XR Controller Support Step 4: Controller Drawing

Addresses T77127 (Controller Drawing).

Adds VR controller visualization and custom drawing via draw
handlers. Add-ons can draw to the XR surface (headset display) and
mirror window by adding a View3D draw handler of region type 'XR' and
draw type 'POST_VIEW'.  Controller drawing and custom overlays can be
toggled individually as XR session options, which will be added in a
future update to the VR Scene Inspection add-on.

For the actual drawing, the OpenXR XR_MSFT_controller_model extension
is used to load a glTF model provided by the XR runtime. The model's
vertex data is then used to create a GPUBatch in the XR session
state. Finally, this batch is drawn via the XR surface draw handler
mentioned above.

For runtimes that do not support the controller model extension, a
a simple fallback shape (sphere) is drawn instead.

Reviewed By: Severin, fclem

Differential Revision: https://developer.blender.org/D10948

1 files changed, 1 insertions, 0 deletions

diff --git a/source/blender/makesrna/intern/rna_screen.c b/source/blender/makesrna/intern/rna_screen.c
index 912f47ba9aa..a8f28f6091c 100644
--- a/source/blender/makesrna/intern/rna_screen.c
+++ b/source/blender/makesrna/intern/rna_screen.c
@@ -46,6 +46,7 @@ const EnumPropertyItem rna_enum_region_type_items[] = {
     {RGN_TYPE_EXECUTE, "EXECUTE", 0, "Execute Buttons", ""},
     {RGN_TYPE_FOOTER, "FOOTER", 0, "Footer", ""},
     {RGN_TYPE_TOOL_HEADER, "TOOL_HEADER", 0, "Tool Header", ""},
+    {RGN_TYPE_XR, "XR", 0, "XR", ""},
     {0, NULL, 0, NULL, NULL},
 };