mesecons/mesecons_movestones/init.lua

-- MOVESTONE
-- Non-sticky:
-- Moves along mesecon lines
-- Pushes all blocks in front of it
--
-- Sticky one
-- Moves along mesecon lines
-- Pushes all block in front of it
-- Pull all blocks in its back

function mesecon:get_movestone_direction(pos)
	getactivated = 0
	local lpos
	local getactivated = 0
	local rules = {
		{x=0,  y=1,  z=-1},
		{x=0,  y=0,  z=-1},
		{x=0,  y=-1, z=-1},
		{x=0,  y=1,  z=1},
		{x=0,  y=-1, z=1},
		{x=0,  y=0,  z=1},
		{x=1,  y=0,  z=0},
		{x=1,  y=1,  z=0},
		{x=1,  y=-1, z=0},
		{x=-1, y=1,  z=0},
		{x=-1, y=-1, z=0},
		{x=-1, y=0,  z=0}}

	lpos = {x=pos.x+1, y=pos.y, z=pos.z}
	for n = 1, 3 do
		if mesecon:is_power_on(lpos, rules[n].x, rules[n].y, rules[n].z) then
			return {x=0, y=0, z=-1}
		end
	end

	lpos = {x = pos.x-1, y = pos.y, z = pos.z}
	for n=4, 6 do
		if mesecon:is_power_on(lpos, rules[n].x, rules[n].y, rules[n].z) then
			return {x=0, y=0, z=1}
		end
	end

	lpos = {x = pos.x, y = pos.y, z = pos.z+1}
	for n=7, 9 do
		if mesecon:is_power_on(lpos, rules[n].x, rules[n].y, rules[n].z) then
			return {x=-1, y=0, z=0}
		end
	end

	lpos = {x = pos.x, y = pos.y, z = pos.z-1}
	for n=10, 12 do
		if mesecon:is_power_on(lpos, rules[n].x, rules[n].y, rules[n].z) then
			return {x=1, y=0, z=0}
		end
	end
end

minetest.register_node("mesecons_movestones:movestone", {
	tiles = {"jeija_movestone_side.png", "jeija_movestone_side.png", "jeija_movestone_side.png", "jeija_movestone_side.png", "jeija_movestone_arrows.png", "jeija_movestone_arrows.png"},
	paramtype2 = "facedir",
	legacy_facedir_simple = true,
	groups = {cracky=3},
    	description="Movestone",
	sounds = default.node_sound_stone_defaults(),
	mesecons = {effector = {
		action_on = function (pos, node)
			local direction=mesecon:get_movestone_direction(pos)
			if not direction then return end
			minetest.remove_node(pos)
			mesecon:update_autoconnect(pos)
			minetest.add_entity(pos, "mesecons_movestones:movestone_entity")
		end
	}}
})

minetest.register_entity("mesecons_movestones:movestone_entity", {
	physical = false,
	visual = "sprite",
	textures = {"jeija_movestone_side.png", "jeija_movestone_side.png", "jeija_movestone_side.png", "jeija_movestone_side.png", "jeija_movestone_arrows.png", "jeija_movestone_arrows.png"},
	collisionbox = {-0.5,-0.5,-0.5, 0.5, 0.5, 0.5},
	visual = "cube",
	lastdir = {x=0, y=0, z=0},

	on_punch = function(self, hitter)
		self.object:remove()
		hitter:get_inventory():add_item("main", "mesecons_movestones:movestone")
	end,

	on_step = function(self, dtime)
		local pos = self.object:getpos()
		pos.x, pos.y, pos.z = math.floor(pos.x+0.5), math.floor(pos.y+0.5), math.floor(pos.z+0.5)
		local direction = mesecon:get_movestone_direction(pos)

		if not direction then -- no mesecon power
			--push only solid nodes
			local name = minetest.get_node(pos).name
			if  name ~= "air" and name ~= "ignore"
			and ((not minetest.registered_nodes[name])
			or minetest.registered_nodes[name].liquidtype == "none") then
				mesecon:mvps_push(pos, self.lastdir, MOVESTONE_MAXIMUM_PUSH)
			end
			minetest.add_node(pos, {name="mesecons_movestones:movestone"})
			self.object:remove()
			return
		end

		local success, stack, oldstack =
			mesecon:mvps_push(pos, direction, MOVESTONE_MAXIMUM_PUSH)
		if not success then -- Too large stack/stopper in the way
			minetest.add_node(pos, {name="mesecons_movestones:movestone"})
			self.object:remove()
			return
		else
			mesecon:mvps_process_stack (stack)
			mesecon:mvps_move_objects  (pos, direction, oldstack)
			self.lastdir = direction
		end

		self.object:setvelocity({x=direction.x*2, y=direction.y*2, z=direction.z*2})
	end,
})

minetest.register_craft({
	output = "mesecons_movestones:movestone 2",
	recipe = {
		{"default:stone", "default:stone", "default:stone"},
		{"group:mesecon_conductor_craftable", "group:mesecon_conductor_craftable", "group:mesecon_conductor_craftable"},
		{"default:stone", "default:stone", "default:stone"},
	}
})



-- STICKY_MOVESTONE

minetest.register_node("mesecons_movestones:sticky_movestone", {
	tiles = {"jeija_movestone_side.png", "jeija_movestone_side.png", "jeija_movestone_side.png", "jeija_movestone_side.png", "jeija_sticky_movestone.png", "jeija_sticky_movestone.png"},
	inventory_image = minetest.inventorycube("jeija_sticky_movestone.png", "jeija_movestone_side.png", "jeija_movestone_side.png"),
	paramtype2 = "facedir",
	legacy_facedir_simple = true,
	groups = {cracky=3},
    	description="Sticky Movestone",
	sounds = default.node_sound_stone_defaults(),
	mesecons = {effector = {
		action_on = function (pos, node)
			local direction=mesecon:get_movestone_direction(pos)
			if not direction then return end
			minetest.remove_node(pos)
			mesecon:update_autoconnect(pos)
			minetest.add_entity(pos, "mesecons_movestones:sticky_movestone_entity")
		end
	}}
})

minetest.register_craft({
	output = "mesecons_movestones:sticky_movestone 2",
	recipe = {
		{"mesecons_materials:glue", "mesecons_movestones:movestone", "mesecons_materials:glue"},
	}
})

minetest.register_entity("mesecons_movestones:sticky_movestone_entity", {
	physical = false,
	visual = "sprite",
	textures = {"jeija_movestone_side.png", "jeija_movestone_side.png", "jeija_movestone_side.png", "jeija_movestone_side.png", "jeija_sticky_movestone.png", "jeija_sticky_movestone.png"},
	collisionbox = {-0.5, -0.5, -0.5, 0.5, 0.5, 0.5},
	visual = "cube",
	lastdir = {x=0, y=0, z=0},

	on_punch = function(self, hitter)
		self.object:remove()
		hitter:get_inventory():add_item("main", 'mesecons_movestones:sticky_movestone')
	end,

	on_step = function(self, dtime)
		local pos = self.object:getpos()
		pos.x, pos.y, pos.z = math.floor(pos.x+0.5), math.floor(pos.y+0.5), math.floor(pos.z+0.5)
		local direction = mesecon:get_movestone_direction(pos)

		if not direction then -- no mesecon power
			--push only solid nodes
			local name = minetest.get_node(pos).name
			if  name ~= "air" and name ~= "ignore"
			and ((not minetest.registered_nodes[name])
			or minetest.registered_nodes[name].liquidtype == "none") then
				mesecon:mvps_push(pos, self.lastdir, MOVESTONE_MAXIMUM_PUSH)
				--STICKY
				mesecon:mvps_pull_all(pos, self.lastdir)
			end
			minetest.add_node(pos, {name="mesecons_movestones:sticky_movestone"})
			self.object:remove()
			return
		end

		local success, stack, oldstack =
			mesecon:mvps_push(pos, direction, MOVESTONE_MAXIMUM_PUSH)
		if not success then -- Too large stack/stopper in the way
			minetest.add_node(pos, {name="mesecons_movestones:sticky_movestone"})
			self.object:remove()
			return
		else
			mesecon:mvps_process_stack (stack)
			mesecon:mvps_move_objects  (pos, direction, oldstack)
			self.lastdir = direction
		end

		self.object:setvelocity({x=direction.x*2, y=direction.y*2, z=direction.z*2})

		--STICKY
		mesecon:mvps_pull_all(pos, direction)
	end,
})


mesecon:register_mvps_unmov("mesecons_movestones:movestone_entity")
mesecon:register_mvps_unmov("mesecons_movestones:sticky_movestone_entity")