--[[
    This file is part of Ice Lua Components.

    Ice Lua Components is free software: you can redistribute it and/or modify
    it under the terms of the GNU Lesser General Public License as published by
    the Free Software Foundation, either version 3 of the License, or
    (at your option) any later version.

    Ice Lua Components is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU Lesser General Public License for more details.

    You should have received a copy of the GNU Lesser General Public License
    along with Ice Lua Components.  If not, see <http://www.gnu.org/licenses/>.
]]

function trace_map(x1,y1,z1, x2,y2,z2, bx1,by1,bz1, bx2,by2,bz2)
	-- delta
	local dx,dy,dz
	dx = x2-x1
	dy = y2-y1
	dz = z2-z1
	
	-- offsets
	local fx,fy,fz
	if dx < 0 then fx = bx1 else fx = bx2 end
	if dy < 0 then fy = by1 else fy = by2 end
	if dz < 0 then fz = bz1 else fz = bz2 end
	
	-- direction
	local gx,gy,gz
	if dx < 0 then gx = -1 else gx = 1 end
	if dy < 0 then gy = -1 else gy = 1 end
	if dz < 0 then gz = -1 else gz = 1 end
	dx = dx * gx
	dy = dy * gy
	dz = dz * gz
	
	-- apply offset
	x1 = x1 + fx
	y1 = y1 + fy
	z1 = z1 + fz
	x2 = x2 + fx
	y2 = y2 + fy
	z2 = z2 + fz
	
	-- cell
	local cx,cy,cz
	cx = x1
	cy = y1
	cz = z1
	
	-- TODO!
	return nil
end