Use initial_properties, backup old_pos for loading

Clear driver on leave using the detach callback (0.5.x and later)
Fix upright_sprite attachment position
Fallback to the regular node sound when metal does not exist
Set animation to "stand" on attach

README.txt

@@ -1,23 +1,57 @@
-Minetest mod: boost_cart
-=======================
-Based on the mod "carts" by PilzAdam
-Target: Run smoothly and do not use too much CPU
+ Minetest mod: boost_cart
+==========================
+Based on (and fully compatible with) the mod "carts" by PilzAdam
+and the one contained in the subgame "minetest_game".
+Target: Run smoothly as possible, even on laggy servers.
 
-License of source code:
------------------------
-WTFPL
 
-License of media (textures, sounds and models):
------------------------------------------------
-CC-0
+ Features
+----------
+- A fast cart for your railway or roller coaster
+- Easily configurable cart speed using the Advanced Settings
+- Boost and brake rails
+- By mesecons controlled Start-Stop rails
+- Detector rails that send a mesecons signal when the cart drives over them
+- Rail junction switching with the 'right/left' walking keys
+- Handbrake with the 'back' key
+- Support for non-minetest_game subgames
 
-Authors of media files:
------------------------
-kddekadenz:
-  cart_bottom.png
-  cart_side.png
-  cart_top.png
 
-Zeg9:
-  cart.x
-  cart.png
+ Settings
+----------
+This mod can be adjusted to fit the conditions of a player or server.
+Use the Advanced Settings dialog in the main menu or tune your
+minetest.conf file manually:
+
+boost_cart.speed_max = 10
+   ^ Possible values: 1 ... 100
+   ^ Maximal speed of the cart in m/s
+
+boost_cart.punch_speed_max = 7
+   ^ Possible values: -1 ... 100
+   ^ Maximal speed to which the driving player can accelerate the cart
+     by punching from inside the cart. -1 will disable this feature.
+
+
+ License for everything
+------------------------
+CC-0, if not specified otherwise below
+
+
+ Authors
+---------
+Various authors
+	carts_rail_*.png
+
+kddekadenz
+	cart_bottom.png
+	cart_side.png
+	cart_top.png
+
+klankbeeld (CC-BY 3.0)
+	http://freesound.org/people/klankbeeld/sounds/174042/
+	cart_rail.*.ogg
+
+Zeg9
+	cart.x
+	cart.png

cart_entity.lua

@@ -0,0 +1,452 @@
+
+local HAVE_MESECONS_ENABLED = minetest.global_exists("mesecon")
+
+function boost_cart:on_rail_step(entity, pos, distance)
+	-- Play rail sound
+	if entity.sound_counter <= 0 then
+		minetest.sound_play("cart_rail", {
+			pos = pos,
+			max_hear_distance = 40,
+			gain = 0.5
+		})
+		entity.sound_counter = math.random(4, 15)
+	end
+	entity.sound_counter = entity.sound_counter - distance
+
+	if HAVE_MESECONS_ENABLED then
+		boost_cart:signal_detector_rail(pos)
+	end
+end
+
+local cart_entity = {
+	initial_properties = {
+		physical = false,
+		collisionbox = {-0.5, -0.5, -0.5, 0.5, 0.5, 0.5},
+		visual = "mesh",
+		mesh = "cart.x",
+		visual_size = {x=1, y=1},
+		textures = {"cart.png"},
+	},
+
+	driver = nil,
+	punched = false, -- used to re-send velocity and position
+	velocity = {x=0, y=0, z=0}, -- only used on punch
+	old_dir = {x=1, y=0, z=0}, -- random value to start the cart on punch
+	old_pos = nil,
+	old_switch = 0,
+	sound_counter = 0,
+	railtype = nil,
+	attached_items = {}
+}
+
+-- Model and textures
+if boost_cart.mtg_compat then
+	cart_entity.initial_properties.mesh = "carts_cart.b3d"
+	cart_entity.initial_properties.textures = {"carts_cart.png"}
+end
+
+function cart_entity:on_rightclick(clicker)
+	if not clicker or not clicker:is_player() then
+		return
+	end
+	local player_name = clicker:get_player_name()
+	if self.driver and player_name == self.driver then
+		self.driver = nil
+		boost_cart:manage_attachment(clicker, nil)
+	elseif not self.driver then
+		self.driver = player_name
+		boost_cart:manage_attachment(clicker, self.object)
+
+		if default.player_set_animation then
+			-- player_api(/default) does not update the animation
+			-- when the player is attached, reset to default animation
+			default.player_set_animation(clicker, "stand")
+		end
+	end
+end
+
+function cart_entity:on_activate(staticdata, dtime_s)
+	self.object:set_armor_groups({immortal=1})
+	self.sound_counter = math.random(4, 15)
+
+	if string.sub(staticdata, 1, string.len("return")) ~= "return" then
+		return
+	end
+	local data = minetest.deserialize(staticdata)
+	if type(data) ~= "table" then
+		return
+	end
+	self.railtype = data.railtype
+	self.old_dir = data.old_dir or self.old_dir
+	self.old_pos = data.old_pos or self.old_pos
+	-- Correct the position when the cart drives further after the last 'step()'
+	if self.old_pos and boost_cart:is_rail(self.old_pos, self.railtype) then
+		self.object:set_pos(self.old_pos)
+	end
+end
+
+function cart_entity:get_staticdata()
+	return minetest.serialize({
+		railtype = self.railtype,
+		old_dir = self.old_dir,
+		old_pos = self.old_pos
+	})
+end
+
+-- 0.5.x and later: When the driver leaves
+function cart_entity:on_detach_child(child)
+	if child and child:get_player_name() == self.driver then
+		self.driver = nil
+	end
+end
+
+function cart_entity:on_punch(puncher, time_from_last_punch, tool_capabilities, direction)
+	local pos = self.object:get_pos()
+	local vel = self.object:get_velocity()
+	if not self.railtype or vector.equals(vel, {x=0, y=0, z=0}) then
+		local node = minetest.get_node(pos).name
+		self.railtype = minetest.get_item_group(node, "connect_to_raillike")
+	end
+
+	if not puncher or not puncher:is_player() then
+		local cart_dir = boost_cart:get_rail_direction(pos, self.old_dir, nil, nil, self.railtype)
+		if vector.equals(cart_dir, {x=0, y=0, z=0}) then
+			return
+		end
+		self.velocity = vector.multiply(cart_dir, 3)
+		self.punched = true
+		return
+	end
+
+	if puncher:get_player_control().sneak then
+		-- Pick up cart: Drop all attachments
+		if self.driver then
+			if self.old_pos then
+				self.object:set_pos(self.old_pos)
+			end
+			local player = minetest.get_player_by_name(self.driver)
+			boost_cart:manage_attachment(player, nil)
+		end
+		for _, obj_ in pairs(self.attached_items) do
+			if obj_ then
+				obj_:set_detach()
+			end
+		end
+
+		local leftover = puncher:get_inventory():add_item("main", "carts:cart")
+		if not leftover:is_empty() then
+			minetest.add_item(pos, leftover)
+		end
+
+		self.object:remove()
+		return
+	end
+
+	-- Driver punches to accelerate the cart
+	if puncher:get_player_name() == self.driver then
+		if math.abs(vel.x + vel.z) > boost_cart.punch_speed_max then
+			return
+		end
+	end
+
+	local punch_dir = boost_cart:velocity_to_dir(puncher:get_look_dir())
+	punch_dir.y = 0
+	local cart_dir = boost_cart:get_rail_direction(pos, punch_dir, nil, nil, self.railtype)
+	if vector.equals(cart_dir, {x=0, y=0, z=0}) then
+		return
+	end
+
+	local punch_interval = 1
+	if tool_capabilities and tool_capabilities.full_punch_interval then
+		punch_interval = tool_capabilities.full_punch_interval
+	end
+	time_from_last_punch = math.min(time_from_last_punch or punch_interval, punch_interval)
+	local f = 3 * (time_from_last_punch / punch_interval)
+
+	self.velocity = vector.multiply(cart_dir, f)
+	self.old_dir = cart_dir
+	self.punched = true
+end
+
+local v3_len = vector.length
+function cart_entity:on_step(dtime)
+	local vel = self.object:get_velocity()
+	if self.punched then
+		vel = vector.add(vel, self.velocity)
+		self.object:set_velocity(vel)
+		self.old_dir.y = 0
+	elseif vector.equals(vel, {x=0, y=0, z=0}) then
+		return
+	end
+
+	local pos = self.object:get_pos()
+	local cart_dir = boost_cart:velocity_to_dir(vel)
+	local same_dir = vector.equals(cart_dir, self.old_dir)
+	local update = {}
+
+	if self.old_pos and not self.punched and same_dir then
+		local flo_pos = vector.round(pos)
+		local flo_old = vector.round(self.old_pos)
+		if vector.equals(flo_pos, flo_old) then
+			-- Do not check one node multiple times
+			return
+		end
+	end
+
+	local ctrl, player
+	local distance = 1
+
+	-- Get player controls
+	if self.driver then
+		player = minetest.get_player_by_name(self.driver)
+		if player then
+			ctrl = player:get_player_control()
+		end
+	end
+
+	local stop_wiggle = false
+	if self.old_pos and same_dir then
+		-- Detection for "skipping" nodes (perhaps use average dtime?)
+		-- It's sophisticated enough to take the acceleration in account
+		local acc = self.object:get_acceleration()
+		distance = dtime * (v3_len(vel) + 0.5 * dtime * v3_len(acc))
+
+		local new_pos, new_dir = boost_cart:pathfinder(
+			pos, self.old_pos, self.old_dir, distance, ctrl,
+			self.old_switch, self.railtype
+		)
+
+		if new_pos then
+			-- No rail found: set to the expected position
+			pos = new_pos
+			update.pos = true
+			cart_dir = new_dir
+		end
+	elseif self.old_pos and self.old_dir.y ~= 1 and not self.punched then
+		-- Stop wiggle
+		stop_wiggle = true
+	end
+
+	-- dir:         New moving direction of the cart
+	-- switch_keys: Currently pressed L(1) or R(2) key,
+	--              used to ignore the key on the next rail node
+	local dir, switch_keys = boost_cart:get_rail_direction(
+		pos, cart_dir, ctrl, self.old_switch, self.railtype
+	)
+	local dir_changed = not vector.equals(dir, self.old_dir)
+
+	local acc = 0
+	if stop_wiggle or vector.equals(dir, {x=0, y=0, z=0}) then
+		vel = {x=0, y=0, z=0}
+		local pos_r = vector.round(pos)
+		if not boost_cart:is_rail(pos_r, self.railtype)
+				and self.old_pos then
+			pos = self.old_pos
+		elseif not stop_wiggle then
+			pos = pos_r
+		else
+			pos.y = math.floor(pos.y + 0.5)
+		end
+		update.pos = true
+		update.vel = true
+	else
+		-- Direction change detected
+		if dir_changed then
+			vel = vector.multiply(dir, math.abs(vel.x + vel.z))
+			update.vel = true
+			if dir.y ~= self.old_dir.y then
+				pos = vector.round(pos)
+				update.pos = true
+			end
+		end
+		-- Center on the rail
+		if dir.z ~= 0 and math.floor(pos.x + 0.5) ~= pos.x then
+			pos.x = math.floor(pos.x + 0.5)
+			update.pos = true
+		end
+		if dir.x ~= 0 and math.floor(pos.z + 0.5) ~= pos.z then
+			pos.z = math.floor(pos.z + 0.5)
+			update.pos = true
+		end
+
+		-- Calculate current cart acceleration
+		acc = nil
+
+		local acc_meta = minetest.get_meta(pos):get_string("cart_acceleration")
+		if acc_meta == "halt" and not self.punched then
+			-- Stop rail
+			vel = {x=0, y=0, z=0}
+			acc = false
+			pos = vector.round(pos)
+			update.pos = true
+			update.vel = true
+		end
+		if acc == nil then
+			-- Meta speed modifier
+			local speed_mod = tonumber(acc_meta)
+			if speed_mod and speed_mod ~= 0 then
+				-- Try to make it similar to the original carts mod
+				acc = speed_mod * 10
+			end
+		end
+		if acc == nil and boost_cart.mtg_compat then
+			-- MTG Cart API adaption
+			local rail_node = minetest.get_node(vector.round(pos))
+			local railparam = carts.railparams[rail_node.name]
+			if railparam and railparam.acceleration then
+				acc = railparam.acceleration
+			end
+		end
+		if acc ~= false then
+			-- Handbrake
+			if ctrl and ctrl.down then
+				acc = (acc or 0) - 2
+			elseif acc == nil then
+				acc = -0.4
+			end
+		end
+
+		if acc then
+			-- Slow down or speed up, depending on Y direction
+			acc = acc + dir.y * -2.1
+		else
+			acc = 0
+		end
+	end
+
+	-- Limit cart speed
+	local vel_len = vector.length(vel)
+	if vel_len > boost_cart.speed_max then
+		vel = vector.multiply(vel, boost_cart.speed_max / vel_len)
+		update.vel = true
+	end
+	if vel_len >= boost_cart.speed_max and acc > 0 then
+		acc = 0
+	end
+
+	self.object:set_acceleration(vector.multiply(dir, acc))
+
+	self.old_pos = vector.round(pos)
+	local old_y_dir = self.old_dir.y
+	if not vector.equals(dir, {x=0, y=0, z=0}) and not stop_wiggle then
+		self.old_dir = dir
+	else
+		-- Cart stopped, set the animation to 0
+		self.old_dir.y = 0
+	end
+	self.old_switch = switch_keys
+
+	boost_cart:on_rail_step(self, self.old_pos, distance)
+
+	if self.punched then
+		-- Collect dropped items
+		for _, obj_ in pairs(minetest.get_objects_inside_radius(pos, 1)) do
+			if not obj_:is_player() and
+					obj_:get_luaentity() and
+					not obj_:get_luaentity().physical_state and
+					obj_:get_luaentity().name == "__builtin:item" then
+
+				obj_:set_attach(self.object, "", {x=0, y=0, z=0}, {x=0, y=0, z=0})
+				self.attached_items[#self.attached_items + 1] = obj_
+			end
+		end
+		self.punched = false
+		update.vel = true
+	end
+
+	if not (update.vel or update.pos) then
+		return
+	end
+	-- Re-use "dir", localize self.old_dir
+	dir = self.old_dir
+
+	local yaw = 0
+	if dir.x < 0 then
+		yaw = 0.5
+	elseif dir.x > 0 then
+		yaw = 1.5
+	elseif dir.z < 0 then
+		yaw = 1
+	end
+	self.object:set_yaw(yaw * math.pi)
+
+	local anim = {x=0, y=0}
+	if dir.y == -1 then
+		anim = {x=1, y=1}
+	elseif dir.y == 1 then
+		anim = {x=2, y=2}
+	end
+	self.object:set_animation(anim, 1, 0)
+
+	-- Change player model rotation, depending on the Y direction
+	if player and dir.y ~= old_y_dir then
+		local feet = {x=0, y=0, z=0}
+		local eye = {x=0, y=-4, z=0}
+		feet.y = boost_cart.old_player_model and 6 or -4
+		if dir.y ~= 0 then
+			-- TODO: Find a better way to calculate this
+			if boost_cart.old_player_model then
+				feet.y = feet.y + 2
+				feet.z = -dir.y * 6
+			else
+				feet.y = feet.y + 4
+				feet.z = -dir.y * 2
+			end
+			eye.z = -dir.y * 8
+		end
+		player:set_attach(self.object, "", feet,
+			{x=dir.y * -30, y=0, z=0})
+		player:set_eye_offset(eye, eye)
+	end
+
+	if update.vel then
+		self.object:set_velocity(vel)
+	end
+	if update.pos then
+		if dir_changed then
+			self.object:set_pos(pos)
+		else
+			self.object:move_to(pos)
+		end
+	end
+end
+
+minetest.register_entity(":carts:cart", cart_entity)
+
+-- Register item to place the entity
+if not boost_cart.mtg_compat then
+	minetest.register_craftitem(":carts:cart", {
+		description = "Cart (Sneak+Click to pick up)",
+		inventory_image = minetest.inventorycube(
+			"cart_top.png",
+			"cart_side.png",
+			"cart_side.png"
+		),
+		wield_image = "cart_side.png",
+		on_place = function(itemstack, placer, pointed_thing)
+			if not pointed_thing.type == "node" then
+				return
+			end
+			if boost_cart:is_rail(pointed_thing.under) then
+				minetest.add_entity(pointed_thing.under, "carts:cart")
+			elseif boost_cart:is_rail(pointed_thing.above) then
+				minetest.add_entity(pointed_thing.above, "carts:cart")
+			else
+				return
+			end
+
+			if not minetest.settings:get_bool("creative_mode") then
+				itemstack:take_item()
+			end
+			return itemstack
+		end,
+	})
+
+	minetest.register_craft({
+		output = "carts:cart",
+		recipe = {
+			{"default:steel_ingot", "", "default:steel_ingot"},
+			{"default:steel_ingot", "default:steel_ingot", "default:steel_ingot"},
+		},
+	})
+end

depends.txt

@@ -1 +1,4 @@
-default
+default
+mesecons?
+moreores?
+carts?

description.txt

@@ -0,0 +1 @@
+This mod offers improved minecarts and a few more rail types.

detector.lua

@@ -0,0 +1,58 @@
+local mesecons_rules = mesecon.rules.flat
+
+function boost_cart:turnoff_detector_rail(pos)
+	local node = minetest.get_node(pos)
+	if minetest.get_item_group(node.name, "detector_rail") == 1 then
+		if node.name == "boost_cart:detectorrail_on" then --has not been dug
+			minetest.swap_node(pos, {name = "boost_cart:detectorrail", param2=node.param2})
+		end
+		mesecon.receptor_off(pos, mesecons_rules)
+	end
+end
+
+function boost_cart:signal_detector_rail(pos)
+	local node = minetest.get_node(pos)
+	if minetest.get_item_group(node.name, "detector_rail") ~= 1 then
+		return
+	end
+
+	if node.name == "boost_cart:detectorrail" then
+		minetest.swap_node(pos, {name = "boost_cart:detectorrail_on", param2=node.param2})
+	end
+	mesecon.receptor_on(pos, mesecons_rules)
+	minetest.after(0.5, boost_cart.turnoff_detector_rail, boost_cart, pos)
+end
+
+boost_cart:register_rail("boost_cart:detectorrail", {
+	description = "Detector rail",
+	tiles = {
+		"carts_rail_straight_dtc.png", "carts_rail_curved_dtc.png",
+		"carts_rail_t_junction_dtc.png", "carts_rail_crossing_dtc.png"
+	},
+	groups = boost_cart:get_rail_groups({detector_rail = 1}),
+
+	mesecons = {receptor = {state = "off", rules = mesecons_rules}},
+})
+
+boost_cart:register_rail("boost_cart:detectorrail_on", {
+	description = "Detector rail ON (you hacker you)",
+	tiles = {
+		"carts_rail_straight_dtc_on.png", "carts_rail_curved_dtc_on.png",
+		"carts_rail_t_junction_dtc_on.png", "carts_rail_crossing_dtc_on.png"
+	},
+	groups = boost_cart:get_rail_groups({
+		detector_rail = 1, not_in_creative_inventory = 1
+	}),
+	drop = "boost_cart:detectorrail",
+
+	mesecons = {receptor = {state = "on", rules = mesecons_rules}},
+})
+
+minetest.register_craft({
+	output = "boost_cart:detectorrail 6",
+	recipe = {
+		{"default:steel_ingot", "mesecons:wire_00000000_off", "default:steel_ingot"},
+		{"default:steel_ingot", "group:stick", "default:steel_ingot"},
+		{"default:steel_ingot", "mesecons:wire_00000000_off", "default:steel_ingot"},
+	},
+})

doc/mod_api.txt

@@ -0,0 +1,71 @@
+boost_cart API
+==============
+
+This file provides information about the API of boost_cart for the use in
+mods. The API might change slightly when the development goes on, so avoid
+using internal tables or functions which are not documented here.
+
+
+Types
+-----
+
+* `SwitchIgnore` -> `number/nil`
+	* Specifies which player control was pressed. This value is used to prefer
+	  straight rails instead of preferring left and right rail checks.
+		* `1`: Ignore left rail
+		* `2`: Ignore right rail
+		* `nil`: Ignore no rail
+
+
+Entity movement
+---------------
+These functions are grouped so that they make sense and then sorted alphabetically.
+
+* `boost_cart:manage_attachment(player, obj)`
+	* Attaches or detaches the player to/from an object, depending on what is
+	  supplied to `obj`.
+	* `player`: `ObjectRef` of the player
+	* `obj`: `ObjectRef` (to attach) or `nil` (to detach)
+* `boost_cart:get_sign(n)` -> `number`
+	* Returns the sign for the given number. Values: `-1`, `0`, `1`
+	* `n`: any `number`
+* `boost_cart:velocity_to_dir(vel)` -> `vector`
+	* Returns the cart direction depending on `vel`. Each coordinate can have
+	  one of the `get_sign()` return values.
+	* `vel`: velocity as `vector`
+* `boost_cart:boost_rail(pos, amount)`
+	* Sets the rail acceleration for the given position to `amount` and punches
+	  carts which are at the given position.
+	* `pos`: `vector`, rail position
+	* `amount`: `number`, negative to brake, positive to boost
+* `boost_cart:get_rail_direction(pos, dir, ctrl, old_switch, railtype)`
+	-> `vector, SwitchIgnore`
+	* Returns the direction to where the next rail is, and which player control that
+	  should be ignored in the next call.
+	* `pos`: `vector`, position of the cart
+	* `dir`: `vector`, movement direction of the cart (see `velocity_to_dir()`)
+	* `ctrl`: Player controls table or `nil` (no player)
+	* `old_switch`: `SwitchIgnore`
+	* `railtype`: (optional) `number`, gets passed indirectly to `is_rail()`
+
+
+Rail helper functions
+---------------------
+* `boost_cart:get_rail_groups(groups)` -> `table`
+	* Returns a group table with preset values for a common rail node
+	* `groups`: (optional) `table`, additional groups append (or overwrite)
+	* Hint: To register an incompatible rail type, set the group
+	  `connect_to_raillike` to the value returned by
+	  `minetest.raillike_group(new_rail_type)`
+* `boost_cart:is_rail(pos, [railtype])` -> `boolean`
+	* Returns whether the node at `pos` is a rail. When `railtype` is specified,
+	  `true` is only returned when the node is in the same rail group.
+	* `pos`: `vector` of the node to check
+	* `railtype`: (optional) `number`, rail group number
+* `boost_cart:register_rail(name, def)`
+	* Registers a new rail with preset node definition defaults as fallback
+	* `name`: `string`, node name of the new rail
+	* `def`: Node definition table, containing at least the following keys:
+		* `description`
+		* `groups`
+		* `tiles`

functions.lua

@@ -6,98 +6,264 @@ function boost_cart:get_sign(z)
 	end
 end
 
-function boost_cart:velocity_to_dir(v)
-	if math.abs(v.x) > math.abs(v.z) then
-		return {x=boost_cart:get_sign(v.x), y=boost_cart:get_sign(v.y), z=0}
+function boost_cart:manage_attachment(player, obj)
+	if not player then
+		return
+	end
+	local status = obj ~= nil
+	local player_name = player:get_player_name()
+	if default.player_attached[player_name] == status then
+		return
+	end
+	default.player_attached[player_name] = status
+
+	if status then
+		local y_pos = self.old_player_model and 6 or -4
+		if player:get_properties().visual == "upright_sprite" then
+			y_pos = -4
+		end
+		player:set_attach(obj, "", {x=0, y=y_pos, z=0}, {x=0, y=0, z=0})
+		player:set_eye_offset({x=0, y=-4, z=0},{x=0, y=-4, z=0})
 	else
-		return {x=0, y=boost_cart:get_sign(v.y), z=boost_cart:get_sign(v.z)}
+		player:set_detach()
+		player:set_eye_offset({x=0, y=0, z=0},{x=0, y=0, z=0})
+		-- HACK in effect! Force updating the attachment rotation
+		player:set_properties({})
 	end
 end
 
-function boost_cart:is_rail(pos)
-	local node = minetest.get_node(pos).name
-	return minetest.get_item_group(node, "rail") ~= 0
+function boost_cart:velocity_to_dir(v)
+	if math.abs(v.x) > math.abs(v.z) then
+		return {x=self:get_sign(v.x), y=self:get_sign(v.y), z=0}
+	else
+		return {x=0, y=self:get_sign(v.y), z=self:get_sign(v.z)}
+	end
 end
 
-function boost_cart:get_rail_direction(pos_, dir_)
-	local pos = vector.round(pos_)
+local get_node = minetest.get_node
+local get_item_group = minetest.get_item_group
+function boost_cart:is_rail(pos, railtype)
+	local node = get_node(pos).name
+	if node == "ignore" then
+		local vm = minetest.get_voxel_manip()
+		local emin, emax = vm:read_from_map(pos, pos)
+		local area = VoxelArea:new{
+			MinEdge = emin,
+			MaxEdge = emax,
+		}
+		local data = vm:get_data()
+		local vi = area:indexp(pos)
+		node = minetest.get_name_from_content_id(data[vi])
+	end
+	if get_item_group(node, "rail") == 0 then
+		return false
+	end
+	if not railtype then
+		return true
+	end
+	return get_item_group(node, "connect_to_raillike") == railtype
+end
+
+function boost_cart:check_front_up_down(pos, dir_, check_up, railtype)
 	local dir = vector.new(dir_)
 	local cur = nil
-	
+
 	-- Front
 	dir.y = 0
 	cur = vector.add(pos, dir)
-	if boost_cart:is_rail(cur) then
+	if self:is_rail(cur, railtype) then
 		return dir
 	end
-	
-	-- Down
-	dir.y = -1
-	cur = vector.add(pos, dir)
-	if boost_cart:is_rail(cur) then
-		return dir
-	end
-	
 	-- Up
-	dir.y = 1
+	if check_up then
+		dir.y = 1
+		cur = vector.add(pos, dir)
+		if self:is_rail(cur, railtype) then
+			return dir
+		end
+	end
+	-- Down
+	dir.y = -1
 	cur = vector.add(pos, dir)
-	if boost_cart:is_rail(cur) then
+	if self:is_rail(cur, railtype) then
 		return dir
 	end
-	
-	-- Left, right
-	dir.y = 0
-	
+	return nil
+end
+
+function boost_cart:get_rail_direction(pos_, dir, ctrl, old_switch, railtype)
+	local pos = vector.round(pos_)
+	local cur = nil
+	local left_check, right_check = true, true
+
 	-- Check left and right
-	local view, opposite, val
-	
-	if dir.x == 0 and dir.z ~= 0 then
-		view = "z"
-		other = "x"
-		if dir.z < 0 then
-			val = {1, -1}
-		else
-			val = {-1, 1}
+	local left = {x=0, y=0, z=0}
+	local right = {x=0, y=0, z=0}
+	if dir.z ~= 0 and dir.x == 0 then
+		left.x = -dir.z
+		right.x = dir.z
+	elseif dir.x ~= 0 and dir.z == 0 then
+		left.z = dir.x
+		right.z = -dir.x
+	end
+
+	local straight_priority = ctrl and dir.y ~= 0
+
+	-- Normal, to disallow rail switching up- & downhill
+	if straight_priority then
+		cur = self:check_front_up_down(pos, dir, true, railtype)
+		if cur then
+			return cur
 		end
-	elseif dir.z == 0 and dir.x ~= 0 then
-		view = "x"
-		other = "z"
-		if dir.x > 0 then
-			val = {1, -1}
-		else
-			val = {-1, 1}
+	end
+
+	if ctrl then
+		if old_switch == 1 then
+			left_check = false
+		elseif old_switch == 2 then
+			right_check = false
+		end
+		if ctrl.left and left_check then
+			cur = self:check_front_up_down(pos, left, false, railtype)
+			if cur then
+				return cur, 1
+			end
+			left_check = false
+		end
+		if ctrl.right and right_check then
+			cur = self:check_front_up_down(pos, right, false, railtype)
+			if cur then
+				return cur, 2
+			end
+			right_check = true
 		end
-	else
-		return {x=0, y=0, z=0}
 	end
-	
-	dir[view] = 0
-	dir[other] = val[1]
-	cur = vector.add(pos, dir)
-	if boost_cart:is_rail(cur) then
-		return dir
+
+	-- Normal
+	if not straight_priority then
+		cur = self:check_front_up_down(pos, dir, true, railtype)
+		if cur then
+			return cur
+		end
 	end
-	
-	-- Down
-	dir.y = -1
-	cur = vector.add(pos, dir)
-	if boost_cart:is_rail(cur) then
-		return dir
+
+	-- Left, if not already checked
+	if left_check then
+		cur = self:check_front_up_down(pos, left, false, railtype)
+		if cur then
+			return cur
+		end
 	end
-	dir.y = 0
-	
-	dir[other] = val[2]
-	cur = vector.add(pos, dir)
-	if boost_cart:is_rail(cur) then
-		return dir
+
+	-- Right, if not already checked
+	if right_check then
+		cur = self:check_front_up_down(pos, right, false, railtype)
+		if cur then
+			return cur
+		end
 	end
-	
-	-- Down
-	dir.y = -1
-	cur = vector.add(pos, dir)
-	if boost_cart:is_rail(cur) then
-		return dir
+
+	-- Backwards
+	if not old_switch then
+		cur = self:check_front_up_down(pos, {
+				x = -dir.x,
+				y = dir.y,
+				z = -dir.z
+			}, true, railtype)
+		if cur then
+			return cur
+		end
 	end
-	
+
 	return {x=0, y=0, z=0}
 end
+
+function boost_cart:pathfinder(pos_, old_pos, old_dir, distance, ctrl,
+		pf_switch, railtype)
+
+	local pos = vector.round(pos_)
+	if vector.equals(old_pos, pos) then
+		return
+	end
+
+	local pf_pos = vector.round(old_pos)
+	local pf_dir = vector.new(old_dir)
+	distance = math.min(boost_cart.path_distance_max,
+		math.floor(distance + 1))
+
+	for i = 1, distance do
+		pf_dir, pf_switch = self:get_rail_direction(
+			pf_pos, pf_dir, ctrl, pf_switch or 0, railtype)
+
+		if vector.equals(pf_dir, {x=0, y=0, z=0}) then
+			-- No way forwards
+			return pf_pos, pf_dir
+		end
+
+		pf_pos = vector.add(pf_pos, pf_dir)
+
+		if vector.equals(pf_pos, pos) then
+			-- Success! Cart moved on correctly
+			return
+		end
+	end
+	-- Not found. Put cart to predicted position
+	return pf_pos, pf_dir
+end
+
+function boost_cart:boost_rail(pos, amount)
+	minetest.get_meta(pos):set_string("cart_acceleration", tostring(amount))
+	for _,obj_ in ipairs(minetest.get_objects_inside_radius(pos, 0.5)) do
+		if not obj_:is_player() and
+				obj_:get_luaentity() and
+				obj_:get_luaentity().name == "carts:cart" then
+			obj_:get_luaentity():on_punch()
+		end
+	end
+end
+
+function boost_cart:register_rail(name, def_overwrite)
+	local sound_func = default.node_sound_metal_defaults
+		or default.node_sound_defaults
+
+	local def = {
+		drawtype = "raillike",
+		paramtype = "light",
+		sunlight_propagates = true,
+		is_ground_content = false,
+		walkable = false,
+		selection_box = {
+			type = "fixed",
+			fixed = {-1/2, -1/2, -1/2, 1/2, -1/2+1/16, 1/2},
+		},
+		sounds = sound_func()
+	}
+	for k, v in pairs(def_overwrite) do
+		def[k] = v
+	end
+	if not def.inventory_image then
+		def.wield_image = def.tiles[1]
+		def.inventory_image = def.tiles[1]
+	end
+
+	minetest.register_node(name, def)
+end
+
+function boost_cart:get_rail_groups(additional_groups)
+	-- Get the default rail groups and add more when a table is given
+	local groups = {
+		dig_immediate = 2,
+		attached_node = 1,
+		rail = 1,
+		connect_to_raillike = 1
+	}
+	if minetest.raillike_group then
+		groups.connect_to_raillike = minetest.raillike_group("rail")
+	end
+	if type(additional_groups) == "table" then
+		for k, v in pairs(additional_groups) do
+			groups[k] = v
+		end
+	end
+	return groups
+end

init.lua

@@ -1,208 +1,46 @@
--- TODO: 
---  Fix way-up
---  Add rail-cross switching
---  Prevent from floating carts
---  Speed up and brake rails
 
 boost_cart = {}
 boost_cart.modpath = minetest.get_modpath("boost_cart")
-boost_cart.speed_max = 8
+
+
+if not minetest.settings then
+	error("[boost_cart] Your Minetest version is no longer supported."
+		.. " (Version <= 0.4.15)")
+end
+
+local function getNum(setting)
+	return tonumber(minetest.settings:get(setting))
+end
+
+-- Maximal speed of the cart in m/s
+boost_cart.speed_max = getNum("boost_cart.speed_max") or 10
+-- Set to -1 to disable punching the cart from inside
+boost_cart.punch_speed_max = getNum("boost_cart.punch_speed_max") or 7
+-- Maximal distance for the path correction (for dtime peaks)
+boost_cart.path_distance_max = 3
+
+
+-- Support for non-default games
+if not default.player_attached then
+	default.player_attached = {}
+end
+
+minetest.after(0, function()
+	boost_cart.old_player_model = not minetest.global_exists("player_api")
+end)
 
 dofile(boost_cart.modpath.."/functions.lua")
 dofile(boost_cart.modpath.."/rails.lua")
 
-boost_cart.cart = {
-	physical = false,
-	collisionbox = {-0.5, -0.5, -0.5, 0.5, 0.5, 0.5},
-	visual = "mesh",
-	mesh = "cart.x",
-	visual_size = {x=1, y=1},
-	textures = {"cart.png"},
-	
-	driver = nil,
-	punch = false, -- used to re-send velocity and position
-	velocity = {x=0, y=0, z=0}, -- only used on punch
-	old_dir = {x=0, y=0, z=0},
-	old_pos = nil
-}
-
-function boost_cart.cart:on_rightclick(clicker)
-	if not clicker or not clicker:is_player() then
-		return
-	end
-	local player_name = clicker:get_player_name()
-	if self.driver and player_name == self.driver then
-		self.driver = nil
-		clicker:set_detach()
-	elseif not self.driver then
-		self.driver = player_name
-		clicker:set_attach(self.object, "", {x=0,y=5,z=0}, {x=0,y=0,z=0})
-	end
+if minetest.global_exists("mesecon") then
+	dofile(boost_cart.modpath.."/detector.lua")
+--else
+--	minetest.register_alias("carts:powerrail", "boost_cart:detectorrail")
+--	minetest.register_alias("carts:powerrail", "boost_cart:detectorrail_on")
 end
 
-function boost_cart.cart:on_activate(staticdata, dtime_s)
-	self.object:set_armor_groups({immortal=1})
-	self.old_pos = self.object:getpos()
+boost_cart.mtg_compat = minetest.global_exists("carts") and carts.pathfinder
+if boost_cart.mtg_compat then
+	minetest.log("action", "[boost_cart] Overwriting definitions of similar carts mod")
 end
-
-function boost_cart.cart:on_punch(puncher, time_from_last_punch, tool_capabilities, direction)
-	if not puncher or not puncher:is_player() then
-		return
-	end
-
-	if puncher:get_player_control().sneak then
-		if self.driver then
-			local player = minetest.get_player_by_name(self.driver)
-			if player then
-				player:set_detach()
-			end
-		end
-    	self.object:remove()
-		puncher:get_inventory():add_item("main", "boost_cart:cart")
-		return
-	end
-	
-	local vel = self.velocity
-	if puncher:get_player_name() == self.driver then
-		if math.abs(vel.x) > 2 or math.abs(vel.z) > 2 then
-			return
-		end
-	end
-	
-	local cart_dir = boost_cart:velocity_to_dir(direction)
-	if cart_dir.x == 0 and cart_dir.z == 0 then
-		local fd = minetest.dir_to_facedir(puncher:get_look_dir())
-		if fd == 0 then
-			cart_dir.x = 1
-		elseif fd == 1 then
-			cart_dir.z = -1
-		elseif fd == 2 then
-			cart_dir.x = -1
-		elseif fd == 3 then
-			cart_dir.z = 1
-		end
-	end
-
-	if time_from_last_punch > tool_capabilities.full_punch_interval then
-		time_from_last_punch = tool_capabilities.full_punch_interval
-	end
-	local dir = boost_cart:get_rail_direction(self.object:getpos(), cart_dir)
-	
-	local f = 3 * (time_from_last_punch / tool_capabilities.full_punch_interval)
-	vel.x = dir.x * f
-	vel.z = dir.y * f
-	vel.z = dir.z * f
-	self.velocity = vel
-	self.punch = true
-end
-
-function boost_cart.cart:on_step(dtime)
-	local vel = self.object:getvelocity()
-	if self.punch then
-		vel = vector.add(vel, self.velocity)
-		self.velocity = {x=0,y=0,z=0}
-	elseif vector.equals(vel, {x=0,y=0,z=0}) then
-		return
-	end
-	
-	local pos = self.object:getpos()
-	local fpos, fold_pos = vector.round(pos), vector.round(self.old_pos)
-	if vector.equals(fpos, fold_pos) and not self.punch then
-		return
-	end
-	self.old_pos = vector.new(pos)
-	
-	local cart_dir = {
-		x = boost_cart:get_sign(vel.x),
-		y = boost_cart:get_sign(vel.y),
-		z = boost_cart:get_sign(vel.z)
-	}
-	local dir = boost_cart:get_rail_direction(pos, cart_dir)
-	if vector.equals(dir, {x=0, y=0, z=0}) then
-		vel = {x=0, y=0, z=0}
-		self.object:setacceleration({x=0, y=0, z=0})
-		self.punch = true
-	else
-		-- If the direction changed
-		if dir.x ~= 0 and self.old_dir.z ~= 0 then
-			vel.x = dir.x * math.abs(vel.z)
-			vel.z = 0
-			pos.z = math.floor(pos.z + 0.5)
-			self.punch = true
-		end
-		if dir.z ~= 0 and self.old_dir.x ~= 0 then
-			vel.z = dir.z * math.abs(vel.x)
-			vel.x = 0
-			pos.x = math.floor(pos.x + 0.5)
-			self.punch = true
-		end
-		-- Up, down?
-		if dir.y ~= self.old_dir.y then
-			vel.y = dir.y * (math.abs(vel.x) + math.abs(vel.z))
-			pos.y = math.floor(pos.y + 0.5)
-			self.punch = true
-		end
-		
-		-- Slow down or speed up..
-		local acc = -2 * dir.y - 0.4
-		self.object:setacceleration({
-			x = dir.x * acc, 
-			y = dir.y * (math.abs(dir.x) + math.abs(dir.z)) * acc, 
-			z = dir.z * acc
-		})
-	end
-	
-	self.old_dir = vector.new(dir)
-	
-	-- Limits
-	for _,v in ipairs({"x","y","z"}) do
-		if math.abs(vel[v]) > boost_cart.speed_max then
-			vel[v] = boost_cart:get_sign(vel[v]) * boost_cart.speed_max
-			self.punch = true
-		end
-	end
-	
-	if dir.x < 0 then
-		self.object:setyaw(math.pi / 2)
-	elseif dir.x > 0 then
-		self.object:setyaw(3 * math.pi / 2)
-	elseif dir.z < 0 then
-		self.object:setyaw(math.pi)
-	elseif dir.z > 0 then
-		self.object:setyaw(0)
-	end
-
-	if dir.y == -1 then
-		self.object:set_animation({x=1, y=1}, 1, 0)
-	elseif dir.y == 1 then
-		self.object:set_animation({x=2, y=2}, 1, 0)
-	else
-		self.object:set_animation({x=0, y=0}, 1, 0)
-	end
-	if self.punch then
-		self.object:setvelocity(vel)
-		self.object:setpos(pos)
-		self.old_pos = {x=0, y=0, z=0}
-	end
-	self.punch = false
-end
-
-minetest.register_entity("boost_cart:cart", boost_cart.cart)
-minetest.register_craftitem("boost_cart:cart", {
-	description = "Cart",
-	inventory_image = minetest.inventorycube("cart_top.png", "cart_side.png", "cart_side.png"),
-	wield_image = "cart_side.png",
-	on_place = function(itemstack, placer, pointed_thing)
-		if not pointed_thing.type == "node" then
-			return
-		end
-		if boost_cart:is_rail(pointed_thing.under) then
-			minetest.add_entity(pointed_thing.under, "boost_cart:cart")
-		elseif boost_cart:is_rail(pointed_thing.above) then
-			minetest.add_entity(pointed_thing.above, "boost_cart:cart")
-		else return end
-		
-		itemstack:take_item()
-		return itemstack
-	end,
-})
+dofile(boost_cart.modpath.."/cart_entity.lua")

mod.conf

@@ -0,0 +1 @@
+name = boost_cart

rails.lua

@@ -1,16 +1,146 @@
-minetest.register_node(":default:rail", {
+-- Common rail registrations
+
+local regular_rail_itemname = "default:rail"
+if minetest.registered_nodes["carts:rail"] then
+	-- MTG Compatibility
+	regular_rail_itemname = "carts:rail"
+end
+
+boost_cart:register_rail(":"..regular_rail_itemname, {
 	description = "Rail",
-	drawtype = "raillike",
-	tiles = {"default_rail.png", "default_rail_curved.png", "default_rail_t_junction.png", "default_rail_crossing.png"},
-	inventory_image = "default_rail.png",
-	wield_image = "default_rail.png",
-	paramtype = "light",
-	sunlight_propagates = true,
-	is_ground_content = true,
-	walkable = false,
-	selection_box = {
-		type = "fixed",
-		fixed = {-1/2, -1/2, -1/2, 1/2, -1/2+1/16, 1/2},
+	tiles = {
+		"carts_rail_straight.png", "carts_rail_curved.png",
+		"carts_rail_t_junction.png", "carts_rail_crossing.png"
 	},
-	groups = {dig_immediate = 2, attached_node = 1, rail = 1, connect_to_raillike = 1},
-})
+	groups = boost_cart:get_rail_groups()
+})
+
+-- Moreores' copper rail
+if minetest.get_modpath("moreores") then
+	minetest.register_alias("carts:copperrail", "moreores:copper_rail")
+
+	if minetest.raillike_group then
+		-- Ensure that this rail uses the same connect_to_raillike
+		local new_groups = minetest.registered_nodes["moreores:copper_rail"].groups
+		new_groups.connect_to_raillike = minetest.raillike_group("rail")
+		minetest.override_item("moreores:copper_rail", {
+			groups = new_groups
+		})
+	end
+else
+	boost_cart:register_rail(":carts:copperrail", {
+		description = "Copper rail",
+		tiles = {
+			"carts_rail_straight_cp.png", "carts_rail_curved_cp.png",
+			"carts_rail_t_junction_cp.png", "carts_rail_crossing_cp.png"
+		},
+		groups = boost_cart:get_rail_groups()
+	})
+
+	minetest.register_craft({
+		output = "carts:copperrail 12",
+		recipe = {
+			{"default:copper_ingot", "", "default:copper_ingot"},
+			{"default:copper_ingot", "group:stick", "default:copper_ingot"},
+			{"default:copper_ingot", "", "default:copper_ingot"},
+		}
+	})
+end
+
+-- Power rail
+boost_cart:register_rail(":carts:powerrail", {
+	description = "Powered rail",
+	tiles = {
+		"carts_rail_straight_pwr.png", "carts_rail_curved_pwr.png",
+		"carts_rail_t_junction_pwr.png", "carts_rail_crossing_pwr.png"
+	},
+	groups = boost_cart:get_rail_groups(),
+	after_place_node = function(pos, placer, itemstack)
+		if not mesecon then
+			minetest.get_meta(pos):set_string("cart_acceleration", "0.5")
+		end
+	end,
+	mesecons = {
+		effector = {
+			action_on = function(pos, node)
+				boost_cart:boost_rail(pos, 0.5)
+			end,
+			action_off = function(pos, node)
+				minetest.get_meta(pos):set_string("cart_acceleration", "0")
+			end,
+		},
+	},
+})
+
+minetest.register_craft({
+	output = "carts:powerrail 6",
+	recipe = {
+		{"default:steel_ingot", "default:mese_crystal_fragment", "default:steel_ingot"},
+		{"default:steel_ingot", "group:stick", "default:steel_ingot"},
+		{"default:steel_ingot", "default:mese_crystal_fragment", "default:steel_ingot"},
+	}
+})
+
+-- Brake rail
+boost_cart:register_rail(":carts:brakerail", {
+	description = "Brake rail",
+	tiles = {
+		"carts_rail_straight_brk.png", "carts_rail_curved_brk.png",
+		"carts_rail_t_junction_brk.png", "carts_rail_crossing_brk.png"
+	},
+	groups = boost_cart:get_rail_groups(),
+	after_place_node = function(pos, placer, itemstack)
+		if not mesecon then
+			minetest.get_meta(pos):set_string("cart_acceleration", "-0.3")
+		end
+	end,
+	mesecons = {
+		effector = {
+			action_on = function(pos, node)
+				minetest.get_meta(pos):set_string("cart_acceleration", "-0.3")
+			end,
+			action_off = function(pos, node)
+				minetest.get_meta(pos):set_string("cart_acceleration", "0")
+			end,
+		},
+	},
+})
+
+minetest.register_craft({
+	output = "carts:brakerail 6",
+	recipe = {
+		{"default:steel_ingot", "default:coal_lump", "default:steel_ingot"},
+		{"default:steel_ingot", "group:stick", "default:steel_ingot"},
+		{"default:steel_ingot", "default:coal_lump", "default:steel_ingot"},
+	}
+})
+
+boost_cart:register_rail("boost_cart:startstoprail", {
+	description = "Start-stop rail",
+	tiles = {
+		"carts_rail_straight_ss.png", "carts_rail_curved_ss.png",
+		"carts_rail_t_junction_ss.png", "carts_rail_crossing_ss.png"
+	},
+	groups = boost_cart:get_rail_groups(),
+	after_place_node = function(pos, placer, itemstack)
+		if not mesecon then
+			minetest.get_meta(pos):set_string("cart_acceleration", "halt")
+		end
+	end,
+	mesecons = {
+		effector = {
+			action_on = function(pos, node)
+				boost_cart:boost_rail(pos, 0.5)
+			end,
+			action_off = function(pos, node)
+				minetest.get_meta(pos):set_string("cart_acceleration", "halt")
+			end,
+		},
+	},
+})
+
+minetest.register_craft({
+	type = "shapeless",
+	output = "boost_cart:startstoprail 2",
+	recipe = {"carts:powerrail", "carts:brakerail"},
+})

settingtypes.txt

@@ -0,0 +1,6 @@
+#    Maximal speed of the cart in m/s (min=1, max=100)
+boost_cart.speed_max (Maximal speed) int 10 1 100
+
+#    Maximal speed to which the driving player can accelerate the cart by punching
+#    from inside the cart. -1 will disable this feature. (min=-1, max=100)
+boost_cart.punch_speed_max (Maximal punch speed) int 7 -1 100