From 049ebdd54203183d5865fbcc7679c33e726d900c Mon Sep 17 00:00:00 2001
From: Andrey Antukh <niwi@niwi.nz>
Date: Tue, 9 May 2023 14:08:35 +0200
Subject: [PATCH] :bug: Fix intermitent exception on viewport ref ns

---
 .../src/app/main/ui/workspace/viewport/viewport_ref.cljs     | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/frontend/src/app/main/ui/workspace/viewport/viewport_ref.cljs b/frontend/src/app/main/ui/workspace/viewport/viewport_ref.cljs
index aa293f191..32bd7fccf 100644
--- a/frontend/src/app/main/ui/workspace/viewport/viewport_ref.cljs
+++ b/frontend/src/app/main/ui/workspace/viewport/viewport_ref.cljs
@@ -39,7 +39,6 @@
 
 (defn create-viewport-ref
   []
-  
   (let [ref (mf/use-ref nil)]
     [ref
      (mf/use-memo
@@ -51,11 +50,13 @@
 (defn point->viewport
   [pt]
   (let [zoom (dm/get-in @st/state [:workspace-local :zoom])]
-    (when (some? @viewport-ref)
+    (when (and (some? @viewport-ref)
+               (some? @viewport-brect))
       (let [vbox     (.. ^js @viewport-ref -viewBox -baseVal)
             brect    @viewport-brect
             box      (gpt/point (.-x vbox) (.-y vbox))
             zoom     (gpt/point zoom)]
+
         (-> (gpt/subtract pt brect)
             (gpt/divide zoom)
             (gpt/add box))))))