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, 24 insertions, 0 deletions

diff --git a/intern/ghost/GHOST_C-api.h b/intern/ghost/GHOST_C-api.h
index b78aac6f5eb..784febe8581 100644
--- a/intern/ghost/GHOST_C-api.h
+++ b/intern/ghost/GHOST_C-api.h
@@ -1140,6 +1140,30 @@ void GHOST_XrGetActionCustomdataArray(GHOST_XrContextHandle xr_context,
                                       const char *action_set_name,
                                       void **r_customdata_array);
 
+/* controller model */
+/**
+ * Load the OpenXR controller model.
+ */
+int GHOST_XrLoadControllerModel(GHOST_XrContextHandle xr_context, const char *subaction_path);
+
+/**
+ * Unload the OpenXR controller model.
+ */
+void GHOST_XrUnloadControllerModel(GHOST_XrContextHandle xr_context, const char *subaction_path);
+
+/**
+ * Update component transforms for the OpenXR controller model.
+ */
+int GHOST_XrUpdateControllerModelComponents(GHOST_XrContextHandle xr_context,
+                                            const char *subaction_path);
+
+/**
+ * Get vertex data for the OpenXR controller model.
+ */
+int GHOST_XrGetControllerModelData(GHOST_XrContextHandle xr_context,
+                                   const char *subaction_path,
+                                   GHOST_XrControllerModelData *r_data);
+
 #endif /* WITH_XR_OPENXR */
 
 #ifdef __cplusplus