Unported the getFrameVelocity() method from PositionTransition3f and

PositionTransition3d since a) it's not a velocity and b) embeds a few too
many assumptions on how to handle half a frame... assumptions the caller
wouldn't have to make and could easily do the calculation themselves.
Officially deprecated it on PositionTransition (even though the class is
already completely deprecated) just for documentation purposes.

Author: pspeed42

release-notes.md

@@ -10,6 +10,8 @@ Version 1.3.0 (unreleased)
 * Added PositionTransition3f and PositionTransition3d.
 * Deprecated PositionTransition in favor of PositionTransition3f or 
     PositionTransition3d.
+* Deprecated PositionTransition.getFrameVelocity() and did not port it
+    to PositionTransition3f or PositionTransition3d.
 
 
 Version 1.2.0 (latest)

src/main/java/com/simsilica/mathd/trans/PositionTransition.java

@@ -120,6 +120,13 @@ protected final float tween( long time ) {
         return part / length;   
     }
 
+    /**
+     *  @deprecated This is actually not a velocity and doesn't properly cover
+     *              the case where an end is null.  The caller can easily calculate
+     *              this information themselves and decide what to do with a null
+     *              end point.
+     */
+    @Deprecated
     public Vector3f getFrameVelocity() {
         return new Vector3f( endPos.x - startPos.x, endPos.y - startPos.y, endPos.z - startPos.z );
     }

src/main/java/com/simsilica/mathd/trans/PositionTransition3d.java

@@ -109,10 +109,6 @@ protected final double tween( long time ) {
         return part / length;   
     }
 
-    public Vec3d getFrameVelocity() {
-        return new Vec3d( endPos.x - startPos.x, endPos.y - startPos.y, endPos.z - startPos.z );
-    }
-    
     public Vec3d getPosition( long time ) {
         return getPosition(time, false);
     }

src/main/java/com/simsilica/mathd/trans/PositionTransition3f.java

@@ -117,10 +117,6 @@ protected final float tween( long time ) {
         return part / length;   
     }
 
-    public Vector3f getFrameVelocity() {
-        return new Vector3f( endPos.x - startPos.x, endPos.y - startPos.y, endPos.z - startPos.z );
-    }
-    
     public Vector3f getPosition( long time ) {
         return getPosition(time, false);
     }