Document the new GDK_VULKAN_DEVICE envvar

Best to document them while they're fresh.

diff --git a/docs/reference/gtk/running.sgml b/docs/reference/gtk/running.sgml
index b717d717c244c3cb03b157066f1e13d28712b20d..827f7b715bf900b652e05a3285cdd47f757b2293 100644 (file)
--- a/docs/reference/gtk/running.sgml
+++ b/docs/reference/gtk/running.sgml
@@ -471,7 +471,7 @@ nevertheless.
       <listitem><para>Disable Vulkan support</para></listitem>
     </varlistentry>
     <varlistentry>
-      <term>validate </term>
+      <term>validate</term>
       <listitem><para>Enable the Vulkan validation layer</para></listitem>
     </varlistentry>
   </variablelist>
@@ -481,6 +481,17 @@ nevertheless.
   </para>
 </formalpara>
 
+<formalpara>
+  <title><envar>GDK_VULKAN_DEVICE</envar></title>
+
+  <para>
+    This variable can be set to the index of a Vulkan device to override the
+    default selection of the device that is used for Vulkan rendering.
+    The special value <literal>list</literal> can be used to obtain a list
+    of all Vulkan devices.
+  </para>
+</formalpara>
+
 <formalpara>
   <title><envar>GTK_CSD</envar></title>