A game of snake

buba/__main__.py

@@ -7,6 +7,7 @@ from geventwebsocket.websocket import WebSocket
 
 from buba.animations.dbf import DBFAnimation
 from buba.animations.icalevents import IcalEvents
+from buba.animations.snake import SnakeAnimation
 from buba.animations.time import BubaTime
 from buba.appconfig import AppConfig
 from buba.bubaanimator import BubaAnimator
@@ -33,7 +34,7 @@ animator.add(DBFAnimation, ds100="AHST", station="Holstenstraße")
 animator.add(DBFAnimation, ds100="AHS", station="Altona", count=9)
 animator.add(IcalEvents, url="https://cloud.hamburg.ccc.de/remote.php/dav/public-calendars/QJAdExziSnNJEz5g?export",
              title="CCCHH Events")
-
+animator.add(SnakeAnimation)
 
 @app.route("/static/<filepath>")
 def server_static(filepath):

buba/animations/snake.py

@@ -0,0 +1,92 @@
+import random
+from time import sleep
+
+from buba.bubaanimator import BubaAnimation
+
+
+class SnakeAnimation(BubaAnimation):
+    def __init__(self, buba):
+        super().__init__(buba)
+        # characters to render the grid and the snake
+        # Because of Python's limited codec, instead of using the correct Unicode
+        # codepoints, we're using the CP437 codepoints directly.
+        self.width = 20
+        self.height = 4
+        self.grid = []
+        # 0:Space
+        self.charset = " "
+        # 1:up 2:right 3:down 4:left
+        self.charset += "\u001e\u0010\u001f\u0011"
+        # 5:vertical 6:horizontal
+        self.charset += "\u2551\u2550"
+        # 7:up-right 8:down-right 9:down-left 10:up-left
+        self.charset += "\u255a\u2554\u2557\u255d"
+        # 11:tail
+        self.charset += "\u25a0"
+        self.turn = [
+            [5, 8, 5, 9],   # have been going up, so coming from down
+            [10, 6, 9, 6],  # have been going right, so coming from left
+            [5, 7, 5, 10],  # have been going down, so coming from up
+            [7, 6, 8, 6],   # have been going left, so coming from right
+        ]
+
+        random.seed()
+
+    def run(self):
+        self.grid = [list([0] * self.width) for i in range(self.height)]
+        x = random.randrange(self.width)
+        y = random.randrange(self.height)
+        d = random.randrange(4)
+        self.grid[y][x] = 1 + d
+        for r in range(self.height):
+            self.buba.simple_text(0, r, 0, "") # clear display
+        self.render()
+        while True:
+            if self.is_blocked(x, y, d):
+                end = True
+                prev_d = d
+                for n in self.shift(list(range(4))):
+                    if not self.is_blocked(x, y, n):
+                        end = False
+                        d = n
+                        break
+                if end:
+                    self.grid[y][x] = 11
+                    self.render()
+                    break
+                self.grid[y][x] = self.turn[prev_d][d]
+            else:
+                self.grid[y][x] = 5 + (d % 2)
+            (x, y) = self.next(x, y, d)
+            self.grid[y][x] = 1 + d
+            self.render()
+            sleep(0.5)
+        sleep(5)
+
+    @staticmethod
+    def shift(a):
+        i = random.randrange(1, len(a))
+        return a[i:] + a[:i]
+
+    def next(self, x, y, d):
+        match d:
+            case 0:
+                y -= 1
+            case 1:
+                x += 1
+            case 2:
+                y += 1
+            case 3:
+                x -= 1
+        return (x, y)
+
+    def is_blocked(self, x, y, d):
+        (x, y) = self.next(x, y, d)
+        return (y < 0 or y >= self.height or
+                x < 0 or x >= self.width or
+                self.grid[y][x] != 0)
+
+    def render(self):
+        for r, row in enumerate(self.grid):
+            for c, col in enumerate(row):
+                self.buba.text(0, r, c*6, (c+1)*6-1, self.charset[col])