Update to "Implement linear and angular velocity damping"

DanielChappuis/reactphysics3d@2e6f571b98f6247c
d007ca265d16c1b728897fbc

Author: DDoS

src/main/java/org/spout/physics/body/RigidBody.java

@@ -47,6 +47,8 @@ public class RigidBody extends CollisionBody {
     private final Vector3 mExternalTorque = new Vector3();
     private final Vector3 mLinearVelocity = new Vector3();
     private final Vector3 mAngularVelocity = new Vector3();
+    private float mLinearDamping;
+    private float mAngularDamping;
 
     /**
      * Constructs a new rigid body from its transform, mass, local inertia tensor, collision shape and ID.
@@ -64,6 +66,8 @@ public RigidBody(Transform transform, float mass, Matrix3x3 inertiaTensorLocal,
         mInertiaTensorLocalInverse = inertiaTensorLocal.getInverse();
         mMassInverse = 1 / mass;
         mIsGravityEnabled = true;
+        mLinearDamping = 0;
+        mAngularDamping = 0;
     }
 
     /**
@@ -251,4 +255,46 @@ public void setMaterial(Material material) {
     public Material getMaterial() {
         return mMaterial;
     }
+
+    /**
+     * Returns the linear velocity damping factor.
+     *
+     * @return The linear damping
+     */
+    public float getLinearDamping() {
+        return mLinearDamping;
+    }
+
+    /**
+     * Sets the linear damping factor.
+     *
+     * @param linearDamping The liner damping
+     */
+    public void setLinearDamping(float linearDamping) {
+        if (linearDamping < 0) {
+            throw new IllegalArgumentException("Linear damping must be greater or equal to 0");
+        }
+        mLinearDamping = linearDamping;
+    }
+
+    /**
+     * Returns the angular velocity damping factor.
+     *
+     * @return The angular damping
+     */
+    public float getAngularDamping() {
+        return mAngularDamping;
+    }
+
+    /**
+     * Sets the angular damping factor.
+     *
+     * @param angularDamping The angular damping
+     */
+    public void setAngularDamping(float angularDamping) {
+        if (angularDamping < 0) {
+            throw new IllegalArgumentException("Angular damping must be greater or equal to 0");
+        }
+        mAngularDamping = angularDamping;
+    }
 }

src/main/java/org/spout/physics/engine/DynamicsWorld.java

@@ -53,6 +53,7 @@
 import org.spout.physics.constraint.HingeJoint.HingeJointInfo;
 import org.spout.physics.constraint.SliderJoint;
 import org.spout.physics.constraint.SliderJoint.SliderJointInfo;
+import org.spout.physics.math.Mathematics;
 import org.spout.physics.math.Matrix3x3;
 import org.spout.physics.math.Quaternion;
 import org.spout.physics.math.Transform;
@@ -355,6 +356,12 @@ private void integrateRigidBodiesVelocities() {
                 if (rigidBody.isGravityEnabled() && mIsGravityOn) {
                     mConstrainedLinearVelocities.get(i).add(Vector3.multiply(dt * rigidBody.getMassInverse() * rigidBody.getMass(), mGravity));
                 }
+                final float linDampingFactor = rigidBody.getLinearDamping();
+                final float angDampingFactor = rigidBody.getAngularDamping();
+                final float linearDamping = Mathematics.clamp(1 - dt * linDampingFactor, 0, 1);
+                final float angularDamping = Mathematics.clamp(1 - dt * angDampingFactor, 0, 1);
+                mConstrainedLinearVelocities.get(i).multiply(Mathematics.clamp(linearDamping, 0, 1));
+                mConstrainedAngularVelocities.get(i).multiply(Mathematics.clamp(angularDamping, 0, 1));
                 rigidBody.updateOldTransform();
             } else {
                 mConstrainedLinearVelocities.add(i, new Vector3(0, 0, 0));