add `src.ui.qtree` module

src/ui/qtree.py

+from dataclasses import dataclass
+
+import pygame
+import sys
+
+COLORS = {
+    "background": (0, 0, 0),
+}
+
+
+@dataclass
+class Canva:
+    width: int
+    height: int
+    caption: str
+    frame_rate: int
+    screen: pygame.surface.Surface = None
+    clock: pygame.time.Clock = None
+
+    def setup(self):
+        pygame.init()
+
+        self.screen = pygame.display.set_mode((self.width, self.height))
+        pygame.display.set_caption(self.caption)
+
+        self.clock = pygame.time.Clock()
+
+        self.mouse = None
+        self.points = []
+
+    def __handle_events(self):
+        for event in pygame.event.get():
+            if event.type == pygame.QUIT or (
+                event.type == pygame.KEYDOWN and
+                event.key == pygame.K_ESCAPE
+            ):
+                pygame.quit()
+                sys.exit()
+            elif event.type == pygame.MOUSEMOTION:
+                self.mouse = event.pos
+
+    def __render_qtree(self, qtree):
+        x = qtree.boundary.x
+        y = qtree.boundary.y
+        w = qtree.boundary.w
+        h = qtree.boundary.h
+        pygame.draw.rect(
+            self.screen,
+            (255, 255, 255),
+            (x - w / 2, y - h / 2, w, h),
+            width=1,
+        )
+
+        if qtree.divided:
+            self.__render_qtree(qtree.ne)
+            self.__render_qtree(qtree.nw)
+            self.__render_qtree(qtree.se)
+            self.__render_qtree(qtree.sw)
+
+    def __render(self, f):
+        self.screen.fill(COLORS["background"])
+
+        res = f(self.points, self.mouse)
+        if isinstance(res, list) and isinstance(res[0], bool):
+            for p, c in zip(self.points, res):
+                pygame.draw.circle(
+                    self.screen,
+                    (255, 255, 255) if c else (100, 100, 100),
+                    (p.x, p.y),
+                    p.r,
+                )
+        else:
+            qtree, range = res
+            self.__render_qtree(qtree)
+
+            for p in self.points:
+                pygame.draw.circle(
+                    self.screen, (255, 255, 255), (p.x, p.y), p.r
+                )
+
+            pygame.draw.rect(
+                self.screen,
+                (0, 255, 0),
+                (range.x - range.w / 2, range.y - range.h / 2, range.w, range.h),
+                width=1,
+            )
+
+            for p in qtree.query(range):
+                pygame.draw.circle(self.screen, (0, 255, 0), (p.x, p.y), p.r)
+
+        pygame.display.flip()
+
+    def step(self, u, f):
+        self.__handle_events()
+        self.points = u(self.points)
+        self.__render(f)
+        self.clock.tick(self.frame_rate)
+
+    def loop(self, u, f):
+        while True:
+            self.step(u, f)