box, false otherwise

contains

public final boolean contains(Point3 p)
Checks to see if the specified pointis inside the volume defined by this box. Returns false if the parameter is null.
Parameters:
p - point to be tested for containment
Returns:
true if the point is inside the box, false otherwise

enlargeUlps

public final void enlargeUlps()
Enlarge the bounding box by the minimum possible amount to avoid numeric precision related problems.

getArea

public final float getArea()
Gets the surface area of the box.
Returns:
surface area

getBound

public final float getBound(int i)
Gets a specific coordinate of the surface's bounding box.
Parameters:
i - index of a side from 0 to 5
Returns:
value of the request bounding box side

getCenter

public final Point3 getCenter()
Gets the center of the box, computed as (min + max) / 2.
Returns:
a reference to the center of the box

getCorner

public final Point3 getCorner(int i)
Gets a corner of the bounding box. The index scheme uses the binary representation of the index to decide which corner to return. Corner 0 is equivalent to the minimum and corner 7 is equivalent to the maximum.
Parameters:
i - a corner index, from 0 to 7
Returns:
the corresponding corner

getExtents

public final Vector3 getExtents()
Gets the extents vector for the box. This vector is computed as (max - min). Its coordinates are always positive and represent the dimensions of the box along the three axes.
Returns:
a refreence to the extent vector

getMaximum

public final Point3 getMaximum()
Gets the maximum corner of the box. That is the corner of largest coordinates on each axis. Note that the returned reference is not cloned for efficiency purposes so care must be taken not to change the coordinates of the point.
Returns:
a reference to the maximum corner

getMinimum

public final Point3 getMinimum()
Gets the minimum corner of the box. That is the corner of smallest coordinates on each axis. Note that the returned reference is not cloned for efficiency purposes so care must be taken not to change the coordinates of the point.
Returns:
a reference to the minimum corner

getVolume

public final float getVolume()
Gets the box's volume
Returns:
volume

include

public final void include(float x,
                          float y,
                          float z)
Changes the extents of the box as needed to include the given point into this box.
Parameters:
x - x coordinate of the point
y - y coordinate of the point
z - z coordinate of the point

include

public final void include(BoundingBox b)
Changes the extents of the box as needed to include the given box into this box. Does nothing if the parameter is null.
Parameters:
b - box to be included

include

public final void include(Point3 p)
Changes the extents of the box as needed to include the given pointinto this box. Does nothing if the parameter is null.
Parameters:
p - point to be included

intersects

public final boolean intersects(BoundingBox b)
Returns true if the specified bounding box intersects this one. The boxes are treated as volumes, so a box inside another will return true. Returns false if the parameter is null.
Parameters:
b - box to be tested for intersection
Returns:
true if the boxes overlap, false otherwise

isEmpty

public final boolean isEmpty()
Returns true when the box has just been initialized, and is still empty. This method might also return true if the state of the box becomes inconsistent and some component of the minimum corner is larger than the corresponding coordinate of the maximum corner.
Returns:
true if the box is empty, false otherwise

toString

public final String toString()