Begin standardization of unload bounds check

- New near_unloaded API that supports custom
  distance parameter, map bounds check, and
  some optimizations.
- Add area automatic unload check support to ABM
  API and add to applicable ABMs, replacing many
  old manual checks.

Note that the explicit unload check is only strictly
necessary when something will happen due to
a node NOT being present in the area, e.g. something
igniting due to absent coolant, or soaking quantity
being reset due to missing sources.  In simple cases
where the absence of a thing causes the ABM to do
nothing, then the standard check can work because
the default action is to do nothing anyway.

mods/nc_api/mapgen_limits.lua

@@ -1,6 +1,6 @@
 -- LUALOCALS < ---------------------------------------------------------
-local math, minetest, nodecore, string, tonumber
-    = math, minetest, nodecore, string, tonumber
+local math, minetest, nodecore, string, tonumber, vector
+    = math, minetest, nodecore, string, tonumber, vector
 local math_floor, string_format
     = math.floor, string.format
 -- LUALOCALS > ---------------------------------------------------------
@@ -11,17 +11,74 @@ local chunksize = tonumber(minetest.get_mapgen_setting("chunksize")) or 5
 chunksize = chunksize * 16
 local limitchunks = math_floor(limit / chunksize)
 
-nodecore.map_limit_min = (-limitchunks + 0.5) * chunksize + 7.5
-nodecore.map_limit_max = (limitchunks - 0.5) * chunksize + 7.5
+local min = (-limitchunks + 0.5) * chunksize + 7.5
+nodecore.map_limit_min = min
+local max = (limitchunks - 0.5) * chunksize + 7.5
+nodecore.map_limit_max = max
 
 nodecore.log("info", string_format("mapgen limit: %d, chunk: %d, bounds: %0.1f to %0.1f",
 		limit, chunksize, nodecore.map_limit_min, nodecore.map_limit_max))
 
 function nodecore.within_map_limits(pos)
-	return pos.x >= nodecore.map_limit_min
-	and pos.y >= nodecore.map_limit_min
-	and pos.z >= nodecore.map_limit_min
-	and pos.x <= nodecore.map_limit_max
-	and pos.y <= nodecore.map_limit_max
-	and pos.z <= nodecore.map_limit_max
+	return pos.x >= min
+	and pos.y >= min
+	and pos.z >= min
+	and pos.x <= max
+	and pos.y <= max
+	and pos.z <= max
+end
+
+function nodecore.near_unloaded(pos, node, dist)
+	pos = vector.floor(pos)
+	if not (node or minetest.get_node_or_nil(pos)) then return true end
+
+	if (not dist) or (dist < 1) then return end
+	dist = math_floor(dist)
+
+	-- Clamp area to check to map bounds; areas outside the map
+	-- are always considered "loaded" and their ignores are
+	-- treated as canonical.
+
+	local zmin = pos.z - dist
+	if zmin < min then zmin = min end
+	local zmax = pos.z + dist
+	if zmax > max then zmax = max end
+
+	local ymin = pos.y - dist
+	if ymin < min then ymin = min end
+	local ymax = pos.y + dist
+	if ymax > max then ymax = max end
+
+	local xmin = pos.x - dist
+	if xmin < min then xmin = min end
+	local xmax = pos.x + dist
+	if xmax > max then xmax = max end
+
+	-- Check corners of area
+	local step = dist * 2
+	for z = zmin, zmax, step do
+		pos.z = z
+		for y = ymin, ymax, step do
+			pos.y = y
+			for x = xmin, xmax, step do
+				pos.x = x
+				if not minetest.get_node_or_nil(pos) then return true end
+			end
+		end
+	end
+
+	-- If area is wide enough to have entire mapblocks not
+	-- covered by the center and corners, then check each
+	-- mapblock in case internal ones are unloaded.
+	if dist <= 16 then return end
+	for z = zmin, zmax, 16 do
+		pos.z = z
+		for y = ymin, ymax, 16 do
+			pos.y = y
+			for x = xmin, xmax, 16 do
+				pos.x = x
+				if not minetest.get_node_or_nil(pos) then return true end
+			end
+		end
+	end
 end

mods/nc_api/util_misc.lua

@@ -404,10 +404,6 @@ function nodecore.grav_air_accel_ent(obj)
 	return obj:set_acceleration(new)
 end
 
-function nodecore.near_unloaded(pos, radius)
-	return minetest.find_node_near(pos, radius or 1, {"ignore"}, true)
-end
-
 function nodecore.get_objects_at_pos(pos)
 	pos = vector.round(pos)
 	local t = {}

mods/nc_api_active/abmarea.lua

@@ -0,0 +1,17 @@
+-- LUALOCALS < ---------------------------------------------------------
+local minetest, nodecore
+    = minetest, nodecore
+-- LUALOCALS > ---------------------------------------------------------
+
+local oldreg = minetest.register_abm
+function minetest.register_abm(def)
+	if def.arealoaded then
+		local dist = def.arealoaded
+		local oldact = def.action
+		def.action = function(pos, node, ...)
+			if nodecore.near_unloaded(pos, node, dist) then return end
+			return oldact(pos, node, ...)
+		end
+	end
+	return oldreg(def)
+end

mods/nc_api_active/init.lua

@@ -13,6 +13,7 @@ end
 
 include("abmmux")
 include("abminvert")
+include("abmarea")
 include("stasis")
 include("dnts")
 include("aism")

mods/nc_api_craft/register_cook_abm.lua

@@ -96,6 +96,7 @@ function nodecore.register_cook_abm(def)
 	def.label = def.label or "cook " .. minetest.write_json(def.nodenames)
 	def.interval = def.interval or 1
 	def.chance = def.chance or 1
+	def.arealoaded = def.arealoaded or 1
 	def.action = cookcheck
 	nodecore.group_expand(def.nodenames, function(k) cooknames[k] = true end)
 	minetest.register_abm(def)

mods/nc_api_loose/loose.lua

@@ -83,6 +83,7 @@ nodecore.register_soaking_abm({
 		fieldname = "repack",
 		nodenames = {"group:loose_repack"},
 		interval = 10,
+		arealoaded = 1,
 		soakrate = function(pos, node)
 			local def = minetest.registered_items[node.name] or {}
 			if def.no_repack or def.no_self_repack then return end

mods/nc_api_loose/repose.lua

@@ -81,6 +81,7 @@ minetest.register_abm({
 		neighbors = {"air"},
 		interval = 2,
 		chance = 5,
+		arealoaded = 1,
 		action = function(pos)
 			if not reposeq then
 				reposeq = {}

mods/nc_concrete/stylus.lua

@@ -89,6 +89,7 @@ nodecore.register_soaking_abm({
 		interval = 1,
 		nodenames = {"group:concrete_etchable"},
 		fieldname = "plycuring",
+		arealoaded = 1,
 		soakrate = function(pos)
 			if minetest.find_node_near(pos,
 				1, {"group:concrete_flow", "group:water"}) then

mods/nc_concrete/wet.lua

@@ -103,6 +103,7 @@ nodecore.register_soaking_abm({
 		interval = 5,
 		nodenames = {"group:concrete_source"},
 		fieldname = "curing",
+		arealoaded = 1,
 		soakrate = function(pos)
 			if minetest.find_node_near(pos,
 				1, {"group:concrete_flow", "group:water"}) then

mods/nc_fire/abm.lua

@@ -48,6 +48,7 @@ do
 			label = "fire consume",
 			interval = 1,
 			chance = 1,
+			arealoaded = 1,
 			nodenames = {modname .. ":fire"},
 			action = function(pos)
 				sparks_add(pos)
@@ -75,6 +76,7 @@ minetest.register_abm({
 		nodenames = {"group:flammable"},
 		neighbors = {"group:igniter"},
 		neighbors_invert = true,
+		arealoaded = 1,
 		action = function(pos)
 			nodecore.fire_check_ignite(pos)
 		end
@@ -85,6 +87,7 @@ minetest.register_abm({
 		interval = 1,
 		chance = 1,
 		nodenames = {"group:ember"},
+		arealoaded = 1,
 		action = function(pos, node)
 			local snuff, vents = nodecore.fire_check_snuff(pos, node)
 			if snuff or not vents then return end

mods/nc_flora/flowers.lua

@@ -184,6 +184,7 @@ minetest.register_abm({
 		interval = 1,
 		chance = 100,
 		nodenames = {"group:flower_living"},
+		arealoaded = 2,
 		action = function(pos, node)
 			local function die()
 				local wilt = minetest.registered_items[node.name].flower_wilts_to

mods/nc_flora/rushes.lua

@@ -99,6 +99,7 @@ minetest.register_abm({
 		label = "rush drying/spreading",
 		interval = 1,
 		chance = 50,
+		arealoaded = 2,
 		nodenames = {modname .. ":rush"},
 		action = function(pos)
 			local subst, below = rushcheck(pos)

mods/nc_flora/sedges.lua

@@ -113,6 +113,7 @@ minetest.register_abm({
 		label = "sedge growth/death",
 		interval = 2,
 		chance = 250,
+		arealoaded = 1,
 		nodenames = {"group:flora_sedges"},
 		action = function(pos, node)
 			local below = {x = pos.x, y = pos.y - 1, z = pos.z}

mods/nc_igneous/amalgam.lua

@@ -72,6 +72,7 @@ minetest.register_abm({
 		interval = 1,
 		chance = 2,
 		nodenames = {"group:amalgam"},
+		arealoaded = 1,
 		action = function(pos)
 			if nodecore.quenched(pos) then return end
 			return nodecore.set_loud(pos, {name = lavasrc})

mods/nc_igneous/pumice.lua

@@ -52,6 +52,7 @@ minetest.register_abm({
 		chance = 2,
 		nodenames = {pumname},
 		neighbors = {"group:lava"},
+		arealoaded = 1,
 		action = function(pos)
 			if math_random() < 0.95 and nodecore.quenched(pos) then return end
 			nodecore.set_loud(pos, {name = "nc_terrain:lava_flowing", param2 = 7})

mods/nc_items/hooks.lua

@@ -51,6 +51,7 @@ minetest.register_abm({
 		nodenames = {"group:visinv"},
 		interval = 2,
 		chance = 1,
+		arealoaded = 1,
 		action = function(pos)
 			if nevermatch[nodecore.stack_get(pos):get_name()] then return end
 			return nodecore.dnt_set(pos, dntname)

mods/nc_lode/anvils.lua

@@ -29,6 +29,7 @@ minetest.register_abm({
 		nodenames = {cracked},
 		interval = 1,
 		chance = 1,
+		arealoaded = 1,
 		action = function(pos)
 			if nodecore.quenched(pos) or #nodecore.find_nodes_around(
 				pos, "group:flame", 1) < 1 then

mods/nc_lux/fluid.lua

@@ -72,6 +72,7 @@ minetest.register_abm({
 		interval = 1,
 		chance = 2,
 		nodenames = {modname .. ":flux_source"},
+		arealoaded = 1,
 		action = function(pos)
 			for _, v in pairs(indirs) do
 				local p = vector.add(pos, v)

mods/nc_lux/react.lua

@@ -8,6 +8,7 @@ minetest.register_abm({
 		interval = 1,
 		chance = 2,
 		nodenames = {"group:lux_cobble"},
+		arealoaded = 1,
 		action = function(pos, node)
 			local qty = nodecore.lux_react_qty(pos)
 			local name = node.name:gsub("cobble%d", "cobble" .. qty)

mods/nc_lux/renew.lua

@@ -10,6 +10,7 @@ nodecore.register_soaking_abm({
 		fieldname = "lavalux",
 		interval = 10,
 		nodenames = {"group:amalgam"},
+		arealoaded = 14,
 		soakrate = nodecore.lux_soak_rate,
 		soakcheck = function(data, pos)
 			if data.total < 12500 then return end

mods/nc_scaling/abm.lua

@@ -11,6 +11,7 @@ minetest.register_abm({
 		chance = 1,
 		nodenames = {"group:" .. modname},
 		ignore_stasis = true,
+		arealoaded = 1,
 		action = function(pos)
 			local data = minetest.get_meta(pos):get_string("data")
 			if (not data) or (data == "") then

mods/nc_sponge/abm.lua

@@ -54,6 +54,7 @@ minetest.register_abm({
 		interval = 1,
 		chance = 100,
 		nodenames = {modname .. ":sponge_wet"},
+		arealoaded = 1,
 		action = function(pos)
 			local above = {x = pos.x, y = pos.y + 1, z = pos.z}
 			if nodecore.is_full_sun(above) and #findwater(pos) < 1 then

mods/nc_sponge/cultivate.lua

@@ -76,6 +76,7 @@ minetest.register_abm({
 		interval = 1,
 		chance = 10,
 		nodenames = {living},
+		arealoaded = 1,
 		action = function(pos, node)
 			if not spongesurvive({pos = pos, node = node}) then
 				nodecore.set_loud(pos, {name = wet})
@@ -109,9 +110,9 @@ nodecore.register_soaking_abm({
 		nodenames = {living},
 		interval = 5,
 		chance = 2,
+		arealoaded = 6,
 		soakrate = function() return 2 end,
 		soakcheck = function(data, pos)
-			if nodecore.near_unloaded(pos) then return end
 			if data.total < basecost then return end
 
 			local count = 0

mods/nc_terrain/api.lua

@@ -72,6 +72,7 @@ minetest.register_abm({
 		label = "artificial water check",
 		interval = 1,
 		chance = 1,
+		arealoaded = 1,
 		nodenames = {graywatersrc},
 		action = function(pos) return nodecore.artificial_water_check(pos) end
 	})

mods/nc_tree/grow_active.lua

@@ -38,9 +38,9 @@ nodecore.register_soaking_abm({
 		fieldname = "eggcorn",
 		nodenames = {modname .. ":eggcorn_planted"},
 		interval = 10,
+		arealoaded = 1,
 		soakrate = nodecore.tree_growth_rate,
 		soakcheck = function(data, pos)
-			if nodecore.near_unloaded(pos) then return end
 			if data.total >= sproutcost then
 				nodecore.node_sound(pos, "dig")
 				nodecore.set_loud(pos, {name = modname .. ":root"})
@@ -77,9 +77,9 @@ nodecore.register_soaking_abm({
 		fieldname = "treegrow",
 		nodenames = {modname .. ":tree_bud"},
 		interval = 10,
+		arealoaded = 1,
 		soakrate = nodecore.tree_trunk_growth_rate,
 		soakcheck = function(data, pos, node)
-			if nodecore.near_unloaded(pos) then return end
 			if data.total < trunkcost then
 				return growparticles(pos, data.rate, 0.45)
 			end
@@ -131,12 +131,12 @@ nodecore.register_soaking_abm({
 		nodenames = {modname .. ":leaves_bud"},
 		fieldname = "leafgrow",
 		interval = 10,
+		arealoaded = 1,
 		soakrate = function(pos)
 			local rate = minetest.get_meta(pos):get_float("growrate") or 0
 			return rate and rate ~= 0 and rate or 10
 		end,
 		soakcheck = function(data, pos, node)
-			if nodecore.near_unloaded(pos) then return end
 			if data.total < leafcost then return end
 
 			nodecore.set_loud(pos, nodecore.calc_leaves(pos))

mods/nc_writing/leaching.lua

@@ -22,6 +22,7 @@ function nodecore.register_dirt_leaching(fromnode, tonode, rate)
 			fieldname = "leach",
 			nodenames = {fromnode},
 			interval = 5,
+			arealoaded = 1,
 			quickcheck = function(pos)
 				return waterat(pos, 0, 1, 0)
 			end,