Events.onDragUpdate has a new 6th property fromStart which is a boolean. You can determine if the event was the result of the start of a drag movement or not by polling it (phaserjs#2155)

Author: photonstorm

README.md

@@ -307,6 +307,7 @@ If you are an exceptional JavaScript developer and would like to join the Phaser
 * EarCut now replaces PolyK, which fixes advanced Graphics mask triangulation issues such as #1941
 * Camera.checkBounds now takes the scale of the Camera into account (thanks @ForGorNorPor #2263)
 * InputHandler.consumePointerEvent has been removed, as it was never used internally anyway, so was misleading (thanks @GregoryAveryWeir #2227)
+* Events.onDragUpdate has a new 6th property `fromStart` which is a boolean. You can determine if the event was the result of the start of a drag movement or not by polling it (#2155)
 
 ### Bug Fixes
 

src/input/InputHandler.js

@@ -1036,14 +1036,19 @@ Phaser.InputHandler.prototype = {
     * @param {Phaser.Pointer} pointer
     * @return {boolean}
     */
-    updateDrag: function (pointer) {
+    updateDrag: function (pointer, fromStart) {
 
         if (pointer.isUp)
         {
             this.stopDrag(pointer);
             return false;
         }
 
+        if (fromStart === undefined)
+        {
+            fromStart = false;
+        }
+
         var px = this.globalToLocalX(pointer.x) + this._dragPoint.x + this.dragOffset.x;
         var py = this.globalToLocalY(pointer.y) + this._dragPoint.y + this.dragOffset.y;
 
@@ -1106,7 +1111,7 @@ Phaser.InputHandler.prototype = {
             }
         }
 
-        this.sprite.events.onDragUpdate.dispatch(this.sprite, pointer, px, py, this.snapPoint);
+        this.sprite.events.onDragUpdate.dispatch(this.sprite, pointer, px, py, this.snapPoint, fromStart);
 
         return true;
 
@@ -1330,7 +1335,7 @@ Phaser.InputHandler.prototype = {
             this._dragPoint.setTo(this.sprite.x - this.globalToLocalX(pointer.x), this.sprite.y - this.globalToLocalY(pointer.y));
         }
 
-        this.updateDrag(pointer);
+        this.updateDrag(pointer, true);
 
         if (this.bringToTop)
         {