hellocoffee.coffee

#Игра змейка, массив змеи - массив координат блоков игрового поля

pointIndicator    = null
points            = 0
gameOverIndicator = null
newGame           = null
fieldWidth        = 80
fieldHeight       = 30
gameField         = null
startX            = 40
startY            = 15
caneat            = false

#направления движения

LEFT  = 1
UP    = 2
RIGHT = 3
DOWN  = 4

direction = RIGHT

snake = [[startX, startY], [startX - 1, startY], [startX - 2, startY]]

xeatcoord = null
yeatcoord = null

go = null

#создание игрового поля
createGameField = ->
  table = document.createElement("table")
  table.id = "snake"
  thead = document.createElement("thead")
  thead.appendChild row = document.createElement("tr")

  for [0...3]        
    row.appendChild th = document.createElement("th")        
    if !_i 
      th.colSpan = 20
      pointIndicator = document.createElement("span");
      pointIndicator.innerHTML = "POINTS: " + 0
      th.appendChild pointIndicator
    else if _i == 1
      th.colSpan = 40
      newGame = document.createElement("span")
      newGame.innerHTML = "START"
      newGame.style.cursor = "pointer"
      th.appendChild newGame
      newGame.onclick = -> start()
    else 
      gameOverIndicator = document.createElement("span")
      gameOverIndicator.style.color = "red"
      th.appendChild gameOverIndicator            
      th.colSpan = 20
  gameField = tbody = document.createElement("tbody")
  for [0...fieldHeight]
    tbody.appendChild row = document.createElement("tr")        
    for [0...fieldWidth]
      row.appendChild td = document.createElement("td")    
  table.appendChild thead
  table.appendChild tbody
  document.body.appendChild table    

#обработчик смены неправления движения    
document.body.onkeydown =(e)->
  e = e || window.event
  switch e.keyCode
    when 37 then if direction != RIGHT then direction = LEFT
    when 38 then if direction != DOWN then direction = UP            
    when 39 then if direction != LEFT then direction = RIGHT
    when 40 then if direction != UP then direction = DOWN

move =->
  canmove = false    
  switch direction
    when LEFT then canmove  = leftMovePossible()
    when RIGHT then canmove = rightMovePossible()
    when DOWN then canmove  = downMovePossible()
    when UP then canmove    = upMovePossible()
  if canmove
    if caneat
      grow()
      caneat = false
      placeEat()
    else
      moveSnake()
  else
      endGame()

leftMovePossible = ->   
  if snake[0][0] - 1 < 0 or gameField.rows[snake[0][1]].cells[snake[0][0] - 1].className == "snakeBody" then return false
  if gameField.rows[snake[0][1]].cells[snake[0][0] - 1].className == "eat" then caneat = true
  return true

rightMovePossible = ->
  if snake[0][0] + 1 == fieldWidth or gameField.rows[snake[0][1]].cells[snake[0][0] + 1].className == "snakeBody" then return false
  if gameField.rows[snake[0][1]].cells[snake[0][0] + 1].className == "eat" then caneat = true
  return true

downMovePossible = ->
  if snake[0][1] + 1 == fieldHeight or gameField.rows[snake[0][1] + 1].cells[snake[0][0]].className == "snakeBody" then return false
  if gameField.rows[snake[0][1] + 1].cells[snake[0][0]].className == "eat" then caneat = true
  return true
               
upMovePossible = ->
  if snake[0][1] - 1 < 0 or gameField.rows[snake[0][1] - 1].cells[snake[0][0]].className == "snakeBody" then return false
  if gameField.rows[snake[0][1] - 1].cells[snake[0][0]].className == "eat" then caneat = true
  return true

moveSnake = ->
  #стерли змею
  for [0...snake.length]
    gameField.rows[snake[_i][1]].cells[snake[_i][0]].className = ""
  snake.pop()
  snake.unshift([snake[0][0], snake[0][1]])
  switch direction
    when LEFT then snake[0][0]  -= 1
    when RIGHT then snake[0][0] += 1
    when DOWN then snake[0][1]  += 1
    when UP then snake[0][1]    -= 1
  #нарисовали змею
  for [0...snake.length]
    gameField.rows[snake[_j][1]].cells[snake[_j][0]].className = "snakeBody"    

grow = ->
  snake.unshift([snake[0][0], snake[0][1]])
  switch direction        
    when LEFT then snake[0][0]  -= 1
    when RIGHT then snake[0][0] += 1
    when DOWN then snake[0][1]  += 1
    when UP then snake[0][1]    -= 1
  gameField.rows[snake[0][1]].cells[snake[0][0]].className = "snakeBody"
  pointIndicator.innerHTML = "POINTS: " + ++points    
     
placeEat = ->
  xeatcoord = getRandNum(0, fieldWidth - 1)
  yeatcoord = getRandNum(0, fieldHeight - 1)
  while gameField.rows[yeatcoord].cells[xeatcoord].className == "snakeBody" 
    xeatcoord = getRandNum(0, fieldWidth - 1)
    yeatcoord = getRandNum(0, fieldHeight - 1)
  gameField.rows[yeatcoord].cells[xeatcoord].className = "eat"

endGame = ->
  gameOverIndicator.innerHTML = "YOU LOOSE"
  clearInterval(go)    

getRandNum =(min, max)->
  rand = min - 0.5 + Math.random()*(max-min+1);
  return Math.round(rand);

#создали поле
createGameField()

start = ->    
  #если игра уже идет, или закончилась, очистим поле, убьем таймер
  #очистим змею
  for [0...snake.length]
    gameField.rows[snake[_i][1]].cells[snake[_i][0]].className = ""
  #начальное положение змея
  snake = [[startX, startY], [startX - 1, startY], [startX - 2, startY]]
  clearInterval(go)
  if xeatcoord != null
    gameField.rows[yeatcoord].cells[xeatcoord].className = ""
  direction = RIGHT
  pointIndicator.innerHTML = "POINTS: " + 0
  points = 0;
  gameOverIndicator.innerHTML = ""
  #положили змею
  for [0...snake.length]
    gameField.rows[snake[_j][1]].cells[snake[_j][0]].className = "snakeBody"
  #положили еду
  placeEat()
  #запустили змею
  go = setInterval(move, 100)

start()