Standardize high-resolution gametime.

Use high-res version in a few places we were using integer-res
timer before.  This should e.g. smooth time variation of wind
strength for ambient sounds.

mods/nc_api/init.lua

@@ -57,6 +57,7 @@ include("util_facedir")
 include("util_sound")
 include("util_translate")
 include("util_ezschematic")
+include("util_gametime")
 include("match")
 
 include("fx_digparticles")

mods/nc_api/register_soaking.lua

@@ -27,7 +27,7 @@ local function soaking_core(def, reg, getmeta)
 	end
 
 	def.action = function(...)
-		local now = minetest.get_gametime()
+		local now = nodecore.gametime
 
 		local meta = getmeta(...)
 		local total = meta:get_float(def.qtyfield) or 0

mods/nc_api/util_gametime.lua

@@ -0,0 +1,22 @@
+-- LUALOCALS < ---------------------------------------------------------
+local math, minetest, nodecore
+    = math, minetest, nodecore
+local math_abs
+    = math.abs
+-- LUALOCALS > ---------------------------------------------------------
+
+minetest.register_globalstep(function(dtime)
+		local mtt = minetest.get_gametime()
+		local nct = nodecore.gametime
+		if not nct then
+			minetest.log("nodecore.gametime: init to " .. mtt)
+			nct = mtt
+		end
+		nct = nct + dtime
+		if math_abs(nct - mtt) >= 2 then
+			minetest.log("nodecore.gametime: excess drift; nct="
+				.. nct .. ", mtt=" .. mtt)
+			nct = mtt
+		end
+		nodecore.gametime = nct
+	end)

mods/nc_api/util_sound.lua

@@ -18,7 +18,7 @@ end
 function nodecore.windiness(y)
 	if y < 0 then return 0 end
 	if y > 512 then y = 512 end
-	return math_sqrt(y) * (1 + 0.5 * math_sin(minetest.get_gametime() / 5))
+	return math_sqrt(y) * (1 + 0.5 * math_sin(nodecore.gametime / 5))
 end
 
 function nodecore.stack_sounds(pos, kind, stack)

mods/nc_api_craft/register_cook_abm.lua

@@ -16,7 +16,7 @@ local function getduration(_, data)
 	or not md.start
 	then return 0 end
 
-	return minetest.get_gametime() - md.start
+	return nodecore.gametime - md.start
 end
 
 local function playcookfx(pos, cookfx, sound, smokeqty, smoketime)
@@ -45,7 +45,7 @@ local function inprogress(pos, data)
 		md = {
 			label = recipe.label,
 			count = count,
-			start = minetest.get_gametime()
+			start = nodecore.gametime
 		}
 		meta:set_string(modname, minetest.serialize(md))
 	end

mods/nc_torch/abm.lua

@@ -39,7 +39,7 @@ nodecore.register_limited_abm({
 		nodenames = {modname .. ":torch_lit"},
 		action = function(pos)
 			if nodecore.quenched(pos) or
-			minetest.get_gametime() > minetest.get_meta(pos):get_float("expire") then
+			nodecore.gametime > minetest.get_meta(pos):get_float("expire") then
 				minetest.remove_node(pos)
 				minetest.add_item(pos, {name = "nc_fire:lump_ash"})
 				minetest.sound_play("nc_fire_snuff", {gain = 1, pos = pos})
@@ -52,7 +52,7 @@ nodecore.register_aism({
 		itemnames = {modname .. ":torch_lit"},
 		action = function(stack, data)
 			local expire = stack:get_meta():get_float("expire") or 0
-			if expire < minetest.get_gametime() then
+			if expire < nodecore.gametime then
 				minetest.sound_play("nc_fire_snuff", {gain = 1, pos = data.pos})
 				return "nc_fire:lump_ash"
 			end

mods/nc_torch/node.lua

@@ -30,7 +30,7 @@ minetest.register_node(modname .. ":torch", {
 		on_ignite = function(pos)
 			minetest.set_node(pos, {name = modname .. ":torch_lit"})
 			minetest.sound_play("nc_fire_ignite", {gain = 1, pos = pos})
-			local expire = minetest.get_gametime() + nodecore.boxmuller() * 5 + 60
+			local expire = nodecore.gametime + nodecore.boxmuller() * 5 + 60
 			minetest.get_meta(pos):set_float("expire", expire)
 			return true
 		end

mods/nc_torch/wield.lua

@@ -1,6 +1,6 @@
 -- LUALOCALS < ---------------------------------------------------------
-local ItemStack, minetest, pairs, setmetatable, vector
-    = ItemStack, minetest, pairs, setmetatable, vector
+local ItemStack, minetest, nodecore, pairs, setmetatable, vector
+    = ItemStack, minetest, nodecore, pairs, setmetatable, vector
 -- LUALOCALS > ---------------------------------------------------------
 
 local modname = minetest.get_current_modname()
@@ -21,12 +21,10 @@ local function wieldlight(pos)
 	return minetest.get_node_timer(pos):start(0.3)
 end
 
-local now
 local wltimers = {}
 local ambtimers = {}
-minetest.register_globalstep(function(dt)
-		now = now or minetest.get_gametime()
-		now = now + dt
+minetest.register_globalstep(function()
+		local now = nodecore.gametime
 		for _, player in pairs(minetest.get_connected_players()) do
 			local inv = player:get_inventory()
 			local ppos = player:get_pos()