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, 3 insertions, 0 deletions

diff --git a/source/blender/makesdna/DNA_view3d_types.h b/source/blender/makesdna/DNA_view3d_types.h
index 4d88f6f0c15..fafc470b95a 100644
--- a/source/blender/makesdna/DNA_view3d_types.h
+++ b/source/blender/makesdna/DNA_view3d_types.h
@@ -373,6 +373,7 @@ typedef struct View3D {
 #define V3D_HIDE_HELPLINES (1 << 2)
 #define V3D_FLAG_UNUSED_2 (1 << 3) /* cleared */
 #define V3D_XR_SESSION_MIRROR (1 << 4)
+#define V3D_XR_SESSION_SURFACE (1 << 5)
 
 #define V3D_FLAG_UNUSED_10 (1 << 10) /* cleared */
 #define V3D_SELECT_OUTLINE (1 << 11)
@@ -465,6 +466,8 @@ enum {
 #define V3D_FLAG2_UNUSED_13 (1 << 13) /* cleared */
 #define V3D_FLAG2_UNUSED_14 (1 << 14) /* cleared */
 #define V3D_FLAG2_UNUSED_15 (1 << 15) /* cleared */
+#define V3D_XR_SHOW_CONTROLLERS (1 << 16)
+#define V3D_XR_SHOW_CUSTOM_OVERLAYS (1 << 17)
 
 /** #View3D.gp_flag (short) */
 #define V3D_GP_FADE_OBJECTS (1 << 0) /* Fade all non GP objects */