From 9ce9c959abb993b1c4edf242ff56ed5f568db791 Mon Sep 17 00:00:00 2001
From: dzil123 <5725958+dzil123@users.noreply.github.com>
Date: Sat, 19 Nov 2022 03:22:27 -0800
Subject: [PATCH] RenderingServer::create_local_rendering_device null check and
 docs

Co-authored-by: Clay John <claynjohn@gmail.com>
---
 doc/classes/RenderingServer.xml | 4 ++++
 servers/rendering_server.cpp    | 6 +++++-
 2 files changed, 9 insertions(+), 1 deletion(-)

diff --git a/doc/classes/RenderingServer.xml b/doc/classes/RenderingServer.xml
index 13e5470a56e..2ffa4dc50ba 100644
--- a/doc/classes/RenderingServer.xml
+++ b/doc/classes/RenderingServer.xml
@@ -838,6 +838,8 @@
 		<method name="create_local_rendering_device" qualifiers="const">
 			<return type="RenderingDevice" />
 			<description>
+				Creates a RenderingDevice that can be used to do draw and compute operations on a separate thread. Cannot draw to the screen nor share data with the global RenderingDevice.
+				[b]Note:[/b] When using the OpenGL backend or when running in headless mode, this function always returns [code]null[/code].
 			</description>
 		</method>
 		<method name="decal_create">
@@ -1273,6 +1275,8 @@
 		<method name="get_rendering_device" qualifiers="const">
 			<return type="RenderingDevice" />
 			<description>
+				Returns the global RenderingDevice.
+				[b]Note:[/b] When using the OpenGL backend or when running in headless mode, this function always returns [code]null[/code].
 			</description>
 		</method>
 		<method name="get_rendering_info">
diff --git a/servers/rendering_server.cpp b/servers/rendering_server.cpp
index a18a9d7460f..6cb1684baf5 100644
--- a/servers/rendering_server.cpp
+++ b/servers/rendering_server.cpp
@@ -1476,7 +1476,11 @@ RenderingDevice *RenderingServer::get_rendering_device() const {
 }
 
 RenderingDevice *RenderingServer::create_local_rendering_device() const {
-	return RenderingDevice::get_singleton()->create_local_device();
+	RenderingDevice *device = RenderingDevice::get_singleton();
+	if (!device) {
+		return nullptr;
+	}
+	return device->create_local_device();
 }
 
 static Vector<Ref<Image>> _get_imgvec(const TypedArray<Image> &p_layers) {