Fixish reorganizing, initial train implementation

mods/ENTITIES/mcl_minecarts/carts.lua

@@ -27,21 +27,6 @@ local max_step_distance = 0.5
 local MINECART_MAX_HP = 4
 local PASSENGER_ATTACH_POSITION = vector.new(0, -1.75, 0)
 
-local function detach_minecart(self)
-	local staticdata = self._staticdata
-
-	staticdata.connected_at = nil
-	self.object:set_velocity(staticdata.dir * staticdata.velocity)
-end
-local function try_detach_minecart(self)
-	local staticdata = self._staticdata
-
-	local node = minetest.get_node(staticdata.connected_at)
-	if minetest.get_item_group(node.name, "rail") == 0 then
-		detach_minecart(self)
-	end
-end
-
 local function detach_driver(self)
 	if not self._driver then
 		return

mods/ENTITIES/mcl_minecarts/init.lua

@@ -9,6 +9,6 @@ mcl_minecarts.speed_max = 10
 mcl_minecarts.check_float_time = 15
 mcl_minecarts.FRICTION = 0.4
 
-for _,filename in pairs({"functions","rails","train","storage","carts"}) do
+for _,filename in pairs({"storage","functions","rails","train","carts"}) do
 	dofile(modpath.."/"..filename..".lua")
 end

mods/ENTITIES/mcl_minecarts/movement.lua

@@ -10,6 +10,7 @@ local friction = mcl_minecarts.FRICTION
 -- Imports
 local train_length = mod.train_length
 local update_train = mod.update_train
+local link_cart_ahead = mod.link_cart_ahead
 local update_cart_orientation = mod.update_cart_orientation
 local get_cart_data = mod.get_cart_data
 
@@ -141,10 +142,10 @@ local function handle_cart_collision(cart1, prev_pos, next_dir)
 	local m1 = cart1_staticdata.mass
 	local m2 = cart2_staticdata.mass
 
-	if u2 == 0 and u1 < 1 and train_length(cart1) < 3 then
-		-- Link carts
-		cart2_staticdata.behind = cart1_staticdata.uuid
-		cart1_staticdata.ahead = cart1_staticdata.uuid
+	print("u1="..tostring(u1)..",u2="..tostring(u2))
+	if u2 == 0 and u1 < 4 and train_length(cart1) < 3 then
+		link_cart_ahead(cart1, cart2)
+		cart2_staticdata.dir = mcl_minecarts:get_rail_direction(cart2_staticdata.connected_at, cart1_staticdata.dir)
 		cart2_staticdata.velocity = cart1_staticdata.velocity
 		return
 	end
@@ -243,7 +244,7 @@ local function reverse_direction(self, staticdata)
 	-- Complete moving thru this block into the next, reverse direction, and put us back at the same position we were at
 	local next_dir = -staticdata.dir
 	staticdata.connected_at = staticdata.connected_at + staticdata.dir
-	staticdata.distance = 1 - staticdata.distance
+	staticdata.distance = 1 - (staticdata.distance or 0)
 
 	-- recalculate direction
 	local next_dir,_ = mcl_minecarts:get_rail_direction(staticdata.connected_at, next_dir, nil, nil, staticdata.railtype)

mods/ENTITIES/mcl_minecarts/train.lua

@@ -1,5 +1,72 @@
-function mcl_minecarts.update_train(cart)
+local modname = minetest.get_current_modname()
+local modpath = minetest.get_modpath(modname)
+local mod = mcl_minecarts
+
+-- Imports
+local get_cart_data = mod.get_cart_data
+
+local function find_back(start)
+	while start.behind do
+		local nxt = get_cart_data(start.behind)
+		if not nxt then return start end
+		start = nxt
+	end
+	return start
 end
 
-function mcl_minecarts.train_length(cart)
+local function train_cars(anchor)
+	local back = find_back(anchor._staticdata)
+	return function()
+		if not back then return end
+
+		local ret = back
+		if back.ahead then
+			back = get_cart_data(back.ahead)
+		else
+			back = nil
+		end
+		return ret
+	end
+end
+
+function mod.update_train(cart)
+	local sum_velocity = 0
+	local count = 0
+	for cart in train_cars(cart) do
+		count = count + 1
+		sum_velocity = sum_velocity + (cart.velocity or 0)
+	end
+	local avg_velocity = sum_velocity / count
+	if count == 0 then return end
+
+	print("Using velocity "..tostring(avg_velocity))
+
+	-- Set the entire train to the average velocity
+	for c in train_cars(cart) do
+		print(tostring(c.behind).."->"..c.uuid.."->"..tostring(c.ahead).."  setting cart #"..c.uuid.." velocity to "..tostring(avg_velocity))
+		c.velocity = avg_velocity
+	end
+end
+
+function mod.train_length(cart)
+	local count = 0
+	for cart in train_cars(cart) do
+		count = count + 1
+	end
+	return count
+end
+function mod.link_cart_ahead(cart, cart_ahead)
+	local staticdata = cart._staticdata
+	local ca_staticdata = cart_ahead._staticdata
+
+	minetest.log("action","Linking cart #"..staticdata.uuid.." to cart #"..ca_staticdata.uuid)
+
+	staticdata.ahead = ca_staticdata.uuid
+	ca_staticdata.behind = staticdata.uuid
+end
+function mod.is_in_same_train(anchor, other)
+	for cart in train_cars(anchor) do
+		if cart.uuid == other.uuid then return true end
+	end
+	return false
 end