Added mouse wheel event to submap scatter.

lib/pixi/maps/scatter.js

@@ -272,15 +272,49 @@ export class SubmapScatter extends DisplayObjectScatter {
         })
 
         super(displayObject, renderer, opts)
-
-        console.log('onResize', opts.onResize)
         this.onResize = opts.onResize
     }
 
+
+    /**
+     * Adds mouse wheel resizing to the submap.
+     * 
+     * @param {MouseEvent} event - Event containing the mouse data.
+     * @memberof SubmapScatter
+     */
+    onMouseWheel(event) {
+        super.onMouseWheel(event)
+
+        if (this.onResize) {
+            const zoomFactor = 0.001
+            let zoom = 1 + zoomFactor * event.deltaY
+
+            let anchor = {
+                x: event.offsetX,
+                y: event.offsetY
+            }
+
+            this.onResize(anchor, zoom)
+        }
+    }
+
+
+    /**
+     * Overwrites the gesture to get access to the interaction pivot and scaling information.
+     * This calls the resize method to resize the submap.
+     *
+     * @private
+     * @param {interaction} interaction - Interaction element containing various informations about the touch interaction.
+     * @memberof SubmapScatter
+     */
     gesture(interaction) {
         super.gesture(interaction)
 
-        if (this.onResize) this.onResize(interaction)
+        if (this.onResize) {
+            let delta = interaction.delta()
+
+            this.onResize(delta.about, delta.zoom)
+        }
     }
 
     get width() {