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, 1 deletions

diff --git a/intern/ghost/GHOST_Types.h b/intern/ghost/GHOST_Types.h
index 898ee451baf..2c8014a08cc 100644
--- a/intern/ghost/GHOST_Types.h
+++ b/intern/ghost/GHOST_Types.h
@@ -754,8 +754,31 @@ typedef struct GHOST_XrActionProfileInfo {
   const char *profile_path;
   uint32_t count_subaction_paths;
   const char **subaction_paths;
-  /* Bindings for each subaction path. */
+  /** Bindings for each subaction path. */
   const GHOST_XrActionBindingInfo *bindings;
 } GHOST_XrActionProfileInfo;
 
+typedef struct GHOST_XrControllerModelVertex {
+  float position[3];
+  float normal[3];
+} GHOST_XrControllerModelVertex;
+
+typedef struct GHOST_XrControllerModelComponent {
+  /** World space transform. */
+  float transform[4][4];
+  uint32_t vertex_offset;
+  uint32_t vertex_count;
+  uint32_t index_offset;
+  uint32_t index_count;
+} GHOST_XrControllerModelComponent;
+
+typedef struct GHOST_XrControllerModelData {
+  uint32_t count_vertices;
+  const GHOST_XrControllerModelVertex *vertices;
+  uint32_t count_indices;
+  const uint32_t *indices;
+  uint32_t count_components;
+  const GHOST_XrControllerModelComponent *components;
+} GHOST_XrControllerModelData;
+
 #endif /* WITH_XR_OPENXR */