Method UpdatePlayerMaps

src/game/server/gamecontext.cpp:4668–4727

}

void CGameContext::UpdatePlayerMaps()
{
	const auto DistCompare = [](std::pair<float, int> a, std::pair<float, int> b) -> bool {
		return (a.first < b.first);
	};

	if(Server()->Tick() % g_Config.m_SvMapUpdateRate != 0)
		return;

	std::pair<float, int> Dist[MAX_CLIENTS];
	for(int i = 0; i < MAX_CLIENTS; i++)
	{
		if(!Server()->ClientIngame(i))
			continue;
		if(Server()->GetClientVersion(i) >= VERSION_DDNET_OLD)
			continue;
		int *pMap = Server()->GetIdMap(i);

		// compute distances
		for(int j = 0; j < MAX_CLIENTS; j++)
		{
			Dist[j].second = j;
			if(j == i)
				continue;
			if(!Server()->ClientIngame(j) || !m_apPlayers[j])
			{
				Dist[j].first = 1e10;
				continue;
			}
			CCharacter *pChr = m_apPlayers[j]->GetCharacter();
			if(!pChr)
			{
				Dist[j].first = 1e9;
				continue;
			}
			if(!pChr->CanSnapCharacter(i))
				Dist[j].first = 1e8;
			else
				Dist[j].first = length_squared(m_apPlayers[i]->m_ViewPos - pChr->GetPos());
		}

		// always send the player themselves, even if all in same position
		Dist[i].first = -1;

		std::nth_element(&Dist[0], &Dist[VANILLA_MAX_CLIENTS - 1], &Dist[MAX_CLIENTS], DistCompare);

		int Index = 1; // exclude self client id
		for(int j = 0; j < VANILLA_MAX_CLIENTS - 1; j++)
		{
			pMap[j + 1] = -1; // also fill player with empty name to say chat msgs
			if(Dist[j].second == i || Dist[j].first > 5e9f)
				continue;
			pMap[Index++] = Dist[j].second;
		}

		// sort by real client ids, guarantee order on distance changes, O(Nlog(N)) worst case
		// sort just clients in game always except first (self client id) and last (fake client id) indexes
		std::sort(&pMap[1], &pMap[minimum(Index, VANILLA_MAX_CLIENTS - 1)]);