Negative speed now plays an animation backwards

jme3-core/src/main/java/com/jme3/anim/tween/action/Action.java

@@ -22,7 +22,10 @@ public abstract class Action implements Tween {
 
     @Override
     public boolean interpolate(double t) {
-        return subInterpolate(t * speed);
+        t = t * speed;
+        // make sure negative time is in [0, length] range
+        t = (t % length + length) % length;
+        return subInterpolate(t);
     }
 
     public abstract boolean subInterpolate(double t);

jme3-examples/src/main/java/jme3test/model/anim/TestAnimMigration.java

@@ -165,20 +165,14 @@ public class TestAnimMigration extends SimpleApplication {
             composer.actionSequence("Sequence",
                     composer.makeAction("Walk"),
                     composer.makeAction("Run"),
-                    composer.makeAction("Jumping")).setSpeed(4);
+                    composer.makeAction("Jumping")).setSpeed(2);
 
             action = composer.actionBlended("Blend", new LinearBlendSpace(1, 4),
                     "Walk", "Run");
 
             action.getBlendSpace().setValue(1);
 
-            composer.action("Walk").setSpeed(2);
-
-//            composer.actionSequence("Sequence",
-//                    composer.tweenFromClip("Walk"),
-//                    composer.tweenFromClip("Dodge"),
-//                    composer.tweenFromClip("push"));
-
+            composer.action("Walk").setSpeed(-1);
 
             anims.addFirst("Sequence");
             anims.addFirst("Blend");