Make max breath configurable and respect it

* You can only hold your breath for 20 seconds and
  this should be customizable, this is a implementation
  backporting https://github.com/minetest/minetest/pull/6411
* Customizeable maximal breath for players
  backported dc2314bf7a
* Fix for https://codeberg.org/minenux/minetest-engine-minetest/issues/33
  by closing https://github.com/minetest/minetest/issues/2246

builtin/game/constants.lua

@@ -23,8 +23,8 @@ core.EMERGE_GENERATED   = 4
 core.MAP_BLOCKSIZE = 16
 -- Default maximal HP of a player
 core.PLAYER_MAX_HP_DEFAULT = 20
--- Maximal breath of a player
-core.PLAYER_MAX_BREATH = 11
+-- Default maximal breath of a player
+core.PLAYER_MAX_BREATH_DEFAULT = 11
 
 -- light.h
 -- Maximum value for node 'light_source' parameter

builtin/game/statbars.lua

@@ -17,7 +17,7 @@ local breath_bar_definition =
 	hud_elem_type = "statbar",
 	position = { x=0.5, y=1 },
 	text = "bubble.png",
-	number = core.PLAYER_MAX_BREATH,
+	number = core.PLAYER_MAX_BREATH_DEFAULT,
 	direction = 0,
 	size = { x=24, y=24 },
 	offset = {x=25,y=-(48+24+16)},
@@ -25,6 +25,15 @@ local breath_bar_definition =
 
 local hud_ids = {}
 
+local function scaleToDefault(player, field)
+	-- Scale "hp" or "breath" to the default dimensions
+	local current = player["get_" .. field](player)
+	local nominal = core["PLAYER_MAX_".. field:upper() .. "_DEFAULT"]
+	local max_display = math.max(nominal,
+ 		math.max(player:get_properties()[field .. "_max"], current))
+ 	return current / max_display * nominal 
+end
+
 local function initialize_builtin_statbars(player)
 
 	if not player:is_player() then
@@ -47,31 +56,22 @@ local function initialize_builtin_statbars(player)
 
 	if player:hud_get_flags().healthbar and enable_damage then
 		if hud.id_healthbar == nil then
-			local hp = player:get_hp()
-			local max_display_hp = math.max(core.PLAYER_MAX_HP_DEFAULT,
-				math.max(player:get_properties().hp_max, hp))
-			-- Limit width of health bar: Scale to the default maximal HP
-			health_bar_definition.number =
-				hp / max_display_hp * core.PLAYER_MAX_HP_DEFAULT
-			hud.id_healthbar  = player:hud_add(health_bar_definition)
-		end
-	else
-		if hud.id_healthbar ~= nil then
-			player:hud_remove(hud.id_healthbar)
-			hud.id_healthbar = nil
+			local hud_def = table.copy(health_bar_definition)
+			hud_def.number = scaleToDefault(player, "hp")
+			hud.id_healthbar = player:hud_add(hud_def)
 		end
+	elseif hud.id_healthbar ~= nil then
+		player:hud_remove(hud.id_healthbar)
+		hud.id_healthbar = nil
 	end
 
-	if player:get_breath() < core.PLAYER_MAX_BREATH then
-		if player:hud_get_flags().breathbar and enable_damage then
-			if hud.id_breathbar == nil then
-				hud.id_breathbar = player:hud_add(breath_bar_definition)
-			end
-		else
-			if hud.id_breathbar ~= nil then
-				player:hud_remove(hud.id_breathbar)
-				hud.id_breathbar = nil
-			end
+	local breath_max = player:get_properties().breath_max
+	if player:hud_get_flags().breathbar and enable_damage and
+			player:get_breath() < breath_max then
+		if hud.id_breathbar == nil then
+ 			local hud_def = table.copy(breath_bar_definition)
+ 			hud_def.number = 2 * scaleToDefault(player, "breath")
+			hud.id_breathbar = player:hud_add(hud_def)
 		end
 	elseif hud.id_breathbar ~= nil then
 		player:hud_remove(hud.id_breathbar)
@@ -107,12 +107,8 @@ local function player_event_handler(player,eventname)
 		initialize_builtin_statbars(player)
 
 		if hud_ids[name].id_healthbar ~= nil then
-			local hp = player:get_hp()
-			local max_display_hp = math.max(core.PLAYER_MAX_HP_DEFAULT,
-				math.max(player:get_properties().hp_max, hp))
-			-- Limit width of health bar: Scale to the default maximal HP
-			local hp_count = hp / max_display_hp * core.PLAYER_MAX_HP_DEFAULT
-			player:hud_change(hud_ids[name].id_healthbar, "number", hp_count)
+			player:hud_change(hud_ids[name].id_healthbar,
+				"number", scaleToDefault(player, "hp"))
 			return true
 		end
 	end
@@ -121,7 +117,8 @@ local function player_event_handler(player,eventname)
 		initialize_builtin_statbars(player)
 
 		if hud_ids[name].id_breathbar ~= nil then
-			player:hud_change(hud_ids[name].id_breathbar, "number", player:get_breath() * 2)
+			player:hud_change(hud_ids[name].id_breathbar,
+				"number", 2 * scaleToDefault(player, "breath"))
 			return true
 		end
 	end

doc/lua_api.txt

@@ -4022,7 +4022,8 @@ Definition tables
 ### Object Properties
 
     {
-        hp_max = 1, -- For players, the maximal HP defaults to `minetest.PLAYER_MAX_HP_DEFAULT`
+        hp_max = 1, -- For players, defaults to `minetest.PLAYER_MAX_HP_DEFAULT`
+        breath_max = 0, --  ^ For players defaults to `minetest.PLAYER_MAX_BREATH_DEFAULT`
         physical = true,
         collide_with_objects = true, -- collide with other objects if physical = true
         weight = 5,

src/constants.h

@@ -87,11 +87,11 @@ with this program; if not, write to the Free Software Foundation, Inc.,
 // Size of player's main inventory
 #define PLAYER_INVENTORY_SIZE (8 * 4)
 
-// Maximum hit points of a player
+// Default Maximum hit points of a player
 #define PLAYER_MAX_HP_DEFAULT 20
 
-// Maximal breath of a player
-#define PLAYER_MAX_BREATH 11
+// Default Maximal breath of a player
+#define PLAYER_MAX_BREATH_DEFAULT 11
 
 // Number of different files to try to save a player to if the first fails
 // (because of a case-insensitive filesystem)

src/content_sao.cpp

@@ -796,6 +796,7 @@ PlayerSAO::PlayerSAO(ServerEnvironment *env_, RemotePlayer *player_, u16 peer_id
 	assert(m_peer_id != 0);	// pre-condition
 
 	m_prop.hp_max = PLAYER_MAX_HP_DEFAULT;
+	m_prop.breath_max = PLAYER_MAX_BREATH_DEFAULT;
 	m_prop.physical = false;
 	m_prop.weight = 75;
 	m_prop.collisionbox = aabb3f(-0.3f, -1.0f, -0.3f, 0.3f, 0.75f, 0.3f);
@@ -812,6 +813,7 @@ PlayerSAO::PlayerSAO(ServerEnvironment *env_, RemotePlayer *player_, u16 peer_id
 	m_prop.is_visible = true;
 	m_prop.makes_footstep_sound = true;
 	m_hp = m_prop.hp_max;
+	m_breath = m_prop.breath_max;
 }
 
 PlayerSAO::~PlayerSAO()
@@ -939,7 +941,7 @@ void PlayerSAO::step(float dtime, bool send_recommended)
 		MapNode n = m_env->getMap().getNodeNoEx(p);
 		const ContentFeatures &c = m_env->getGameDef()->ndef()->get(n);
 		// If player is alive & no drowning, breath
-		if (m_hp > 0 && m_breath < PLAYER_MAX_BREATH && c.drowning == 0)
+		if (m_hp > 0 && m_breath < m_prop.breath_max && c.drowning == 0)
 			setBreath(m_breath + 1);
 	}
 
@@ -1270,7 +1272,7 @@ void PlayerSAO::setBreath(const u16 breath, bool send)
 	if (m_player && breath != m_breath)
 		m_player->setDirty(true);
 
-	m_breath = MYMIN(breath, PLAYER_MAX_BREATH);
+	m_breath = MYMIN(breath, m_prop.breath_max);
 
 	if (send)
 		m_env->getGameDef()->SendPlayerBreath(this);

src/object_properties.cpp

@@ -54,6 +54,7 @@ std::string ObjectProperties::dump()
 {
 	std::ostringstream os(std::ios::binary);
 	os<<"hp_max="<<hp_max;
+	os<<", breath_max=" << breath_max;
 	os<<", physical="<<physical;
 	os<<", collideWithObjects="<<collideWithObjects;
 	os<<", weight="<<weight;
@@ -118,6 +119,7 @@ void ObjectProperties::serialize(std::ostream &os) const
 	writeF1000(os, automatic_face_movement_max_rotation_per_sec);
 	os << serializeString(infotext);
 	os << serializeString(wield_item);
+	writeU16(os, breath_max);
 
 	// Add stuff only at the bottom.
 	// Never remove anything, because we don't want new versions of this
@@ -161,6 +163,7 @@ void ObjectProperties::deSerialize(std::istream &is)
 			automatic_face_movement_max_rotation_per_sec = readF1000(is);
 			infotext = deSerializeString(is);
 			wield_item = deSerializeString(is);
+			breath_max = readU16(is);
 		}catch(SerializationError &e){}
 	}
 	else

src/object_properties.h

@@ -30,6 +30,7 @@ struct ObjectProperties
 {
 	// Values are BS=1
 	s16 hp_max;
+	u16 breath_max;
 	bool physical;
 	bool collideWithObjects;
 	float weight;

src/script/common/c_content.cpp

@@ -187,6 +187,7 @@ void read_object_properties(lua_State *L, int index,
 	if (getintfield(L, -1, "hp_max", hp_max))
 		prop->hp_max = (s16)rangelim(hp_max, 0, S16_MAX);
 
+	getintfield(L, -1, "breath_max", prop->breath_max);
 	getboolfield(L, -1, "physical", prop->physical);
 	getboolfield(L, -1, "collide_with_objects", prop->collideWithObjects);
 
@@ -288,6 +289,8 @@ void push_object_properties(lua_State *L, ObjectProperties *prop)
 	lua_newtable(L);
 	lua_pushnumber(L, prop->hp_max);
 	lua_setfield(L, -2, "hp_max");
+	lua_pushnumber(L, prop->breath_max);
+	lua_setfield(L, -2, "breath_max");
 	lua_pushboolean(L, prop->physical);
 	lua_setfield(L, -2, "physical");
 	lua_pushboolean(L, prop->collideWithObjects);

src/server.cpp

@@ -2684,7 +2684,7 @@ void Server::RespawnPlayer(u16 peer_id)
 			<< " respawns" << std::endl;
 
 	playersao->setHP(playersao->accessObjectProperties()->hp_max);
-	playersao->setBreath(PLAYER_MAX_BREATH);
+	playersao->setBreath(playersao->accessObjectProperties()->breath_max);
 
 	bool repositioned = m_script->on_respawnplayer(playersao);
 	if (!repositioned) {