add an example, bouncing_balls.py

Author: gottadiveintopython

examples/bouncing_balls.py

@@ -0,0 +1,54 @@
+from typing import Unpack
+from functools import partial
+
+import pygame
+from pygame.colordict import THECOLORS
+from pygame import Rect, Vector2, Color
+
+import asyncpygame as apg
+
+
+async def bouncing_ball(*, dest: Rect, space: Rect, color, velocity: Vector2, **kwargs: Unpack[apg.CommonParams]):
+    draw_func = partial(pygame.draw.ellipse, kwargs["draw_target"], color, dest)
+    with kwargs["executor"].register(draw_func, kwargs["priority"]):
+        async for dt in kwargs["clock"].anim_with_dt():
+            dest.move_ip(velocity * (dt / 1000.0))
+            if not dest.colliderect(space):
+                return
+            if dest.left < space.left or dest.right > space.right:
+                velocity.x = -velocity.x
+            if dest.top < space.top or dest.bottom > space.bottom:
+                velocity.y = -velocity.y
+
+
+async def main(**kwargs: Unpack[apg.CommonParams]):
+    from random import randint
+    pygame.init()
+    pygame.display.set_caption("Bouncing Balls")
+
+    kwargs["draw_target"] = screen = pygame.display.set_mode((1280, 720))
+
+    r = kwargs["executor"].register
+    r(partial(screen.fill, THECOLORS["black"]), priority=0)
+    r(pygame.display.flip, priority=0xFFFFFF00)
+
+    async with apg.open_nursery() as nursery:
+        clock = kwargs["clock"]
+        priority = 0x100
+        screen_rect = screen.get_rect()
+        while True:
+            await clock.sleep(randint(1000, 2000))
+            ball_size = randint(20, 150)
+            nursery.start(bouncing_ball(
+                dest=Rect(0, 0, ball_size, ball_size).move_to(center=screen_rect.center),
+                space=screen_rect,
+                color=Color(randint(0, 255), randint(0, 255), randint(0, 255)),
+                velocity=Vector2(randint(-150, 150), randint(-150, 150)),
+                priority=priority,
+                **kwargs
+            ))
+            priority += 1
+
+
+if __name__ == "__main__":
+    apg.run(main)