From 68c98d1293e048dcee57778386a4b98a6fb33551 Mon Sep 17 00:00:00 2001
From: Uwe Oestermeier <u.oestermeier@iwm-tuebingen.de>
Date: Fri, 19 Jul 2019 15:05:46 +0200
Subject: [PATCH] Added check for rotation by narrow distance between touch
 points.

---
 lib/interaction.js | 7 +++++--
 lib/scatter.js     | 6 +++++-
 2 files changed, 10 insertions(+), 3 deletions(-)

diff --git a/lib/interaction.js b/lib/interaction.js
index cf85729..2468842 100755
--- a/lib/interaction.js
+++ b/lib/interaction.js
@@ -131,15 +131,17 @@ export class InteractionDelta {
      * @param {*} rotate
      * @param {*} about
      * @param {*} number - number of involved pointer
+     * @param {*} distance - distance of farthests touch points
      * @memberof InteractionDelta
      */
-    constructor(x, y, zoom, rotate, about, number) {
+    constructor(x, y, zoom, rotate, about, number, distance) {
         this.x = x
         this.y = y
         this.zoom = zoom
         this.rotate = rotate
         this.about = about
         this.number = number
+        this.distance = distance
     }
 
     toString() {
@@ -235,7 +237,8 @@ export class InteractionPoints {
                 zoom,
                 alpha,
                 cm,
-                csize
+                csize,
+                distance2
             )
         } else if (
             csize == 1 &&
diff --git a/lib/scatter.js b/lib/scatter.js
index c29c22a..3ab314e 100644
--- a/lib/scatter.js
+++ b/lib/scatter.js
@@ -286,6 +286,7 @@ export class AbstractScatter extends Throwable {
         scaleCloseThreshold = 0.1,
         scaleCloseBuffer = 0.05,
         maxRotation = Angle.degree2radian(5),
+        minRotationDistance = 200,
         useLowPassFilter = true
     } = {}) {
         if (rotationDegrees != null && rotation != null) {
@@ -331,6 +332,7 @@ export class AbstractScatter extends Throwable {
         this.mouseZoomFactor = mouseZoomFactor
         this.autoBringToFront = autoBringToFront
         this.useLowPassFilter = useLowPassFilter
+        this.minRotationDistance = minRotationDistance
         if (useLowPassFilter) {
             this.rotateLPF = new LowPassFilter()
             this.zoomLPF = new LowPassFilter()
@@ -387,7 +389,9 @@ export class AbstractScatter extends Throwable {
             if (this.useLowPassFilter) {
                 rotate = this.rotateLPF.next(rotate)
                 zoom = this.zoomLPF.next(zoom)
-                // console.log({rotate, zoom})
+                if (delta.distance < this.minRotationDistance) {
+                    rotate = 0
+                }
             }
             this.transform(delta, zoom, rotate, delta.about)
             if (zoom != 1) this.interactionAnchor = delta.about