Complete 'segments_intersections' function

lycantropos · Mar 25, 2021 · c1026a4 · c1026a4
1 parent 33f2da1
commit c1026a4
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Showing 2 changed files with 18 additions and 24 deletions.
diff --git a/bentley_ottmann/core/utils.py b/bentley_ottmann/core/utils.py
@@ -1,10 +1,7 @@
 from typing import (Iterable,
-                    Sequence,
                     Tuple,
                     TypeVar)
 
-from .hints import Ids
-
 _T = TypeVar('_T')
 
 
@@ -16,9 +13,5 @@ def pairwise(ids: Iterable[_T]) -> Iterable[Tuple[_T, _T]]:
         value = next_value
 
 
-def to_ids_pairs(id_: int, other_ids: Ids) -> Sequence[Tuple[int, int]]:
-    return [to_sorted_pair(id_, other_id) for other_id in other_ids]
-
-
 def to_sorted_pair(first: _T, second: _T) -> Tuple[_T, _T]:
     return (first, second) if first < second else (second, first)
diff --git a/bentley_ottmann/planar.py b/bentley_ottmann/planar.py
@@ -1,4 +1,5 @@
-from itertools import chain
+from itertools import (chain,
+                       product)
 from typing import (Callable,
                     Dict,
                     Hashable,
@@ -16,7 +17,7 @@
 from .core import (bentley_ottmann as _bentley_ottmann,
                    shamos_hoey as _shamos_hoey)
 from .core.utils import (pairwise as _pairwise,
-                         to_ids_pairs as _to_ids_pairs)
+                         to_sorted_pair as _to_sorted_pair)
 
 
 def edges_intersect(contour: Contour) -> bool:
@@ -217,15 +218,14 @@ def segments_intersections(segments: Sequence[Segment]
     result = {}
     context = _get_context()
 
-    def segments_intersector(first_start: Point,
-                             first_end: Point,
-                             second_start: Point,
-                             second_end: Point,
-                             relation: _Relation,
-                             intersector
-                             : Callable[[Point, Point, Point, Point], Point]
-                             = context.segments_intersection
-                             ) -> Tuple[Point, ...]:
+    def to_intersections(first_start: Point,
+                         first_end: Point,
+                         second_start: Point,
+                         second_end: Point,
+                         relation: _Relation,
+                         intersector: Callable[[Point, Point, Point, Point],
+                                               Point]
+                         = context.segments_intersection) -> Tuple[Point, ...]:
         if relation is _Relation.TOUCH or relation is _Relation.CROSS:
             return intersector(first_start, first_end, second_start,
                                second_end),
@@ -240,12 +240,13 @@ def segments_intersector(first_start: Point,
         segments_ids = event.segments_ids
         for relation, other_segments_ids in event.relations.items():
             for other_segment_ids in other_segments_ids:
-                other_segment_id = other_segment_ids[0]
-                ids_pairs = _to_ids_pairs(other_segment_id, segments_ids)
-                other_segment = segments[other_segment_id]
-                for point in segments_intersector(segment_start, segment_end,
-                                                  other_segment.start,
-                                                  other_segment.end, relation):
+                ids_pairs = {_to_sorted_pair(segment_id, other_segment_id)
+                             for segment_id, other_segment_id
+                             in product(segments_ids, other_segment_ids)}
+                other_segment = segments[other_segment_ids[0]]
+                for point in to_intersections(segment_start, segment_end,
+                                              other_segment.start,
+                                              other_segment.end, relation):
                     result.setdefault(point, set()).update(ids_pairs)
         for ids_pair in _pairwise(segments_ids):
             result.setdefault(segment_start, set()).add(ids_pair)