snake

snake.rb

require 'Win32API'

def field( size )
  array = Array.new(size)
  for i in 0...size 
    array[i] = Array.new(size, 1)
  end

  for i in 1...size-1 
    for j in 1...size-1
     array[i][j] = 0
    end
  end 

  return array
end


def add_snake_to_field(x, y, field)
  field[x][y] = 2

  # Возвращет текущие координаты
  return [x, y]
end


def get_pressed_key
  if ENV['OS'] == "Windows_NT"
    return Win32API.new('crtdll','_getch', [], 'L').Call
  end

  begin
    system("stty raw -echo")
    str = STDIN.getc
  ensure
    system("stty -raw echo")
  end
  return str
end


def update_game_field (game_field, old_coordinates, new_coordinates)
  game_field[old_coordinates[0]][old_coordinates[1]] = 0
  game_field[new_coordinates[0]][new_coordinates[1]] = 2
end


def snake_move(current_coordinates, game_field, direction)  
  old_coordinates = current_coordinates.clone()
  case direction
  when :up
    current_coordinates[0] = current_coordinates[0] - 1
  when :down
    current_coordinates[0] = current_coordinates[0] + 1
  when :right
    current_coordinates[1] = current_coordinates[1] + 1
  when :left
    current_coordinates[1] = current_coordinates[1] - 1
  end
  update_game_field(game_field, old_coordinates, current_coordinates)
end


def print_game_field( game_field )
  system("clear")
  game_field.each do |array|
    array.each do |element|
      print " #{element} "
    end
    print "\n"
  end  
end


KEY_UP = "i"
KEY_DOWN = "k"
KEY_LEFT = "j"
KEY_RIGHT = "l"
KEY_EXIT = "e"
def run_game()
  game_field = field( 10 )

  current_coordinates = add_snake_to_field(5, 5, game_field)

  print_game_field( game_field )
  loop do 
    key = get_pressed_key()
    if key == KEY_UP
      snake_move(current_coordinates, game_field, :up)      
    elsif key == KEY_RIGHT
      snake_move(current_coordinates, game_field, :right)
    elsif key == KEY_LEFT
      snake_move(current_coordinates, game_field, :left)
    elsif key == KEY_DOWN
      snake_move(current_coordinates, game_field, :down)
    else  key == KEY_EXIT
      return "Exit!"
    end
    #sleep 0.5
    print_game_field( game_field )
  end
end


run_game()