from __future__ import annotations import typing as t from abc import (ABC, abstractmethod) import typing_extensions as te from dendroid import red_black from dendroid.hints import KeyedSet from prioq.base import PriorityQueue from rene import (Orientation, hints) from rene._utils import (is_even, orient, to_segments_intersection_point, to_sorted_pair) from .event import (Event, is_event_left, is_event_right, left_event_to_position) from .events_queue_key import EventsQueueKey from .sweep_line_key import SweepLineKey class Operation(ABC, t.Generic[hints.Scalar]): @classmethod def from_segments_iterables( cls, first: t.Iterable[hints.Segment[hints.Scalar]], second: t.Iterable[hints.Segment[hints.Scalar]], / ) -> te.Self: endpoints: t.List[hints.Point[hints.Scalar]] = [] _populate_with_segments(first, endpoints) first_segments_count = len(endpoints) >> 1 _populate_with_segments(second, endpoints) second_segments_count = (len(endpoints) >> 1) - first_segments_count return cls(first_segments_count, second_segments_count, endpoints) @abstractmethod def reduce_events( self, events: t.List[Event], segment_cls: t.Type[hints.Segment[hints.Scalar]], / ) -> t.List[hints.Segment[hints.Scalar]]: pass def to_event_end(self, event: Event, /) -> hints.Point[hints.Scalar]: return self.to_event_start(self.to_opposite_event(event)) def to_event_start(self, event: Event, /) -> hints.Point[hints.Scalar]: return self.endpoints[event] def to_opposite_event(self, event: Event, /) -> Event: return self._opposites[event] _sweep_line_data: KeyedSet[SweepLineKey[hints.Scalar], Event] __slots__ = ( 'first_segments_count', 'second_segments_count', 'endpoints', '_events_queue_data', '_opposites', '_segments_ids', '_sweep_line_data' ) def __init__(self, first_segments_count: int, second_segments_count: int, endpoints: t.List[hints.Point[hints.Scalar]], /) -> None: ( self.endpoints, self.first_segments_count, self.second_segments_count ) = endpoints, first_segments_count, second_segments_count segments_count = first_segments_count + second_segments_count initial_events_count = 2 * segments_count self._opposites = [Event(((index >> 1) << 1) + is_even(index)) for index in range(initial_events_count)] self._segments_ids = list(range(segments_count)) self._events_queue_data: PriorityQueue[ EventsQueueKey[hints.Scalar], Event ] = PriorityQueue( *map(Event, range(initial_events_count)), key=lambda event: EventsQueueKey( event, self._is_event_from_first_operand(event), self.endpoints, self._opposites ) ) self._sweep_line_data = red_black.set_(key=self._to_sweep_line_key) def __bool__(self) -> bool: return bool(self._events_queue_data) def __iter__(self) -> t.Iterator[Event]: while self: event = self._pop() if is_event_right(event): opposite_event = self.to_opposite_event(event) assert is_event_left(opposite_event) equal_segment_event = self._find(opposite_event) if equal_segment_event is not None: above_event, below_event = ( self._above(equal_segment_event), self._below(equal_segment_event) ) self._remove(equal_segment_event) if below_event is not None and above_event is not None: self._detect_intersection(below_event, above_event) elif self._find(event) is None: self._add(event) above_event, below_event = ( self._above(event), self._below(event) ) if above_event is not None: self._detect_intersection(event, above_event) if below_event is not None: self._detect_intersection(below_event, event) yield event def _above(self, event: Event, /) -> t.Optional[Event]: assert is_event_left(event) try: return self._sweep_line_data.next(event) except ValueError: return None def _add(self, event: Event, /) -> None: assert is_event_left(event) self._sweep_line_data.add(event) def _below(self, event: Event, /) -> t.Optional[Event]: assert is_event_left(event) try: return self._sweep_line_data.prev(event) except ValueError: return None def _detect_intersection( self, below_event: Event, event: Event, / ) -> None: event_start = self.to_event_start(event) event_end = self.to_event_end(event) below_event_start = self.to_event_start(below_event) below_event_end = self.to_event_end(below_event) event_start_orientation = orient(below_event_end, below_event_start, event_start) event_end_orientation = orient(below_event_end, below_event_start, event_end) if event_start_orientation is event_end_orientation: if event_start_orientation is Orientation.COLLINEAR: assert (self._is_left_event_from_first_operand(below_event) is not self._is_left_event_from_first_operand(event)) if event_start == below_event_start: if event_end != below_event_end: max_end_event, min_end_event = ( (below_event, event) if event_end < below_event_end else (event, below_event) ) min_end = self.to_event_end(min_end_event) min_end_start_event, min_end_max_end_event = ( self._divide(max_end_event, min_end) ) self._push(min_end_start_event) self._push(min_end_max_end_event) elif event_end == below_event_end: max_start_event, min_start_event = ( (below_event, event) if event_start < below_event_start else (event, below_event) ) max_start = self.to_event_start(max_start_event) ( max_start_to_min_start_event, max_start_to_end_event ) = self._divide(min_start_event, max_start) self._push(max_start_to_min_start_event) self._push(max_start_to_end_event) elif below_event_start < event_start < below_event_end: if event_end < below_event_end: self._divide_event_by_mid_segment_event_endpoints( below_event, event_start, event_end ) else: max_start, min_end = event_start, below_event_end self._divide_overlapping_events(below_event, event, max_start, min_end) elif event_start < below_event_start < event_end: if below_event_end < event_end: self._divide_event_by_mid_segment_event_endpoints( event, below_event_start, below_event_end ) else: max_start, min_end = below_event_start, event_end self._divide_overlapping_events(event, below_event, max_start, min_end) elif event_start_orientation is Orientation.COLLINEAR: if below_event_start < event_start < below_event_end: point = event_start self._divide_event_by_midpoint(below_event, point) elif event_end_orientation is Orientation.COLLINEAR: if below_event_start < event_end < below_event_end: point = event_end self._divide_event_by_midpoint(below_event, point) else: below_event_start_orientation = orient(event_start, event_end, below_event_start) below_event_end_orientation = orient(event_start, event_end, below_event_end) if below_event_start_orientation is Orientation.COLLINEAR: assert below_event_end_orientation is not Orientation.COLLINEAR if event_start < below_event_start < event_end: point = below_event_start self._divide_event_by_midpoint(event, point) elif below_event_end_orientation is Orientation.COLLINEAR: if event_start < below_event_end < event_end: point = below_event_end self._divide_event_by_midpoint(event, point) elif (below_event_start_orientation is not below_event_end_orientation): cross_point = to_segments_intersection_point( event_start, event_end, below_event_start, below_event_end ) assert event_start < cross_point < event_end assert below_event_start < cross_point < below_event_end self._divide_event_by_midpoint(below_event, cross_point) self._divide_event_by_midpoint(event, cross_point) def _divide( self, event: Event, mid_point: hints.Point[hints.Scalar], / ) -> t.Tuple[Event, Event]: assert is_event_left(event) opposite_event = self.to_opposite_event(event) mid_point_to_event_end_event: Event = Event(len(self.endpoints)) self._segments_ids.append(self._left_event_to_segment_id(event)) self.endpoints.append(mid_point) self._opposites.append(opposite_event) self._opposites[opposite_event] = mid_point_to_event_end_event mid_point_to_event_start_event = Event(len(self.endpoints)) self.endpoints.append(mid_point) self._opposites.append(event) self._opposites[event] = mid_point_to_event_start_event assert (self._is_left_event_from_first_operand(event) is self._is_event_from_first_operand( mid_point_to_event_start_event )) assert (self._is_left_event_from_first_operand(event) is self._is_left_event_from_first_operand( mid_point_to_event_end_event )) return mid_point_to_event_start_event, mid_point_to_event_end_event def _divide_event_by_mid_segment_event_endpoints( self, event: Event, mid_segment_event_start: hints.Point[hints.Scalar], mid_segment_event_end: hints.Point[hints.Scalar], / ) -> None: self._divide_event_by_midpoint(event, mid_segment_event_end) self._divide_event_by_midpoint(event, mid_segment_event_start) def _divide_event_by_midpoint( self, event: Event, point: hints.Point[hints.Scalar], / ) -> None: point_to_event_start_event, point_to_event_end_event = self._divide( event, point ) self._push(point_to_event_start_event) self._push(point_to_event_end_event) def _divide_overlapping_events( self, min_start_event: Event, max_start_event: Event, max_start: hints.Point[hints.Scalar], min_end: hints.Point[hints.Scalar], / ) -> None: self._divide_event_by_midpoint(max_start_event, min_end) self._divide_event_by_midpoint(min_start_event, max_start) def _find(self, event: Event, /) -> t.Optional[Event]: assert is_event_left(event) candidate = self._sweep_line_data.tree.find( self._to_sweep_line_key(event) ) return (None if candidate is red_black.NIL else candidate.value) def _is_event_from_first_operand(self, event: Event, /) -> bool: return self._is_left_event_from_first_operand( self._to_left_event(event) ) def _is_left_event_from_first_operand(self, event: Event, /) -> bool: return (self._left_event_to_segment_id(event) < self.first_segments_count) def _left_event_to_segment_id(self, event: Event, /) -> int: return self._segments_ids[left_event_to_position(event)] def _pop(self) -> Event: return self._events_queue_data.pop() def _push(self, event: Event, /) -> None: self._events_queue_data.push(event) def _remove(self, event: Event, /) -> None: assert is_event_left(event) self._sweep_line_data.remove(event) def _to_event_endpoints( self, event: Event, / ) -> t.Tuple[hints.Point[hints.Scalar], hints.Point[hints.Scalar]]: return self.to_event_start(event), self.to_event_end(event) def _to_left_event(self, event: Event, /) -> Event: return (event if is_event_left(event) else self.to_opposite_event(event)) def _to_sweep_line_key( self, event: Event, / ) -> SweepLineKey[hints.Scalar]: return SweepLineKey( event, self._is_left_event_from_first_operand(event), self.endpoints, self._opposites ) def _populate_with_segments( segments: t.Iterable[hints.Segment[hints.Scalar]], endpoints: t.List[hints.Point[hints.Scalar]], / ) -> None: for segment in segments: start, end = to_sorted_pair(segment.start, segment.end) endpoints.append(start) endpoints.append(end)