refactor: store storyboard entry mapping as JSON

src/addons/ui_skybrush_studio.py

@@ -55,7 +55,6 @@
     LEDControlPanelProperties,
     LightEffect,
     LightEffectCollection,
-    MappingType,
     SafetyCheckProperties,
     ScheduleOverride,
     StoryboardEntry,
@@ -147,7 +146,6 @@
     FormationsPanelProperties,
     LightEffect,
     LightEffectCollection,
-    MappingType,
     ScheduleOverride,
     StoryboardEntry,
     Storyboard,

src/modules/sbstudio/plugin/model/__init__.py

@@ -6,7 +6,7 @@
 from .safety_check import SafetyCheckProperties
 from .settings import DroneShowAddonFileSpecificSettings
 from .show import DroneShowAddonProperties
-from .storyboard import MappingType, ScheduleOverride, StoryboardEntry, Storyboard
+from .storyboard import ScheduleOverride, StoryboardEntry, Storyboard
 
 __all__ = (
     "DroneShowAddonFileSpecificSettings",
@@ -17,7 +17,6 @@
     "LEDControlPanelProperties",
     "LightEffect",
     "LightEffectCollection",
-    "MappingType",
     "SafetyCheckProperties",
     "ScheduleOverride",
     "StoryboardEntry",

src/modules/sbstudio/plugin/model/storyboard.py

@@ -1,4 +1,5 @@
 import bpy
+import json
 
 from bpy.props import (
     BoolProperty,
@@ -25,7 +26,7 @@
 from .formation import count_markers_in_formation
 from .mixins import ListMixin
 
-__all__ = ("MappingType", "ScheduleOverride", "StoryboardEntry", "Storyboard")
+__all__ = ("ScheduleOverride", "StoryboardEntry", "Storyboard")
 
 
 class ScheduleOverride(PropertyGroup):
@@ -84,17 +85,11 @@ def _handle_formation_change(operator, context):
         operator.name = operator.formation.name if operator.formation else ""
 
 
-class MappingType(bpy.types.PropertyGroup):
-    target = bpy.props.IntProperty()
-
-
 class StoryboardEntry(PropertyGroup):
     """Blender property group representing a single entry in the storyboard
     of the drone show.
     """
 
-    mapping = CollectionProperty(type=MappingType)
-
     maybe_uuid_do_not_use = StringProperty(
         name="Identifier",
         description=(
@@ -201,6 +196,20 @@ class StoryboardEntry(PropertyGroup):
         ),
     )
 
+    # mapping is stored as a string so we don't need to maintain a separate
+    # Blender collection as it would not be efficient
+
+    _mapping = StringProperty(
+        name="Mapping",
+        description=(
+            "Mapping where the i-th element is the index of the drone that "
+            "marker i was matched to in the storyboard entry, or -1 if the "
+            "marker is unmatched."
+        ),
+        default="",
+        options={"HIDDEN"},
+    )
+
     #: Sorting key for storyboard entries
     sort_key = attrgetter("frame_start", "frame_end")
 
@@ -295,6 +304,21 @@ def get_enabled_schedule_override_map(self) -> Dict[int, ScheduleOverride]:
 
         return result
 
+    def get_mapping(self) -> Optional[List[int]]:
+        """Returns the mapping of the markers in the storyboard entry to drone
+        indices, or ``None`` if there is no mapping yet.
+        """
+        encoded_mapping = self._mapping.strip()
+        if (
+            not encoded_mapping
+            or len(encoded_mapping) < 2
+            or encoded_mapping[0] != "["
+            or encoded_mapping[-1] != "]"
+        ):
+            return None
+        else:
+            return json.loads(encoded_mapping)
+
     def remove_active_schedule_override_entry(self) -> None:
         """Removes the active schedule override entry from the collection and
         adjusts the active entry index as needed.
@@ -309,6 +333,20 @@ def remove_active_schedule_override_entry(self) -> None:
             max(0, index), len(self.schedule_overrides)
         )
 
+    def update_mapping(self, mapping: Optional[List[int]]) -> None:
+        """Updates the mapping of the markers in the storyboard entry to drone
+        indices.
+
+        Arguments:
+            mapping: mapping where the i-th item contains the index of the drone
+                that the i-th marker was mapped to, or -1 if the marker is
+                 unmapped. You can also pass ``None`` to clear the entire mapping.
+        """
+        if mapping is None:
+            self._mapping = ""
+        else:
+            self._mapping = json.dumps(mapping)
+
 
 class Storyboard(PropertyGroup, ListMixin):
     """Blender property group representing the entire storyboard of the
@@ -558,11 +596,11 @@ def get_mapping_at_frame(self, frame: int):
         """
         index = self.get_index_of_entry_containing_frame(frame)
         if index >= 0:
-            return self.entries[index].mapping
+            return self.entries[index].get_mapping()
 
         index = self.get_index_of_entry_before_frame(frame)
         if index >= 0:
-            return self.entries[index].mapping
+            return self.entries[index].get_mapping()
 
         return None
 

src/modules/sbstudio/plugin/operators/recalculate_transitions.py

@@ -468,15 +468,19 @@ def update_transition_for_storyboard_entry(
         num_targets=num_markers,
     )
 
-    # store mapping in Blender-compatible format for later use
-    entry.mapping.clear()
-    for i in range(len(mapping)):
-        try:
-            j = mapping.index(i)
-            entry.mapping.add()
-            entry.mapping[-1].target = j
-        except ValueError:
-            break
+    # Store mapping in Blender-compatible format for later use
+    #
+    # 'mapping' is a list where the i-th element contains the index of the
+    # target point that the i-th drone was matched to, or ``None`` if the drone
+    # was left unmatched; we need to invert that so we get a vector where the
+    # i-th element is the index of the drone that marker i was matched to or
+    # -1 if the marker is unmatched
+    inv_mapping: List[int] = []
+    for drone_index, marker_index in enumerate(inv_mapping):
+        if len(inv_mapping) <= marker_index:
+            inv_mapping.extend([-1] * (marker_index - len(inv_mapping) + 1))
+        inv_mapping[marker_index] = drone_index
+    entry.update_mapping(inv_mapping)
 
     # Calculate how many drones will participate in the transition
     num_drones_transitioning = sum(