/*
* Copyright (c) 2009-2010 jMonkeyEngine
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are
* met:
*
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* * Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
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* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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* TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
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package com.jme3.bounding;
import com.jme3.collision.Collidable;
import com.jme3.collision.CollisionResult;
import com.jme3.collision.CollisionResults;
import com.jme3.collision.UnsupportedCollisionException;
import com.jme3.export.JmeExporter;
import com.jme3.export.JmeImporter;
import com.jme3.math.*;
import com.jme3.util.BufferUtils;
import com.jme3.util.TempVars;
import java.io.IOException;
import java.nio.FloatBuffer;
import java.util.logging.Level;
import java.util.logging.Logger;
/**
* BoundingSphere
defines a sphere that defines a container for a
* group of vertices of a particular piece of geometry. This sphere defines a
* radius and a center.
*
* A typical usage is to allow the class define the center and radius by calling
* either containAABB
or averagePoints
. A call to
* computeFramePoint
in turn calls containAABB
.
*
* @author Mark Powell
* @version $Id: BoundingSphere.java,v 1.59 2007/08/17 10:34:26 rherlitz Exp $
*/
public class BoundingSphere extends BoundingVolume {
private static final Logger logger =
Logger.getLogger(BoundingSphere.class.getName());
float radius;
private static final float RADIUS_EPSILON = 1f + 0.00001f;
/**
* Default contstructor instantiates a new BoundingSphere
* object.
*/
public BoundingSphere() {
}
/**
* Constructor instantiates a new BoundingSphere
object.
*
* @param r
* the radius of the sphere.
* @param c
* the center of the sphere.
*/
public BoundingSphere(float r, Vector3f c) {
this.center.set(c);
this.radius = r;
}
public Type getType() {
return Type.Sphere;
}
/**
* getRadius
returns the radius of the bounding sphere.
*
* @return the radius of the bounding sphere.
*/
public float getRadius() {
return radius;
}
/**
* setRadius
sets the radius of this bounding sphere.
*
* @param radius
* the new radius of the bounding sphere.
*/
public void setRadius(float radius) {
this.radius = radius;
}
/**
* computeFromPoints
creates a new Bounding Sphere from a
* given set of points. It uses the calcWelzl
method as
* default.
*
* @param points
* the points to contain.
*/
public void computeFromPoints(FloatBuffer points) {
calcWelzl(points);
}
/**
* computeFromTris
creates a new Bounding Box from a given
* set of triangles. It is used in OBBTree calculations.
*
* @param tris
* @param start
* @param end
*/
public void computeFromTris(Triangle[] tris, int start, int end) {
if (end - start <= 0) {
return;
}
Vector3f[] vertList = new Vector3f[(end - start) * 3];
int count = 0;
for (int i = start; i < end; i++) {
vertList[count++] = tris[i].get(0);
vertList[count++] = tris[i].get(1);
vertList[count++] = tris[i].get(2);
}
averagePoints(vertList);
}
//
// /**
// * computeFromTris
creates a new Bounding Box from a given
// * set of triangles. It is used in OBBTree calculations.
// *
// * @param indices
// * @param mesh
// * @param start
// * @param end
// */
// public void computeFromTris(int[] indices, Mesh mesh, int start, int end) {
// if (end - start <= 0) {
// return;
// }
//
// Vector3f[] vertList = new Vector3f[(end - start) * 3];
//
// int count = 0;
// for (int i = start; i < end; i++) {
// mesh.getTriangle(indices[i], verts);
// vertList[count++] = new Vector3f(verts[0]);
// vertList[count++] = new Vector3f(verts[1]);
// vertList[count++] = new Vector3f(verts[2]);
// }
//
// averagePoints(vertList);
// }
/**
* Calculates a minimum bounding sphere for the set of points. The algorithm
* was originally found in C++ at
*
* http://www.flipcode.com/cgi-bin/msg.cgi?showThread=COTD-SmallestEnclosingSpheres&forum=cotd&id=-1
broken link
and translated to java by Cep21
* * @param points * The points to calculate the minimum bounds from. */ public void calcWelzl(FloatBuffer points) { if (center == null) { center = new Vector3f(); } FloatBuffer buf = BufferUtils.createFloatBuffer(points.limit()); points.rewind(); buf.put(points); buf.flip(); recurseMini(buf, buf.limit() / 3, 0, 0); } /** * Used from calcWelzl. This function recurses to calculate a minimum * bounding sphere a few points at a time. * * @param points * The array of points to look through. * @param p * The size of the list to be used. * @param b * The number of points currently considering to include with the * sphere. * @param ap * A variable simulating pointer arithmatic from C++, and offset * inpoints
.
*/
private void recurseMini(FloatBuffer points, int p, int b, int ap) {
//TempVars vars = TempVars.get();
Vector3f tempA = new Vector3f(); //vars.vect1;
Vector3f tempB = new Vector3f(); //vars.vect2;
Vector3f tempC = new Vector3f(); //vars.vect3;
Vector3f tempD = new Vector3f(); //vars.vect4;
switch (b) {
case 0:
this.radius = 0;
this.center.set(0, 0, 0);
break;
case 1:
this.radius = 1f - RADIUS_EPSILON;
BufferUtils.populateFromBuffer(center, points, ap - 1);
break;
case 2:
BufferUtils.populateFromBuffer(tempA, points, ap - 1);
BufferUtils.populateFromBuffer(tempB, points, ap - 2);
setSphere(tempA, tempB);
break;
case 3:
BufferUtils.populateFromBuffer(tempA, points, ap - 1);
BufferUtils.populateFromBuffer(tempB, points, ap - 2);
BufferUtils.populateFromBuffer(tempC, points, ap - 3);
setSphere(tempA, tempB, tempC);
break;
case 4:
BufferUtils.populateFromBuffer(tempA, points, ap - 1);
BufferUtils.populateFromBuffer(tempB, points, ap - 2);
BufferUtils.populateFromBuffer(tempC, points, ap - 3);
BufferUtils.populateFromBuffer(tempD, points, ap - 4);
setSphere(tempA, tempB, tempC, tempD);
//vars.release();
return;
}
for (int i = 0; i < p; i++) {
BufferUtils.populateFromBuffer(tempA, points, i + ap);
if (tempA.distanceSquared(center) - (radius * radius) > RADIUS_EPSILON - 1f) {
for (int j = i; j > 0; j--) {
BufferUtils.populateFromBuffer(tempB, points, j + ap);
BufferUtils.populateFromBuffer(tempC, points, j - 1 + ap);
BufferUtils.setInBuffer(tempC, points, j + ap);
BufferUtils.setInBuffer(tempB, points, j - 1 + ap);
}
recurseMini(points, i, b + 1, ap + 1);
}
}
//vars.release();
}
/**
* Calculates the minimum bounding sphere of 4 points. Used in welzl's
* algorithm.
*
* @param O
* The 1st point inside the sphere.
* @param A
* The 2nd point inside the sphere.
* @param B
* The 3rd point inside the sphere.
* @param C
* The 4th point inside the sphere.
* @see #calcWelzl(java.nio.FloatBuffer)
*/
private void setSphere(Vector3f O, Vector3f A, Vector3f B, Vector3f C) {
Vector3f a = A.subtract(O);
Vector3f b = B.subtract(O);
Vector3f c = C.subtract(O);
float Denominator = 2.0f * (a.x * (b.y * c.z - c.y * b.z) - b.x
* (a.y * c.z - c.y * a.z) + c.x * (a.y * b.z - b.y * a.z));
if (Denominator == 0) {
center.set(0, 0, 0);
radius = 0;
} else {
Vector3f o = a.cross(b).multLocal(c.lengthSquared()).addLocal(
c.cross(a).multLocal(b.lengthSquared())).addLocal(
b.cross(c).multLocal(a.lengthSquared())).divideLocal(
Denominator);
radius = o.length() * RADIUS_EPSILON;
O.add(o, center);
}
}
/**
* Calculates the minimum bounding sphere of 3 points. Used in welzl's
* algorithm.
*
* @param O
* The 1st point inside the sphere.
* @param A
* The 2nd point inside the sphere.
* @param B
* The 3rd point inside the sphere.
* @see #calcWelzl(java.nio.FloatBuffer)
*/
private void setSphere(Vector3f O, Vector3f A, Vector3f B) {
Vector3f a = A.subtract(O);
Vector3f b = B.subtract(O);
Vector3f acrossB = a.cross(b);
float Denominator = 2.0f * acrossB.dot(acrossB);
if (Denominator == 0) {
center.set(0, 0, 0);
radius = 0;
} else {
Vector3f o = acrossB.cross(a).multLocal(b.lengthSquared()).addLocal(b.cross(acrossB).multLocal(a.lengthSquared())).divideLocal(Denominator);
radius = o.length() * RADIUS_EPSILON;
O.add(o, center);
}
}
/**
* Calculates the minimum bounding sphere of 2 points. Used in welzl's
* algorithm.
*
* @param O
* The 1st point inside the sphere.
* @param A
* The 2nd point inside the sphere.
* @see #calcWelzl(java.nio.FloatBuffer)
*/
private void setSphere(Vector3f O, Vector3f A) {
radius = FastMath.sqrt(((A.x - O.x) * (A.x - O.x) + (A.y - O.y)
* (A.y - O.y) + (A.z - O.z) * (A.z - O.z)) / 4f) + RADIUS_EPSILON - 1f;
center.interpolate(O, A, .5f);
}
/**
* averagePoints
selects the sphere center to be the average
* of the points and the sphere radius to be the smallest value to enclose
* all points.
*
* @param points
* the list of points to contain.
*/
public void averagePoints(Vector3f[] points) {
logger.info("Bounding Sphere calculated using average points.");
center = points[0];
for (int i = 1; i < points.length; i++) {
center.addLocal(points[i]);
}
float quantity = 1.0f / points.length;
center.multLocal(quantity);
float maxRadiusSqr = 0;
for (int i = 0; i < points.length; i++) {
Vector3f diff = points[i].subtract(center);
float radiusSqr = diff.lengthSquared();
if (radiusSqr > maxRadiusSqr) {
maxRadiusSqr = radiusSqr;
}
}
radius = (float) Math.sqrt(maxRadiusSqr) + RADIUS_EPSILON - 1f;
}
/**
* transform
modifies the center of the sphere to reflect the
* change made via a rotation, translation and scale.
*
* @param trans
* the transform to apply
* @param store
* sphere to store result in
* @return BoundingVolume
* @return ref
*/
public BoundingVolume transform(Transform trans, BoundingVolume store) {
BoundingSphere sphere;
if (store == null || store.getType() != BoundingVolume.Type.Sphere) {
sphere = new BoundingSphere(1, new Vector3f(0, 0, 0));
} else {
sphere = (BoundingSphere) store;
}
center.mult(trans.getScale(), sphere.center);
trans.getRotation().mult(sphere.center, sphere.center);
sphere.center.addLocal(trans.getTranslation());
sphere.radius = FastMath.abs(getMaxAxis(trans.getScale()) * radius) + RADIUS_EPSILON - 1f;
return sphere;
}
public BoundingVolume transform(Matrix4f trans, BoundingVolume store) {
BoundingSphere sphere;
if (store == null || store.getType() != BoundingVolume.Type.Sphere) {
sphere = new BoundingSphere(1, new Vector3f(0, 0, 0));
} else {
sphere = (BoundingSphere) store;
}
trans.mult(center, sphere.center);
Vector3f axes = new Vector3f(1, 1, 1);
trans.mult(axes, axes);
float ax = getMaxAxis(axes);
sphere.radius = FastMath.abs(ax * radius) + RADIUS_EPSILON - 1f;
return sphere;
}
private float getMaxAxis(Vector3f scale) {
float x = FastMath.abs(scale.x);
float y = FastMath.abs(scale.y);
float z = FastMath.abs(scale.z);
if (x >= y) {
if (x >= z) {
return x;
}
return z;
}
if (y >= z) {
return y;
}
return z;
}
/**
* whichSide
takes a plane (typically provided by a view
* frustum) to determine which side this bound is on.
*
* @param plane
* the plane to check against.
* @return side
*/
public Plane.Side whichSide(Plane plane) {
float distance = plane.pseudoDistance(center);
if (distance <= -radius) {
return Plane.Side.Negative;
} else if (distance >= radius) {
return Plane.Side.Positive;
} else {
return Plane.Side.None;
}
}
/**
* merge
combines this sphere with a second bounding sphere.
* This new sphere contains both bounding spheres and is returned.
*
* @param volume
* the sphere to combine with this sphere.
* @return a new sphere
*/
public BoundingVolume merge(BoundingVolume volume) {
if (volume == null) {
return this;
}
switch (volume.getType()) {
case Sphere: {
BoundingSphere sphere = (BoundingSphere) volume;
float temp_radius = sphere.getRadius();
Vector3f temp_center = sphere.center;
BoundingSphere rVal = new BoundingSphere();
return merge(temp_radius, temp_center, rVal);
}
case AABB: {
BoundingBox box = (BoundingBox) volume;
Vector3f radVect = new Vector3f(box.xExtent, box.yExtent,
box.zExtent);
Vector3f temp_center = box.center;
BoundingSphere rVal = new BoundingSphere();
return merge(radVect.length(), temp_center, rVal);
}
// case OBB: {
// OrientedBoundingBox box = (OrientedBoundingBox) volume;
// BoundingSphere rVal = (BoundingSphere) this.clone(null);
// return rVal.mergeOBB(box);
// }
default:
return null;
}
}
/**
* mergeLocal
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
*/
public BoundingVolume mergeLocal(BoundingVolume volume) {
if (volume == null) {
return this;
}
switch (volume.getType()) {
case Sphere: {
BoundingSphere sphere = (BoundingSphere) volume;
float temp_radius = sphere.getRadius();
Vector3f temp_center = sphere.center;
return merge(temp_radius, temp_center, this);
}
case AABB: {
BoundingBox box = (BoundingBox) volume;
TempVars vars = TempVars.get();
Vector3f radVect = vars.vect1;
radVect.set(box.xExtent, box.yExtent, box.zExtent);
Vector3f temp_center = box.center;
float len = radVect.length();
vars.release();
return merge(len, temp_center, this);
}
// case OBB: {
// return mergeOBB((OrientedBoundingBox) volume);
// }
default:
return null;
}
}
// /**
// * Merges this sphere with the given OBB.
// *
// * @param volume
// * The OBB to merge.
// * @return This sphere, after merging.
// */
// private BoundingSphere mergeOBB(OrientedBoundingBox volume) {
// // compute edge points from the obb
// if (!volume.correctCorners)
// volume.computeCorners();
// _mergeBuf.rewind();
// for (int i = 0; i < 8; i++) {
// _mergeBuf.put(volume.vectorStore[i].x);
// _mergeBuf.put(volume.vectorStore[i].y);
// _mergeBuf.put(volume.vectorStore[i].z);
// }
//
// // remember old radius and center
// float oldRadius = radius;
// Vector3f oldCenter = _compVect2.set( center );
//
// // compute new radius and center from obb points
// computeFromPoints(_mergeBuf);
// Vector3f newCenter = _compVect3.set( center );
// float newRadius = radius;
//
// // restore old center and radius
// center.set( oldCenter );
// radius = oldRadius;
//
// //merge obb points result
// merge( newRadius, newCenter, this );
//
// return this;
// }
private BoundingVolume merge(float temp_radius, Vector3f temp_center,
BoundingSphere rVal) {
TempVars vars = TempVars.get();
Vector3f diff = temp_center.subtract(center, vars.vect1);
float lengthSquared = diff.lengthSquared();
float radiusDiff = temp_radius - radius;
float fRDiffSqr = radiusDiff * radiusDiff;
if (fRDiffSqr >= lengthSquared) {
if (radiusDiff <= 0.0f) {
vars.release();
return this;
}
Vector3f rCenter = rVal.center;
if (rCenter == null) {
rVal.setCenter(rCenter = new Vector3f());
}
rCenter.set(temp_center);
rVal.setRadius(temp_radius);
vars.release();
return rVal;
}
float length = (float) Math.sqrt(lengthSquared);
Vector3f rCenter = rVal.center;
if (rCenter == null) {
rVal.setCenter(rCenter = new Vector3f());
}
if (length > RADIUS_EPSILON) {
float coeff = (length + radiusDiff) / (2.0f * length);
rCenter.set(center.addLocal(diff.multLocal(coeff)));
} else {
rCenter.set(center);
}
rVal.setRadius(0.5f * (length + radius + temp_radius));
vars.release();
return rVal;
}
/**
* clone
creates a new BoundingSphere object containing the
* same data as this one.
*
* @param store
* where to store the cloned information. if null or wrong class,
* a new store is created.
* @return the new BoundingSphere
*/
public BoundingVolume clone(BoundingVolume store) {
if (store != null && store.getType() == Type.Sphere) {
BoundingSphere rVal = (BoundingSphere) store;
if (null == rVal.center) {
rVal.center = new Vector3f();
}
rVal.center.set(center);
rVal.radius = radius;
rVal.checkPlane = checkPlane;
return rVal;
}
return new BoundingSphere(radius,
(center != null ? (Vector3f) center.clone() : null));
}
/**
* toString
returns the string representation of this object.
* The form is: "Radius: RRR.SSSS Center: