8 files changed, 0 insertions, 2597 deletions

diff --git a/src/alden/CollidableObject.java b/src/alden/CollidableObject.java
deleted file mode 100644
index 9745665..0000000
--- a/src/alden/CollidableObject.java
+++ /dev/null
@@ -1,533 +0,0 @@
-package alden;

-import java.io.IOException;

-import java.io.ObjectInputStream;

-import java.io.ObjectOutputStream;

-import java.io.Serializable;

-import java.util.*;

-

-import javax.media.j3d.*;

-import javax.vecmath.*;

-

-import com.sun.j3d.utils.geometry.GeometryInfo;

-import com.sun.j3d.utils.geometry.Primitive;

-

-@SuppressWarnings("restriction")

-public abstract class CollidableObject implements Serializable {

-	private static final long serialVersionUID = 3667108226485766929L;

-	protected float inverseMass;

-	// The center of mass in the local coordinate system

-	protected Vector3f centerOfMass;

-	protected Vector3f position, previousPosition;

-	protected Vector3f velocity, previousVelocity;

-	protected Vector3f forceAccumulator;

-	protected Quat4f orientation;

-	protected Vector3f angularVelocity;

-	protected Vector3f previousRotationalVelocity;

-	protected Vector3f torqueAccumulator;

-	protected Matrix3f inverseInertiaTensor;

-	protected float coefficientOfRestitution;

-	protected float penetrationCorrection;

-	protected float dynamicFriction;

-	protected float rotationalFriction;

-	transient protected BranchGroup BG;

-	transient protected TransformGroup TG;

-	transient protected Node node;

-	transient private ArrayList<Vector3f> vertexCache;

-	transient private ArrayList<CollisionDetector.Triangle> triangleCache;

-	transient private Bounds boundsCache;

-	// The inverse inertia tensor in world coordinates

-	transient private Matrix3f inverseInertiaTensorCache;

-	

-	public CollidableObject() {

-		this(1);

-	}

-

-	public CollidableObject(float mass) {

-		if (mass <= 0)

-			throw new IllegalArgumentException();

-		inverseMass = 1 / mass;

-		centerOfMass = new Vector3f();

-		position = new Vector3f();

-		previousPosition = new Vector3f();

-		velocity = new Vector3f();

-		previousVelocity = new Vector3f();

-		forceAccumulator = new Vector3f();

-		orientation = new Quat4f(0, 0, 0, 1);

-		angularVelocity = new Vector3f();

-		previousRotationalVelocity = new Vector3f();

-		torqueAccumulator = new Vector3f();

-		inverseInertiaTensor = new Matrix3f();

-		coefficientOfRestitution = 0.75f;

-		penetrationCorrection = 1.05f;

-		dynamicFriction = 0.02f;

-		rotationalFriction = 0.05f;

-		TG = new TransformGroup();

-		TG.setCapability(TransformGroup.ALLOW_TRANSFORM_WRITE);

-		BG = new BranchGroup();

-		BG.setCapability(BranchGroup.ALLOW_DETACH);

-		BG.addChild(TG);

-	}

-

-	protected void setShape(Node node) {

-		this.node = node;

-		TG.addChild(node);

-//		TG.addChild(CollisionDetector.createShape(CollisionDetector.triangularize(node)));

-	}

-

-	public Group getGroup() {

-		return BG;

-	}

-

-	public void detach() {

-		BG.detach();

-	}

-

-	public void updateState(float duration) {

-		previousPosition.set(position);

-		previousVelocity.set(velocity);

-		// The force vector now becomes the acceleration vector.

-		forceAccumulator.scale(inverseMass);

-		position.scaleAdd(duration, velocity, position);

-		position.scaleAdd(duration * duration / 2, forceAccumulator, position);

-		velocity.scaleAdd(duration, forceAccumulator, velocity);

-		// The force vector is cleared.

-		forceAccumulator.set(0, 0, 0);

-		

-		angularVelocity.scaleAdd(duration, torqueAccumulator, angularVelocity);

-		torqueAccumulator.set(0, 0, 0);

-		UnQuat4f tmp = new UnQuat4f(angularVelocity.x, angularVelocity.y, angularVelocity.z, 0);

-		tmp.scale(duration / 2);

-		tmp.mul(orientation);

-		orientation.add(tmp);

-		orientation.normalize();

-	}

-

-	protected void updateTransformGroup() {

-		Vector3f com = new Vector3f(-centerOfMass.x, -centerOfMass.y, -centerOfMass.z);

-		Transform3D tmp = new Transform3D();

-		tmp.setTranslation(com);

-		Transform3D tmp2 = new Transform3D();

-		tmp2.setRotation(orientation);

-		com.negate();

-		com.add(position);

-		tmp2.setTranslation(com);

-		tmp2.mul(tmp);

-		TG.setTransform(tmp2);

-		clearCaches();

-	}

-

-	public ArrayList<Vector3f> getVertices() {

-		if (vertexCache == null)

-			vertexCache = CollisionDetector.extractVertices(node);

-		return vertexCache;

-	}

-	

-	protected ArrayList<CollisionDetector.Triangle> getCollisionTriangles() {

-		if (triangleCache == null)

-			triangleCache = CollisionDetector.triangularize(node);

-		return triangleCache;

-	}

-

-	protected Bounds getBounds() {

-		if (boundsCache == null) {

-			boundsCache = node.getBounds();

-			Transform3D tmp = new Transform3D();

-			node.getLocalToVworld(tmp);

-			boundsCache.transform(tmp);

-		}

-		return boundsCache;

-	}

-

-	protected Matrix3f getInverseInertiaTensor() {

-		if (inverseInertiaTensorCache == null) {

-			inverseInertiaTensorCache = new Matrix3f();

-			inverseInertiaTensorCache.set(orientation);

-			Matrix3f tmp = new Matrix3f(inverseInertiaTensor);

-			Matrix3f tmp2 = new Matrix3f(inverseInertiaTensorCache);

-			tmp2.invert();

-			tmp.mul(tmp2);

-			inverseInertiaTensorCache.mul(tmp);

-		}

-		return inverseInertiaTensorCache;

-	}

-

-	protected void clearCaches() {

-		vertexCache = null;

-		triangleCache = null;

-		boundsCache = null;

-		inverseInertiaTensorCache = null;

-	}

-

-	public void resolveCollisions(CollidableObject other) {

-		ArrayList<CollisionInfo> collisions = CollisionDetector.calculateCollisions(this, other);

-		if (collisions.isEmpty())

-			return;

-

-		CollisionInfo finalCollision = null;

-		float max = Float.NEGATIVE_INFINITY;

-		int count = 0;

-		for (CollisionInfo collision : collisions) {

-			Vector3f thisRelativeContactPosition = new Vector3f();

-			thisRelativeContactPosition.scaleAdd(-1, position, collision.contactPoint);

-			thisRelativeContactPosition.scaleAdd(-1, centerOfMass, thisRelativeContactPosition);

-			Vector3f thisContactVelocity = new Vector3f();

-			thisContactVelocity.cross(angularVelocity, thisRelativeContactPosition);

-			thisContactVelocity.add(previousVelocity);

-			Vector3f otherRelativeContactPosition = new Vector3f();

-			otherRelativeContactPosition.scaleAdd(-1, other.position, collision.contactPoint);

-			otherRelativeContactPosition.scaleAdd(-1, other.centerOfMass, otherRelativeContactPosition);

-			Vector3f otherContactVelocity = new Vector3f();

-			otherContactVelocity.cross(other.angularVelocity, otherRelativeContactPosition);

-			otherContactVelocity.add(other.previousVelocity);

-			float speed = collision.contactNormal.dot(thisContactVelocity) - collision.contactNormal.dot(otherContactVelocity);

-			if (speed > 0)

-				if (speed > max + CollisionDetector.EPSILON) {

-					finalCollision = collision;

-					max = speed;

-					count = 1;

-				} else if (speed >= max - CollisionDetector.EPSILON) {

-					finalCollision.contactPoint.add(collision.contactPoint);

-					finalCollision.penetration += collision.penetration;

-					count++;

-				}

-		}

-		if (finalCollision != null) {

-			finalCollision.contactPoint.scale(1f / count);

-			finalCollision.penetration /= count;

-			resolveCollision(other, finalCollision);

-			updateTransformGroup();

-			other.updateTransformGroup();

-		}

-	}

-

-	public void resolveCollision(CollidableObject other, CollisionInfo ci) {

-		if (ci.penetration <= 0)

-			return;

-		

-		Vector3f thisRelativeContactPosition = new Vector3f();

-		thisRelativeContactPosition.scaleAdd(-1, position, ci.contactPoint);

-		thisRelativeContactPosition.scaleAdd(-1, centerOfMass, thisRelativeContactPosition);

-		

-		Vector3f otherRelativeContactPosition = new Vector3f();

-		otherRelativeContactPosition.scaleAdd(-1, other.position, ci.contactPoint);

-		otherRelativeContactPosition.scaleAdd(-1, other.centerOfMass, otherRelativeContactPosition);

-		

-		Vector3f thisContactVelocity = new Vector3f();

-		thisContactVelocity.cross(angularVelocity, thisRelativeContactPosition);

-		thisContactVelocity.add(previousVelocity);

-		

-		Vector3f otherContactVelocity = new Vector3f();

-		otherContactVelocity.cross(other.angularVelocity, otherRelativeContactPosition);

-		otherContactVelocity.add(other.previousVelocity);

-		

-		float initialClosingSpeed = ci.contactNormal.dot(thisContactVelocity) - ci.contactNormal.dot(otherContactVelocity);

-		float finalClosingSpeed = -initialClosingSpeed * coefficientOfRestitution;

-		float deltaClosingSpeed = finalClosingSpeed - initialClosingSpeed;

-		float totalInverseMass = inverseMass + other.inverseMass;

-		if (totalInverseMass == 0)

-			return;

-		

-		/* Dynamic Friction */

-		if (dynamicFriction > 0) {

-			Vector3f acceleration = new Vector3f();

-			Vector3f perpVelocity = new Vector3f();

-			float contactSpeed = ci.contactNormal.dot(velocity) - ci.contactNormal.dot(other.velocity);

-			

-			perpVelocity.scaleAdd(-contactSpeed, ci.contactNormal, previousVelocity);

-			if (perpVelocity.length() > 0) {

-				perpVelocity.normalize();

-				acceleration.scaleAdd(-1, previousVelocity, velocity);

-				velocity.scaleAdd(dynamicFriction * acceleration.dot(ci.contactNormal), perpVelocity, velocity);

-			}

-			

-			perpVelocity.scaleAdd(contactSpeed, ci.contactNormal, other.previousVelocity);

-			if (perpVelocity.length() > 0) {

-				perpVelocity.normalize();

-				acceleration.scaleAdd(-1, other.previousVelocity, other.velocity);

-				other.velocity.scaleAdd(dynamicFriction * acceleration.dot(ci.contactNormal), perpVelocity, other.velocity);

-			}

-		}

-		

-		Vector3f thisMovementUnit = new Vector3f();

-		thisMovementUnit.cross(thisRelativeContactPosition, ci.contactNormal);

-		getInverseInertiaTensor().transform(thisMovementUnit);

-		Vector3f thisAngularVelocityUnit = new Vector3f();

-		thisAngularVelocityUnit.cross(thisMovementUnit, thisRelativeContactPosition);

-		totalInverseMass += thisAngularVelocityUnit.dot(ci.contactNormal);

-		

-		Vector3f otherMovementUnit = new Vector3f();

-		otherMovementUnit.cross(otherRelativeContactPosition, ci.contactNormal);

-		other.getInverseInertiaTensor().transform(otherMovementUnit);

-		Vector3f otherAngularVelocityUnit = new Vector3f();

-		otherAngularVelocityUnit.cross(otherMovementUnit, otherRelativeContactPosition);

-		totalInverseMass += otherAngularVelocityUnit.dot(ci.contactNormal);

-

-		Vector3f impulse = new Vector3f(ci.contactNormal);

-		impulse.scale(deltaClosingSpeed / totalInverseMass);

-	

-		velocity.scaleAdd(inverseMass, impulse, velocity);

-		Vector3f tmp = new Vector3f();

-		tmp.cross(thisRelativeContactPosition, impulse);

-		getInverseInertiaTensor().transform(tmp);

-		angularVelocity.add(tmp);

-		position.scaleAdd(-ci.penetration * penetrationCorrection * inverseMass / totalInverseMass, ci.contactNormal, position);

-		thisMovementUnit.scale(-ci.penetration * penetrationCorrection / totalInverseMass);

-		UnQuat4f tmp2 = new UnQuat4f(thisMovementUnit.x, thisMovementUnit.y, thisMovementUnit.z, 0);

-		tmp2.scale(0.5f);

-		tmp2.mul(orientation);

-		orientation.add(tmp2);

-		orientation.normalize();

-		

-		impulse.negate();

-		other.velocity.scaleAdd(other.inverseMass, impulse, other.velocity);

-		tmp.cross(otherRelativeContactPosition, impulse);

-		other.getInverseInertiaTensor().transform(tmp);

-		other.angularVelocity.add(tmp);

-		other.position.scaleAdd(ci.penetration * penetrationCorrection * other.inverseMass / totalInverseMass, ci.contactNormal, other.position);

-		otherMovementUnit.scale(ci.penetration * penetrationCorrection / totalInverseMass);

-		tmp2.set(otherMovementUnit.x, otherMovementUnit.y, otherMovementUnit.z, 0);

-		tmp2.scale(0.5f);

-		tmp2.mul(other.orientation);

-		other.orientation.add(tmp2);

-		other.orientation.normalize();

-		

-		if (rotationalFriction > 0) {

-			/* Rotational Friction */

-			Vector3f w = new Vector3f();

-			

-			/*float radius = thisRelativeContactPosition.length();

-			w.cross(angularVelocity, ci.contactNormal);

-			velocity.scaleAdd(-1, previousRotationalVelocity, velocity);

-			previousRotationalVelocity.scale(radius, w);

-			velocity.scaleAdd(radius, w, velocity);

-			w.cross(previousRotationalVelocity, ci.contactNormal);

-			angularVelocity.scaleAdd(-0.5f * w.dot(angularVelocity), w, angularVelocity);

-			

-			radius = otherRelativeContactPosition.length();

-			w.cross(other.angularVelocity, ci.contactNormal);

-			other.velocity.scaleAdd(-1, other.previousRotationalVelocity, other.velocity);

-			other.previousRotationalVelocity.scale(radius, w);

-			other.velocity.scaleAdd(radius , w, other.velocity);

-			w.cross(other.previousRotationalVelocity, ci.contactNormal);

-			other.angularVelocity.scaleAdd(-0.5f * w.dot(other.angularVelocity), w, other.angularVelocity);

-			*/

-			

-			angularVelocity.scaleAdd(-rotationalFriction * ci.contactNormal.dot(angularVelocity), ci.contactNormal, angularVelocity);

-			other.angularVelocity.scaleAdd(-rotationalFriction * ci.contactNormal.dot(other.angularVelocity), ci.contactNormal, other.angularVelocity);

-			

-		}

-	}

-

-private static final int NODE_TYPE_BRANCH = 1;

-	private static final int NODE_TYPE_TRANSFORM = 2;

-	private static final int NODE_TYPE_PRIMITIVE = 3;

-	private static final int NODE_TYPE_SHAPE = 4;

-

-	private void writeObject(ObjectOutputStream out) throws IOException {

-		out.defaultWriteObject();

-		writeObject(out, node);

-	}

-

-	private static void writeObject(ObjectOutputStream out, Node node) throws IOException {

-		if (node instanceof BranchGroup) {

-			out.writeInt(NODE_TYPE_BRANCH);

-			out.writeInt(((BranchGroup) node).numChildren());

-			for (int i = 0; i < ((BranchGroup) node).numChildren(); i++) {

-				Node childNode = ((BranchGroup) node).getChild(i);

-				writeObject(out, childNode);

-			}

-		} else if (node instanceof TransformGroup) {

-			out.writeInt(NODE_TYPE_TRANSFORM);

-			Transform3D tgT = new Transform3D();

-			Matrix4f matrix = new Matrix4f();

-			((TransformGroup) node).getTransform(tgT);

-			tgT.get(matrix);

-			out.writeObject(matrix);

-			out.writeInt(((TransformGroup) node).numChildren());

-			for (int i = 0; i < ((TransformGroup) node).numChildren(); i++) {

-				Node childNode = ((TransformGroup) node).getChild(i);

-				writeObject(out, childNode);

-			}

-		} else if (node instanceof Primitive) {

-			out.writeInt(NODE_TYPE_PRIMITIVE);

-			Primitive prim = (Primitive)node;

-			int index = 0;

-			Shape3D shape;

-			out.writeInt(prim.numChildren());

-			while ((shape = prim.getShape(index++)) != null) {

-				Appearance appearance = shape.getAppearance();

-				if (appearance != null) {

-					out.writeBoolean(true);

-					writeObject(out, appearance);

-				} else

-					out.writeBoolean(false);

-				out.writeInt(shape.numGeometries());

-				for (int i = 0; i < shape.numGeometries(); i++)

-					writeObject(out, shape.getGeometry(i));

-			}

-			

-		} else if (node instanceof Shape3D) {

-			out.writeInt(NODE_TYPE_SHAPE);

-			Shape3D shape = (Shape3D) node;

-			Appearance appearance = shape.getAppearance();

-			if (appearance != null) {

-				out.writeBoolean(true);

-				writeObject(out, appearance);

-			} else

-				out.writeBoolean(false);

-			out.writeInt(shape.numGeometries());

-			for (int i = 0; i < shape.numGeometries(); i++)

-				writeObject(out, shape.getGeometry(i));

-			

-		} else 

-			throw new IllegalArgumentException("Illegal node type for serialization");

-	}

-

-	private static void writeObject(ObjectOutputStream out, Geometry geometry) throws IOException {

-		GeometryInfo gi = new GeometryInfo((GeometryArray)geometry);

-		gi.convertToIndexedTriangles();

-		geometry = gi.getIndexedGeometryArray();

-		IndexedTriangleArray trueGeometry = (IndexedTriangleArray)geometry;

-		

-		int format = trueGeometry.getVertexFormat() & (IndexedTriangleArray.COORDINATES | IndexedTriangleArray.NORMALS);

-		out.writeInt(format);

-		Point3f vertices[] = new Point3f[trueGeometry.getValidVertexCount()];

-		for (int i = 0; i < vertices.length; i++) {

-			vertices[i] = new Point3f();

-			trueGeometry.getCoordinate(i, vertices[i]);

-		}

-		out.writeObject(vertices);

-		int indices[] = new int[trueGeometry.getValidIndexCount()];

-		trueGeometry.getCoordinateIndices(0, indices);

-		out.writeObject(indices);

-		

-		if ((format & IndexedTriangleArray.NORMALS) != 0) {

-			Vector3f normals[] = new Vector3f[trueGeometry.getValidVertexCount()];

-			for (int i = 0; i < normals.length; i++) {

-				normals[i] = new Vector3f();

-				trueGeometry.getNormal(i, normals[i]);

-			}

-			out.writeObject(normals);

-			trueGeometry.getNormalIndices(0, indices);

-			out.writeObject(indices);

-		}

-	}

-

-	private static void writeObject(ObjectOutputStream out, Appearance appearance) throws IOException {

-		Material material = appearance.getMaterial();

-		if (material != null) {

-			out.writeBoolean(true);

-			Color3f color = new Color3f();

-			material.getAmbientColor(color);

-			out.writeObject(color);

-			color = new Color3f();

-			material.getDiffuseColor(color);

-			out.writeObject(color);

-			color = new Color3f();

-			material.getSpecularColor(color);

-			out.writeObject(color);

-			color = new Color3f();

-			material.getEmissiveColor(color);

-			out.writeObject(color);

-			out.writeFloat(material.getShininess());

-			out.writeInt(material.getColorTarget());

-		} else

-			out.writeBoolean(false);

-	}

-

-	private void readObject(ObjectInputStream in) throws IOException, ClassNotFoundException {

-		in.defaultReadObject();

-		TG = new TransformGroup();

-		TG.setCapability(TransformGroup.ALLOW_TRANSFORM_WRITE);

-		BG = new BranchGroup();

-		BG.setCapability(BranchGroup.ALLOW_DETACH);

-		BG.addChild(TG);

-		setShape(readNode(in));

-	}

-

-	private static Node readNode(ObjectInputStream in) throws IOException, ClassNotFoundException {

-		int type = in.readInt();

-		switch (type) {

-		case NODE_TYPE_BRANCH:

-			BranchGroup bgroup = new BranchGroup();

-			int numTGChildren = in.readInt();

-			for (int i = 0; i < numTGChildren; i++) {

-				bgroup.addChild(readNode(in));

-			}

-			return bgroup;

-		case NODE_TYPE_TRANSFORM:

-			TransformGroup tgroup = new TransformGroup();

-			Matrix4f matrix = (Matrix4f) in.readObject();

-			Transform3D tgT = new Transform3D(matrix);

-			tgroup.setTransform(tgT);

-			int numChildren = in.readInt();

-			for (int i = 0; i < numChildren; i++) {

-				tgroup.addChild(readNode(in));

-			}

-			return tgroup;

-		case NODE_TYPE_PRIMITIVE:

-			BranchGroup bg = new BranchGroup();

-			int shapes = in.readInt();

-			for (int i = 0; i < shapes; i++) {

-				Shape3D shape = new Shape3D();

-				shape.removeAllGeometries();

-				if (in.readBoolean())

-					shape.setAppearance(readAppearance(in));

-				int geometries = in.readInt();

-				for (int j = 0; j < geometries; j++)

-					shape.addGeometry(readGeometry(in));

-				bg.addChild(shape);			

-			}

-			return bg;

-		case NODE_TYPE_SHAPE:

-			BranchGroup shapeBG = new BranchGroup();

-			Shape3D shape = new Shape3D();

-			shape.removeAllGeometries();

-			boolean hasAppearance = in.readBoolean();

-			Appearance shapeApp = new Appearance(); 

-			if(hasAppearance) {

-				shapeApp = readAppearance(in);

-			}

-			int geometries = in.readInt();

-			for (int i = 0; i < geometries; i++)

-				shape.addGeometry(readGeometry(in));

-			shapeBG.addChild(shape);

-			return shapeBG;

-		default:

-			throw new IllegalArgumentException("Illegal node type for serialization");

-		}

-	}

-

-	private static GeometryArray readGeometry(ObjectInputStream in) throws IOException, ClassNotFoundException {

-		int format = in.readInt();

-		Point3f vertices[] = (Point3f[])in.readObject();

-		int indices[] = (int[])in.readObject();

-		IndexedTriangleArray geometry = new IndexedTriangleArray(vertices.length, format, indices.length);

-		geometry.setCoordinates(0, vertices);

-		geometry.setCoordinateIndices(0, indices);

-

-		if ((format & IndexedTriangleArray.NORMALS) != 0) {

-			Vector3f normals[] = (Vector3f[])in.readObject();

-			indices = (int[])in.readObject();

-			geometry.setNormals(0, normals);

-			geometry.setNormalIndices(0, indices);

-		}

-		

-		return geometry;

-	}

-

-	private static Appearance readAppearance(ObjectInputStream in) throws IOException, ClassNotFoundException {

-		Appearance appearance = new Appearance();

-		if (in.readBoolean()) {

-			Material material = new Material();

-			material.setAmbientColor((Color3f)in.readObject());

-			material.setDiffuseColor((Color3f)in.readObject());

-			material.setSpecularColor((Color3f)in.readObject());

-			material.setEmissiveColor((Color3f)in.readObject());

-			material.setShininess(in.readFloat());

-			material.setColorTarget(in.readInt());

-			appearance.setMaterial(material);

-		}

-		return appearance;

-	}

-}

diff --git a/src/alden/CollisionDetector.java b/src/alden/CollisionDetector.java
deleted file mode 100644
index 84682b8..0000000
--- a/src/alden/CollisionDetector.java
+++ /dev/null
@@ -1,672 +0,0 @@
-package alden;

-

-import java.util.ArrayList;

-

-import javax.media.j3d.Appearance;

-import javax.media.j3d.Geometry;

-import javax.media.j3d.GeometryArray;

-import javax.media.j3d.Group;

-import javax.media.j3d.IndexedTriangleArray;

-import javax.media.j3d.IndexedTriangleFanArray;

-import javax.media.j3d.IndexedTriangleStripArray;

-import javax.media.j3d.Node;

-import javax.media.j3d.PolygonAttributes;

-import javax.media.j3d.Shape3D;

-import javax.media.j3d.Transform3D;

-import javax.media.j3d.TriangleArray;

-import javax.media.j3d.TriangleFanArray;

-import javax.media.j3d.TriangleStripArray;

-import javax.vecmath.Matrix3f;

-import javax.vecmath.Point3f;

-import javax.vecmath.Tuple3f;

-import javax.vecmath.Vector3f;

-

-import tesseract.objects.HalfSpace;

-import tesseract.objects.Particle;

-import tesseract.objects.Polygon;

-import tesseract.objects.Sphere;

-

-import com.sun.j3d.utils.geometry.Primitive;

-

-@SuppressWarnings("restriction")

-public class CollisionDetector {

-	public static final float EPSILON = 0.0001f;

-	private static final ArrayList<CollisionInfo> EMPTY_COLLISION_LIST = new ArrayList<CollisionInfo>();

-

-	public static class Triangle {

-		private Vector3f a;

-		private Vector3f b;

-		private Vector3f c;

-		private Vector3f normal;

-		private float intercept;

-

-		private static class Line {

-			public Vector3f point;

-			public Vector3f direction;

-			

-			public Line() {

-				point = new Vector3f();

-				direction = new Vector3f();

-			}

-		}

-		

-		private static class TPair {

-			public float t0;

-			public float t1;

-		}

-

-		public Triangle(Tuple3f a, Tuple3f b, Tuple3f c) {

-			this.a = new Vector3f(a);

-			this.b = new Vector3f(b);

-			this.c = new Vector3f(c);

-			Vector3f tmp = new Vector3f();

-			tmp.scaleAdd(-1, a, c);

-			Vector3f tmp2 = new Vector3f();

-			tmp2.scaleAdd(-1, b, c);

-			normal = new Vector3f();

-			normal.cross(tmp, tmp2);

-			if (normal.lengthSquared() == 0)

-				throw new IllegalArgumentException("Degenerate triangle");

-			normal.normalize();

-			intercept = normal.dot(this.a);

-		}

-		

-		// Inspired by Tomas Moller's "A Fast Triangle-Triangle Intersection Test"	

-		public CollisionInfo getIntersection(Triangle other) {

-			float d_0_0 = other.normal.dot(a) - other.intercept;

-			float d_0_1 = other.normal.dot(b) - other.intercept;

-			float d_0_2 = other.normal.dot(c) - other.intercept;

-			if (Math.abs(d_0_0) < EPSILON)

-				d_0_0 = 0;

-			if (Math.abs(d_0_1) < EPSILON)

-				d_0_1 = 0;

-			if (Math.abs(d_0_2) < EPSILON)

-				d_0_2 = 0;

-			if (d_0_0 != 0 && d_0_1 != 0 && d_0_2 != 0 && Math.signum(d_0_0) == Math.signum(d_0_1) && Math.signum(d_0_1) == Math.signum(d_0_2))

-				return null;

-			

-			float d_1_0 = normal.dot(other.a) - intercept;

-			float d_1_1 = normal.dot(other.b) - intercept;

-			float d_1_2 = normal.dot(other.c) - intercept;

-			if (Math.abs(d_1_0) < EPSILON)

-				d_1_0 = 0;

-			if (Math.abs(d_1_1) < EPSILON)

-				d_1_1 = 0;

-			if (Math.abs(d_1_2) < EPSILON)

-				d_1_2 = 0;

-			if (d_1_0 != 0 && d_1_1 != 0 && d_1_2 != 0 && Math.signum(d_1_0) == Math.signum(d_1_1) && Math.signum(d_1_1) == Math.signum(d_1_2))

-				return null;

-

-			// Coplanar, assume no collision

-			if (d_0_0 == 0 && d_0_1 == 0 && d_0_2 == 0)

-				return null;

-			

-			Line line = calculateLineOfIntersection(other);

-			TPair r0 = calculateRegionOfIntersection(line, d_0_0, d_0_1, d_0_2);

-			TPair r1 = other.calculateRegionOfIntersection(line, d_1_0, d_1_1, d_1_2);

-			

-			if (r0.t1 < r1.t0 || r0.t0 > r1.t1)

-				return null;

-			

-			Vector3f contactPoint = new Vector3f();

-			if (r0.t0 >= r1.t0 && r0.t1 <= r1.t1)

-				contactPoint.scaleAdd((r0.t0 + r0.t1) / 2, line.direction, line.point);

-			else if (r0.t0 <= r1.t0 && r0.t1 >= r1.t1)

-				contactPoint.scaleAdd((r1.t0 + r1.t1) / 2, line.direction, line.point);

-			else if (r0.t0 < r1.t0)

-				contactPoint.scaleAdd((r0.t1 + r1.t0) / 2, line.direction, line.point);

-			else

-				contactPoint.scaleAdd((r0.t0 + r1.t1) / 2, line.direction, line.point);

-			

-			assert(Math.abs(normal.dot(contactPoint) - intercept) < 0.01);

-			assert(Math.abs(other.normal.dot(contactPoint) - other.intercept) < 0.01);

-			

-			float penetration = Float.NEGATIVE_INFINITY;

-			boolean useThisNormal = false;

-			if (d_0_0 <= 0 && d_0_0 >= penetration)

-				penetration = d_0_0;

-			if (d_0_1 <= 0 && d_0_1 >= penetration)

-				penetration = d_0_1;

-			if (d_0_2 <= 0 && d_0_2 >= penetration)

-				penetration = d_0_2;

-			if (d_1_0 <= 0 && d_1_0 >= penetration) {

-				penetration = d_1_0;

-				useThisNormal = true;

-			}

-			if (d_1_1 <= 0 && d_1_1 >= penetration) {

-				penetration = d_1_1;

-				useThisNormal = true;

-			}

-			if (d_1_2 <= 0 && d_1_2 >= penetration) {

-				penetration = d_1_2;

-				useThisNormal = true;

-			}

-			Vector3f contactNormal;

-			if (useThisNormal)

-				contactNormal = new Vector3f(normal);

-			else {

-				contactNormal = new Vector3f(other.normal);

-				contactNormal.negate();

-			}

-			

-			return new CollisionInfo(contactPoint, contactNormal, -penetration);

-		}

-

-		private Line calculateLineOfIntersection(Triangle other) {

-			Line line = new Line();

-			line.direction.cross(normal, other.normal);

-			if (Math.abs(line.direction.x) < EPSILON)

-				line.direction.x = 0;

-			if (Math.abs(line.direction.y) < EPSILON)

-				line.direction.y = 0;

-			if (Math.abs(line.direction.z) < EPSILON)

-				line.direction.z = 0;

-			line.direction.normalize();

-			

-			if (line.direction.x != 0) { // x <- 0

-				if (normal.y != 0) {

-					line.point.z = (other.normal.y / normal.y * intercept - other.intercept) / (other.normal.y / normal.y * normal.z - other.normal.z);

-					line.point.y = (intercept - normal.z * line.point.z) / normal.y;

-				} else { // normal.z != 0

-					line.point.y = (other.normal.z / normal.z * intercept - other.intercept) / (other.normal.z / normal.z * normal.y - other.normal.y);

-					line.point.z = (intercept - normal.y * line.point.y) / normal.z;

-				}

-			} else if (line.direction.y != 0) { // y <- 0

-				if (normal.x != 0) {

-					line.point.z = (other.normal.x / normal.x * intercept - other.intercept) / (other.normal.x / normal.x * normal.z - other.normal.z);

-					line.point.x = (intercept - normal.z * line.point.z) / normal.x;

-				} else { // normal.z != 0

-					line.point.x = (other.normal.z / normal.z * intercept - other.intercept) / (other.normal.z / normal.z * normal.x - other.normal.x);

-					line.point.z = (intercept - normal.x * line.point.x) / normal.z;

-				}

-			} else { // z <- 0

-				if (normal.x != 0) {

-					line.point.y = (other.normal.x / normal.x * intercept - other.intercept) / (other.normal.x / normal.x * normal.y - other.normal.y);

-					line.point.x = (intercept - normal.y * line.point.y) / normal.x;

-				} else { // normal.y != 0

-					line.point.x = (other.normal.y / normal.y * intercept - other.intercept) / (other.normal.y / normal.y * normal.x - other.normal.x);

-					line.point.y = (intercept - normal.x * line.point.x) / normal.y;

-				}

-			}

-

-			assert(Math.abs(normal.dot(line.point) - intercept) < 0.01);

-			assert(Math.abs(other.normal.dot(line.point) - other.intercept) < 0.01);

-

-			return line;

-		}

-		

-		private TPair calculateRegionOfIntersection(Line line, float d0, float d1, float d2) {

-			Vector3f v0, v1, v2;

-			if (Math.signum(d0) != 0 && Math.signum(d0) != Math.signum(d1) && Math.signum(d0) != Math.signum(d2)) {

-				v0 = b; v1 = a; v2 = c;

-				float tmp = d0; d0 = d1; d1 = tmp;

-			} else if (Math.signum(d1) != 0 && Math.signum(d0) != Math.signum(d1) && Math.signum(d1) != Math.signum(d2)) {

-				v0 = a; v1 = b; v2 = c;

-			} else if (Math.signum(d2) != 0 && Math.signum(d0) != Math.signum(d2) && Math.signum(d1) != Math.signum(d2)) {

-				v0 = a; v1 = c; v2 = b;

-				float tmp = d1; d1 = d2; d2 = tmp; 

-			} else if (Math.signum(d0) == 0) {

-				v0 = b; v1 = a; v2 = c;

-				float tmp = d0; d0 = d1; d1 = tmp;

-			} else if (Math.signum(d1) == 0) {

-				v0 = a; v1 = b; v2 = c;

-			} else {

-				v0 = a; v1 = c; v2 = b;

-				float tmp = d1; d1 = d2; d2 = tmp;

-			}

-			

-			Vector3f tmp = new Vector3f();

-			tmp.scaleAdd(-1, line.point, v0);

-			float p0 = line.direction.dot(tmp);

-			tmp.scaleAdd(-1, line.point, v1);

-			float p1 = line.direction.dot(tmp);

-			tmp.scaleAdd(-1, line.point, v2);

-			float p2 = line.direction.dot(tmp);

-			

-			TPair region = new TPair();

-			region.t0 = p0 + (p1 - p0) * d0 / (d0 - d1);

-			region.t1 = p2 + (p1 - p2) * d2 / (d2 - d1);

-			if (region.t1 < region.t0) {

-				float tmp2 = region.t0;

-				region.t0 = region.t1;

-				region.t1 = tmp2;

-			}

-			return region;

-		}

-	}

-	

-	public static ArrayList<CollisionInfo> calculateCollisions(CollidableObject a, CollidableObject b) {

-		if (a == b)

-			return EMPTY_COLLISION_LIST;

-		if (a instanceof HalfSpace) {

-			if (b instanceof HalfSpace)

-				return EMPTY_COLLISION_LIST;

-			if (b instanceof Particle)

-				return calculateCollisions((HalfSpace)a, (Particle)b);

-			if (b instanceof Sphere)

-				return calculateCollisions((HalfSpace)a, (Sphere)b);

-			return calculateCollisions((HalfSpace)a, b.getVertices());

-		}

-		if (b instanceof HalfSpace) {

-			if (a instanceof Particle)

-				return flipContactNormals(calculateCollisions((HalfSpace)b, (Particle)a));

-			if (a instanceof Sphere)

-				return flipContactNormals(calculateCollisions((HalfSpace)b, (Sphere)a));

-			return flipContactNormals(calculateCollisions((HalfSpace)b, a.getVertices()));

-		}

-		if (a instanceof Particle) {

-			if (b instanceof Particle)

-				return EMPTY_COLLISION_LIST;

-			if (b instanceof Sphere)

-				return calculateCollisions((Particle)a, (Sphere)b);

-			if (b instanceof Polygon)

-				return calculateCollisions((Particle)a, (Polygon)b);

-		}

-		if (b instanceof Particle) {

-			if (a instanceof Sphere)

-				return flipContactNormals(calculateCollisions((Particle)b, (Sphere)a));

-			if (a instanceof Polygon)

-				return flipContactNormals(calculateCollisions((Particle)b, (Polygon)a));

-		}

-		if (a instanceof Sphere && b instanceof Sphere)

-			return calculateCollisions((Sphere)a, (Sphere)b);

-		

-		if (!a.getBounds().intersect(b.getBounds()))

-			return EMPTY_COLLISION_LIST;

-		

-		if (a instanceof Particle)

-			return calculateCollisions((Particle)a, b);

-		if (b instanceof Particle)

-			return flipContactNormals(calculateCollisions((Particle)b, a));

-		if (a instanceof Polygon)

-			return calculateCollisions((Polygon)a, b);

-		if (b instanceof Polygon)

-			return calculateCollisions((Polygon)b, a);

-		return CollisionDetector.calculateCollisions(a.getCollisionTriangles(), b.getCollisionTriangles());

-	}

-	

-	private static ArrayList<CollisionInfo> calculateCollisions(HalfSpace a, Particle b) {

-		float penetration = a.intercept - a.normal.dot(b.position);

-		if (penetration < 0)

-			return EMPTY_COLLISION_LIST;

-		Vector3f contactPoint = new Vector3f();

-		contactPoint.scaleAdd(penetration, a.normal, b.position);

-		assert(Math.abs(a.normal.dot(contactPoint) - a.intercept) < 0.01);

-		ArrayList<CollisionInfo> collisions = new ArrayList<CollisionInfo>();

-		collisions.add(new CollisionInfo(contactPoint, new Vector3f(a.normal), penetration));

-		return collisions;

-	}

-

-	private static ArrayList<CollisionInfo> calculateCollisions(HalfSpace a, Sphere b) {

-		float penetration = b.radius - (a.normal.dot(b.position) - a.intercept);

-		if (penetration < 0)

-			return EMPTY_COLLISION_LIST;

-		Vector3f contactPoint = new Vector3f();

-		contactPoint.scaleAdd(-(b.radius - penetration), a.normal, b.position);

-		assert(Math.abs(a.normal.dot(contactPoint) - a.intercept) < 0.01);

-		ArrayList<CollisionInfo> collisions = new ArrayList<CollisionInfo>();

-		collisions.add(new CollisionInfo(contactPoint, new Vector3f(a.normal), penetration));

-		return collisions;

-	}

-

-	private static ArrayList<CollisionInfo> calculateCollisions(HalfSpace a, ArrayList<Vector3f> setB) {

-		ArrayList<CollisionInfo> collisions = new ArrayList<CollisionInfo>();

-		for (Vector3f vertex : setB) {

-			float penetration = a.intercept - a.normal.dot(vertex);

-			if (penetration >= 0) {

-				Vector3f contactPoint = new Vector3f();

-				contactPoint.scaleAdd(penetration, a.normal, vertex);

-				assert(Math.abs(a.normal.dot(contactPoint) - a.intercept) < 0.01);

-				collisions.add(new CollisionInfo(contactPoint, new Vector3f(a.normal), penetration));

-			}

-		}

-		return collisions;

-	}

-

-	private static ArrayList<CollisionInfo> calculateCollisions(Particle a, Sphere b) {

-		Vector3f delta = new Vector3f();

-		delta.scaleAdd(-1, a.position, b.position);

-		float penetration = b.radius - delta.length();

-		if (penetration < 0)

-			return EMPTY_COLLISION_LIST;

-		

-		ArrayList<CollisionInfo> collisions = new ArrayList<CollisionInfo>();

-		delta.normalize();

-		Vector3f contactPoint = new Vector3f();

-		contactPoint.scaleAdd(-(b.radius - 0.5f * penetration), delta, b.position);

-		collisions.add(new CollisionInfo(contactPoint, delta, penetration));

-		return collisions;

-	}

-

-	private static ArrayList<CollisionInfo> calculateCollisions(Particle a, Polygon b) {

-		float penetration = b.intercept - b.normal.dot(a.position);

-		float previousPenetration = b.intercept - b.normal.dot(a.previousPosition);

-		if (Math.signum(penetration) == Math.signum(previousPenetration))

-			return EMPTY_COLLISION_LIST;

-		

-		for (Triangle triangle : b.getCollisionTriangles()) {

-			Matrix3f tmp = new Matrix3f(a.previousPosition.x - a.position.x, triangle.b.x - triangle.a.x, triangle.c.x - triangle.a.x,

-			                            a.previousPosition.y - a.position.y, triangle.b.y - triangle.a.y, triangle.c.y - triangle.a.y,

-			                            a.previousPosition.z - a.position.z, triangle.b.z - triangle.a.z, triangle.c.z - triangle.a.z);

-			tmp.invert();

-			Vector3f intercept = new Vector3f();

-			intercept.scaleAdd(-1, triangle.a, a.previousPosition);

-			tmp.transform(intercept);

-			

-			assert(intercept.x >= 0 && intercept.x <= 1);

-			

-			if (intercept.y >= 0 && intercept.y <= 1 && intercept.z >= 0 && intercept.z <= 1 && (intercept.y + intercept.z) <= 1) {

-				Vector3f contactPoint = new Vector3f();

-				contactPoint.scaleAdd(-1, a.previousPosition, a.position);

-				contactPoint.scale(intercept.x);

-				contactPoint.add(a.previousPosition);

-				assert(Math.abs(b.normal.dot(contactPoint) - b.intercept) < 0.01);

-				Vector3f contactNormal = new Vector3f(b.normal);

-				if (penetration - previousPenetration > 0)

-					contactNormal.negate();

-				else

-					penetration = -penetration;

-				ArrayList<CollisionInfo> collisions = new ArrayList<CollisionInfo>();

-				collisions.add(new CollisionInfo(contactPoint, contactNormal, penetration));

-				return collisions;

-			}

-		}

-		return EMPTY_COLLISION_LIST;

-	}

-	

-	private static ArrayList<CollisionInfo> calculateCollisions(Particle a, CollidableObject b) {

-		ArrayList<CollisionInfo> collisions = new ArrayList<CollisionInfo>();

-		for (Triangle triangle : b.getCollisionTriangles()) {

-			float penetration = triangle.intercept - triangle.normal.dot(a.position);

-			if (penetration < 0 || (!collisions.isEmpty() && penetration <= collisions.get(0).penetration))

-				continue;

-			float previousPenetration = triangle.intercept - triangle.normal.dot(a.previousPosition);

-			if (Math.signum(penetration) == Math.signum(previousPenetration))

-				continue;

-			

-			Matrix3f tmp = new Matrix3f(a.previousPosition.x - a.position.x, triangle.b.x - triangle.a.x, triangle.c.x - triangle.a.x,

-			                            a.previousPosition.y - a.position.y, triangle.b.y - triangle.a.y, triangle.c.y - triangle.a.y,

-			                            a.previousPosition.z - a.position.z, triangle.b.z - triangle.a.z, triangle.c.z - triangle.a.z);

-			tmp.invert();

-			Vector3f intercept = new Vector3f();

-			intercept.scaleAdd(-1, triangle.a, a.previousPosition);

-			tmp.transform(intercept);

-			

-			assert(intercept.x >= 0 && intercept.x <= 1);

-			

-			if (intercept.y >= 0 && intercept.y <= 1 && intercept.z >= 0 && intercept.z <= 1 && (intercept.y + intercept.z) <= 1) {

-				Vector3f contactPoint = new Vector3f();

-				contactPoint.scaleAdd(-1, a.previousPosition, a.position);

-				contactPoint.scale(intercept.x);

-				contactPoint.add(a.previousPosition);

-				assert(Math.abs(triangle.normal.dot(contactPoint) - triangle.intercept) < 0.01);

-				Vector3f contactNormal = new Vector3f(triangle.normal);

-				if (penetration - previousPenetration > 0)

-					contactNormal.negate();

-				else

-					penetration = -penetration;				

-				collisions.clear();

-				collisions.add(new CollisionInfo(contactPoint, contactNormal, penetration));

-			}

-		}

-		return collisions;

-	}

-	

-	private static ArrayList<CollisionInfo> calculateCollisions(Sphere a, Sphere b) {

-		Vector3f delta = new Vector3f();

-		delta.scaleAdd(-1, a.position, b.position);

-		float penetration = a.radius + b.radius - delta.length();

-		if (penetration < 0)

-			return EMPTY_COLLISION_LIST;

-		

-		ArrayList<CollisionInfo> collisions = new ArrayList<CollisionInfo>();

-		delta.normalize();

-		Vector3f contactPoint = new Vector3f();

-		contactPoint.scaleAdd(a.radius - 0.5f * penetration, delta, a.position);

-		collisions.add(new CollisionInfo(contactPoint, delta, penetration));

-		return collisions;

-	}

-

-	private static ArrayList<CollisionInfo> calculateCollisions(Polygon a, CollidableObject b) {

-		ArrayList<CollisionInfo> collisions = calculateCollisions(a.getCollisionTriangles(), b.getCollisionTriangles());

-		int size = collisions.size();

-		collisions.ensureCapacity(2 * size);

-		for (int i = 0; i < size; i++) {

-			collisions.add(collisions.get(i).clone());

-			collisions.get(collisions.size() - 1).contactNormal.negate();

-		}

-		return collisions;

-	}

-	

-	private static ArrayList<CollisionInfo> calculateCollisions(ArrayList<Triangle> setA, ArrayList<Triangle> setB) {

-		ArrayList<CollisionInfo> collisions = new ArrayList<CollisionInfo>();

-		for (int i = 0; i < setA.size(); i++)

-			for (int j = 0; j < setB.size(); j++) {

-				CollisionInfo collision = setA.get(i).getIntersection(setB.get(j));

-				if (collision != null)

-					collisions.add(collision);

-			}

-		return collisions;

-	}

-

-	private static ArrayList<CollisionInfo> flipContactNormals(ArrayList<CollisionInfo> collisions) {

-		for (CollisionInfo collision : collisions)

-			collision.contactNormal.negate();

-		return collisions;

-	}

-

-	public static ArrayList<Vector3f> extractVertices(Node node) {

-		ArrayList<Vector3f> vertices = new ArrayList<Vector3f>();

-		extractVertices(node, vertices);

-		return vertices;

-	}

-	

-	private static void extractVertices(Node node, ArrayList<Vector3f> vertices) {

-		if (node instanceof Primitive) {

-			Primitive prim = (Primitive)node;

-			int index = 0;

-			Shape3D shape;

-			Transform3D L2V = new Transform3D();

-			while ((shape = prim.getShape(index++)) != null) {

-				shape.getLocalToVworld(L2V);

-				for (int i = 0; i < shape.numGeometries(); i++)

-					extractVertices(shape.getGeometry(i), L2V, vertices);

-			}

-		} else if (node instanceof Shape3D) {

-			Shape3D shape = (Shape3D)node;

-			Transform3D L2V = new Transform3D();

-			shape.getLocalToVworld(L2V);

-			for (int i = 0; i < shape.numGeometries(); i++)

-				extractVertices(shape.getGeometry(i), L2V, vertices);

-		} else if (node instanceof Group) {

-			Group group = (Group)node;

-			for (int i = 0; i < group.numChildren(); i++)

-				extractVertices(group.getChild(i), vertices);

-		} else 

-			throw new IllegalArgumentException("Illegal node type for vertex extraction");

-	}

-

-	private static void extractVertices(Geometry geometry, Transform3D transform, ArrayList<Vector3f> vertices) {

-		if (geometry instanceof GeometryArray) {

-			GeometryArray trueGeometry = (GeometryArray)geometry;

-			vertices.ensureCapacity(vertices.size() + trueGeometry.getValidVertexCount());

-			Point3f vertex = new Point3f();

-			for (int i = 0; i < trueGeometry.getValidVertexCount(); i++) {

-				trueGeometry.getCoordinate(i, vertex);

-				transform.transform(vertex);

-				vertices.add(new Vector3f(vertex));

-			}

-		}  else

-			throw new IllegalArgumentException("Illegal geometry type for vertex extraction");

-	}

-	

-	public static ArrayList<Triangle> triangularize(Node node) {

-		ArrayList<Triangle> triangles = new ArrayList<Triangle>();

-		triangularize(node, triangles);

-		return triangles;

-	}

-	

-	private static void triangularize(Node node, ArrayList<Triangle> triangles) {

-		if (node instanceof Primitive) {

-			Primitive prim = (Primitive)node;

-			triangles.ensureCapacity(prim.getNumTriangles());

-			int index = 0;

-			Shape3D shape;

-			Transform3D L2V = new Transform3D();

-			while ((shape = prim.getShape(index++)) != null) {

-				shape.getLocalToVworld(L2V);

-				for (int i = 0; i < shape.numGeometries(); i++)

-					triangularize(shape.getGeometry(i), L2V, triangles);

-			}

-		} else if (node instanceof Shape3D) {

-			Shape3D shape = (Shape3D)node;

-			Transform3D L2V = new Transform3D();

-			shape.getLocalToVworld(L2V);

-			for (int i = 0; i < shape.numGeometries(); i++)

-				triangularize(shape.getGeometry(i), L2V, triangles);

-		} else if (node instanceof Group) {

-			Group group = (Group)node;

-			for (int i = 0; i < group.numChildren(); i++)

-				triangularize(group.getChild(i), triangles);

-		} else 

-			throw new IllegalArgumentException("Illegal node type for triangularization");

-	}

-

-	private static void triangularize(Geometry geometry, Transform3D transform, ArrayList<Triangle> triangles) {

-		if (geometry instanceof TriangleArray) {

-			TriangleArray trueGeometry = (TriangleArray)geometry;

-			Point3f vertices[] = new Point3f[trueGeometry.getValidVertexCount()];

-			for (int i = 0; i < vertices.length; i++) {

-				vertices[i] = new Point3f();

-				trueGeometry.getCoordinate(i, vertices[i]);

-				transform.transform(vertices[i]);

-			}

-			for (int i = 0; i < vertices.length; i += 3)

-				try {

-					triangles.add(new Triangle(vertices[i], vertices[i+1], vertices[i+2]));

-				} catch (IllegalArgumentException e) {

-				}

-		} else if (geometry instanceof TriangleStripArray) {

-			TriangleStripArray trueGeometry = (TriangleStripArray)geometry;

-			int stripVertexCounts[] = new int[trueGeometry.getNumStrips()];

-			trueGeometry.getStripVertexCounts(stripVertexCounts);

-			Point3f vertices[] = new Point3f[trueGeometry.getValidVertexCount()];

-			for (int i = 0; i < vertices.length; i++) {

-				vertices[i] = new Point3f();

-				trueGeometry.getCoordinate(i, vertices[i]);

-				transform.transform(vertices[i]);

-			}

-			int base = 0;

-			for (int i = 0; i < stripVertexCounts.length; i++) {

-				boolean reverse = false;

-				for (int j = 2; j < stripVertexCounts[i]; j++) {

-					try {

-						if (reverse)

-							triangles.add(new Triangle(vertices[base+j-2], vertices[base+j], vertices[base+j-1]));

-						else

-							triangles.add(new Triangle(vertices[base+j-2], vertices[base+j-1], vertices[base+j]));

-					} catch (IllegalArgumentException e) {

-					}

-					reverse = !reverse;

-				}

-				base += stripVertexCounts[i];

-			}

-		} else if (geometry instanceof TriangleFanArray) {

-			TriangleFanArray trueGeometry = (TriangleFanArray)geometry;

-			int stripVertexCounts[] = new int[trueGeometry.getNumStrips()];

-			trueGeometry.getStripVertexCounts(stripVertexCounts);

-			Point3f vertices[] = new Point3f[trueGeometry.getValidVertexCount()];

-			for (int i = 0; i < vertices.length; i++) {

-				vertices[i] = new Point3f();

-				trueGeometry.getCoordinate(i, vertices[i]);

-				transform.transform(vertices[i]);

-			}

-			int base = 0;

-			for (int i = 0; i < stripVertexCounts.length; i++) {

-				for (int j = 2; j < stripVertexCounts[i]; j++)

-					try {

-						triangles.add(new Triangle(vertices[base], vertices[base+j-1], vertices[base+j]));

-					} catch (IllegalArgumentException e) {

-					}

-				base += stripVertexCounts[i];

-			}

-		} else if (geometry instanceof IndexedTriangleArray) {

-			IndexedTriangleArray trueGeometry = (IndexedTriangleArray)geometry;

-			Point3f vertices[] = new Point3f[trueGeometry.getValidVertexCount()];

-			for (int i = 0; i < vertices.length; i++) {

-				vertices[i] = new Point3f();

-				trueGeometry.getCoordinate(i, vertices[i]);

-				transform.transform(vertices[i]);

-			}

-			int indices[] = new int[trueGeometry.getValidIndexCount()];

-			trueGeometry.getCoordinateIndices(0, indices);

-			for (int i = 0; i < indices.length; i += 3)

-				try {

-					triangles.add(new Triangle(vertices[indices[i]], vertices[indices[i+1]], vertices[indices[i+2]]));

-				} catch (IllegalArgumentException e) {

-				}

-		} else if (geometry instanceof IndexedTriangleStripArray) {

-			IndexedTriangleStripArray trueGeometry = (IndexedTriangleStripArray)geometry;

-			int stripIndexCounts[] = new int[trueGeometry.getNumStrips()];

-			trueGeometry.getStripIndexCounts(stripIndexCounts);

-			Point3f vertices[] = new Point3f[trueGeometry.getValidVertexCount()];

-			for (int i = 0; i < vertices.length; i++) {

-				vertices[i] = new Point3f();

-				trueGeometry.getCoordinate(i, vertices[i]);

-				transform.transform(vertices[i]);

-			}			

-			int indices[] = new int[trueGeometry.getValidIndexCount()];

-			trueGeometry.getCoordinateIndices(0, indices);

-			int base = 0;

-			for (int i = 0; i < stripIndexCounts.length; i++) {

-				boolean reverse = false;

-				for (int j = 2; j < stripIndexCounts[i]; j++) {

-					try {

-						if (reverse)

-							triangles.add(new Triangle(vertices[indices[base+j-2]], vertices[indices[base+j]], vertices[indices[base+j-1]]));

-						else

-							triangles.add(new Triangle(vertices[indices[base+j-2]], vertices[indices[base+j-1]], vertices[indices[base+j]]));

-					} catch (IllegalArgumentException e) {

-					}

-					reverse = !reverse;

-				}

-				base += stripIndexCounts[i];

-			}

-		} else if (geometry instanceof IndexedTriangleFanArray) {

-			IndexedTriangleFanArray trueGeometry = (IndexedTriangleFanArray)geometry;

-			int stripIndexCounts[] = new int[trueGeometry.getNumStrips()];

-			trueGeometry.getStripIndexCounts(stripIndexCounts);

-			Point3f vertices[] = new Point3f[trueGeometry.getValidVertexCount()];

-			for (int i = 0; i < vertices.length; i++) {

-				vertices[i] = new Point3f();

-				trueGeometry.getCoordinate(i, vertices[i]);

-				transform.transform(vertices[i]);

-			}			

-			int indices[] = new int[trueGeometry.getValidIndexCount()];

-			trueGeometry.getCoordinateIndices(0, indices);

-			int base = 0;

-			for (int i = 0; i < stripIndexCounts.length; i++) {

-				for (int j = 2; j < stripIndexCounts[i]; j++)

-					try {

-						triangles.add(new Triangle(vertices[indices[base]], vertices[indices[base+j-1]], vertices[indices[base+j]]));

-					} catch (IllegalArgumentException e) {

-					}

-				base += stripIndexCounts[i];

-			}

-		} else

-			throw new IllegalArgumentException("Illegal geometry type for triangularization");

-	}

-

-	public static Shape3D createShape(ArrayList<Triangle> triangles) {

-		TriangleArray geometry = new TriangleArray(3 * triangles.size(), TriangleArray.COORDINATES);

-		for (int i = 0; i < triangles.size(); i++) {

-			geometry.setCoordinate(3 * i, new Point3f(triangles.get(i).a));

-			geometry.setCoordinate(3 * i + 1, new Point3f(triangles.get(i).b));

-			geometry.setCoordinate(3 * i + 2, new Point3f(triangles.get(i).c));

-		}

-		Appearance appearance = new Appearance();

-		PolygonAttributes polyAttr = new PolygonAttributes(PolygonAttributes.POLYGON_LINE, PolygonAttributes.CULL_NONE, 0);

-		appearance.setPolygonAttributes(polyAttr);

-		return new Shape3D(geometry, appearance);

-	}

-}

diff --git a/src/alden/CollisionInfo.java b/src/alden/CollisionInfo.java
deleted file mode 100644
index dad74a5..0000000
--- a/src/alden/CollisionInfo.java
+++ /dev/null
@@ -1,26 +0,0 @@
-package alden;

-import javax.vecmath.*;

-

-@SuppressWarnings("restriction")

-public class CollisionInfo implements Cloneable {

-	public Vector3f contactPoint;

-	public Vector3f contactNormal;

-	public float penetration;

-	

-	public CollisionInfo(Vector3f contactPoint, Vector3f contactNormal, float penetration) {

-		this.contactPoint = contactPoint;

-		this.contactNormal = contactNormal;

-		this.penetration = penetration;

-	}

-	

-	public CollisionInfo clone() {

-		try {

-			CollisionInfo copy = (CollisionInfo)super.clone();

-			copy.contactPoint = new Vector3f(contactPoint);

-			copy.contactNormal = new Vector3f(contactNormal);

-			return copy;

-		} catch (CloneNotSupportedException e) {

-			return null;

-		}

-	}

-}
\ No newline at end of file
diff --git a/src/alden/Peer.java b/src/alden/Peer.java
deleted file mode 100644
index 931cc10..0000000
--- a/src/alden/Peer.java
+++ /dev/null
@@ -1,588 +0,0 @@
-package alden;

-import java.io.IOException;

-import java.io.ObjectInputStream;

-import java.io.ObjectOutputStream;

-import java.net.InetAddress;

-import java.net.InetSocketAddress;

-import java.net.ServerSocket;

-import java.net.Socket;

-import java.net.SocketException;

-import java.net.UnknownHostException;

-import java.util.ArrayList;

-import java.util.Date;

-import java.util.Observable;

-

-import javax.swing.SwingWorker;

-import javax.vecmath.Vector2f;

-

-

-@SuppressWarnings("restriction")

-public class Peer extends Observable {

-	/**

-	 * The default port number for incoming network connections.

-	 */

-	public static final int DEFAULT_SERVER_PORT = 5507;

-	

-	private PeerInformation myInfo;

-	private ArrayList<PeerInformation> peers;

-	private ServerSocket serverSocket;

-	private SwingWorker<Object,Object> worker;

-	

-	/**

-	 * A flag indicating whether internal operation messages (useful for

-	 * debugging) are logged to the console.  This field may be modified at any

-	 * time.

-	 */

-	public boolean logEnabled;

-

-	/**

-	 * Initializes a new <code>Peer</code> object.  The <code>Peer</code> is

-	 * not connected to a network and sends a log of internal operation

-	 * messages to the console.   

-	 */

-	public Peer() {

-		this(true);

-	}

-

-	/**

-	 * Initializes a new <code>Peer</code> object with message logging

-	 * controlled by the <code>logEnabled</code> parameter.  The

-	 * <code>Peer</code> is not connected to a network.

-	 * 

-	 * @param logEnabled Initial value for the <code>logEnabled</code> field. 

-	 */

-	public Peer(boolean logEnabled) {

-		myInfo = new PeerInformation();

-		this.logEnabled = logEnabled;

-	}

-

-	/**

-	 * Establishes a new peer-to-peer network with this <code>Peer</code>

-	 * as the sole member.  The logical coordinates of this

-	 * <code>Peer</code> are chosen randomly.

-	 * 

-	 * @return <code>true</code> if the new network was established

-	 * successfully, or <code>false</code> otherwise.

-	 */

-	public boolean createNetwork() {

-		return createNetwork(new PeerCoordinates());

-	}

-	

-	/**

-	 * Establishes a new peer-to-peer network with this <code>Peer</code>

-	 * as the sole member.  The logical coordinates of this

-	 * <code>Peer</code> are specified by parameter <code>location</code>.

-	 * 

-	 * @param location Logical coordinates for this <code>Peer</code>

-	 * within the new network.

-	 * 

-	 * @return <code>true</code> if the new network was established

-	 * successfully, or <code>false</code> otherwise.

-	 */

-	public boolean createNetwork(PeerCoordinates location) {

-		if (serverSocket == null)

-			if (!startServer())

-				return false;

-		peers = new ArrayList<PeerInformation>();

-		myInfo.location = location;

-		logMessage("Established network @ " + myInfo.location);

-		return true;

-	}	

-

-	/**

-	 * Connects this <code>Peer</code> to an existing peer-to-peer network. The

-	 * port number of the known <code>Peer</code> must be

-	 * {@link #DEFAULT_SERVER_PORT DEFAULT_SERVER_PORT}. The logical coordinates

-	 * of this <code>Peer</code> are chosen randomly.

-	 * 

-	 * @param host

-	 *            The domain name or IP address of a <code>Peer</code> within

-	 *            the network.

-	 * 

-	 * @return <code>true</code> if this <code>Peer</code> successfully

-	 *         connected to the network, or <code>false</code> otherwise.

-	 */

-	public boolean connectToNetwork(String host) {

-		return connectToNetwork(host, DEFAULT_SERVER_PORT);

-	}

-	

-	/**

-	 * Connects this <code>Peer</code> to an existing peer-to-peer network. The

-	 * port number of the known <code>Peer</code> must be

-	 * {@link #DEFAULT_SERVER_PORT DEFAULT_SERVER_PORT}. The preferred logical

-	 * coordinates of this <code>Peer</code> are specified by parameter

-	 * <code>location</code>, but the actual logical coordinates may be chosen

-	 * randomly to avoid collision with other <code>Peer</code>s.

-	 * 

-	 * @param host

-	 *            The domain name or IP address of a <code>Peer</code> within

-	 *            the network.

-	 * @param location

-	 *            Preferred logical coordinates for this <code>Peer</code>.

-	 * 

-	 * @return <code>true</code> if this <code>Peer</code> successfully

-	 *         connected to the network, or <code>false</code> otherwise.

-	 */

-	public boolean connectToNetwork(String host, PeerCoordinates location) {

-		return connectToNetwork(host, DEFAULT_SERVER_PORT, location);

-	}

-	

-	/**

-	 * Connects this <code>Peer</code> to an existing peer-to-peer network. The

-	 * logical coordinates of this <code>Peer</code> are chosen randomly.

-	 * 

-	 * @param host

-	 *            The domain name or IP address of a <code>Peer</code> within

-	 *            the network.

-	 * @param port

-	 *            The port number of a <code>Peer</code> within the network.

-	 * 

-	 * @return <code>true</code> if this <code>Peer</code> successfully

-	 *         connected to the network, or <code>false</code> otherwise.

-	 */

-	public boolean connectToNetwork(String host, int port) {

-		try {

-			return connectToNetwork(InetAddress.getByName(host), port);

-		} catch (UnknownHostException e) {

-			System.err.println(e);

-			return false;

-		}

-	}

-	

-	/**

-	 * Connects this <code>Peer</code> to an existing peer-to-peer network. The

-	 * preferred logical coordinates of this <code>Peer</code> are specified by

-	 * parameter <code>location</code>, but the actual logical coordinates may

-	 * be chosen randomly to avoid collision with other <code>Peer</code>s.

-	 * 

-	 * @param host

-	 *            The domain name or IP address of a <code>Peer</code> within

-	 *            the network.

-	 * @param port

-	 *            The port number of a <code>Peer</code> within the network.

-	 * @param location

-	 *            Preferred logical coordinates for this <code>Peer</code>.

-	 * 

-	 * @return <code>true</code> if this <code>Peer</code> successfully

-	 *         connected to the network, or <code>false</code> otherwise.

-	 */

-	public boolean connectToNetwork(String host, int port, PeerCoordinates location) {

-		try {

-			return connectToNetwork(InetAddress.getByName(host), port, location);

-		} catch (UnknownHostException e) {

-			System.err.println(e);

-			return false;

-		}

-	}

-

-	/**

-	 * Connects this <code>Peer</code> to an existing peer-to-peer network. The

-	 * port number of the known <code>Peer</code> must be

-	 * {@link #DEFAULT_SERVER_PORT DEFAULT_SERVER_PORT}. The logical coordinates

-	 * of this <code>Peer</code> are chosen randomly.

-	 * 

-	 * @param host

-	 *            The IP address of a <code>Peer</code> within the network.

-	 * 

-	 * @return <code>true</code> if this <code>Peer</code> successfully

-	 *         connected to the network, or <code>false</code> otherwise.

-	 */

-	public boolean connectToNetwork(InetAddress host) {

-		return connectToNetwork(host, DEFAULT_SERVER_PORT);

-	}

-	

-	/**

-	 * Connects this <code>Peer</code> to an existing peer-to-peer network. The

-	 * port number of the known <code>Peer</code> must be

-	 * {@link #DEFAULT_SERVER_PORT DEFAULT_SERVER_PORT}. The preferred logical

-	 * coordinates of this <code>Peer</code> are specified by parameter

-	 * <code>location</code>, but the actual logical coordinates may be chosen

-	 * randomly to avoid collision with other <code>Peer</code>s.

-	 * 

-	 * @param host

-	 *            The IP address of a <code>Peer</code> within the network.

-	 * @param location

-	 *            Preferred logical coordinates for this <code>Peer</code>.

-	 * 

-	 * @return <code>true</code> if this <code>Peer</code> successfully

-	 *         connected to the network, or <code>false</code> otherwise.

-	 */

-	public boolean connectToNetwork(InetAddress host, PeerCoordinates location) {

-		return connectToNetwork(host, DEFAULT_SERVER_PORT, location);

-	}

-	

-	/**

-	 * Connects this <code>Peer</code> to an existing peer-to-peer network. The

-	 * logical coordinates of this <code>Peer</code> are chosen randomly.

-	 * 

-	 * @param host

-	 *            The IP address of a <code>Peer</code> within the network.

-	 * @param port

-	 *            The port number of a <code>Peer</code> within the network.

-	 * 

-	 * @return <code>true</code> if this <code>Peer</code> successfully

-	 *         connected to the network, or <code>false</code> otherwise.

-	 */

-	public boolean connectToNetwork(InetAddress host, int port) {

-		return connectToNetwork(host, port, new PeerCoordinates());

-	}

-

-	/**

-	 * Connects this <code>Peer</code> to an existing peer-to-peer network. The

-	 * preferred logical coordinates of this <code>Peer</code> are specified by

-	 * parameter <code>location</code>, but the actual logical coordinates may

-	 * be chosen randomly to avoid collision with other <code>Peer</code>s.

-	 * 

-	 * @param host

-	 *            The IP address of a <code>Peer</code> within the network.

-	 * @param port

-	 *            The port number of a <code>Peer</code> within the network.

-	 * @param location

-	 *            Preferred logical coordinates for this <code>Peer</code>.

-	 * 

-	 * @return <code>true</code> if this <code>Peer</code> successfully connects

-	 *         to the network, or <code>false</code> otherwise.

-	 */

-	public boolean connectToNetwork(InetAddress host, int port, PeerCoordinates location) {

-		if (serverSocket == null)

-			if (!startServer())

-				return false;

-		try {

-			Socket socket = new Socket();

-			try {

-				socket.connect(new InetSocketAddress(host, port), 10000);

-			} catch (IOException e) {

-				System.out.println("Unable to connect to " + host + ":" + port);

-				return false;

-			}

-			ObjectOutputStream socketOut = new ObjectOutputStream(socket.getOutputStream());

-			socketOut.writeObject(createJoinMessage(location));

-			socket.close();

-			while (myInfo.location == null)

-				Thread.sleep(1000);

-			logMessage("Joined network @ " + myInfo.location);

-			return true;

-		} catch (Exception e) {

-			System.err.println(e);

-			return false;

-		}

-	}

-	

-	/**

-	 * Disconnects this <code>Peer</code> from the peer-to-peer network.

-	 */

-	public synchronized void disconnectFromNetwork() {

-		PeerMessage mesg = createAddPeersMessage();

-		mesg.peers = peers;

-		for (PeerInformation peer : peers)

-			sendMessage(mesg, peer);

-		mesg = createRemovePeersMessage();

-		for (PeerInformation peer : peers)

-			sendMessage(mesg, peer);

-		worker.cancel(true);

-		try {

-			serverSocket.close();

-		} catch (IOException e) {

-		}

-		serverSocket = null;

-		System.out.println(myInfo + " disconnected");

-	}

-

-	/**

-	 * Identifies the <code>Peer</code> in the network adjacent to this

-	 * <code>Peer</code> in the direction (<code>x</code>,<code>y</code>).

-	 * 

-	 * @param x

-	 *            X component of a direction relative to the logical coordinates

-	 *            of this <code>Peer</code>.

-	 * @param y

-	 *            Y component of a direction relative to the logical coordinates

-	 *            of this <code>Peer</code>.

-	 * 

-	 * @return A <code>PeerInformation</code> object representing the adjacent

-	 *         <code>Peer</code>, or <code>null</code> if no adjacent

-	 *         <code>Peer</code> exists.

-	 */

-	public synchronized PeerInformation getPeerInDirection(float x, float y) {

-		float minDistance = Float.POSITIVE_INFINITY;

-		PeerInformation minPeer = null;

-		

-		Vector2f startPoint = new Vector2f(myInfo.location.getX(), myInfo.location.getY());

-		Vector2f direction = new Vector2f(x, y);

-		for (PeerInformation peer : peers) {

-			Vector2f normal = new Vector2f(peer.location.getX() - startPoint.x, peer.location.getY() - startPoint.y);

-			Vector2f midpoint = new Vector2f((peer.location.getX() + startPoint.x) / 2f, (peer.location.getY() + startPoint.y) / 2f);

-			

-			float denominator = direction.dot(normal);

-			if (denominator == 0)

-				continue;

-			midpoint.scaleAdd(-1, startPoint, midpoint);

-			float distance = midpoint.dot(normal) / denominator;

-			if (distance > 0 && distance < minDistance) {

-				minDistance = distance;

-				minPeer = peer;

-			}

-		}

-

-		// Tuples for fixed boundaries: normal.x, normal.y, point.x, point.y

-		float boundaries[] = {1, 0, PeerCoordinates.MIN_X, PeerCoordinates.MIN_Y,

-		                      0, 1, PeerCoordinates.MIN_X, PeerCoordinates.MIN_Y,

-		                      -1, 0, PeerCoordinates.MAX_X, PeerCoordinates.MAX_Y,

-		                      0, -1, PeerCoordinates.MAX_X, PeerCoordinates.MAX_X};

-		for (int i = 0; i < boundaries.length; i += 4) {

-			Vector2f normal = new Vector2f(boundaries[i], boundaries[i+1]);

-			Vector2f point = new Vector2f(boundaries[i+2], boundaries[i+3]);

-			

-			float denominator = direction.dot(normal);

-			if (denominator == 0)

-				continue;

-			point.scaleAdd(-1, startPoint, point);

-			float distance = point.dot(normal) / denominator;

-			if (distance > 0 && distance < minDistance)

-				return null;

-		}

-		

-		return minPeer;

-	}

-

-	/**

-	 * A method that sends a CollidableObject to all

-	 * <code>Peer</code>s in the network.

-	 * 

-	 * @param payload

-	 *            A CollidableObject.

-	 * 

-	 * @return <code>true</code> if the message was successfully sent to all

-	 *         <code>Peer</code>s, or <code>false</code> otherwise.

-	 */

-	public synchronized boolean sendToAllPeers(CollidableObject payload) {

-		PeerMessage message = createPayloadMessage(payload);

-		boolean success = true;

-		for (PeerInformation peer : peers)

-			success = sendMessage(message, peer) && success;

-		return success;		

-	}

-	

-	/**

-	 * A method that sends an object to all

-	 * <code>Peer</code>s in the network.

-	 * 

-	 * @param payload

-	 *            An object.

-	 * 

-	 * @return <code>true</code> if the message was successfully sent to all

-	 *         <code>Peer</code>s, or <code>false</code> otherwise.

-	 */

-	public synchronized boolean sendExtraToAllPeers(Object payload) {

-		PeerMessage message = createExtraMessage(payload);

-		boolean success = true;

-		for (PeerInformation peer : peers)

-			success = sendMessage(message, peer) && success;

-		return success;

-	}

-

-	private boolean startServer() {

-		return startServer(DEFAULT_SERVER_PORT);

-	}

-	

-	private boolean startServer(int port) {

-		while (true) {

-			try {

-				serverSocket = new ServerSocket(port);

-			} catch (IOException e) {

-				port++;

-				continue;

-			} catch (SecurityException e) {

-				System.err.println(e);

-				return false;

-			}

-			try {

-				myInfo.address = InetAddress.getLocalHost();

-			} catch (UnknownHostException e) {

-				System.err.println(e);

-				try {

-					serverSocket.close();

-				} catch (IOException e1) {

-				}

-				serverSocket = null;

-				return false;

-			}

-			myInfo.port = port;

-			break;

-		}

-		

-		System.out.println("Listening on " + myInfo.address + ":" + myInfo.port);

-		

-		worker = new SwingWorker<Object,Object>() {

-			protected Object doInBackground() throws Exception {

-				while (!isCancelled()) {

-					logMessage("Waiting for peer connection...");

-					try {

-						Socket socket = serverSocket.accept();

-						processConnection(socket);

-					} catch (SocketException e) {

-					} catch (IOException e) {

-					    System.err.println(e);

-					}

-				}

-				return null;

-			}

-		};

-		worker.execute();

-		

-		return true;

-	}

-

-	private synchronized void processConnection(Socket socket) {

-		ObjectInputStream socketIn;

-		PeerMessage mesg;

-		try {

-			socketIn = new ObjectInputStream(socket.getInputStream());

-			mesg = (PeerMessage)socketIn.readObject();

-		} catch (Exception e) {

-			System.err.println(e);

-			return;

-		}

-		if (mesg.sender.address == null || mesg.type != PeerMessage.Type.JOIN)

-			mesg.sender.address = socket.getInetAddress();

-		switch (mesg.type) {

-		case JOIN:

-			logMessage("Received JOIN message from " + mesg.sender);

-			while (true) {

-				PeerInformation peer = lookup(mesg.sender.location);

-				if (peer != myInfo) {

-					sendMessage(mesg, peer);

-					break;

-				} else if (myInfo.location.equals(mesg.sender.location))

-					mesg.sender.location.setToRandomCoordinate();

-				else {

-					sendMessage(createJoinResultMessage(mesg.sender.location), mesg.sender);

-					break;

-				}

-			}

-			break;

-		case JOIN_RESULT:

-			logMessage("Received JOIN_RESULT message from " + mesg.sender);

-			assert(peers == null);

-			peers = mesg.peers;

-			assert(myInfo.location == null);

-			myInfo.location = mesg.location;

-			PeerMessage newMesg = createAddPeersMessage();

-			for (PeerInformation peer : peers) {

-				logMessage("Adding peer " + peer);

-				sendMessage(newMesg, peer);

-			}

-			logMessage("Adding peer " + mesg.sender);

-			sendMessage(newMesg, mesg.sender);

-			peers.add(mesg.sender);

-			break;

-		case ADD_PEERS:

-			logMessage("Received ADD_PEERS message from " + mesg.sender);

-			if (!peers.contains(mesg.sender)) {

-				logMessage("Adding peer " + mesg.sender);

-				peers.add(mesg.sender);

-			}

-			for (PeerInformation peer : mesg.peers)

-				if (!peers.contains(peer) && !myInfo.equals(peer)) {

-					logMessage("Adding peer " + peer);

-					peers.add(peer);

-				}

-			break;

-		case REMOVE_PEERS:

-			logMessage("Received REMOVE_PEERS message from " + mesg.sender);

-			if (peers.contains(mesg.sender)) {

-				logMessage("Removing peer " + mesg.sender);

-				peers.remove(mesg.sender);

-			}

-			for (PeerInformation peer : mesg.peers)

-				if (peers.contains(peer)) {

-					logMessage("Removing peer " + peer);

-					peers.remove(peer);

-				}

-			break;

-			

-		case PAYLOAD:

-			logMessage("Received PAYLOAD message from " + mesg.sender);

-			

-			setChanged();

-			notifyObservers(mesg.payload);

-			

-			break;

-			

-		case EXTRA:

-			logMessage("Received EXTRA message from " + mesg.sender);

-			

-			if (mesg.id != null && mesg.id.equals(PeerMessage.DEFAULT_ID)) {

-				setChanged();

-				notifyObservers(mesg.extra);

-			}

-			

-			break;

-		}

-	}

-

-	private synchronized PeerInformation lookup(PeerCoordinates location) {

-		double minDistance = myInfo.location.distanceTo(location);

-		int min = -1;

-		for (int i = 0; i < peers.size(); i++) {

-			double distance = peers.get(i).location.distanceTo(location);

-			if (distance < minDistance) {

-				minDistance = distance;

-				min = i;

-			}

-		}

-		if (min == -1)

-			return myInfo;

-		return peers.get(min);

-	}

-

-	private boolean sendMessage(PeerMessage message, PeerInformation destination) {

-		try {

-			Socket socket = new Socket(destination.address, destination.port);

-			ObjectOutputStream socketOut = new ObjectOutputStream(socket.getOutputStream());

-			socketOut.writeObject(message);

-			socket.close();

-		} catch (IOException e) {

-			System.err.println(e);

-			return false;

-		}

-		return true;

-	}

-

-	private PeerMessage createJoinMessage(PeerCoordinates location) {

-		PeerInformation tmp = new PeerInformation(null, myInfo.port, location);

-		return new PeerMessage(PeerMessage.Type.JOIN, tmp);

-	}

-	

-	private PeerMessage createJoinResultMessage(PeerCoordinates location) {

-		PeerMessage mesg = new PeerMessage(PeerMessage.Type.JOIN_RESULT, myInfo);

-		mesg.peers = peers;

-		mesg.location = location;

-		return mesg;

-	}

-	

-	private PeerMessage createAddPeersMessage() {

-		return new PeerMessage(PeerMessage.Type.ADD_PEERS, myInfo);

-	}

-	

-	private PeerMessage createRemovePeersMessage() {

-		return new PeerMessage(PeerMessage.Type.REMOVE_PEERS, myInfo);

-	}

-	

-	private PeerMessage createPayloadMessage(CollidableObject payload) {

-		PeerMessage mesg = new PeerMessage(PeerMessage.Type.PAYLOAD, myInfo);

-		mesg.payload = payload;

-		return mesg;

-	}

-	

-	private PeerMessage createExtraMessage(Object payload) {

-		PeerMessage mesg = new PeerMessage(PeerMessage.Type.EXTRA, myInfo);

-		mesg.extra = payload;

-		return mesg;

-	}

-	

-	private void logMessage(String text) {

-		if (logEnabled)

-			System.out.println(new Date() + " -- " + text);

-	}

-}

diff --git a/src/alden/PeerCoordinates.java b/src/alden/PeerCoordinates.java
deleted file mode 100644
index 4d0e445..0000000
--- a/src/alden/PeerCoordinates.java
+++ /dev/null
@@ -1,53 +0,0 @@
-package alden;

-import java.io.*;

-

-public class PeerCoordinates implements Serializable {

-	private static final long serialVersionUID = 3667108226485766929L;

-	public static final int MIN_X = 0;

-	public static final int MAX_X = 99;

-	public static final int MIN_Y = 0;

-	public static final int MAX_Y = 99;

-	

-	private int x;

-	private int y;

-

-	public PeerCoordinates() {

-		setToRandomCoordinate();

-	}

-	

-	public PeerCoordinates(int x, int y) {

-		if (x < MIN_X || x > MAX_X || y < MIN_Y || y > MAX_Y)

-			throw new IllegalArgumentException();

-		

-		this.x = x;

-		this.y = y;

-	}

-

-	public int getX() {

-		return x;

-	}

-	

-	public int getY() {

-		return y;

-	}

-

-	public double distanceTo(PeerCoordinates other) {

-		return Math.sqrt((x - other.x) * (x - other.x) + (y - other.y) * (y - other.y));

-	}

-

-	public String toString() {

-		return "(" + x + ", " + y + ")";

-	}

-

-	public boolean equals(Object other) {

-		if (!(other instanceof PeerCoordinates))

-			return false;

-		

-		return x == ((PeerCoordinates)other).x && y == ((PeerCoordinates)other).y;

-	}

-

-	public void setToRandomCoordinate() {

-		x = MIN_X + (int)((MAX_X - MIN_X + 1) * Math.random());

-		y = MIN_Y + (int)((MAX_Y - MIN_Y + 1) * Math.random());

-	}

-}

diff --git a/src/alden/PeerInformation.java b/src/alden/PeerInformation.java
deleted file mode 100644
index 3d94f11..0000000
--- a/src/alden/PeerInformation.java
+++ /dev/null
@@ -1,39 +0,0 @@
-package alden;

-import java.io.*;

-import java.net.*;

-

-public class PeerInformation implements Serializable {

-	private static final long serialVersionUID = 3667108226485766929L;

-	public static final String DEFAULT_ID = "something unique";

-

-	public InetAddress address;

-	public int port;

-	public PeerCoordinates location;

-	public String id;	

-	

-	public PeerInformation() {

-		id = DEFAULT_ID;

-	}

-

-	public PeerInformation(PeerInformation other) {

-		this(other.address, other.port, other.location);

-	}

-	

-	public PeerInformation(InetAddress address, int port, PeerCoordinates location) {

-		this();

-		this.address = address;

-		this.port = port;

-		this.location = location;

-	}

-	

-	public String toString() {

-		return address + ":" + port + " @ " + location;

-	}

-

-	public boolean equals(Object other) {

-		if (!(other instanceof PeerInformation))

-			return false;

-		

-		return location.equals(((PeerInformation)other).location);

-	}

-}

diff --git a/src/alden/PeerMessage.java b/src/alden/PeerMessage.java
deleted file mode 100644
index a5af7de..0000000
--- a/src/alden/PeerMessage.java
+++ /dev/null
@@ -1,28 +0,0 @@
-package alden;

-import java.io.*;

-import java.util.*;

-

-

-public class PeerMessage implements Serializable {

-	private static final long serialVersionUID = 3667108226485766929L;

-	public static final String DEFAULT_ID = "TesseractProject"; 

-	

-	public enum Type {

-		JOIN, JOIN_RESULT, ADD_PEERS, REMOVE_PEERS, PAYLOAD, EXTRA;

-	}

-

-	public Type type;

-	public PeerInformation sender;

-	public PeerCoordinates location;

-	public ArrayList<PeerInformation> peers;

-	public CollidableObject payload;

-	public Object extra;

-	public String id;

-

-	public PeerMessage(Type type, PeerInformation sender) {

-		this.type = type;

-		this.sender = sender;

-		peers = new ArrayList<PeerInformation>();

-		this.id = DEFAULT_ID;

-	}

-}

diff --git a/src/alden/UnQuat4f.java b/src/alden/UnQuat4f.java
deleted file mode 100644
index 59295a9..0000000
--- a/src/alden/UnQuat4f.java
+++ /dev/null
@@ -1,658 +0,0 @@
-package alden;

-import javax.vecmath.*;

-

-/**

- * A 4 element unit quaternion represented by single precision floating 

- * point x,y,z,w coordinates.

- *

- */

-@SuppressWarnings("restriction")

-public class UnQuat4f extends Tuple4f implements java.io.Serializable {

-

-  // Combatible with 1.1

-  static final long serialVersionUID = 2675933778405442383L;

-

-  final static double EPS = 0.000001;

-  final static double EPS2 = 1.0e-30;

-  final static double PIO2 = 1.57079632679;

-

-  /**

-   * Constructs and initializes a Quat4f from the specified xyzw coordinates.

-   * @param x the x coordinate

-   * @param y the y coordinate

-   * @param z the z coordinate

-   * @param w the w scalar component

-   */

-  public UnQuat4f(float x, float y, float z, float w)

-  {

-      this.x =  x;

-      this.y =  y;

-      this.z =  z;

-      this.w =  w;

-

-  }

-

-  /**

-   * Constructs and initializes a Quat4f from the array of length 4. 

-   * @param q the array of length 4 containing xyzw in order

-   */

-  public UnQuat4f(float[] q)

-  {

-      x =  q[0];

-      y =  q[1];

-      z =  q[2];

-      w =  q[3];

-

-  }

-

-

-  /**

-   * Constructs and initializes a Quat4f from the specified Quat4f.

-   * @param q1 the Quat4f containing the initialization x y z w data

-   */

-  public UnQuat4f(UnQuat4f q1)

-  {

-       super(q1);

-  }

-

-

-    /** 

-     * Constructs and initializes a Quat4f from the specified Tuple4f. 

-     * @param t1 the Tuple4f containing the initialization x y z w data 

-     */  

-    public UnQuat4f(Tuple4f t1)  

-    { 

-      x =  t1.x;

-      y =  t1.y;

-      z =  t1.z;

-      w =  t1.w;

-

-    }

- 

- 

-    /** 

-     * Constructs and initializes a Quat4f from the specified Tuple4d.  

-     * @param t1 the Tuple4d containing the initialization x y z w data 

-     */  

-    public UnQuat4f(Tuple4d t1)

-    {

-      x =  (float)(t1.x);

-      y =  (float)(t1.y);

-      z =  (float)(t1.z);

-      w =  (float)(t1.w);

-    }

-

-

-  /**

-   * Constructs and initializes a Quat4f to (0.0,0.0,0.0,0.0).

-   */

-  public UnQuat4f()

-  {

-      super();

-  }

-

-

-  /**

-   * Sets the value of this quaternion to the conjugate of quaternion q1.

-   * @param q1 the source vector

-   */

-  public final void conjugate(UnQuat4f q1)

-  {

-    this.x = -q1.x;

-    this.y = -q1.y;

-    this.z = -q1.z;

-    this.w = q1.w;

-  }

-

-  /**

-   * Sets the value of this quaternion to the conjugate of itself.

-   */

-  public final void conjugate()

-  {

-    this.x = -this.x;

-    this.y = -this.y;

-    this.z = -this.z;

-  }

-

-

-  /**

-   * Sets the value of this quaternion to the quaternion product of

-   * quaternions q1 and q2 (this = q1 * q2).  

-   * Note that this is safe for aliasing (e.g. this can be q1 or q2).

-   * @param q1 the first quaternion

-   * @param q2 the second quaternion

-   */

-  public final void mul(UnQuat4f q1, UnQuat4f q2)

-  {

-    if (this != q1 && this != q2) {

-      this.w = q1.w*q2.w - q1.x*q2.x - q1.y*q2.y - q1.z*q2.z;

-      this.x = q1.w*q2.x + q2.w*q1.x + q1.y*q2.z - q1.z*q2.y;

-      this.y = q1.w*q2.y + q2.w*q1.y - q1.x*q2.z + q1.z*q2.x;

-      this.z = q1.w*q2.z + q2.w*q1.z + q1.x*q2.y - q1.y*q2.x;

-    } else {

-      float	x, y, w;

-

-      w = q1.w*q2.w - q1.x*q2.x - q1.y*q2.y - q1.z*q2.z;

-      x = q1.w*q2.x + q2.w*q1.x + q1.y*q2.z - q1.z*q2.y;

-      y = q1.w*q2.y + q2.w*q1.y - q1.x*q2.z + q1.z*q2.x;

-      this.z = q1.w*q2.z + q2.w*q1.z + q1.x*q2.y - q1.y*q2.x;

-      this.w = w;

-      this.x = x;

-      this.y = y;

-    }

-  }

-

-

- /**

-   * Sets the value of this quaternion to the quaternion product of

-   * itself and q1 (this = this * q1).  

-   * @param q1 the other quaternion

-   */

-  public final void mul(UnQuat4f q1)

-  {

-      float     x, y, w; 

-

-       w = this.w*q1.w - this.x*q1.x - this.y*q1.y - this.z*q1.z;

-       x = this.w*q1.x + q1.w*this.x + this.y*q1.z - this.z*q1.y;

-       y = this.w*q1.y + q1.w*this.y - this.x*q1.z + this.z*q1.x;

-       this.z = this.w*q1.z + q1.w*this.z + this.x*q1.y - this.y*q1.x;

-       this.w = w;

-       this.x = x;

-       this.y = y;

-  } 

-

-  /**

-   * Sets the value of this quaternion to the quaternion product of

-   * itself and q1 (this = this * q1).  

-   * @param q1 the other quaternion

-   */

-  public final void mul(Quat4f q1)

-  {

-      float     x, y, w; 

-

-       w = this.w*q1.w - this.x*q1.x - this.y*q1.y - this.z*q1.z;

-       x = this.w*q1.x + q1.w*this.x + this.y*q1.z - this.z*q1.y;

-       y = this.w*q1.y + q1.w*this.y - this.x*q1.z + this.z*q1.x;

-       this.z = this.w*q1.z + q1.w*this.z + this.x*q1.y - this.y*q1.x;

-       this.w = w;

-       this.x = x;

-       this.y = y;

-  }

-

- /** 

-   * Multiplies quaternion q1 by the inverse of quaternion q2 and places

-   * the value into this quaternion.  The value of both argument quaternions 

-   * is preservered (this = q1 * q2^-1).

-   * @param q1 the first quaternion

-   * @param q2 the second quaternion

-   */ 

-  public final void mulInverse(UnQuat4f q1, UnQuat4f q2) 

-  {   

-      UnQuat4f  tempQuat = new UnQuat4f(q2);  

- 

-      tempQuat.inverse(); 

-      this.mul(q1, tempQuat); 

-  }

- 

-

-

- /**

-   * Multiplies this quaternion by the inverse of quaternion q1 and places

-   * the value into this quaternion.  The value of the argument quaternion

-   * is preserved (this = this * q^-1).

-   * @param q1 the other quaternion

-   */

-  public final void mulInverse(UnQuat4f q1)

-  {  

-      UnQuat4f  tempQuat = new UnQuat4f(q1);

-

-      tempQuat.inverse();

-      this.mul(tempQuat);

-  }

-

-

-

-  /**

-   * Sets the value of this quaternion to quaternion inverse of quaternion q1.

-   * @param q1 the quaternion to be inverted

-   */

-  public final void inverse(UnQuat4f q1)

-  {

-    this.w =  q1.w;

-    this.x = -q1.x;

-    this.y = -q1.y;

-    this.z = -q1.z;

-  }

-

-

-  /**

-   * Sets the value of this quaternion to the quaternion inverse of itself.

-   */

-  public final void inverse()

-  {

-    this.w *=  1;

-    this.x *= -1;

-    this.y *= -1;

-    this.z *= -1;

-  }

-

-

-  /**

-   * Sets the value of this quaternion to the normalized value

-   * of quaternion q1.

-   * @param q1 the quaternion to be normalized.

-   */

-  public final void normalize(UnQuat4f q1)

-  {

-    float norm;

-

-    norm = (q1.x*q1.x + q1.y*q1.y + q1.z*q1.z + q1.w*q1.w);

-

-    if (norm > 0.0f) {

-      norm = 1.0f/(float)Math.sqrt(norm);

-      this.x = norm*q1.x;

-      this.y = norm*q1.y;

-      this.z = norm*q1.z;

-      this.w = norm*q1.w;

-    } else {

-      this.x = (float) 0.0;

-      this.y = (float) 0.0;

-      this.z = (float) 0.0;

-      this.w = (float) 0.0;

-    }

-  }

-

-

-  /**

-   * Normalizes the value of this quaternion in place.

-   */

-  public final void normalize()

-  {

-    float norm;

-

-    norm = (this.x*this.x + this.y*this.y + this.z*this.z + this.w*this.w);

-

-    if (norm > 0.0f) {

-      norm = 1.0f / (float)Math.sqrt(norm);

-      this.x *= norm;

-      this.y *= norm;

-      this.z *= norm;

-      this.w *= norm;

-    } else {

-      this.x = (float) 0.0;

-      this.y = (float) 0.0;

-      this.z = (float) 0.0;

-      this.w = (float) 0.0;

-    }

-  }

-

-

-  /**

-   * Sets the value of this quaternion to the rotational component of

-   * the passed matrix.

-   * @param m1 the Matrix4f

-   */

-   public final void set(Matrix4f m1) 

-   {

-       float ww = 0.25f*(m1.m00 + m1.m11 + m1.m22 + m1.m33);

-

-       if (ww >= 0) {

-	   if (ww >= EPS2) {

-	       this.w = (float) Math.sqrt((double)ww);

-	       ww =  0.25f/this.w;

-	       this.x = (m1.m21 - m1.m12)*ww;

-	       this.y = (m1.m02 - m1.m20)*ww;

-	       this.z = (m1.m10 - m1.m01)*ww;

-	       return;

-	   } 

-       } else {

-	   this.w = 0;

-	   this.x = 0;

-	   this.y = 0;

-	   this.z = 1;

-	   return;

-       }

-

-       this.w = 0;

-       ww = -0.5f*(m1.m11 + m1.m22);

-       

-       if (ww >= 0) {

-	   if (ww >= EPS2) {

-	       this.x = (float) Math.sqrt((double) ww);

-	       ww = 1.0f/(2.0f*this.x);

-	       this.y = m1.m10*ww;

-	       this.z = m1.m20*ww;

-	       return;

-	   }

-       } else {

-	   this.x = 0;

-	   this.y = 0;

-	   this.z = 1;

-	   return;

-       }

-     

-       this.x = 0;

-       ww = 0.5f*(1.0f - m1.m22);

-

-       if (ww >= EPS2) {

-	   this.y = (float) Math.sqrt((double) ww);

-	   this.z = m1.m21/(2.0f*this.y);

-	   return;

-       }

-     

-       this.y = 0;

-       this.z = 1;

-   }

-

-

-    /**

-     * Sets the value of this quaternion to the rotational component of

-     * the passed matrix.

-     * @param m1 the Matrix4d

-     */

-    public final void set(Matrix4d m1)

-    {

-	double ww = 0.25*(m1.m00 + m1.m11 + m1.m22 + m1.m33);

-

-	if (ww >= 0) {

-	    if (ww >= EPS2) {

-		this.w = (float) Math.sqrt(ww);

-		ww = 0.25/this.w;

-		this.x = (float) ((m1.m21 - m1.m12)*ww);

-		this.y = (float) ((m1.m02 - m1.m20)*ww);

-		this.z = (float) ((m1.m10 - m1.m01)*ww);

-		return;

-	    }

-	} else {

-	    this.w = 0;

-	    this.x = 0;

-	    this.y = 0;

-	    this.z = 1;

-	    return;

-	}

-

-	this.w = 0;

-	ww = -0.5*(m1.m11 + m1.m22);

-	if (ww >= 0) {

-	    if (ww >= EPS2) {

-		this.x = (float) Math.sqrt(ww);

-		ww = 0.5/this.x;

-		this.y = (float)(m1.m10*ww);

-		this.z = (float)(m1.m20*ww);

-		return;

-	    } 

-	} else {

-	    this.x = 0;

-	    this.y = 0;

-	    this.z = 1;

-	    return;

-	}

-     

-	this.x = 0;

-	ww = 0.5*(1.0 - m1.m22);

-	if (ww >= EPS2) {

-	    this.y = (float) Math.sqrt(ww);

-	    this.z = (float) (m1.m21/(2.0*(double)(this.y)));

-	    return;

-	}

-     

-	this.y = 0;

-	this.z = 1;

-    }

-

-

-    /**

-     * Sets the value of this quaternion to the rotational component of

-     * the passed matrix.

-     * @param m1 the Matrix3f

-     */

-    public final void set(Matrix3f m1)

-    {

-	float ww = 0.25f*(m1.m00 + m1.m11 + m1.m22 + 1.0f);

-

-	if (ww >= 0) {

-	    if (ww >= EPS2) {

-		this.w = (float) Math.sqrt((double) ww);

-		ww = 0.25f/this.w;

-		this.x = (m1.m21 - m1.m12)*ww;

-		this.y = (m1.m02 - m1.m20)*ww;

-		this.z = (m1.m10 - m1.m01)*ww;

-		return;

-	    }

-	} else {

-	    this.w = 0;

-	    this.x = 0;

-	    this.y = 0;

-	    this.z = 1;

-	    return;

-	}

-

-	this.w = 0;

-	ww = -0.5f*(m1.m11 + m1.m22);

-	if (ww >= 0) {

-	    if (ww >= EPS2) {

-		this.x = (float) Math.sqrt((double) ww);

-		ww = 0.5f/this.x;

-		this.y = m1.m10*ww;

-		this.z = m1.m20*ww;

-		return;

-	    }

-	} else {

-	    this.x = 0;

-	    this.y = 0;

-	    this.z = 1;

-	    return;

-	}

-

-	this.x = 0;

-	ww =  0.5f*(1.0f - m1.m22);

-	if (ww >= EPS2) {

-	    this.y = (float) Math.sqrt((double) ww);

-	    this.z = m1.m21/(2.0f*this.y);

-	    return;

-	}

-     

-	this.y = 0;

-	this.z = 1;

-    }

-

-

-    /**

-     * Sets the value of this quaternion to the rotational component of

-     * the passed matrix.

-     * @param m1 the Matrix3d

-     */

-    public final void set(Matrix3d m1)

-    {

-	double ww = 0.25*(m1.m00 + m1.m11 + m1.m22 + 1.0f);

-

-	if (ww >= 0) {

-	    if (ww >= EPS2) {

-		this.w = (float) Math.sqrt(ww);

-		ww = 0.25/this.w;

-		this.x = (float) ((m1.m21 - m1.m12)*ww);

-		this.y = (float) ((m1.m02 - m1.m20)*ww);

-		this.z = (float) ((m1.m10 - m1.m01)*ww);

-		return;

-	    }

-	} else {

-	    this.w = 0;

-	    this.x = 0;

-	    this.y = 0;

-	    this.z = 1;

-	    return;

-	}

-

-	this.w = 0;

-	ww = -0.5*(m1.m11 + m1.m22);

-	if (ww >= 0) {

-	    if (ww >= EPS2) {

-		this.x = (float) Math.sqrt(ww);

-		ww = 0.5/this.x;

-		this.y = (float) (m1.m10*ww);

-		this.z = (float) (m1.m20*ww);

-		return;

-	    }

-	} else {

-	    this.x = 0;

-	    this.y = 0;

-	    this.z = 1;

-	    return;

-	}

-     

-	this.x = 0;

-	ww = 0.5*(1.0 - m1.m22);

-	if (ww >= EPS2) {

-	    this.y = (float) Math.sqrt(ww);

-	    this.z = (float) (m1.m21/(2.0*(double)(this.y)));

-	    return;

-	}

-     

-	this.y = 0;

-	this.z = 1;

-    }

-

-

-    /**

-     * Sets the value of this quaternion to the equivalent rotation

-     * of the AxisAngle argument.

-     * @param a  the AxisAngle to be emulated

-     */

-    public final void set(AxisAngle4f a)

-    {

-	float mag,amag;

-	// Quat = cos(theta/2) + sin(theta/2)(roation_axis) 

-	amag = (float)Math.sqrt( a.x*a.x + a.y*a.y + a.z*a.z);

-	if (amag < EPS ) {

-	    w = 0.0f;

-	    x = 0.0f;

-	    y = 0.0f;

-	    z = 0.0f;

-	} else {  

-	    amag = 1.0f/amag; 

-	    mag = (float)Math.sin(a.angle/2.0);

-	    w = (float)Math.cos(a.angle/2.0);

-	    x = a.x*amag*mag;

-	    y = a.y*amag*mag;

-	    z = a.z*amag*mag;

-	}

-    }

-

-

-    /**

-     * Sets the value of this quaternion to the equivalent rotation

-     * of the AxisAngle argument.

-     * @param a  the AxisAngle to be emulated

-     */

-    public final void set(AxisAngle4d a)

-    {

-	float mag,amag;

-	// Quat = cos(theta/2) + sin(theta/2)(roation_axis) 

-	

-	amag = (float)(1.0/Math.sqrt( a.x*a.x + a.y*a.y + a.z*a.z));

-	

-	if (amag < EPS ) {

-	    w = 0.0f;

-	    x = 0.0f;

-	    y = 0.0f;

-	    z = 0.0f;

-	} else {  

-	    amag = 1.0f/amag; 

-	    mag = (float)Math.sin(a.angle/2.0);

-	    w = (float)Math.cos(a.angle/2.0);

-	    x = (float)a.x*amag*mag;

-	    y = (float)a.y*amag*mag;

-	    z = (float)a.z*amag*mag;

-	}

-	

-    }

-    

-

-    /**

-     *  Performs a great circle interpolation between this quaternion

-     *  and the quaternion parameter and places the result into this

-     *  quaternion.

-     *  @param q1  the other quaternion

-     *  @param alpha  the alpha interpolation parameter

-     */

-    public final void interpolate(UnQuat4f q1, float alpha) {

-	// From "Advanced Animation and Rendering Techniques"

-	// by Watt and Watt pg. 364, function as implemented appeared to be 

-	// incorrect.  Fails to choose the same quaternion for the double

-	// covering. Resulting in change of direction for rotations.

-	// Fixed function to negate the first quaternion in the case that the

-	// dot product of q1 and this is negative. Second case was not needed. 

-    

-     double dot,s1,s2,om,sinom;

-

-     dot = x*q1.x + y*q1.y + z*q1.z + w*q1.w;

-

-     if ( dot < 0 ) {

-        // negate quaternion

-       q1.x = -q1.x;  q1.y = -q1.y;  q1.z = -q1.z;  q1.w = -q1.w;

-       dot = -dot;

-     }

-

-     if ( (1.0 - dot) > EPS ) {

-       om = Math.acos(dot);

-       sinom = Math.sin(om);

-       s1 = Math.sin((1.0-alpha)*om)/sinom;

-       s2 = Math.sin( alpha*om)/sinom;

-     } else{

-       s1 = 1.0 - alpha;

-       s2 = alpha;

-     }

-

-     w = (float)(s1*w + s2*q1.w);

-     x = (float)(s1*x + s2*q1.x);

-     y = (float)(s1*y + s2*q1.y);

-     z = (float)(s1*z + s2*q1.z);

-  }

-

-

-

-  /** 

-    *  Performs a great circle interpolation between quaternion q1

-    *  and quaternion q2 and places the result into this quaternion. 

-    *  @param q1  the first quaternion

-    *  @param q2  the second quaternion

-    *  @param alpha  the alpha interpolation parameter 

-    */   

-    public final void interpolate(UnQuat4f q1, UnQuat4f q2, float alpha) { 

-	// From "Advanced Animation and Rendering Techniques"

-	// by Watt and Watt pg. 364, function as implemented appeared to be 

-	// incorrect.  Fails to choose the same quaternion for the double

-	// covering. Resulting in change of direction for rotations.

-	// Fixed function to negate the first quaternion in the case that the

-	// dot product of q1 and this is negative. Second case was not needed. 

-

-     double dot,s1,s2,om,sinom;

-

-     dot = q2.x*q1.x + q2.y*q1.y + q2.z*q1.z + q2.w*q1.w;

-     

-     if ( dot < 0 ) {

-        // negate quaternion

-       q1.x = -q1.x;  q1.y = -q1.y;  q1.z = -q1.z;  q1.w = -q1.w;

-       dot = -dot;

-     }

-

-     if ( (1.0 - dot) > EPS ) {

-       om = Math.acos(dot);

-       sinom = Math.sin(om);

-       s1 = Math.sin((1.0-alpha)*om)/sinom;

-       s2 = Math.sin( alpha*om)/sinom;

-     } else{

-       s1 = 1.0 - alpha;

-       s2 = alpha;

-     }

-     w = (float)(s1*q1.w + s2*q2.w);

-     x = (float)(s1*q1.x + s2*q2.x);

-     y = (float)(s1*q1.y + s2*q2.y);

-     z = (float)(s1*q1.z + s2*q2.z);

-  }

-

-}

-

-

-

-