Dig rate limiter (#48)

* limit_dig_rate config option
* digging rate limiter

builtin.lua

@@ -77,6 +77,8 @@ if xp_redo.enable_dignode_rewards then
 end
 
 -- bonus on digging
+local dig_limiter = (xp_redo.limit_dig_rate and xp_redo.limit_dig_rate > 0) and
+	create_limiter(1 / xp_redo.limit_dig_rate)
 minetest.register_on_dignode(function(_, oldnode, digger)
 	if digger ~= nil and digger:is_player() and not digger.is_fake_player then
 		if not oldnode.name then
@@ -88,6 +90,11 @@ minetest.register_on_dignode(function(_, oldnode, digger)
 			return
 		end
 
+		-- digging rate limiter
+		if dig_limiter and dig_limiter(digger:get_player_name()) then
+			return
+		end
+
 		-- no reward for nodes that are fast to dig and add no tool wear
 		local dig_immediate = minetest.get_item_group(oldnode.name, "dig_immediate")
 		if dig_immediate == 2 or dig_immediate == 3 then

init.lua

@@ -15,6 +15,9 @@ xp_redo = {
 	-- xp penalty on player death
 	enable_death_malus = minetest.settings:get_bool("xp.enable_death_malus", true),
 
+	-- digging rate limiter
+	limit_dig_rate = tonumber(minetest.settings:get("xp.limit_dig_rate")),
+
 	hud = {
 		posx = tonumber(minetest.settings:get("xp.hud.offsetx") or 0.8),
 		posy = tonumber(minetest.settings:get("xp.hud.offsety") or 0.7)