From b4a75ff58eae83605751f896cd97fc9694092bed Mon Sep 17 00:00:00 2001
From: Ellpeck <megamaximal@gmail.com>
Date: Mon, 15 Jun 2020 16:49:13 +0200
Subject: [PATCH] better touch controls!

---
 TouchyTickets/ParkMap.cs | 17 +++++++----------
 1 file changed, 7 insertions(+), 10 deletions(-)

diff --git a/TouchyTickets/ParkMap.cs b/TouchyTickets/ParkMap.cs
index 80cf52a..d18ef4c 100644
--- a/TouchyTickets/ParkMap.cs
+++ b/TouchyTickets/ParkMap.cs
@@ -79,15 +79,12 @@ namespace TouchyTickets {
             if (GameImpl.Instance.DrawMap && GameImpl.Instance.UiSystem.Controls.HandleTouch) {
                 var camera = GameImpl.Instance.Camera;
                 if (MlemGame.Input.GetGesture(GestureType.Pinch, out var pinch)) {
-                    var startDiff = pinch.Position2 - pinch.Position;
-                    var endDiff = pinch.Position2 + pinch.Delta2 - (pinch.Position + pinch.Delta);
-                    if (startDiff.LengthSquared() < endDiff.LengthSquared()) {
-                        // zooming in
-                        camera.Zoom(pinch.Delta.Length() / camera.Scale);
-                    } else {
-                        // zooming out
-                        camera.Zoom(-pinch.Delta.Length() / camera.Scale);
-                    }
+                    // pinch zoom
+                    var center = (pinch.Position + pinch.Position2) / 2;
+                    var newDist = Vector2.Distance(pinch.Position + pinch.Delta, pinch.Position2 + pinch.Delta2);
+                    var oldDist = Vector2.Distance(pinch.Position, pinch.Position2);
+                    var newScale = newDist / oldDist * camera.Scale;
+                    camera.Zoom(newScale - camera.Scale, center);
                 } else if (MlemGame.Input.GetGesture(GestureType.FreeDrag, out var drag)) {
                     if (this.draggingAttraction) {
                         // move the current placing position
@@ -98,7 +95,7 @@ namespace TouchyTickets {
                             this.PlacingPosition = nextPos;
                     } else {
                         // move the camera
-                        camera.Position -= drag.Delta / camera.Scale;
+                        camera.Position -= drag.Delta / camera.ActualScale;
                     }
                 } else if (this.PlacingAttraction != null) {
                     foreach (var touch in MlemGame.Input.TouchState) {