1 files changed, 121 insertions, 0 deletions
diff --git a/src/tesseract/PhysicalObject.java b/src/tesseract/PhysicalObject.java
new file mode 100644
index 0000000..b334082
--- /dev/null
+++ b/src/tesseract/PhysicalObject.java
@@ -0,0 +1,121 @@
+package tesseract;
+
+import java.awt.Color;
+
+import javax.media.j3d.Appearance;
+import javax.media.j3d.BranchGroup;
+import javax.media.j3d.ColoringAttributes;
+import javax.media.j3d.Group;
+import javax.media.j3d.Node;
+import javax.media.j3d.Transform3D;
+import javax.media.j3d.TransformGroup;
+import javax.vecmath.Color3f;
+import javax.vecmath.Vector3f;
+
+import com.sun.j3d.utils.geometry.Sphere;
+
+/**
+ * This class is the parent of all objects in the world.
+ * 
+ * @author Jesse Morgan
+ */
+public abstract class PhysicalObject {
+	/**
+	 * The inverse of the object's mass.
+	 */
+	protected float inverseMass;
+	
+	/**
+	 * The object's current position.
+	 */
+	private Vector3f myPosition;
+	
+	/**
+	 * The object's previous position.
+	 */
+	private Vector3f myPrevPosition;
+	
+	private Vector3f myVelocity;
+	
+	private BranchGroup BG;
+	private TransformGroup TG;
+
+	public PhysicalObject(final Vector3f position, final float mass) {
+		inverseMass = 1 / mass;
+		myPosition = new Vector3f(position);
+		myPrevPosition = new Vector3f(position);
+	}
+	
+	public Particle(Color3f color, Vector3f position, Vector3f velocity) {
+		inverseMass = 1;
+		this.position = new Vector3f(position);
+		prevPosition = new Vector3f(position);
+		this.velocity = new Vector3f(velocity);
+		force = new Vector3f();
+		TG = new TransformGroup();
+		TG.setCapability(TransformGroup.ALLOW_TRANSFORM_WRITE);
+		TG.addChild(createShape(color));
+		BG = new BranchGroup();
+		BG.setCapability(BranchGroup.ALLOW_DETACH);
+		BG.addChild(TG);
+		updateTransformGroup();
+	}
+	
+	public float getInverseMass() {
+		return inverseMass;
+	}
+
+	public Vector3f getPosition() {
+		return myPosition;
+	}
+
+	public Vector3f getPreviousPosition() {
+		return myPrevPosition;
+	}
+
+	public Vector3f getVelocity() {
+		return velocity;
+	}
+
+	public Group getGroup() {
+		return BG;
+	}
+	
+	public void detach() {
+		BG.detach();
+	}
+
+	public void addForce(Vector3f force) {
+		this.force.add(force);
+	}
+
+	public void updateState(float duration) {
+		// The force vector now becomes the acceleration vector.
+		force.scale(inverseMass);
+		prevPosition.set(position);
+		position.scaleAdd(duration, velocity, position);
+		position.scaleAdd(duration * duration / 2, force, position);
+		velocity.scaleAdd(duration, force, velocity);
+		// The force vector is cleared.
+		force.x = force.y = force.z = 0;
+		updateTransformGroup();
+	}
+
+	public void updateTransformGroup() {
+		Transform3D tmp = new Transform3D();
+		tmp.setTranslation(position);
+		TG.setTransform(tmp);
+	}
+	
+	private Node createShape(Color3f color) {
+		ColoringAttributes cAttr;
+		if (color == null) {
+			Color randomColor = Color.getHSBColor((float)Math.random(), 1, 1);
+			color = new Color3f(randomColor);
+		}
+		cAttr = new ColoringAttributes(color, ColoringAttributes.FASTEST);
+		Appearance appearance = new Appearance();
+		appearance.setColoringAttributes(cAttr);
+		return new Sphere(RADIUS, 0, 8, appearance);
+	}
+}