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, 10 insertions, 1 deletions

diff --git a/source/blender/makesdna/DNA_xr_types.h b/source/blender/makesdna/DNA_xr_types.h
index a9d427777f7..6f4f7e3e8ae 100644
--- a/source/blender/makesdna/DNA_xr_types.h
+++ b/source/blender/makesdna/DNA_xr_types.h
@@ -42,7 +42,9 @@ typedef struct XrSessionSettings {
 
   /** View3D draw flags (V3D_OFSDRAW_NONE, V3D_OFSDRAW_SHOW_ANNOTATION, ...). */
   char draw_flags;
-  char _pad2[3];
+  /** Draw style for controller visualization. */
+  char controller_draw_style;
+  char _pad2[2];
 
   /** Clipping distance. */
   float clip_start, clip_end;
@@ -61,6 +63,13 @@ typedef enum eXRSessionBasePoseType {
   XR_BASE_POSE_CUSTOM = 2,
 } eXRSessionBasePoseType;
 
+typedef enum eXrSessionControllerDrawStyle {
+  XR_CONTROLLER_DRAW_DARK = 0,
+  XR_CONTROLLER_DRAW_LIGHT = 1,
+  XR_CONTROLLER_DRAW_DARK_RAY = 2,
+  XR_CONTROLLER_DRAW_LIGHT_RAY = 3,
+} eXrSessionControllerDrawStyle;
+
 /** XR action type. Enum values match those in GHOST_XrActionType enum for consistency. */
 typedef enum eXrActionType {
   XR_BOOLEAN_INPUT = 1,