add sound to the cart

functions.lua

@@ -6,6 +6,25 @@ function boost_cart:get_sign(z)
 	end
 end
 
+function boost_cart:manage_attachment(player, status, obj)
+	if not player then
+		return
+	end
+	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
+		player:set_attach(obj, "", {x=0, y=6, 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
+		player:set_detach()
+		player:set_eye_offset({x=0, y=0, z=0},{x=0, y=0, z=0})
+	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}

init.lua

@@ -5,6 +5,11 @@ boost_cart = {}
 boost_cart.modpath = minetest.get_modpath("boost_cart")
 boost_cart.speed_max = 10
 
+if not boost_cart.modpath then
+	error("\nWrong mod directory name! Please change it to 'boost_cart'.\n" ..
+			"See also: http://dev.minetest.net/Installing_Mods")
+end
+
 function vector.floor(v)
 	return {
 		x = math.floor(v.x),
@@ -25,6 +30,10 @@ if not default.player_attached then
 	default.player_attached = {}
 end
 
+local function get_v(v)
+    return math.sqrt(v.x ^ 2 + v.z ^ 2)
+end
+
 boost_cart.cart = {
 	physical = false,
 	collisionbox = {-0.5, -0.5, -0.5, 0.5, 0.5, 0.5},
@@ -50,16 +59,17 @@ function boost_cart.cart:on_rightclick(clicker)
 	local player_name = clicker:get_player_name()
 	if self.driver and player_name == self.driver then
 		self.driver = nil
-		clicker:set_detach()
+		boost_cart:manage_attachment(clicker, false)
 	elseif not self.driver then
 		self.driver = player_name
-		default.player_attached[player_name] = true
-		clicker:set_attach(self.object, "", {x=0, y=3, z=0}, {x=0, y=0, z=0})
+		boost_cart:manage_attachment(clicker, true, self.object)
 	end
 end
 
 function boost_cart.cart:on_activate(staticdata, dtime_s)
 	self.object:set_armor_groups({immortal=1})
+    self.snd = 0
+    self.handle = nil
 end
 
 function boost_cart.cart:on_punch(puncher, time_from_last_punch, tool_capabilities, direction)
@@ -85,11 +95,15 @@ function boost_cart.cart:on_punch(puncher, time_from_last_punch, tool_capabiliti
 			if self.old_pos then
 				self.object:setpos(self.old_pos)
 			end
-			default.player_attached[self.driver] = nil
+            
+            if self.handle then
+               minetest.sound_stop(self.handle)
+               self.handle = nil
+               self.snd = 0
+            end
+
 			local player = minetest.get_player_by_name(self.driver)
-			if player then
-				player:set_detach()
-			end
+			boost_cart:manage_attachment(player, false)
 		end
 		for _,obj_ in ipairs(self.attached_items) do
 			if obj_ then
@@ -97,8 +111,11 @@ function boost_cart.cart:on_punch(puncher, time_from_last_punch, tool_capabiliti
 			end
 		end
 
+		local leftover = puncher:get_inventory():add_item("main", "carts:cart")
+		if not leftover:is_empty() then
+			minetest.add_item(self.object:getpos(), leftover)
+		end
 		self.object:remove()
-		puncher:get_inventory():add_item("main", "carts:cart")
 		return
 	end
 
@@ -131,6 +148,31 @@ end
 function boost_cart.cart:on_step(dtime)
 	local vel = self.object:getvelocity()
 	local update = {}
+    local vv = get_v(vel) ; --print ("vel", vv, self.driver)
+    if vv > 1 and self.driver and self.snd == 0 then
+    
+       self.handle = minetest.sound_play("cart_ride", {
+               -- to_player = self.player,
+               object = self.object,
+               gain = 1.0,
+               loop = true,
+           })
+           if self.handle then
+               self.snd = 1
+           end
+        
+        end
+        
+        if (vv < 1 or not self.driver) and self.snd == 1 then
+        
+           if self.handle then
+               print ("handle", self.handle)
+               minetest.sound_stop(self.handle)
+               self.handle = nil
+               self.snd = 0
+           end
+        
+        end
 	if self.punched then
 		vel = vector.add(vel, self.velocity)
 		self.object:setvelocity(vel)
@@ -299,7 +341,7 @@ end
 
 minetest.register_entity(":carts:cart", boost_cart.cart)
 minetest.register_craftitem(":carts:cart", {
-	description = "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)
@@ -323,4 +365,4 @@ minetest.register_craft({
 		{"default:steel_ingot", "", "default:steel_ingot"},
 		{"default:steel_ingot", "default:steel_ingot", "default:steel_ingot"},
 	},
-})
+})