From 31f58ade96c2a32cb8951bdbe35b31ae39ce0b72 Mon Sep 17 00:00:00 2001
From: hey24sheep <hey24sheep@gmail.com>
Date: Mon, 13 Sep 2021 22:17:34 +0530
Subject: [PATCH] ctrl zoom feature

---
 source/viewer/navigation.js | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/source/viewer/navigation.js b/source/viewer/navigation.js
index a4a290d..dcbf9e6 100644
--- a/source/viewer/navigation.js
+++ b/source/viewer/navigation.js
@@ -396,7 +396,15 @@ OV.Navigation = class
 
 		let moveDiff = this.mouse.GetMoveDiff ();
 		let mouseButton = this.mouse.GetButton ();
-		if (mouseButton === 1) {
+		if (mouseButton === 1 && ev.ctrlKey) {
+			let params = ev || window.event;
+			let delta = -params.movementY / 40;
+			let ratio = 0.01;
+			if (delta < 0) {
+				ratio = ratio * -1.0;
+			}
+			this.Zoom(ratio);
+		} else if (mouseButton === 1) {
 			let orbitRatio = 0.5;
 			this.Orbit (moveDiff.x * orbitRatio, moveDiff.y * orbitRatio);
 		} else if (mouseButton === 2 || mouseButton === 3) {