Merge pull request #503 from rnmallick/master

Snake game added.

Author: spmallick

SnakeGame/snake.py

@@ -0,0 +1,163 @@
+import cv2
+import numpy as np
+from random import randint
+from random import choice
+
+
+class SnakePart:
+  def __init__(self, front, x, y):
+    self.front = front
+    self.x = x
+    self.y = y
+
+  def move(self):
+    # Moves by following the part in front of it
+    self.x = self.front.x
+    self.y = self.front.y
+
+class Head:
+  def __init__(self, direction, x, y):
+    self.direction = direction
+    self.x = x
+    self.y = y
+
+  def move(self):
+    # Checks what its current direction is and moves accordingly
+    if self.direction == 0:
+        self.x += 1
+    elif self.direction == 1:
+        self.y += 1
+    elif self.direction == 2:
+        self.x -= 1
+    elif self.direction == 3:
+        self.y -= 1
+
+def display():
+
+  # Create a blank image
+  board = np.zeros([BOARD_SIZE, BOARD_SIZE, 3])
+
+  # Color the snake green
+  for part in snake:
+    board[part.y, part.x] = [0, 255, 0]
+  
+  # Color the apple red
+  board[appley, applex] = [0, 0, 255]
+  
+  # Display board
+  cv2.imshow("Snake Game", np.uint8(board.repeat(CELL_SIZE, 0).repeat(CELL_SIZE, 1)))
+  key = cv2.waitKey(int(1000/SPEED))
+  
+  # Return the key pressed. It is -1 if no key is pressed. 
+  return key
+  
+def win_focus():
+  # Ugly trick to get the window in focus.
+  # Opens an image in fullscreen and then back to normal window
+  cv2.namedWindow("Snake Game", cv2.WINDOW_NORMAL);
+  board = np.zeros([BOARD_SIZE * CELL_SIZE, BOARD_SIZE * CELL_SIZE, 3])
+  cv2.imshow("Snake Game", board);
+  cv2.setWindowProperty("Snake Game", cv2.WND_PROP_FULLSCREEN, cv2.WINDOW_FULLSCREEN);
+  cv2.waitKey(2000)
+  cv2.setWindowProperty("Snake Game", cv2.WND_PROP_FULLSCREEN, cv2.WINDOW_AUTOSIZE)
+
+
+if __name__ == '__main__' : 
+
+  # Size of each cell in the board game
+  CELL_SIZE = 20
+  # Number of cells along the width in the game
+  BOARD_SIZE = 45
+  # Change SPEED to make the game go faster
+  SPEED = 12
+  # After eating an apple the snake grows by GROWTH units
+  GROWTH = 3
+
+  
+  # Variable to track if apple is eaten
+  eaten = True
+  # Variable to check if the game should quit
+  quit = False
+  # Variable to track growth. 
+  grow = 0
+  
+  # Array for storing snake
+  snake = []
+
+  #snake's head starts at the center of the board. 
+  head = Head(0, int((BOARD_SIZE - 1)/2), int((BOARD_SIZE - 1)/2))
+  snake.append(head)
+
+  # Start the game by printing instructions
+  print('w = top, a = left, s = down, d = right')
+  # Ugly trick to bring the window in focus
+  win_focus()
+
+  while True:
+
+    # Checks if the apple is eaten and generates a new one
+    if eaten:
+      # Create a list of all possible locations
+      s = list(range(0, BOARD_SIZE ** 2))
+      # Delete cells that are part of the snake
+      for part in snake:
+          s.remove(part.x * BOARD_SIZE + part.y)
+      
+      # Randomly pick from one of the remaining cells    
+      a = choice(s)
+      applex = int(a/BOARD_SIZE)
+      appley = a % BOARD_SIZE
+      
+      eaten = False
+
+    # Makes and displays the board
+    key = display()
+
+    
+    # Gets key presses and moves accordingly
+    # 8 and 27 are delete and escape keys
+    # Arrow keys are tricky in OpenCV. So we use
+    # keys 'w', 'a','s','d' for movement. 
+    # w = top, a = left, s = down, d = right
+
+
+    if key == 8 or key == 27:
+      break
+    elif key == ord("d") :
+      head.direction = 0
+    elif key == ord("s") :
+      head.direction = 1
+    elif key == ord("a") :
+      head.direction = 2
+    elif key == ord("w") :
+      head.direction = 3
+
+    # Moving the snake
+    for part in snake[::-1]:
+      part.move()    
+
+    # Collision rules
+
+    if head.x < 0 or head.x > BOARD_SIZE - 1 or head.y < 0 or head.y > BOARD_SIZE - 1:
+      break
+        
+    for part in snake[1:]:
+      if head.x == part.x and head.y == part.y:
+        quit = True
+        break
+        
+    if quit:
+      break
+      
+    # The snake grows graduallly over multiple frames    
+    if grow > 0:
+      snake.append(SnakePart(snake[-1], subx, suby))
+      grow -= 1
+      
+    # Grows the snake when it eats an apple
+    if applex == head.x and appley == head.y:
+      subx = snake[-1].x
+      suby = snake[-1].y
+      eaten = True
+      grow += GROWTH
+