feat: implement SceneBuilder.add_frame()

pyproject.toml

@@ -57,6 +57,7 @@ ignore = [
   "D107",   # __init__ docstrings are not necessary
   "D203",   # incompatible with D211
   "D213",   # incompatible with D212
+  "D413",   # rule by convention which looks weird
   "D417",   # kwargs can not be typed for the filter function
 
   "FBT001", # flags in functions are not bad practice

raillabel/scene_builder/scene_builder.py

@@ -5,10 +5,12 @@
 
 from copy import deepcopy
 from dataclasses import dataclass
+from decimal import Decimal
 from uuid import UUID
 
 from raillabel.format import (
     Camera,
+    Frame,
     GpsImu,
     IntrinsicsPinhole,
     IntrinsicsRadar,
@@ -84,6 +86,31 @@ def add_sensor(self, sensor_id: str) -> SceneBuilder:
 
         return SceneBuilder(scene)
 
+    def add_frame(self, frame_id: int | None = None, timestamp: float | None = None) -> SceneBuilder:
+        """Add a frame to the scene.
+
+        If no frame_id is provided, the frame_id is the lowest number not currently occupied by
+        another frame_id.
+
+        Example:
+        ```python
+        scene = SceneBuilder.empty().add_frame(frame_id=1).add_frame(frame_id=3).add_frame().result
+        assert sorted(list(scene.frames.keys())) == [1, 2, 3]
+        ```
+        """
+        scene = deepcopy(self.result)
+
+        if frame_id is None:
+            frame_id = 1
+            while frame_id in scene.frames:
+                frame_id += 1
+
+        scene.frames[frame_id] = Frame(
+            timestamp=Decimal(timestamp) if timestamp is not None else None
+        )
+
+        return SceneBuilder(scene)
+
 
 def _resolve_empty_object_name_or_type(
     object_type: str | None, object_name: str | None

tests/test_raillabel/scene_builder/test_scene_builder.py

@@ -3,6 +3,7 @@
 
 from __future__ import annotations
 from uuid import UUID
+from decimal import Decimal
 
 import pytest
 
@@ -19,6 +20,7 @@
     OtherSensor,
     IntrinsicsPinhole,
     IntrinsicsRadar,
+    Frame,
 )
 
 
@@ -173,5 +175,30 @@ def test_add_sensor__other():
     )
 
 
+def test_add_frame():
+    actual = SceneBuilder.empty().add_frame(1, 1631691173)
+    assert actual.result == Scene(
+        metadata=Metadata(schema_version="1.0.0"), frames={1: Frame(timestamp=Decimal(1631691173))}
+    )
+
+
+def test_add_frame__no_timestamp():
+    actual = SceneBuilder.empty().add_frame(1)
+    assert actual.result == Scene(
+        metadata=Metadata(schema_version="1.0.0"), frames={1: Frame(timestamp=None)}
+    )
+
+
+def test_add_frame__no_frame_id():
+    actual = SceneBuilder.empty().add_frame().add_frame()
+    assert actual.result == Scene(
+        metadata=Metadata(schema_version="1.0.0"),
+        frames={
+            1: Frame(),
+            2: Frame(),
+        },
+    )
+
+
 if __name__ == "__main__":
     pytest.main([__file__, "-vv"])