From 8d1d2efea46fd258029546b815ad6ef558dde71b Mon Sep 17 00:00:00 2001
From: Mike Welsh <mwelsh@gmail.com>
Date: Wed, 6 Jan 2021 13:01:07 -0800
Subject: [PATCH] webgl: Request OES_element_index_uint extension on WebGL1

Needed to support u32 index buffers.
---
 render/webgl/src/lib.rs | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/render/webgl/src/lib.rs b/render/webgl/src/lib.rs
index b0578ae33..ce575bfec 100644
--- a/render/webgl/src/lib.rs
+++ b/render/webgl/src/lib.rs
@@ -146,6 +146,12 @@ impl WebGlRenderBackend {
                     .into_js_result()?
                     .ok_or("VAO extension not found")?
                     .unchecked_into::<OesVertexArrayObject>();
+
+                // On WebGL1, we need to explicitly request support for u32 index buffers.
+                let _ext = gl
+                    .get_extension("OES_element_index_uint")
+                    .into_js_result()?
+                    .ok_or("OES_element_index_uint extension not available")?;
                 (gl, None, vao, 1)
             } else {
                 return Err("Unable to create WebGL rendering context".into());