Allow player to run by double tapping 'W'

mods/PLAYER/mcl_sprint/init.lua

@@ -151,7 +151,13 @@ minetest.register_on_respawnplayer(function(player)
 	cancelClientSprinting(player:get_player_name())
 end)
 
+local maximum_double_press_interval = 0.4
+local last_w_press_timer = 0	-- time since ctrl.up was pressed last
+local w_prev_pressed = false	-- if ctrl.up was pressed the tick before
+local w_double_pressed = false
+
 minetest.register_globalstep(function(dtime)
+	last_w_press_timer = last_w_press_timer + dtime
 	--Get the gametime
 	local gameTime = get_gametime()
 
@@ -160,8 +166,22 @@ minetest.register_globalstep(function(dtime)
 		local player = get_player_by_name(playerName)
 		if player then
 			local ctrl = player:get_player_control()
+			
+			-- stuff to check if player double-tapped 'W' key
+			if ctrl.up then
+				if w_prev_pressed == false then
+					if last_w_press_timer < maximum_double_press_interval then
+						w_double_pressed = true
+					end
+					last_w_press_timer = 0
+					w_prev_pressed = true
+				end
+			else
+				w_prev_pressed = false
+				w_double_pressed = false
+			end
 			--Check if the player should be sprinting
-			if players[playerName]["clientSprint"] or ctrl.aux1 and ctrl.up and not ctrl.sneak then
+			if players[playerName]["clientSprint"] or ctrl.aux1 or w_double_pressed and ctrl.up and ctrl.sneak==false then
 				players[playerName]["shouldSprint"] = true
 			else
 				players[playerName]["shouldSprint"] = false