XR: Allow variable count of action map subactions

Previously, the number of action map subactions was limited to two per
action (identified by user_path0, user_path1), however for devices with
more than two user paths (e.g. Vive Tracker) it will be useful to
support a variable amount instead.

For example, a single pose action could then be used to query the
positions of all connected trackers, with each tracker having its own
subaction tracking space.

NOTE: This introduces breaking changes for the XR Python API as follows:
- XrActionMapItem: The new `user_paths` collection property
replaces the `user_path0`/`user_path1` properties.
- XrActionMapBinding: The new `component_paths` collection property
replaces the `component_path0`/`component_path1` properties.

Reviewed By: Severin

Differential Revision: https://developer.blender.org/D13949

1 files changed, 22 insertions, 4 deletions

diff --git a/source/blender/makesdna/DNA_xr_types.h b/source/blender/makesdna/DNA_xr_types.h
index bf77339a494..09eab0d7bf7 100644
--- a/source/blender/makesdna/DNA_xr_types.h
+++ b/source/blender/makesdna/DNA_xr_types.h
@@ -106,8 +106,23 @@ typedef enum eXrPoseFlag {
   XR_POSE_AIM = (1 << 1),
 } eXrPoseFlag;
 
+/**
+ * The following user and component path lengths are dependent on OpenXR's XR_MAX_PATH_LENGTH
+ * (256). A user path will be combined with a component path to identify an action binding, and
+ * that combined path should also have a max of XR_MAX_PATH_LENGTH (e.g. user_path =
+ * /user/hand/left, component_path = /input/trigger/value, full_path =
+ * /user/hand/left/input/trigger/value).
+ */
+#define XR_MAX_USER_PATH_LENGTH 64
+#define XR_MAX_COMPONENT_PATH_LENGTH 192
+
 /* -------------------------------------------------------------------- */
 
+typedef struct XrComponentPath {
+  struct XrComponentPath *next, *prev;
+  char path[192]; /* XR_MAX_COMPONENT_PATH_LENGTH */
+} XrComponentPath;
+
 typedef struct XrActionMapBinding {
   struct XrActionMapBinding *next, *prev;
 
@@ -117,8 +132,7 @@ typedef struct XrActionMapBinding {
   /** OpenXR interaction profile path. */
   char profile[256];
   /** OpenXR component paths. */
-  char component_path0[192];
-  char component_path1[192];
+  ListBase component_paths; /* XrComponentPath */
 
   /** Input threshold/region. */
   float float_threshold;
@@ -132,6 +146,11 @@ typedef struct XrActionMapBinding {
 
 /* -------------------------------------------------------------------- */
 
+typedef struct XrUserPath {
+  struct XrUserPath *next, *prev;
+  char path[64]; /* XR_MAX_USER_PATH_LENGTH */
+} XrUserPath;
+
 typedef struct XrActionMapItem {
   struct XrActionMapItem *next, *prev;
 
@@ -142,8 +161,7 @@ typedef struct XrActionMapItem {
   char _pad[7];
 
   /** OpenXR user paths. */
-  char user_path0[64];
-  char user_path1[64];
+  ListBase user_paths; /* XrUserPath */
 
   /** Operator to be called on XR events. */
   char op[64]; /* OP_MAX_TYPENAME */