Merge pull request Dentosal#165 from jaros3/find-ramps-faster

Find ramps faster

sc2/game_info.py

@@ -1,5 +1,6 @@
 from typing import Tuple, Set, FrozenSet, Sequence, Generator
 
+from collections import deque
 from copy import deepcopy
 import itertools
 
@@ -176,33 +177,53 @@ def _find_ramps(self) -> List[Ramp]:
 
     def _find_groups(self, points: Set[Point2], minimum_points_per_group: int=8, max_distance_between_points: int=2) -> List[Set[Point2]]:
         """ From a set/list of points, this function will try to group points together """
-        foundGroups = []
-        currentGroup = set()
-        newlyAdded = set()
-        pointsPool = set(points)
-
-        while pointsPool or currentGroup:
-            if not currentGroup:
-                randomPoint = pointsPool.pop()
-                currentGroup.add(randomPoint)
-                newlyAdded.add(randomPoint)
-
-            newlyAddedOld = newlyAdded
-            newlyAdded = set()
-            for p1 in newlyAddedOld:
-                # create copy as we change set size during iteration
-                for p2 in pointsPool.copy():
-                    if abs(p1.x - p2.x) + abs(p1.y - p2.y) <= max_distance_between_points:
-                        currentGroup.add(p2)
-                        newlyAdded.add(p2)
-                        pointsPool.discard(p2)
-
-            # Check if all connected points were found
-            if not newlyAdded:
-                # Add to group if number of points reached threshold - discard group if not enough points
-                if len(currentGroup) >= minimum_points_per_group:
-                    foundGroups.append(currentGroup)
-                currentGroup = set()
+        """ Paint clusters of points in rectangular map using flood fill algorithm. """
+        NOT_INTERESTED = -2
+        NOT_COLORED_YET = -1
+        currentColor: int = NOT_COLORED_YET
+        picture: List[List[int]] = [[NOT_INTERESTED
+                                     for j in range (self.pathing_grid.width)]
+                                    for i in range (self.pathing_grid.height)]
+
+        def paint (pt: Point2) -> None:
+            picture[pt.y][pt.x] = currentColor
+
+        nearby: Set[Point2] = set ()
+        for dx in range (-max_distance_between_points, max_distance_between_points + 1):
+            for dy in range (-max_distance_between_points, max_distance_between_points + 1):
+                if abs (dx) + abs (dy) <= max_distance_between_points:
+                    nearby.add (Point2 ((dx, dy)))
+
+        for point in points:
+            paint (point)
+
+        remaining: Set[Point2] = set (points)
+        queue: Deque[Point2] = deque ()
+        foundGroups: List[Set[Point2]] = []
+        while remaining:
+            currentGroup: Set[Point2] = set ()
+            if not queue:
+                currentColor += 1
+                start = remaining.pop ()
+                paint (start)
+                queue.append (start)
+                currentGroup.add (start)
+            while queue:
+                base: Point2 = queue.popleft ()
+                for offset in nearby:
+                    px, py = base.x + offset.x, base.y + offset.y
+                    if px < 0 or py < 0 or px >= self.pathing_grid.width or py >= self.pathing_grid.height:
+                        continue
+                    if picture[py][px] != NOT_COLORED_YET:
+                        continue
+                    point: Point2 = Point2 ((px, py))
+                    remaining.remove (point)
+                    paint (point)
+                    queue.append (point)
+                    currentGroup.add (point)
+            if len (currentGroup) >= minimum_points_per_group:
+                foundGroups.append (currentGroup)
+
         """ Returns groups of points as list
         [{p1, p2, p3}, {p4, p5, p6, p7, p8}]
         """