iterCube.lua

--- Iterator over positions of a cube.
-- @param pos Reference to starting position (lowest x, y, and z coordinates).  Note that this is overwritten.
-- @param size Size of the cube
local function iterCube(pos, size)
	local startx, starty = pos.x, pos.y
	local endx, endy, endz = pos.x + size, pos.y + size, pos.z + size
	pos.x = pos.x - 1
	return function()
		if pos.x < endx then
			pos.x = pos.x + 1
		else
			pos.x = startx
			if pos.y < endy then
				pos.y = pos.y + 1
			else
				pos.y = starty
				if pos.z < endz then
					pos.z = pos.z + 1
				else
					return nil
				end
			end
		end
		return pos
	end
end