From 48c84a7efa1c737d092a515143e37e65a36147f2 Mon Sep 17 00:00:00 2001
From: Rob Watson <rob@netflux.io>
Date: Tue, 25 Jan 2022 20:06:15 +0100
Subject: [PATCH] Bug fix: avoid NaN in helper

---
 frontend/src/Waveform.tsx | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/frontend/src/Waveform.tsx b/frontend/src/Waveform.tsx
index a421cb5..aa9235e 100644
--- a/frontend/src/Waveform.tsx
+++ b/frontend/src/Waveform.tsx
@@ -109,7 +109,12 @@ export const Waveform: React.FC<Props> = ({
   // helpers
 
   const frameToCanvasX = (frame: number): number => {
-    const pixelsPerFrame = CanvasLogicalWidth / (viewport.end - viewport.start);
+    const numFrames = viewport.end - viewport.start;
+    if (numFrames == 0) {
+      return 0;
+    }
+
+    const pixelsPerFrame = CanvasLogicalWidth / numFrames;
     return Math.round((frame - viewport.start) * pixelsPerFrame);
   };