compute the "colliding color" based on #collisions

src/README.md

@@ -107,8 +107,8 @@ def update(points: list) -> list:
 
 # gives back to the canva the things to show.
 # it should be either
-# - a list of booleans, one for each point, that indicates whether or not a
-# point is colliding with others
+# - a list of integers, one for each point, that indicates how many other nodes
+# are colliding with a each node
 # - a quad-tree and the query range
 def f(points: list, mouse: (int, int)):
     ...

src/ui/qtree.py

@@ -65,14 +65,19 @@ class Canva:
         self.screen.fill(COLORS["background"])
 
         res = f(self.points, self.mouse)
-        if isinstance(res, list) and isinstance(res[0], bool):
+        if isinstance(res, list) and isinstance(res[0], int):
             for p, c in zip(self.points, res):
-                pygame.draw.circle(
-                    self.screen,
-                    COLORS["colliding ball"] if c else COLORS["ball"],
-                    (p.x, p.y),
-                    p.r,
-                )
+                if c == 0:
+                    color = (255, 0, 0)
+                elif c == 1:
+                    color = (255, 128, 0)
+                elif c == 2:
+                    color = (255, 255, 0)
+                elif c == 3:
+                    color = (128, 255, 0)
+                else:
+                    color = (0, 255, 0)
+                pygame.draw.circle(self.screen, color, (p.x, p.y), p.r)
         else:
             qtree, range = res
             self.__render_qtree(qtree)