Add exclude_player to particle spawners

builtin/game/features.lua

@@ -49,6 +49,7 @@ core.features = {
 	httpfetch_additional_methods = true,
 	object_guids = true,
 	on_timer_four_args = true,
+	particlespawner_exclude_player = true,
 }
 
 function core.has_feature(arg)

doc/lua_api.md

@@ -5843,6 +5843,8 @@ Utilities
       object_guids = true,
       -- The NodeTimer `on_timer` callback is passed additional `node` and `timeout` args (5.14.0)
       on_timer_four_args = true,
+      -- `ParticleSpawner` definition supports `exclude_player` field (5.14.0)
+      particlespawner_exclude_player = true,
   }
   ```
 
@@ -7471,6 +7473,7 @@ Particles
 ---------
 
 * `core.add_particle(particle definition)`
+    * Spawn a single particle
     * Deprecated: `core.add_particle(pos, velocity, acceleration,
       expirationtime, size, collisiondetection, texture, playername)`
 
@@ -11487,6 +11490,9 @@ Used by `core.add_particle`.
     playername = "singleplayer",
     -- Optional, if specified spawns particle only on the player's client
 
+    -- Note that `exclude_player` is not supported here. You can use a single-use
+    -- particlespawner if needed.
+
     animation = {Tile Animation definition},
     -- Optional, specifies how to animate the particle texture
 
@@ -11550,6 +11556,9 @@ will be ignored.
     -- If time is 0 spawner has infinite lifespan and spawns the `amount` on
     -- a per-second basis.
 
+    size = 1,
+    -- Size of the particle.
+
     collisiondetection = false,
     -- If true collide with `walkable` nodes and, depending on the
     -- `object_collision` field, objects too.
@@ -11576,7 +11585,12 @@ will be ignored.
     -- following section.
 
     playername = "singleplayer",
-    -- Optional, if specified spawns particles only on the player's client
+    -- Optional, if specified spawns particles only for this player
+    -- Can't be used together with `exclude_player`.
+
+    exclude_player = "singleplayer",
+    -- Optional, if specified spawns particles not for this player
+    -- Added in v5.14.0. Can't be used together with `playername`.
 
     animation = {Tile Animation definition},
     -- Optional, specifies how to animate the particles' texture

src/script/lua_api/l_particles.cpp

@@ -157,7 +157,7 @@ int ModApiParticles::l_add_particlespawner(lua_State *L)
 	// Get parameters
 	ParticleSpawnerParameters p;
 	ServerActiveObject *attached = NULL;
-	std::string playername;
+	std::string playername, not_playername;
 
 	using namespace ParticleParamTypes;
 	if (lua_gettop(L) > 1) //deprecated
@@ -257,7 +257,6 @@ int ModApiParticles::l_add_particlespawner(lua_State *L)
 		lua_pop(L, 1);
 
 		p.vertical = getboolfield_default(L, 1, "vertical", p.vertical);
-		playername = getstringfield_default(L, 1, "playername", "");
 		p.glow = getintfield_default(L, 1, "glow", p.glow);
 
 		lua_getfield(L, 1, "texpool");
@@ -279,12 +278,16 @@ int ModApiParticles::l_add_particlespawner(lua_State *L)
 		lua_pop(L, 1);
 
 		p.node_tile = getintfield_default(L, 1, "node_tile", p.node_tile);
+
+		// meta parameters
+		playername = getstringfield_default(L, 1, "playername", "");
+		not_playername = getstringfield_default(L, 1, "exclude_player", "");
 	}
 
 	if (p.time < 0)
 		throw LuaError("particle spawner 'time' must be >= 0");
 
-	u32 id = getServer(L)->addParticleSpawner(p, attached, playername);
+	u32 id = getServer(L)->addParticleSpawner(p, attached, playername, not_playername);
 	lua_pushnumber(L, id);
 
 	return 1;

src/server.cpp

@@ -1646,45 +1646,61 @@ void Server::SendSpawnParticle(session_t peer_id, u16 protocol_version,
 	Send(&pkt);
 }
 
-// Adds a ParticleSpawner on peer with peer_id
-void Server::SendAddParticleSpawner(session_t peer_id, u16 protocol_version,
+void Server::SendAddParticleSpawner(const std::string &to_player,
+	const std::string &exclude_player,
 	const ParticleSpawnerParameters &p, u16 attached_id, u32 id)
 {
 	static thread_local const float radius =
 			g_settings->getS16("max_block_send_distance") * MAP_BLOCKSIZE * BS;
+	const float radius_sq = radius * radius;
 
-	if (peer_id == PEER_ID_INEXISTENT) {
-		std::vector<session_t> clients = m_clients.getClientIDs();
+	// Average position where particles would spawn (approximate)
 	const v3f pos = (
 		p.pos.start.min.val +
 		p.pos.start.max.val +
 		p.pos.end.min.val +
 		p.pos.end.max.val
 	) / 4.0f * BS;
-		const float radius_sq = radius * radius;
 	/* Don't send short-lived spawners to distant players.
 	 * This could be replaced with proper tracking at some point.
-		 * A lifetime of 0 means that the spawner exists forever.*/
+	 * A lifetime of 0 means that the spawner exists forever. */
 	const bool distance_check = !attached_id && p.time <= 1.0f && p.time != 0.0f;
 
+	const auto &consider_player = [&] (RemotePlayer *player) {
+		if (distance_check) {
+			PlayerSAO *sao = player->getPlayerSAO();
+			if (!sao)
+				return;
+			if (sao->getBasePosition().getDistanceFromSQ(pos) > radius_sq)
+				return;
+		}
+
+		SendAddParticleSpawner(player->getPeerId(), player->protocol_version,
+			p, attached_id, id);
+	};
+
+	// Send to one -or- all (except one)
+	if (!to_player.empty()) {
+		RemotePlayer *player = m_env->getPlayer(to_player);
+		if (player)
+			consider_player(player);
+		return;
+	}
+	std::vector<session_t> clients = m_clients.getClientIDs();
 	for (const session_t client_id : clients) {
 		RemotePlayer *player = m_env->getPlayer(client_id);
 		if (!player)
 			continue;
-
-			if (distance_check) {
-				PlayerSAO *sao = player->getPlayerSAO();
-				if (!sao)
-					continue;
-				if (sao->getBasePosition().getDistanceFromSQ(pos) > radius_sq)
+		if (!exclude_player.empty() && exclude_player == player->getName())
 			continue;
+		consider_player(player);
 	}
+}
 
-			SendAddParticleSpawner(client_id, player->protocol_version,
-				p, attached_id, id);
-		}
-		return;
-	}
+void Server::SendAddParticleSpawner(session_t peer_id, u16 protocol_version,
+	const ParticleSpawnerParameters &p, u16 attached_id, u32 id)
+{
+	assert(peer_id != PEER_ID_INEXISTENT);
 	assert(protocol_version != 0);
 
 	NetworkPacket pkt(TOCLIENT_ADD_PARTICLESPAWNER, 100, peer_id);
@@ -3619,22 +3635,12 @@ void Server::spawnParticle(const std::string &playername,
 }
 
 u32 Server::addParticleSpawner(const ParticleSpawnerParameters &p,
-	ServerActiveObject *attached, const std::string &playername)
+	ServerActiveObject *attached, const std::string &to_player,
+	const std::string &exclude_player)
 {
-	// m_env will be NULL if the server is initializing
 	if (!m_env)
 		return -1;
 
-	session_t peer_id = PEER_ID_INEXISTENT;
-	u16 proto_ver = 0;
-	if (!playername.empty()) {
-		RemotePlayer *player = m_env->getPlayer(playername.c_str());
-		if (!player)
-			return -1;
-		peer_id = player->getPeerId();
-		proto_ver = player->protocol_version;
-	}
-
 	u16 attached_id = attached ? attached->getId() : 0;
 
 	u32 id;
@@ -3643,13 +3649,12 @@ u32 Server::addParticleSpawner(const ParticleSpawnerParameters &p,
 	else
 		id = m_env->addParticleSpawner(p.time, attached_id);
 
-	SendAddParticleSpawner(peer_id, proto_ver, p, attached_id, id);
+	SendAddParticleSpawner(to_player, exclude_player, p, attached_id, id);
 	return id;
 }
 
 void Server::deleteParticleSpawner(const std::string &playername, u32 id)
 {
-	// m_env will be NULL if the server is initializing
 	if (!m_env)
 		throw ServerError("Can't delete particle spawners during initialisation!");
 
@@ -3661,7 +3666,11 @@ void Server::deleteParticleSpawner(const std::string &playername, u32 id)
 		peer_id = player->getPeerId();
 	}
 
+	// FIXME: we don't track which client still knows about this spawner, so
+	// just deleting it entirely is problematic!
+	// We also don't check if the ID is even in use. FAIL!
 	m_env->deleteParticleSpawner(id);
+
 	SendDeleteParticleSpawner(peer_id, id);
 }
 

src/server.h

@@ -291,7 +291,8 @@ public:
 		const ParticleParameters &p);
 
 	u32 addParticleSpawner(const ParticleSpawnerParameters &p,
-		ServerActiveObject *attached, const std::string &playername);
+		ServerActiveObject *attached, const std::string &to_player,
+		const std::string &exclude_player);
 
 	void deleteParticleSpawner(const std::string &playername, u32 id);
 
@@ -593,7 +594,11 @@ private:
 			const std::unordered_set<std::string> &tosend);
 	void stepPendingDynMediaCallbacks(float dtime);
 
-	// Adds a ParticleSpawner on peer with peer_id (PEER_ID_INEXISTENT == all)
+	/// @brief send particle spawner to a selection of clients
+	void SendAddParticleSpawner(const std::string &to_player,
+		const std::string &exclude_player,
+		const ParticleSpawnerParameters &p, u16 attached_id, u32 id);
+	/// @brief send particle spawner to one client (internal)
 	void SendAddParticleSpawner(session_t peer_id, u16 protocol_version,
 		const ParticleSpawnerParameters &p, u16 attached_id, u32 id);