pipeworks/autoplace.lua

--define the functions from https://github.com/minetest/minetest/pull/834 while waiting for the devs to notice it
local function dir_to_facedir(dir, is6d)
	--account for y if requested
	if is6d and math.abs(dir.y) > math.abs(dir.x) and math.abs(dir.y) > math.abs(dir.z) then
		
		--from above
		if dir.y < 0 then
			if math.abs(dir.x) > math.abs(dir.z) then
				if dir.x < 0 then
					return 19
				else
					return 13
				end
			else
				if dir.z < 0 then
					return 10
				else
					return 4
				end
			end
		
		--from below
		else
			if math.abs(dir.x) > math.abs(dir.z) then
				if dir.x < 0 then
					return 15
				else
					return 17
				end
			else
				if dir.z < 0 then
					return 6
				else
					return 8
				end
			end
		end
	
	--otherwise, place horizontally
	elseif math.abs(dir.x) > math.abs(dir.z) then
		if dir.x < 0 then
			return 3
		else
			return 1
		end
	else
		if dir.z < 0 then
			return 2
		else
			return 0
		end
	end
end

local function facedir_to_dir(facedir)
	--a table of possible dirs
	return ({{x=0, y=0, z=1},
					{x=1, y=0, z=0},
					{x=0, y=0, z=-1},
					{x=-1, y=0, z=0},
					{x=0, y=-1, z=0},
					{x=0, y=1, z=0}})
					
					--indexed into by a table of correlating facedirs
					[({[0]=1, 2, 3, 4,
						5, 2, 6, 4,
						6, 2, 5, 4,
						1, 5, 3, 6,
						1, 6, 3, 5,
						1, 4, 3, 2})
						
						--indexed into by the facedir in question
						[facedir]]
end

-- autorouting for pipes

function pipe_scanforobjects(pos)
	pipe_autoroute({ x=pos.x-1, y=pos.y  , z=pos.z   }, "_loaded")
	pipe_autoroute({ x=pos.x+1, y=pos.y  , z=pos.z   }, "_loaded")
	pipe_autoroute({ x=pos.x  , y=pos.y-1, z=pos.z   }, "_loaded")
	pipe_autoroute({ x=pos.x  , y=pos.y+1, z=pos.z   }, "_loaded")
	pipe_autoroute({ x=pos.x  , y=pos.y  , z=pos.z-1 }, "_loaded")
	pipe_autoroute({ x=pos.x  , y=pos.y  , z=pos.z+1 }, "_loaded")
	pipe_autoroute(pos, "_loaded")

	pipe_autoroute({ x=pos.x-1, y=pos.y  , z=pos.z   }, "_empty")
	pipe_autoroute({ x=pos.x+1, y=pos.y  , z=pos.z   }, "_empty")
	pipe_autoroute({ x=pos.x  , y=pos.y-1, z=pos.z   }, "_empty")
	pipe_autoroute({ x=pos.x  , y=pos.y+1, z=pos.z   }, "_empty")
	pipe_autoroute({ x=pos.x  , y=pos.y  , z=pos.z-1 }, "_empty")
	pipe_autoroute({ x=pos.x  , y=pos.y  , z=pos.z+1 }, "_empty")
	pipe_autoroute(pos, "_empty")
end

function pipe_autoroute(pos, state)
	nctr = minetest.get_node(pos)
	if (string.find(nctr.name, "pipeworks:pipe_") == nil) then return end

	pipes_scansurroundings(pos)

	nsurround = pxm..pxp..pym..pyp..pzm..pzp
	if nsurround == "000000" then nsurround = "110000" end
	minetest.add_node(pos, { name = "pipeworks:pipe_"..nsurround..state })
end

-- autorouting for pneumatic tubes

function tube_scanforobjects(pos)
	if pos == nil then return end
	print("tubes_scanforobjects called at pos "..dump(pos))
	tube_autoroute({ x=pos.x-1, y=pos.y  , z=pos.z   })
	tube_autoroute({ x=pos.x+1, y=pos.y  , z=pos.z   })
	tube_autoroute({ x=pos.x  , y=pos.y-1, z=pos.z   })
	tube_autoroute({ x=pos.x  , y=pos.y+1, z=pos.z   })
	tube_autoroute({ x=pos.x  , y=pos.y  , z=pos.z-1 })
	tube_autoroute({ x=pos.x  , y=pos.y  , z=pos.z+1 })
	tube_autoroute(pos)
end

function in_table(table,element)
	for _,el in ipairs(table) do
		if el==element then return true end
	end
	return false
end

function is_tube(nodename)
	return in_table(tubenodes,nodename)
end

function tube_autoroute(pos)
	local nctr = minetest.get_node(pos)

--a function for determining which side of the node we are on
	local function nodeside(node, tubedir)
		
		--get a vector pointing back
		local backdir = facedir_to_dir(node.param2)
		
		--check whether the vector is equivalent to the tube direction; if it is, the tube's on the backside
		if backdir.x == tubedir.x and backdir.y == tubedir.y and backdir.z == tubedir.z then
			return "back"
		end
		
		--check whether the vector is antiparallel with the tube direction; that indicates the front
		if backdir.x == -tubedir.x and backdir.y == -tubedir.y and backdir.z == -tubedir.z then
			return "front"
		end
		
		--facedir is defined in terms of the top-bottom axis of the node; we'll take advantage of that
		local topdir = ({[0]={x=0, y=1, z=0},
										{x=0, y=0, z=1},
										{x=0, y=0, z=-1},
										{x=1, y=0, z=0},
										{x=-1, y=0, z=0},
										{x=0, y=-1, z=0}})[math.floor(node.param2/4)]
		
		--is this the top?
		if topdir.x == tubedir.x and topdir.y == tubedir.y and topdir.z == tubedir.z then
			return "top"
		end
		
		--or the bottom?
		if topdir.x == -tubedir.x and topdir.y == -tubedir.y and topdir.z == -tubedir.z then
			return "bottom"
		end
		
		--we shall apply some maths to obtain the right-facing vector
		local rightdir = {x=topdir.y*backdir.z - backdir.y*topdir.z,
											y=topdir.z*backdir.x - backdir.z*topdir.x,
											z=topdir.x*backdir.y - backdir.x*topdir.y}
		
		--is this the right side?
		if rightdir.x == tubedir.x and rightdir.y == tubedir.y and rightdir.z == tubedir.z then
			return "right"
		end
		
		--or the left?
		if rightdir.x == -tubedir.x and rightdir.y == -tubedir.y and rightdir.z == -tubedir.z then
			return "left"
		end
		
		--we should be done by now; initiate panic mode
		minetest.log("error", "nodeside has been confused by its parameters; see pipeworks autoplace.lua, line 382")
		
	end
	
--a further function for determining whether we should extend a tube in a certain direction
	local function surchar(dir)
		
		--get the node in that direction
		local node = minetest.get_node{x=pos.x+dir.x, y=pos.y+dir.y, z=pos.z+dir.z}
		
		--and its tube table
		local nodetube = minetest.registered_nodes[node.name].tube
		
		--choose a surround character
		if nodetube and nodetube.connect_sides
						and nodetube.connect_sides[nodeside(node, {x=-dir.x, y=-dir.y, z=-dir.z})] then
			return '1'
		else
			return '0'
		end
		
	end
	
--keep track of the tube surroundings
	local nsurround = ""
	
--look in each direction
	nsurround = nsurround..surchar{x=-1, y=0, z=0}
	nsurround = nsurround..surchar{x=1, y=0, z=0}
	nsurround = nsurround..surchar{x=0, y=-1, z=0}
	nsurround = nsurround..surchar{x=0, y=1, z=0}
	nsurround = nsurround..surchar{x=0, y=0, z=-1}
	nsurround = nsurround..surchar{x=0, y=0, z=1}
	
-- Apply the final routing decisions to the existing tube (if any)

	if is_tube(nctr.name) then
		local meta=minetest.get_meta(pos)
		local meta0=meta:to_table()
		nctr.name=string.sub(nctr.name,1,-7)..nsurround
		minetest.add_node(pos, nctr)
		local meta=minetest.get_meta(pos)
		meta:from_table(meta0)
	end

end

-- auto-rotation code for various devices the tubes attach to

function pipes_scansurroundings(pos)
	pxm=0
	pxp=0
	pym=0
	pyp=0
	pzm=0
	pzp=0

	nxm = minetest.get_node({ x=pos.x-1, y=pos.y  , z=pos.z   })
	nxp = minetest.get_node({ x=pos.x+1, y=pos.y  , z=pos.z   })
	nym = minetest.get_node({ x=pos.x  , y=pos.y-1, z=pos.z   })
	nyp = minetest.get_node({ x=pos.x  , y=pos.y+1, z=pos.z   })
	nzm = minetest.get_node({ x=pos.x  , y=pos.y  , z=pos.z-1 })
	nzp = minetest.get_node({ x=pos.x  , y=pos.y  , z=pos.z+1 })

	if (string.find(nxm.name, "pipeworks:pipe_") ~= nil) then pxm=1 end
	if (string.find(nxp.name, "pipeworks:pipe_") ~= nil) then pxp=1 end
	if (string.find(nym.name, "pipeworks:pipe_") ~= nil) then pym=1 end
	if (string.find(nyp.name, "pipeworks:pipe_") ~= nil) then pyp=1 end
	if (string.find(nzm.name, "pipeworks:pipe_") ~= nil) then pzm=1 end
	if (string.find(nzp.name, "pipeworks:pipe_") ~= nil) then pzp=1 end

-- Special handling for valves...

	if (string.find(nxm.name, "pipeworks:valve") ~= nil)
	  and (nxm.param2 == 0 or nxm.param2 == 2) then
		pxm=1
	end

	if (string.find(nxp.name, "pipeworks:valve") ~= nil)
	  and (nxp.param2 == 0 or nxp.param2 == 2) then
		pxp=1
	end

	if (string.find(nzm.name, "pipeworks:valve") ~= nil)
	  and (nzm.param2 == 1 or nzm.param2 == 3) then
		pzm=1
	end

	if (string.find(nzp.name, "pipeworks:valve") ~= nil)
	  and (nzp.param2 == 1 or nzp.param2 == 3) then
		pzp=1
	end

-- ...flow sensors...

	if (string.find(nxm.name, "pipeworks:flow_sensor") ~= nil)
	  and (nxm.param2 == 0 or nxm.param2 == 2) then
		pxm=1
	end

	if (string.find(nxp.name, "pipeworks:flow_sensor") ~= nil)
	  and (nxp.param2 == 0 or nxp.param2 == 2) then
		pxp=1
	end

	if (string.find(nzm.name, "pipeworks:flow_sensor") ~= nil)
	  and (nzm.param2 == 1 or nzm.param2 == 3) then
		pzm=1
	end

	if (string.find(nzp.name, "pipeworks:flow_sensor") ~= nil)
	  and (nzp.param2 == 1 or nzp.param2 == 3) then
		pzp=1
	end

-- ...spigots...

	if (string.find(nxm.name, "pipeworks:spigot") ~= nil)
	  and nxm.param2 == 1 then
		pxm=1
	end

	if (string.find(nxp.name, "pipeworks:spigot") ~= nil)
	  and nxp.param2 == 3 then
		pxp=1
	end

	if (string.find(nzm.name, "pipeworks:spigot") ~= nil)
	  and nzm.param2 == 0 then
		pzm=1
	end

	if (string.find(nzp.name, "pipeworks:spigot") ~= nil)
	  and nzp.param2 == 2 then
		pzp=1
	end

-- ...sealed pipe entry/exit...

	if (string.find(nxm.name, "pipeworks:entry_panel") ~= nil)
	  and (nxm.param2 == 1 or nxm.param2 == 3) then
		pxm=1
	end

	if (string.find(nxp.name, "pipeworks:entry_panel") ~= nil)
	  and (nxp.param2 == 1 or nxp.param2 == 3) then
		pxp=1
	end

	if (string.find(nzm.name, "pipeworks:entry_panel") ~= nil)
	  and (nzm.param2 == 0 or nzm.param2 == 2) then
		pzm=1
	end

	if (string.find(nzp.name, "pipeworks:entry_panel") ~= nil)
	  and (nzp.param2 == 0 or nzp.param2 == 2) then
		pzp=1
	end

	if (string.find(nym.name, "pipeworks:entry_panel") ~= nil)
	  and nym.param2 == 13 then
		pym=1
	end

	if (string.find(nyp.name, "pipeworks:entry_panel") ~= nil)
	  and nyp.param2 == 13 then
		pyp=1
	end


-- ...pumps, grates...

	if (string.find(nym.name, "pipeworks:grating") ~= nil) or
	   (string.find(nym.name, "pipeworks:pump") ~= nil) then
		pym=1
	end

-- ... and storage tanks.

	if (string.find(nym.name, "pipeworks:storage_tank_") ~= nil) then
		pym=1
	end

	if (string.find(nyp.name, "pipeworks:storage_tank_") ~= nil) then
		pyp=1
	end

-- ...extra devices specified via the function's parameters
-- ...except that this part is not implemented yet
--
-- xxx = nxm, nxp, nym, nyp, nzm, or nzp depending on the direction to check
-- yyy = pxm, pxp, pym, pyp, pzm, or pzp accordingly.
--
--	if string.find(xxx.name, "modname:nodename") ~= nil then
--		yyy = 1
--	end
--
-- for example:
--
--	if string.find(nym.name, "aero:outlet") ~= nil then
--		pym = 1
--	end
--

end

function pipe_look_for_stackable_tanks(pos)
	local tym = minetest.get_node({ x=pos.x  , y=pos.y-1, z=pos.z   })

	if string.find(tym.name, "pipeworks:storage_tank_") ~= nil or
	    string.find(tym.name, "pipeworks:expansion_tank_") ~= nil then
		minetest.add_node(pos, { name =  "pipeworks:expansion_tank_0", param2 = tym.param2})
	end
end