rem..om 11 years ago
parent 1b2b9a6e88
commit 9bf532b95e
  1. 226
      engine/src/core/com/jme3/bounding/BoundingBox.java

@ -1,5 +1,5 @@
/*
* Copyright (c) 2009-2012 jMonkeyEngine
* Copyright (c) 2009-2013 jMonkeyEngine
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
@ -47,31 +47,40 @@ import java.nio.FloatBuffer;
//import com.jme.scene.TriMesh;
/**
* <code>BoundingBox</code> defines an axis-aligned cube that defines a
* container for a group of vertices of a particular piece of geometry. This box
* defines a center and extents from that center along the x, y and z axis. <br>
* <code>BoundingBox</code> describes a bounding volume as an axis-aligned box.
* <br>
* A typical usage is to allow the class define the center and radius by calling
* either <code>containAABB</code> or <code>averagePoints</code>. A call to
* <code>computeFramePoint</code> in turn calls <code>containAABB</code>.
*
* Instances may be initialized by invoking the <code>containAABB</code> method.
*
* @author Joshua Slack
* @version $Id: BoundingBox.java,v 1.50 2007/09/22 16:46:35 irrisor Exp $
*/
public class BoundingBox extends BoundingVolume {
float xExtent, yExtent, zExtent;
/**
* Default constructor instantiates a new <code>BoundingBox</code>
* object.
* the X-extent of the box (>=0, may be +Infinity)
*/
float xExtent;
/**
* the Y-extent of the box (>=0, may be +Infinity)
*/
float yExtent;
/**
* the Z-extent of the box (>=0, may be +Infinity)
*/
float zExtent;
/**
* Instantiate a <code>BoundingBox</code> without initializing it.
*/
public BoundingBox() {
}
/**
* Contstructor instantiates a new <code>BoundingBox</code> object with
* given specs.
* Instantiate a <code>BoundingBox</code> with given center and extents.
*
* @param c the coordinates of the center of the box (not null, not altered)
* @param x the X-extent of the box (>=0, may be +Infinity)
* @param y the Y-extent of the box (>=0, may be +Infinity)
* @param z the Z-extent of the box (>=0, may be +Infinity)
*/
public BoundingBox(Vector3f c, float x, float y, float z) {
this.center.set(c);
@ -80,6 +89,11 @@ public class BoundingBox extends BoundingVolume {
this.zExtent = z;
}
/**
* Instantiate a <code>BoundingBox</code> equivalent to an existing box.
*
* @param source the existing box (not null, not altered)
*/
public BoundingBox(BoundingBox source) {
this.center.set(source.center);
this.xExtent = source.xExtent;
@ -368,52 +382,28 @@ public class BoundingBox extends BoundingVolume {
}
/**
* <code>merge</code> combines this bounding box with a second bounding box.
* This new box contains both bounding box and is returned.
*
* @param volume
* the bounding box to combine with this bounding box.
* @return the new bounding box
* <code>merge</code> combines this bounding box locally with a second
* bounding volume. The result contains both the original box and the second
* volume.
*
* @param volume the bounding volume to combine with this box (or null) (not
* altered)
* @return this box (with its components modified) or null if the second
* volume is of some type other than AABB or Sphere
*/
public BoundingVolume merge(BoundingVolume volume) {
if (volume == null) {
return this;
}
switch (volume.getType()) {
case AABB: {
BoundingBox vBox = (BoundingBox) volume;
return merge(vBox.center, vBox.xExtent, vBox.yExtent,
vBox.zExtent, new BoundingBox(new Vector3f(0, 0, 0), 0,
0, 0));
}
case Sphere: {
BoundingSphere vSphere = (BoundingSphere) volume;
return merge(vSphere.center, vSphere.radius, vSphere.radius,
vSphere.radius, new BoundingBox(new Vector3f(0, 0, 0),
0, 0, 0));
}
// case OBB: {
// OrientedBoundingBox box = (OrientedBoundingBox) volume;
// BoundingBox rVal = (BoundingBox) this.clone(null);
// return rVal.mergeOBB(box);
// }
default:
return null;
}
return mergeLocal(volume);
}
/**
* <code>mergeLocal</code> combines this sphere with a second bounding
* sphere locally. Altering this sphere to contain both the original and the
* additional sphere volumes;
*
* @param volume
* the sphere to combine with this sphere.
* @return this
* <code>mergeLocal</code> combines this bounding box locally with a second
* bounding volume. The result contains both the original box and the second
* volume.
*
* @param volume the bounding volume to combine with this box (or null) (not
* altered)
* @return this box (with its components modified) or null if the second
* volume is of some type other than AABB or Sphere
*/
public BoundingVolume mergeLocal(BoundingVolume volume) {
if (volume == null) {
@ -421,17 +411,15 @@ public class BoundingBox extends BoundingVolume {
}
switch (volume.getType()) {
case AABB: {
case AABB:
BoundingBox vBox = (BoundingBox) volume;
return merge(vBox.center, vBox.xExtent, vBox.yExtent,
vBox.zExtent, this);
}
return mergeLocal(vBox.center, vBox.xExtent, vBox.yExtent,
vBox.zExtent);
case Sphere: {
case Sphere:
BoundingSphere vSphere = (BoundingSphere) volume;
return merge(vSphere.center, vSphere.radius, vSphere.radius,
vSphere.radius, this);
}
return mergeLocal(vSphere.center, vSphere.radius,
vSphere.radius, vSphere.radius);
// case OBB: {
// return mergeOBB((OrientedBoundingBox) volume);
@ -486,61 +474,68 @@ public class BoundingBox extends BoundingVolume {
// return this;
// }
/**
* <code>merge</code> combines this bounding box with another box which is
* defined by the center, x, y, z extents.
*
* @param boxCenter
* the center of the box to merge with
* @param boxX
* the x extent of the box to merge with.
* @param boxY
* the y extent of the box to merge with.
* @param boxZ
* the z extent of the box to merge with.
* @param rVal
* the resulting merged box.
* <code>mergeLocal</code> combines this bounding box locally with a second
* bounding box described by its center and extents.
*
* @param c the center of the second box (not null, not altered)
* @param x the X-extent of the second box
* @param y the Y-extent of the second box
* @param z the Z-extent of the second box
* @return the resulting merged box.
*/
private BoundingBox merge(Vector3f boxCenter, float boxX, float boxY,
float boxZ, BoundingBox rVal) {
TempVars vars = TempVars.get();
vars.vect1.x = center.x - xExtent;
if (vars.vect1.x > boxCenter.x - boxX) {
vars.vect1.x = boxCenter.x - boxX;
}
vars.vect1.y = center.y - yExtent;
if (vars.vect1.y > boxCenter.y - boxY) {
vars.vect1.y = boxCenter.y - boxY;
}
vars.vect1.z = center.z - zExtent;
if (vars.vect1.z > boxCenter.z - boxZ) {
vars.vect1.z = boxCenter.z - boxZ;
private BoundingBox mergeLocal(Vector3f c, float x, float y, float z) {
if (xExtent == Float.POSITIVE_INFINITY
|| x == Float.POSITIVE_INFINITY) {
center.x = 0;
xExtent = Float.POSITIVE_INFINITY;
} else {
float low = center.x - xExtent;
if (low > c.x - x) {
low = c.x - x;
}
float high = center.x + xExtent;
if (high < c.x + x) {
high = c.x + x;
}
center.x = (low + high) / 2;
xExtent = high - center.x;
}
vars.vect2.x = center.x + xExtent;
if (vars.vect2.x < boxCenter.x + boxX) {
vars.vect2.x = boxCenter.x + boxX;
}
vars.vect2.y = center.y + yExtent;
if (vars.vect2.y < boxCenter.y + boxY) {
vars.vect2.y = boxCenter.y + boxY;
}
vars.vect2.z = center.z + zExtent;
if (vars.vect2.z < boxCenter.z + boxZ) {
vars.vect2.z = boxCenter.z + boxZ;
if (yExtent == Float.POSITIVE_INFINITY
|| y == Float.POSITIVE_INFINITY) {
center.y = 0;
yExtent = Float.POSITIVE_INFINITY;
} else {
float low = center.y - yExtent;
if (low > c.y - y) {
low = c.y - y;
}
float high = center.y + yExtent;
if (high < c.y + y) {
high = c.y + y;
}
center.y = (low + high) / 2;
yExtent = high - center.y;
}
center.set(vars.vect2).addLocal(vars.vect1).multLocal(0.5f);
xExtent = vars.vect2.x - center.x;
yExtent = vars.vect2.y - center.y;
zExtent = vars.vect2.z - center.z;
vars.release();
if (zExtent == Float.POSITIVE_INFINITY
|| z == Float.POSITIVE_INFINITY) {
center.z = 0;
zExtent = Float.POSITIVE_INFINITY;
} else {
float low = center.z - zExtent;
if (low > c.z - z) {
low = c.z - z;
}
float high = center.z + zExtent;
if (high < c.z + z) {
high = c.z + z;
}
center.z = (low + high) / 2;
zExtent = high - center.z;
}
return rVal;
return this;
}
/**
@ -570,8 +565,9 @@ public class BoundingBox extends BoundingVolume {
/**
* <code>toString</code> returns the string representation of this object.
* The form is: "Radius: RRR.SSSS Center: <Vector>".
*
* The form is: "[Center: <Vector> xExtent: X.XX yExtent: Y.YY zExtent:
* Z.ZZ]".
*
* @return the string representation of this.
*/
@Override
@ -1021,4 +1017,4 @@ public class BoundingBox extends BoundingVolume {
public float getVolume() {
return (8 * xExtent * yExtent * zExtent);
}
}
}
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