Optimize moveBy and friends

This results in realtime speed for dragging where I used to get 10-15 fps before this change.

1 files changed, 1 insertions, 1 deletions

diff --git a/objects.js b/objects.js
index 8d11ff6..1e8060e 100644
--- a/objects.js
+++ b/objects.js
@@ -3290,7 +3290,7 @@ SpriteMorph.prototype.nestingBounds = function () {
 
 // SpriteMorph motion primitives
 
-Morph.prototype.setPosition = function (aPoint, justMe) {
+SpriteMorph.prototype.setPosition = function (aPoint, justMe) {
     // override the inherited default to make sure my parts follow
     // unless it's justMe
     var delta = aPoint.subtract(this.topLeft());