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, 2 insertions, 1 deletions

diff --git a/source/blender/editors/include/ED_view3d_offscreen.h b/source/blender/editors/include/ED_view3d_offscreen.h
index c490e96031f..8b695e61a35 100644
--- a/source/blender/editors/include/ED_view3d_offscreen.h
+++ b/source/blender/editors/include/ED_view3d_offscreen.h
@@ -60,7 +60,7 @@ void ED_view3d_draw_offscreen(struct Depsgraph *depsgraph,
 void ED_view3d_draw_offscreen_simple(struct Depsgraph *depsgraph,
                                      struct Scene *scene,
                                      struct View3DShading *shading_override,
-                                     int drawtype,
+                                     eDrawType drawtype,
                                      int winx,
                                      int winy,
                                      unsigned int draw_flags,
@@ -68,6 +68,7 @@ void ED_view3d_draw_offscreen_simple(struct Depsgraph *depsgraph,
                                      const float winmat[4][4],
                                      float clip_start,
                                      float clip_end,
+                                     bool is_xr_surface,
                                      bool is_image_render,
                                      bool draw_background,
                                      const char *viewname,