Add simple sprinting mod

Based on [sprint] by GunshipPenguin

mods/PLAYER/mcl_sprint/esprint.lua

@@ -0,0 +1,94 @@
+--[[
+Sprint mod for Minetest by GunshipPenguin
+
+To the extent possible under law, the author(s)
+have dedicated all copyright and related and neighboring rights 
+to this software to the public domain worldwide. This software is
+distributed without any warranty. 
+]]
+
+local players = {}
+
+minetest.register_on_joinplayer(function(player)
+	local playerName = player:get_player_name()
+
+	players[playerName] = {
+		sprinting = false,
+		timeOut = 0, 
+		shouldSprint = false,
+	}
+end)
+minetest.register_on_leaveplayer(function(player)
+	local playerName = player:get_player_name()
+	players[playerName] = nil
+end)
+minetest.register_globalstep(function(dtime)
+	--Get the gametime
+	local gameTime = minetest.get_gametime()
+
+	--Loop through all connected players
+	for playerName,playerInfo in pairs(players) do
+		local player = minetest.get_player_by_name(playerName)
+		if player ~= nil then
+			--Check if the player should be sprinting
+			if player:get_player_control()["aux1"] and player:get_player_control()["up"] then
+				players[playerName]["shouldSprint"] = true
+			else
+				players[playerName]["shouldSprint"] = false
+			end
+			
+			--If the player is sprinting, create particles behind him/her 
+			if playerInfo["sprinting"] == true and gameTime % 0.1 == 0 then
+				local numParticles = math.random(1, 2)
+				local playerPos = player:getpos()
+				local playerNode = minetest.get_node({x=playerPos["x"], y=playerPos["y"]-1, z=playerPos["z"]})
+				if playerNode["name"] ~= "air" then
+					for i=1, numParticles, 1 do
+						minetest.add_particle({
+							pos = {x=playerPos["x"]+math.random(-1,1)*math.random()/2,y=playerPos["y"]+0.1,z=playerPos["z"]+math.random(-1,1)*math.random()/2},
+							vel = {x=0, y=5, z=0},
+							acc = {x=0, y=-13, z=0},
+							expirationtime = math.random(),
+							size = math.random()+0.5,
+							collisiondetection = true,
+							vertical = false,
+							texture = "default_dirt.png",
+						})
+					end
+				end
+			end
+
+			--Adjust player states
+			if players[playerName]["shouldSprint"] == true then --Stopped
+				local sprinting
+				-- Prevent sprinting if standing on soul sand
+				if playerplus[playerName].nod_stand == "mcl_nether:soul_sand" then
+					sprinting = false
+				else
+					sprinting = true
+				end
+				setSprinting(playerName, sprinting)
+			elseif players[playerName]["shouldSprint"] == false then
+				setSprinting(playerName, false)
+			end
+			
+		end
+	end
+end)
+
+function setSprinting(playerName, sprinting) --Sets the state of a player (0=stopped/moving, 1=sprinting)
+	local player = minetest.get_player_by_name(playerName)
+	if players[playerName] then
+		players[playerName]["sprinting"] = sprinting
+		-- Don't overwrite physics when standing on soul sand
+		if playerplus[playerName].nod_stand ~= "mcl_nether:soul_sand" then
+			if sprinting == true then
+				player:set_physics_override({speed=SPRINT_SPEED,jump=SPRINT_JUMP})
+			elseif sprinting == false then
+				player:set_physics_override({speed=1.0,jump=1.0})
+			end
+			return true
+		end
+	end
+	return false
+end