redis rewritten as a real TP

Author: parmentelat

notebooks/tps/redis/.teacher/README-redis-corrige-nb.md

@@ -0,0 +1,94 @@
+#!/usr/bin/env python
+
+from argparse import ArgumentParser
+
+import pygame as pg
+from pygame.locals import QUIT
+
+from redis import Redis
+
+from screen import Screen
+from player import Player
+from others import Others
+
+# 2 differents speeds
+#
+# if we do too few frames per second,
+# after another player moves, we may see it very late
+# (worst case: if FRAME_RATE is 4, then the delay may reach 250ms)
+#
+# so, we set our frame rate higher; BUT on the other hand
+# this also results in the player moving too fast
+# so FRAMES_PER_MOVE is defined so we move our player only once every n frames
+
+# how often we redisplay the screen
+FRAME_RATE = 10
+# we move our player that many times slower
+FRAMES_PER_MOVE = 3
+
+
+def main():
+
+    parser = ArgumentParser()
+    parser.add_argument("-s", "--server", default=None,
+                        help="IP adddress for the redis server")
+    parser.add_argument("-a", "--auto-move", action="store_true",
+                        help="auto move")
+    parser.add_argument("name")
+    args = parser.parse_args()
+
+    # player's name as provided on the command line
+    local_player_name = args.name
+    pg.display.set_caption(f"game: {local_player_name}")
+
+
+    screen = Screen()
+    W, H = screen.size()
+
+    clock = pg.time.Clock()
+
+    redis_server = Redis(args.server, decode_responses=True)
+
+    player = Player(local_player_name, H, W, redis_server)
+    player.join()
+
+    others = Others(redis_server)
+
+    # ask the redis server where the other players are
+    players = others.fetch_all_players()
+    screen.display(players)
+
+    # type 'a' to toggle auto move
+    auto_move = args.auto_move
+
+    counter = 0
+    while True:
+        # sync with the frame rate
+        clock.tick(FRAME_RATE)
+        # get the position of other players
+        players = others.fetch_all_players()
+
+        # move the local player
+        # actually do all this only once every FRAMES_PER_MOVE frames
+        counter += 1
+        if counter % FRAMES_PER_MOVE == 0:
+            counter = 0
+            if auto_move:
+                player.random_move()
+
+            for event in pg.event.get():
+                if (event.type == QUIT or
+                    (event.type == pg.KEYDOWN and event.key == pg.K_q)):
+                    player.leave()
+                    return
+                elif event.type == pg.KEYDOWN and event.key == pg.K_a:
+                    auto_move = not auto_move
+                else:
+                    player.handle_event(event)
+
+        # redisplay accordingly every frame
+        screen.display(players)
+
+
+if __name__ == '__main__':
+    main()

notebooks/tps/redis/.teacher/game.py

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+import random
+import json
+
+import pygame as pg
+
+def random_color():
+    return [random.randint(0, 255) for _ in range(3)]
+
+def random_move():
+    moves = [(x, y) for x in (-1, 0, 1) for y in (-1, 0, 1) if abs(x+y) == 1]
+    return random.choice(moves)
+
+
+
+class Player:
+    """
+    manage the local player, and broadcast
+    its position to the redis server
+    """
+
+    def __init__(self, name, width, height, redis_server):
+        """
+        name is the name of the local player
+        """
+        self.name = name
+        self.width = width
+        self.height = height
+        self.position = [ random.randint(0, self.width-1),
+                          random.randint(0, self.height-1)]
+        self.color = random_color()
+        #
+        self.redis_server = redis_server
+
+
+    def join(self):
+        """
+        add local name to database
+        with a random color
+        """
+        self.redis_server.hset(
+            self.name,
+            mapping = {
+                'color' : json.dumps(self.color),
+                'position': json.dumps(self.position),
+            })
+
+
+    def leave(self):
+        """
+        remove local name from database
+        """
+        self.redis_server.delete(self.name)
+
+
+    def random_move(self):
+        self.move(*random_move())
+
+    def move(self, dx, dy):
+        self.position[0] += dx
+        self.position[0] %= self.width
+        self.position[1] += dy
+        self.position[1] %= self.height
+        self.redis_server.hset(self.name, 'position',
+                               json.dumps(self.position))
+
+
+    def handle_event(self, event):
+        if event.type == pg.KEYDOWN:
+            match event.key:
+                case pg.K_UP:
+                    self.move(0, -1)
+                case pg.K_DOWN:
+                    self.move(0, 1)
+                case pg.K_RIGHT:
+                    self.move(1, 0)
+                case pg.K_LEFT:
+                    self.move(-1, 0)
+                case pg.K_c:
+                    self.color = random_color()
+                    self.redis_server.hset(self.name, 'color',
+                                           json.dumps(self.color))

notebooks/tps/redis/others.py notebooks/tps/redis/.teacher/others.pynotebooks/tps/redis/others.py renamed to notebooks/tps/redis/.teacher/others.py

@@ -0,0 +1,50 @@
+import pygame
+
+from itertools import product
+
+# la taille du jeu en nombre de cellules
+BOARD_SIZE = (20, 20)
+BOARD_WIDTH, BOARD_HEIGHT = BOARD_SIZE
+
+# la taille d'une cellule en nombre de pixels
+CELL_SIZE = (15, 15)
+CELL_WIDTH, CELL_HEIGHT = CELL_SIZE
+
+BLACK = (0, 0, 0)
+WHITE = (255, 255, 255)
+
+
+class Screen:
+
+    pygame_inited = False
+
+    def __init__(self):
+
+        if not Screen.pygame_inited:
+            pygame.init()
+            # pygame.display.set_caption("multi-player")
+            Screen.pygame_inited = True
+
+        self.screen = pygame.display.set_mode(
+            (BOARD_WIDTH*CELL_WIDTH, BOARD_HEIGHT*CELL_HEIGHT))
+
+    def size(self):
+        return BOARD_WIDTH, BOARD_HEIGHT
+
+    def draw_cell(self, board_x, board_y, color=WHITE):
+        screen_x, screen_y = CELL_WIDTH * board_x, CELL_HEIGHT * board_y
+        for x, y in product(range(CELL_WIDTH), range(CELL_HEIGHT)):
+            screen_coords = screen_x + x, screen_y + y
+            self.screen.set_at(screen_coords, color)
+
+    def display(self, players):
+        """
+        players is an iterable of dictionaries
+        'color' -> [r g b], 'position' -> [x, y]
+        """
+        self.screen.fill(BLACK)
+        for player in players:
+            x, y = player['position']
+            color = player['color']
+            self.draw_cell(x, y, color)
+        pygame.display.update()

notebooks/tps/redis/.teacher/player.py

@@ -1 +1,4 @@
 requirements.txt
+game.py
+player.py
+screen.py