Particles: Do not send single particles to distant clients (#5760)

Previously, every individual particle on a server is sent to, and rendered by
(even if not actually visible), every client regardless of distance. This
significantly reduces client FPS and creates unnecessary network traffic.
Maximum distance is set by 'max block send distance' as this determines how far
a client is able to see.

diff --git a/src/server.cpp b/src/server.cpp
index bf01fb7eb0577f8ce503f88b9aa2f73358f9dc84..5400dd5951384cb6142c33866a223903a837aa70 100644 (file)
--- a/src/server.cpp
+++ b/src/server.cpp
@@ -1707,13 +1707,25 @@ void Server::SendSpawnParticle(u16 peer_id, u16 protocol_version,
                                const struct TileAnimationParams &animation, u8 glow)
 {
        DSTACK(FUNCTION_NAME);
+       static const float radius =
+                       g_settings->getS16("max_block_send_distance") * MAP_BLOCKSIZE * BS;
+
        if (peer_id == PEER_ID_INEXISTENT) {
-               // This sucks and should be replaced by a better solution in a refactor:
                std::vector<u16> clients = m_clients.getClientIDs();
+
                for (std::vector<u16>::iterator i = clients.begin(); i != clients.end(); ++i) {
                        RemotePlayer *player = m_env->getPlayer(*i);
                        if (!player)
                                continue;
+
+                       PlayerSAO *sao = player->getPlayerSAO();
+                       if (!sao)
+                               continue;
+
+                       // Do not send to distant clients
+                       if (sao->getBasePosition().getDistanceFrom(pos * BS) > radius)
+                               continue;
+
                        SendSpawnParticle(*i, player->protocol_version,
                                        pos, velocity, acceleration,
                                        expirationtime, size, collisiondetection,