From 09e2b6a3c70a16c4416453d057c407929bc5c2fe Mon Sep 17 00:00:00 2001
From: James Darpinian <jdarpinian@gmail.com>
Date: Fri, 3 Jan 2025 22:37:03 -0800
Subject: [PATCH] Fix crash when setting upload sliders to 0 (#485)

---
 sample/workloadSimulator/index.html | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/sample/workloadSimulator/index.html b/sample/workloadSimulator/index.html
index 7b185b8f..b82c22bd 100644
--- a/sample/workloadSimulator/index.html
+++ b/sample/workloadSimulator/index.html
@@ -551,7 +551,8 @@ <h2><center>Web graphics workload simulator</center></h2>
       // We want to actually use this data in rendering so the graphics driver
       // can't optimize away the upload. Fill the first few bytes with our real
       // vertex data.
-      bufferDataArray.set(vertices, 0);
+      if (bufferDataArray.length > 0)
+        bufferDataArray.set(vertices, 0);
     }
   }
 
@@ -563,7 +564,8 @@ <h2><center>Web graphics workload simulator</center></h2>
 
   if (mapAsyncArray.length * 4 != mapAsync.value * 1024 * 1024) {
     mapAsyncArray = new Float32Array(mapAsync.value * 1024 * 1024 / 4);
-    mapAsyncArray.set(vertices, 0);
+    if (mapAsyncArray.length > 0)
+      mapAsyncArray.set(vertices, 0);
   }
 
   // Calculate how many instances and draw calls we need based on slider values.