1 files changed, 89 insertions, 0 deletions
diff --git a/src/tesseract/objects/ForceableObject.java b/src/tesseract/objects/ForceableObject.java
new file mode 100644
index 0000000..3100a5a
--- /dev/null
+++ b/src/tesseract/objects/ForceableObject.java
@@ -0,0 +1,89 @@
+package tesseract.objects;
+
+import java.util.List;
+
+import javax.vecmath.Vector3f;
+
+/**
+ * This class is the an abstract parent class for forceable objects.
+ * 
+ * @author Jesse Morgan
+ */
+public class ForceableObject extends PhysicalObject implements Forceable {
+	/**
+	 * The inverse of the object's mass.
+	 */
+	protected float myInverseMass;
+	
+	/**
+	 * Object's velocity.
+	 */
+	private Vector3f myVelocity;
+	
+	/**
+	 * Sum of all the forces affecting this object.
+	 */
+	private Vector3f myForces;
+	
+	/**
+	 * Construct a new ForceableObject.
+	 * 
+	 * @param position Initial Position.
+	 * @param mass Initial Mass.
+	 */
+	public ForceableObject(final Vector3f position, final float mass) {
+		super(position);
+		
+		myInverseMass = 1 / mass;
+		myVelocity = new Vector3f(0, 0, 0);
+		myForces = new Vector3f(0, 0, 0);
+	}
+
+	/**
+	 * @return The inverse mass of the object.
+	 */
+	public float getInverseMass() {
+		return myInverseMass;
+	}
+	
+	/**
+	 * @return Get the velocity of the object.
+	 */
+	public Vector3f getVelocity() {
+		return myVelocity;
+	}
+
+	/**
+	 * Apply a new force to this object.
+	 * @param force The force to apply.
+	 */
+	public void addForce(final Vector3f force) {
+		myForces.add(force);
+	}
+	
+	/**
+	 * Update the state of the forceable object.
+	 * 
+	 * @param duration The length of time that has passed.
+	 * @return A list of new objects to add to the world.
+	 */
+	public List<PhysicalObject> updateState(final float duration) {
+		List<PhysicalObject> children = super.updateState(duration);
+		
+		// The force vector now becomes the acceleration vector.
+		myForces.scale(myInverseMass);
+		myPosition.scaleAdd(duration, myVelocity, myPosition);
+		myPosition.scaleAdd(duration * duration / 2, myForces, myPosition);
+		myVelocity.scaleAdd(duration, myForces, myVelocity);
+		
+		// The force vector is cleared.
+		myForces.x = 0;
+		myForces.y = 0;
+		myForces.z = 0;
+		
+		updateTransformGroup();
+		
+		return children;
+	}
+
+}