Try to implement fuTris in coffeescript to save some space

fuTris_tryout.coffee

@@ -0,0 +1,53 @@
+field = [1..10*16].map -> 0
+background = [1..10*16].map -> 10+~~(Math.random()*10)
+shapes = ["xxxx", "xx\nxx", "_x_\nxxx", "x__\nxxx", "__x\nxxx", "xx_\n_xx", "_xx\nxx"]
+
+to_xy = (position) ->
+  x: position%10
+  y: ~~(position/10)
+
+rect = (canvas, position, w, h, color) ->
+  context = canvas.getContext("2d")
+  p = to_xy(position)
+  context.fillStyle = "##{color}"
+  context.fillRect(p.x*20, p.y*20, w, h)
+
+brick = (canvas, shape, position) ->
+  pos = position
+  for panel in shape
+    rect(canvas, pos, 20, 20, "ff0000") if panel is "x"
+    switch panel
+      when "x", "_" then pos += 1
+      when "\n" then pos += 10 - shape.indexOf("\n")
+
+rotate = (shape, angle) ->
+  return shape if angle is 0
+  if shape.length is 4
+    return shape if shape.indexOf("\n") is 2
+    return shape if angle%2 is 0
+    return shape.split("").join("\n")
+
+  rotate_order = [2, 5, 1, 4, 0, 3]
+  reordered = shape.split("").filter (p) -> p isnt "\n"
+
+  if angle is 1
+    reordered = reordered.map (p, i) ->
+      reordered[rotate_order[i]]
+
+  reordered = reordered.reverse() if angle > 1
+  ret = []
+  for p, i in reordered
+    ret.push(p)
+    # FIXME: Something is wrong here ...
+    ret.push("\n") if (angle%2 isnt 0 and i%2 is 1) or (angle%2 is 0 and i%2 is 1)
+  console.log(ret)
+  ret.join("")
+
+main_loop = (canvas)->
+  canvas.width = 20*10
+  canvas.height = 20*16
+  for color, pos in background
+    rect(canvas, pos, 20, 20, "#{color}#{color}#{color}")
+  brick(canvas, rotate(shapes[3], 2), 3)
+
+main_loop(document.getElementById('c'))