facing.lua

local sides = require('sides')

local facing = {index = 1}
--[[
sides = {north=2,
         east=5,
         south=3,
         west=4}
--]]
function facing.roll(self, dist)
  dist = dist or 0
  pos = (self.index+dist)%4+1
  return pos
end

function facing.turnRight(self)
  self.index = self:roll()
  return self:facing()
end

function facing.turnLeft(self)
  self.index = self:roll(2)
  return self:facing()
end

function facing.facing(self)
  return facing.dirs[self.index]
end

function facing.getLeft(self)
  return facing.dirs[self:roll(2)]
end

function facing.getRight(self)
  return facing.dirs[self:roll()]
end

function facing.getBack(self)
  return facing.dirs[self:roll(1)]
end

function facing.getSide(self, side)
  if side == 0 or side == 1 then return sides[side]
  elseif side == 2 then return self:getBack()
  elseif side == 3 then return self:facing()
  elseif side == 4 then return self:getRight()
  elseif side == 5 then return self:getLeft()
  end
end

function facing.__tostring(self)
  return tostring(self:facing())
end

function facing.new(self, dir)
  o = {index=dir or 1}
  setmetatable(o, self)
  self.__index = self
  return o
end