sync code with MR and comment on performance issues

* do not check fake players in callbacks due performance impack
  but made proper player checks on each loop cos each loop
  retrieve players at live so a suddent disconected player may
  happened or craker player with invalid object that property
  check at `ck_player(obj)`
* added comments about this, this commit tries to sync the MR at
  https://notabug.org/TenPlus1/stamina/pulls/16
  until (as always) tenplus1 commit their own solution

init.lua

@@ -67,7 +67,7 @@ local damage_enabled = minetest.settings:get_bool("enable_damage")
 
 local function stamina_update_level(player, level)
 
-	if not ck_player(player) then return end
+	if not ck_player(player) then return nil end
 
 	local old = get_int_attribute(player)
 
@@ -156,7 +156,7 @@ local pova_mod = minetest.get_modpath("pova")
 
 local function set_sprinting(name, sprinting)
 
-	local player = minetest.get_player_by_name(name) ; if not ck_player(player) then return end
+	local player = minetest.get_player_by_name(name) ; if not player then return end
 
 	-- get player physics
 	local def = player:get_physics_override()
@@ -225,8 +225,7 @@ local function head_particle(player, texture)
 	if not ck_player(player) then return end
 
 	local prop = player:get_properties()
-	local eye_height = prop.eye_height or 1.23
-	local pos = player:get_pos() ; pos.y = pos.y + eye_height -- mouth level
+	local pos = player:get_pos() ; pos.y = pos.y + (prop.eye_height or 1.23) -- mouth level
 	local dir = player:get_look_dir()
 
 
@@ -251,7 +250,7 @@ local function drunk_tick()
 
 	for _,player in ipairs(minetest.get_connected_players()) do
 
-		if not ck_player(player) then return end
+		if not ck_player(player) then return end -- need cos some rare cases during game running object is not player
 
 		local name = player:get_player_name()
 
@@ -300,7 +299,7 @@ local function health_tick()
 
 	for _,player in ipairs(minetest.get_connected_players()) do
 
-		if not ck_player(player) then return end
+		if not ck_player(player) then return end -- need cos some rare cases during game running object is not player
 
 		local name = player:get_player_name()
 
@@ -312,7 +311,7 @@ local function health_tick()
 
 			-- damage player by 1 hp if saturation is < 2
 			if h and h < STAMINA_STARVE_LVL
-			and hp > 0 then
+			and hp > 1 then
 				player:set_hp(hp - STAMINA_STARVE, {hunger = true})
 			end
 
@@ -336,7 +335,8 @@ local function action_tick()
 
 	for _,player in ipairs(minetest.get_connected_players()) do
 
-		if not ck_player(player) then return end
+		if not ck_player(player) then return end -- need cos some rare cases during game running object is not player
+
 		local controls = player:get_player_control()
 
 		-- Determine if the player is walking or jumping
@@ -356,8 +356,7 @@ local function action_tick()
 		--- START sprint
 		if enable_sprint then
 
-			if not ck_player(player) then return end
-			local name = player:get_player_name()
+			local name = player and player:get_player_name()
 
 			-- check if player can sprint (stamina must be over 6 points)
 			if name
@@ -422,7 +421,7 @@ local function poison_tick()
 
 	for _,player in ipairs(minetest.get_connected_players()) do
 
-		if not ck_player(player) then return end
+		if not ck_player(player) then return end -- need cos some rare cases during game running object is not player
 
 		local name = player:get_player_name()
 
@@ -462,7 +461,7 @@ local function stamina_tick()
 
 	for _,player in ipairs(minetest.get_connected_players()) do
 
-		if not ck_player(player) then return end
+		if not ck_player(player) then return end -- need cos some rare cases during game running object is not player
 
 		local h = get_int_attribute(player)
 
@@ -644,6 +643,7 @@ if damage_enabled and minetest.settings:get_bool("enable_stamina") ~= false then
 
 		-- the code here was redundant cos get_int_attribute already call the level
 		-- but with backguard compat, tenplus1 just inherint the code but with removed backguard compatibility
+		-- also here we do not check if name its valid, object its already valid
 		if get_int_attribute(player) then
 			level = math.min(get_int_attribute(player), STAMINA_VISUAL_MAX)
 		end
@@ -656,8 +656,6 @@ if damage_enabled and minetest.settings:get_bool("enable_stamina") ~= false then
 
 		local name = player:get_player_name()
 
-		if not name then return end
-
 		local id = player:hud_add({
 			name = "stamina",
 			hud_elem_type = "statbar",
@@ -700,7 +698,6 @@ if damage_enabled and minetest.settings:get_bool("enable_stamina") ~= false then
 	minetest.register_globalstep(stamina_globaltimer)
 
 	minetest.register_on_placenode(function(pos, oldnode, player, ext)
-		if not player then return end
 		exhaust_player(player, STAMINA_EXHAUST_PLACE)
 	end)
 

settingtypes.txt

@@ -4,10 +4,10 @@ sprint_particles (Enable sprint particles) bool true
 
 enable_stamina (Enable stamina/hunger) bool true
 
-stamina_tick (Time in seconds after which 1 saturation point is taken) float 800
+stamina_tick (Time in seconds after which 1 saturation point is taken) float 1600
 
 stamina_sprint_speed (Extra sprint speed - 0.0 to 1.0) float 0.3
 
 stamina_sprint_jump (Extra sprint jump height - 0.0 to 1.0) float 0.1
 
-stamina_sprint_drain (Sprint stamina drain - 0.0 to 1.0) float 0.35
+stamina_sprint_drain (Sprint stamina drain - 0.0 to 1.0) float 0.2