VoxeLibre/mods/PLAYER/mcl_sprint/init.lua

--[[
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. 
]]

--Configuration variables, these are all explained in README.md
mcl_sprint = {}

mcl_sprint.SPEED = 1.3

local players = {}

-- Returns true if the player with the given name is sprinting, false if not.
-- Returns nil if player does not exist.
mcl_sprint.is_sprinting = function(playername)
	if players[playername] then
		return players[playername].sprinting
	else
		return nil
	end
end

minetest.register_on_joinplayer(function(player)
	local playerName = player:get_player_name()

	players[playerName] = {
		sprinting = false,
		timeOut = 0, 
		shouldSprint = false,
		lastPos = player:get_pos(),
		sprintDistance = 0,
	}
end)
minetest.register_on_leaveplayer(function(player)
	local playerName = player:get_player_name()
	players[playerName] = nil
end)

local 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
		if sprinting == true then
			playerphysics.add_physics_factor(player, "speed", "mcl_sprint:sprint", mcl_sprint.SPEED)
		elseif sprinting == false then
			playerphysics.remove_physics_factor(player, "speed", "mcl_sprint:sprint")
		end
		return true
	end
	return false
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
			local ctrl = player:get_player_control()
			--Check if the player should be sprinting
			if ctrl.aux1 and ctrl.up and not ctrl.sneak then
				players[playerName]["shouldSprint"] = true
			else
				players[playerName]["shouldSprint"] = false
			end
			
			local playerPos = player:get_pos()
			--If the player is sprinting, create particles behind and cause exhaustion
			if playerInfo["sprinting"] == true and gameTime % 0.1 == 0 then

				-- Exhaust player for sprinting
				local lastPos = players[playerName].lastPos
				local dist = vector.distance({x=lastPos.x, y=0, z=lastPos.z}, {x=playerPos.x, y=0, z=playerPos.z})
				players[playerName].sprintDistance = players[playerName].sprintDistance + dist
				if players[playerName].sprintDistance >= 1 then
					local superficial = math.floor(players[playerName].sprintDistance)
					mcl_hunger.exhaust(playerName, mcl_hunger.EXHAUST_SPRINT * superficial)
					players[playerName].sprintDistance = players[playerName].sprintDistance - superficial
				end

				-- Sprint dirt particles
				local numParticles = math.random(1, 2)
				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},
							velocity = {x=0, y=5, z=0},
							acceleration = {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
			players[playerName].lastPos = playerPos
			if players[playerName]["shouldSprint"] == true then --Stopped
				local sprinting
				-- Prevent sprinting if hungry or sleeping
				if (mcl_hunger.active and mcl_hunger.get_hunger(player) <= 6) or (player:get_meta():get_string("mcl_beds:sleeping") == "true")then
					sprinting = false
				else
					sprinting = true
				end
				setSprinting(playerName, sprinting)
			elseif players[playerName]["shouldSprint"] == false then
				setSprinting(playerName, false)
			end
			
		end
	end
end)