public void addNewNPC(NPC npc, Stream str, Stream updateBlock) {
		synchronized(this) {
			int id = npc.npcId;
			npcInListBitmap[id >> 3] |= 1 << (id&7);
			npcList[npcListSize++] = npc;

			str.writeBits(14, id);

			int z = npc.absY-absY;
			if(z < 0) z += 32;
			str.writeBits(5, z);
			z = npc.absX-absX;
			if(z < 0) z += 32;
			str.writeBits(5, z);

			str.writeBits(1, 0);
			str.writeBits(18, npc.npcType);

			boolean savedUpdateRequired = npc.updateRequired;
			npc.updateRequired = true;
			npc.appendNPCUpdateBlock(updateBlock);
			npc.updateRequired = savedUpdateRequired;
			str.writeBits(1, 1);
		}
	}