File size: 11,818 Bytes
2df2f26 | 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 | import gymnasium as gym
from gymnasium import spaces
import random
import pygame
import numpy as np
import collections
from collections import deque
from Environment_Constants import (
GRID_SIZE, CELL_SIZE, SCREEN_WIDTH, SCREEN_HEIGHT,
WHITE, BLACK, GREEN, RED, BLUE,
UP, DOWN, LEFT, RIGHT,
REWARD_FOOD, REWARD_COLLISION, REWARD_STEP,
FPS, OBSERVATION_SPACE_SIZE
)
class SnakeGameEnv(gym.Env):
metadata = {'render_modes': ['human', 'rgb_array'], 'render_fps': FPS}
def __init__(self, render_mode=None):
super().__init__()
self.grid_size = GRID_SIZE
self.cell_size = CELL_SIZE
self.screen_width = SCREEN_WIDTH
self.screen_height = SCREEN_HEIGHT
self.action_space = spaces.Discrete(3)
self.observation_space = spaces.Box(low=0, high=1,
shape=(OBSERVATION_SPACE_SIZE,),
dtype=np.float32)
self.render_mode = render_mode
self.window = None
self.clock = None
self._init_game_state()
def _init_game_state(self):
self.snake = deque()
self.head = (self.grid_size // 2, self.grid_size // 2)
self.snake.append(self.head)
self.snake.append((self.head[0], self.head[1] + 1))
self.snake.append((self.head[0], self.head[1] + 2))
self.direction = UP
self.score = 0
self.food = self._place_food()
self.game_over = False
self.steps_since_food = 0
self.length = len(self.snake)
def _place_food(self):
while True:
x = random.randrange(self.grid_size)
y = random.randrange(self.grid_size)
food_pos = (x, y)
if food_pos not in self.snake:
return food_pos
def _is_position_safe_for_observation(self, pos):
px, py = pos
if not (0 <= px < self.grid_size and 0 <= py < self.grid_size):
return False
if pos in list(self.snake)[1:]:
return False
return True
def _get_observation(self):
obs = np.zeros(OBSERVATION_SPACE_SIZE, dtype=np.float32)
hx, hy = self.head
if self.direction == UP:
dir_straight = UP
dir_right = RIGHT
dir_left = LEFT
elif self.direction == DOWN:
dir_straight = DOWN
dir_right = LEFT
dir_left = RIGHT
elif self.direction == LEFT:
dir_straight = LEFT
dir_right = UP
dir_left = DOWN
elif self.direction == RIGHT:
dir_straight = RIGHT
dir_right = DOWN
dir_left = UP
check_pos_straight = (hx + dir_straight[0], hy + dir_straight[1])
check_pos_right = (hx + dir_right[0], hy + dir_right[1])
check_pos_left = (hx + dir_left[0], hy + dir_left[1])
obs[0] = 1 if not self._is_position_safe_for_observation(check_pos_straight) else 0
obs[1] = 1 if not self._is_position_safe_for_observation(check_pos_right) else 0
obs[2] = 1 if not self._is_position_safe_for_observation(check_pos_left) else 0
fx, fy = self.food
if fy < hy: obs[3] = 1
if fy > hy: obs[4] = 1
if fx < hx: obs[5] = 1
if fx > hx: obs[6] = 1
if self.direction == UP: obs[7] = 1
elif self.direction == DOWN: obs[8] = 1
elif self.direction == LEFT: obs[9] = 1
elif self.direction == RIGHT: obs[10] = 1
return obs
def _get_action_mask(self):
mask = np.array([True, True, True], dtype=bool)
hx, hy = self.head
potential_directions = [
self.direction,
None,
None
]
if self.direction == UP:
potential_directions[1] = RIGHT
potential_directions[2] = LEFT
elif self.direction == DOWN:
potential_directions[1] = LEFT
potential_directions[2] = RIGHT
elif self.direction == LEFT:
potential_directions[1] = UP
potential_directions[2] = DOWN
elif self.direction == RIGHT:
potential_directions[1] = DOWN
potential_directions[2] = UP
def _is_potential_move_illegal(pos_to_check, current_snake, food_pos):
if not (0 <= pos_to_check[0] < self.grid_size and 0 <= pos_to_check[1] < self.grid_size):
return True
if pos_to_check in list(current_snake)[:-1]:
return True
if pos_to_check == current_snake[-1]:
if pos_to_check != food_pos:
return True
return False
for action_idx, new_dir in enumerate(potential_directions):
dx, dy = new_dir
potential_head = (hx + dx, hy + dy)
if _is_potential_move_illegal(potential_head, self.snake, self.food):
mask[action_idx] = False
if not np.any(mask):
print(f"Warning: All actions masked out at head {self.head}, direction {self.direction}, food {self.food}. Attempting to find a fallback action.")
found_fallback = False
for i in range(3): # Check Straight, Right, Left
dx, dy = potential_directions[i]
potential_head = (hx + dx, hy + dy)
if not _is_potential_move_illegal(potential_head, self.snake, self.food):
mask[i] = True
found_fallback = True
if not found_fallback:
mask[np.random.choice(3)] = True
print("Critical Warning: No legal actions found even after fallback logic. Enabling a random action to prevent deadlock.")
return mask
def reset(self, seed=None, options=None):
super().reset(seed=seed)
self._init_game_state()
observation = self._get_observation()
info = self._get_info()
if not np.any(info['action_mask']):
print("Warning: No valid actions found in initial reset state.")
if self.render_mode == 'human':
self._render_frame()
return observation, info
def _get_info(self):
"""Returns environment information, including the action mask."""
return {
"score": self.score,
"snake_length": len(self.snake),
"action_mask": self._get_action_mask()
}
def step(self, action):
new_direction = self.direction
if action == 1:
if self.direction == UP: new_direction = RIGHT
elif self.direction == DOWN: new_direction = LEFT
elif self.direction == LEFT: new_direction = UP
elif self.direction == RIGHT: new_direction = DOWN
elif action == 2:
if self.direction == UP: new_direction = LEFT
elif self.direction == DOWN: new_direction = RIGHT
elif self.direction == LEFT: new_direction = DOWN
elif self.direction == RIGHT: new_direction = UP
elif action != 0:
raise ValueError(f"Received invalid action={action} which is not part of the action space.")
self.direction = new_direction
hx, hy = self.head
dx, dy = self.direction
new_head = (hx + dx, hy + dy)
reward = REWARD_STEP
terminated = False
truncated = False
if not (0 <= new_head[0] < self.grid_size and 0 <= new_head[1] < self.grid_size):
terminated = True
reward = REWARD_COLLISION
elif new_head in list(self.snake)[:-1]:
terminated = True
reward = REWARD_COLLISION
elif new_head == self.snake[-1] and new_head != self.food:
terminated = True
reward = REWARD_COLLISION
if terminated:
self.game_over = True
else:
self.snake.appendleft(new_head)
self.head = new_head
if new_head == self.food:
self.score += 1
self.length += 1
reward = REWARD_FOOD
self.food = self._place_food()
self.steps_since_food = 0
else:
self.snake.pop()
self.steps_since_food += 1
if self.steps_since_food >= self.grid_size * self.grid_size * 1.5:
terminated = True
truncated = True
reward = REWARD_COLLISION
observation = self._get_observation()
info = self._get_info()
if self.render_mode == 'human':
self._render_frame()
return observation, reward, terminated, truncated, info
def _render_frame(self):
if self.window is None and self.render_mode == 'human':
pygame.init()
pygame.display.init()
self.window = pygame.display.set_mode((self.screen_width, self.screen_height))
pygame.display.set_caption("Snake AI Training")
if self.clock is None and self.render_mode == 'human':
self.clock = pygame.time.Clock()
if self.render_mode == 'human':
self.window.fill(BLACK)
pygame.draw.rect(self.window, RED, (self.food[0] * self.cell_size,
self.food[1] * self.cell_size,
self.cell_size, self.cell_size))
for i, segment in enumerate(self.snake):
color = BLUE if i == 0 else GREEN
pygame.draw.rect(self.window, color, (segment[0] * self.cell_size,
segment[1] * self.cell_size,
self.cell_size, self.cell_size))
for x in range(0, self.screen_width, self.cell_size):
pygame.draw.line(self.window, WHITE, (x, 0), (x, self.screen_height))
for y in range(0, self.screen_height, self.cell_size):
pygame.draw.line(self.window, WHITE, (0, y), (self.screen_width, y))
font = pygame.font.Font(None, 25)
text = font.render(f"Score: {self.score}", True, WHITE)
self.window.blit(text, (5, 5))
pygame.event.pump()
pygame.display.flip()
self.clock.tick(self.metadata["render_fps"])
elif self.render_mode == "rgb_array":
surf = pygame.Surface((self.screen_width, self.screen_height))
surf.fill(BLACK)
pygame.draw.rect(surf, RED, (self.food[0] * self.cell_size,
self.food[1] * self.cell_size,
self.cell_size, self.cell_size))
for i, segment in enumerate(self.snake):
color = BLUE if i == 0 else GREEN
pygame.draw.rect(surf, color, (segment[0] * self.cell_size,
segment[1] * self.cell_size,
self.cell_size, self.cell_size))
return np.transpose(np.array(pygame.surfarray.pixels3d(surf)), axes=(1, 0, 2))
def close(self):
if self.window is not None:
pygame.display.quit()
pygame.quit()
self.window = None
self.clock = None |