From 964451fd7840cb2ad8db89044f0d92180ecd26bd Mon Sep 17 00:00:00 2001
From: tenplus1 <kinsellaja@yahoo.com>
Date: Sat, 3 Aug 2024 11:35:28 +0100
Subject: [PATCH] add mob hearing feature and self.on_sound() function

---
 api.lua          | 76 +++++++++++++++++++++++++++++++++++++++++++++++-
 api.txt          | 10 +++++++
 settingtypes.txt |  3 ++
 3 files changed, 88 insertions(+), 1 deletion(-)

diff --git a/api.lua b/api.lua
index db215d8..f20c8f7 100644
--- a/api.lua
+++ b/api.lua
@@ -21,7 +21,7 @@ end
 -- Global
 mobs = {
 	mod = "redo",
-	version = "20240716",
+	version = "20240803",
 	translate = S,
 	invis = minetest.global_exists("invisibility") and invisibility or {},
 	node_snow = has(minetest.registered_aliases["mapgen_snow"])
@@ -2823,6 +2823,16 @@ local tr = minetest.get_modpath("toolranks")
 -- deal damage and effects when mob punched
 function mob_class:on_punch(hitter, tflp, tool_capabilities, dir, damage)
 
+	-- is punch from sound detection
+	if hitter == "sound" then
+
+		if self.on_sound then
+			self.on_sound(self, tool_capabilities) -- pass sound table to custom function
+		end
+
+		return true
+	end
+
 	-- mob health check
 	if self.health <= 0 then
 		return true
@@ -3786,6 +3796,7 @@ minetest.register_entity(":" .. name, setmetatable({
 	do_punch = def.do_punch,
 	on_breed = def.on_breed,
 	on_grown = def.on_grown,
+	on_sound = def.on_sound,
 
 	on_activate = function(self, staticdata, dtime)
 		return self:mob_activate(staticdata, def, dtime)
@@ -5045,3 +5056,66 @@ minetest.register_chatcommand("clear_mobs", {
 		minetest.chat_send_player(name, S("@1 mobs removed.", count))
 	end
 })
+
+
+-- Is mob hearing enabled, if so override minetest.sound_play with custom function
+if settings:get_bool("mobs_can_hear") ~= false then
+
+local old_sound_play = minetest.sound_play
+
+minetest.sound_play = function(spec, param, eph)
+
+	local op_params = {}
+
+	-- store sound position
+	if param.pos then
+		op_params.pos = param.pos
+	elseif param.object then
+		op_params.pos = param.object:get_pos()
+	elseif param.to_player then
+		op_params.pos = minetest.get_player_by_name(param.to_player):get_pos()
+	end
+
+	-- store sound name and gain
+	if type(spec) == "string" then
+		op_params.sound = spec
+		op_params.gain = param.gain or 1.0
+	elseif type(spec) == "table" then
+		op_params.sound = spec.name
+		op_params.gain = spec.gain or param.gain or 1.0
+	end
+
+	-- store player name or object reference
+	if param.to_player then
+		op_params.player = param.to_player
+	elseif param.object then
+		op_params.object = param.object
+	end
+
+	-- find mobs within sounds max_hear_distance
+	local objs = minetest.get_objects_inside_radius(op_params.pos,
+			param.max_hear_distance or 32)
+
+	for n = 1, #objs do
+
+		local obj = objs[n]
+
+		if not obj:is_player() then
+
+			local ent = obj:get_luaentity()
+
+			if ent and ent._cmi_is_mob then
+
+				-- calculate loudness of sound to mob
+				op_params.distance = get_distance(op_params.pos, obj:get_pos())
+				op_params.loudness = op_params.gain / op_params.distance
+
+				-- run custom mob on_punch with sound information table
+				ent:on_punch("sound", 0, op_params)
+			end
+		end
+	end
+
+	return old_sound_play(spec, param, eph)
+end
+end
diff --git a/api.txt b/api.txt
index 6590a35..b4b1c78 100644
--- a/api.txt
+++ b/api.txt
@@ -345,6 +345,15 @@ enhance mob functionality and have them do many interesting things:
                     active and which has access to all of the self.* variables
                     e.g. (self.health for health or self.standing_in for node
                     status), return with 'false' to skip remainder of mob API.
+   'on_sound'       (self, def) called when mob is inside the hearing distance of
+                    a sound, passes a def table containing:
+      'sound'       the sound being played,
+      'pos'         position sound originated,
+      'gain'        original gain of sound,
+      'distance'    distance of mob from sound source,
+      'loudness'    how loud sound is to mob when calculating gain / distance,
+      'player'      player name sound originated,
+      'object'      object reference sound originated
 
 
 Internal Variables
@@ -819,6 +828,7 @@ External Settings for "minetest.conf"
    'mobs_drop_items'        when false mobs no longer drop items when they die.
    'mobs_griefing'          when false mobs cannot break blocks when using either
                             pathfinding level 2, replace functions or mobs:boom
+   'mobs_can_hear'          True by default, allows mobs to hear sound around them.
                             function.
    'mob_nospawn_range'      Minimum range a mob can spawn near player (def: 12)
    'mob_active_limit'       Number of active mobs in game, 0 for unlimited
diff --git a/settingtypes.txt b/settingtypes.txt
index fcec162..1726bbb 100644
--- a/settingtypes.txt
+++ b/settingtypes.txt
@@ -60,6 +60,9 @@ mob_height_fix (Fix Mob Height) bool true
 
 mob_log_spawn (Log Mob Spawning) bool false
 
+#   Mob hearing, when enabled will override minetest.sound_play for mobs to hear
+mobs_can_hear (Enable Mob hearing) bool true
+
 [Pathfinding]
 #    Enable pathfinding (default Enabled)
 mob_pathfinding_enable (Enable pathfinding) bool true