Source code for simulation.utils.geometry.frame

"""Coordinate frame class that can be connected to other frames.

The idea of this class is to provide a simple API of dealing with geometric objects in
multiple coordinate frames easily.

from dataclasses import dataclass, field
from typing import Any, Dict, NewType

TransformType = NewType("Transform", Any)

[docs]@dataclass class Frame: name: str """Name of the frame.""" _connected_frames: Dict[str, TransformType] = field(init=False, default_factory=dict) """Dictionary with other connected frames."""
[docs] def connect_to(self, frame: "Frame", *, transformation_to_frame: TransformType): """Connect this frame to another frame through a transformation. This also connects the other frame to this one. """ if == raise ValueError("Cannot connect to a frame with the same name.") self._connected_frames[] = transformation_to_frame.inverse frame._connected_frames[] = transformation_to_frame
def __call__(self, geom_obj): """Calling an instance transforms the argument's coordinates into this frame.""" if not hasattr(geom_obj, "_frame"): raise ValueError("Cannot transform object that has no frame.") elif geom_obj._frame is self: return geom_obj if not in self._connected_frames: raise ValueError("Transformation to frame {geom_obj._frame} is unknown.") transformed = self._connected_frames[] * geom_obj transformed._frame = self return transformed
[docs]def validate_and_maintain_frames(func): """Ensure that both objects are in the same coordinate frame.""" def decorator(self, *args, **kwargs): if len(args) == 0 and len(kwargs) == 0: obj2 = None elif len(args) == 0: obj2 = next(iter(kwargs.values())) else: obj2 = args[0] if ( not hasattr(obj2, "_frame") or (self._frame is None or obj2._frame is None) or (self._frame == obj2._frame) ): result = func(self, *args, **kwargs) if hasattr(result, "_frame"): result._frame = self._frame if result._frame is None and hasattr(obj2, "_frame"): result._frame = obj2._frame return result else: raise ValueError( f"The objects {self} and {obj2} are defined in different coordinate frames." ) return decorator