sending updates from server to client only when the client is nearby (i.e. we can assume the chunks are loaded on the client). this is somewhat experimental, since we cannot say with 100% certainty that the chunk isn't loaded on the client. will probably send "important" packets to all clients all the time (e.g. robot move) in the long run, but for now let's see how it turns out.

li/cil/oc/common/PacketBuilder.scala

@@ -1,14 +1,18 @@
 package li.cil.oc.common
 
+import cpw.mods.fml.common.FMLCommonHandler
 import cpw.mods.fml.common.network.PacketDispatcher
 import cpw.mods.fml.common.network.Player
 import java.io.ByteArrayOutputStream
 import java.io.DataOutputStream
 import li.cil.oc.common.tileentity.TileEntity
+import net.minecraft.entity.player.EntityPlayerMP
 import net.minecraft.item.ItemStack
 import net.minecraft.nbt.{NBTTagCompound, NBTBase}
 import net.minecraft.network.packet.Packet250CustomPayload
+import net.minecraft.world.World
 import net.minecraftforge.common.ForgeDirection
+import scala.collection.convert.WrapAsScala._
 
 /** Utility class for packet creation. */
 class PacketBuilder(packetType: PacketType.Value, private val stream: ByteArrayOutputStream = new ByteArrayOutputStream) extends DataOutputStream(stream) {
@@ -35,7 +39,19 @@ class PacketBuilder(packetType: PacketType.Value, private val stream: ByteArrayO
 
   def sendToAllPlayers() = PacketDispatcher.sendPacketToAllPlayers(packet)
 
-  def sendToNearbyPlayers(t: TileEntity, range: Double = 64) = PacketDispatcher.sendPacketToAllAround(t.x, t.y, t.z, range, t.world.provider.dimensionId, packet)
+  def sendToNearbyPlayers(t: TileEntity, range: Double = 64): Unit = sendToNearbyPlayers(t.world, t.x + 0.5, t.y + 0.5, t.z + 0.5, range)
+
+  def sendToNearbyPlayers(world: World, x: Double, y: Double, z: Double, range: Double) {
+    val dimension = world.provider.dimensionId
+    val server = FMLCommonHandler.instance.getMinecraftServerInstance
+    val manager = server.getConfigurationManager
+    for (player <- manager.playerEntityList.map(_.asInstanceOf[EntityPlayerMP]) if player.dimension == dimension) {
+      val playerSpecificRange = range min ((manager.getViewDistance min PacketBuilder.tryGetPlayerRenderDistance(player)) * 16)
+      if (player.getDistanceSq(x, y, z) < playerSpecificRange * playerSpecificRange) {
+        player.playerNetServerHandler.sendPacketToPlayer(packet)
+      }
+    }
+  }
 
   def sendToPlayer(player: Player) = PacketDispatcher.sendPacketToPlayer(packet, player)
 
@@ -49,3 +65,27 @@ class PacketBuilder(packetType: PacketType.Value, private val stream: ByteArrayO
     p
   }
 }
+
+object PacketBuilder {
+  private val renderDistanceField = try {
+    val field = classOf[EntityPlayerMP].getDeclaredField("renderDistance")
+    field.setAccessible(true)
+    Some(field)
+  }
+  catch {
+    case _: Throwable => None
+  }
+
+  private def tryGetPlayerRenderDistance(player: EntityPlayerMP): Int = {
+    try {
+      renderDistanceField match {
+        case Some(field) => return field.get(player).asInstanceOf[Integer]
+        case _ =>
+      }
+    }
+    catch {
+      case _: Throwable =>
+    }
+    Int.MaxValue
+  }
+}

li/cil/oc/server/PacketSender.scala

@@ -30,7 +30,7 @@ object PacketSender {
 
     player match {
       case Some(p) => pb.sendToPlayer(p)
-      case _ => pb.sendToAllPlayers()
+      case _ => pb.sendToNearbyPlayers(t)
     }
   }
 
@@ -42,7 +42,7 @@ object PacketSender {
 
     player match {
       case Some(p) => pb.sendToPlayer(p)
-      case _ => pb.sendToAllPlayers()
+      case _ => pb.sendToNearbyPlayers(t)
     }
   }
 
@@ -67,7 +67,7 @@ object PacketSender {
 
     player match {
       case Some(p) => pb.sendToPlayer(p)
-      case _ => pb.sendToAllPlayers()
+      case _ => pb.sendToNearbyPlayers(t)
     }
   }
 
@@ -82,7 +82,7 @@ object PacketSender {
 
     player match {
       case Some(p) => pb.sendToPlayer(p)
-      case _ => pb.sendToAllPlayers()
+      case _ => pb.sendToNearbyPlayers(t)
     }
   }
 
@@ -96,7 +96,7 @@ object PacketSender {
     pb.writeInt(oz)
     pb.writeDirection(direction)
 
-    pb.sendToAllPlayers()
+    pb.sendToNearbyPlayers(t)
   }
 
   def sendRobotAnimateSwing(t: Robot) {
@@ -105,7 +105,7 @@ object PacketSender {
     pb.writeTileEntity(t.proxy)
     pb.writeInt(t.animationTicksTotal)
 
-    pb.sendToNearbyPlayers(t.proxy)
+    pb.sendToNearbyPlayers(t)
   }
 
   def sendRobotAnimateTurn(t: Robot) {
@@ -115,7 +115,7 @@ object PacketSender {
     pb.writeByte(t.turnAxis)
     pb.writeInt(t.animationTicksTotal)
 
-    pb.sendToNearbyPlayers(t.proxy)
+    pb.sendToNearbyPlayers(t)
   }
 
   def sendRobotEquippedItemChange(t: Robot, stack: ItemStack) {
@@ -124,7 +124,7 @@ object PacketSender {
     pb.writeTileEntity(t.proxy)
     pb.writeItemStack(stack)
 
-    pb.sendToAllPlayers()
+    pb.sendToNearbyPlayers(t)
   }
 
   def sendRobotSelectedSlotChange(t: Robot) {
@@ -133,7 +133,7 @@ object PacketSender {
     pb.writeTileEntity(t.proxy)
     pb.writeInt(t.selectedSlot)
 
-    pb.sendToAllPlayers()
+    pb.sendToNearbyPlayers(t)
   }
 
   def sendRotatableState(t: Rotatable, player: Option[Player] = None) {
@@ -145,7 +145,7 @@ object PacketSender {
 
     player match {
       case Some(p) => pb.sendToPlayer(p)
-      case _ => pb.sendToAllPlayers()
+      case _ => pb.sendToNearbyPlayers(t)
     }
   }
 
@@ -156,7 +156,7 @@ object PacketSender {
     pb.writeInt(foreground)
     pb.writeInt(background)
 
-    pb.sendToAllPlayers()
+    pb.sendToNearbyPlayers(t)
   }
 
   def sendScreenCopy(t: Buffer, col: Int, row: Int, w: Int, h: Int, tx: Int, ty: Int) {
@@ -170,7 +170,7 @@ object PacketSender {
     pb.writeInt(tx)
     pb.writeInt(ty)
 
-    pb.sendToAllPlayers()
+    pb.sendToNearbyPlayers(t)
   }
 
   def sendScreenDepthChange(t: Buffer, value: PackedColor.Depth.Value) {
@@ -179,7 +179,7 @@ object PacketSender {
     pb.writeTileEntity(t)
     pb.writeInt(value.id)
 
-    pb.sendToAllPlayers()
+    pb.sendToNearbyPlayers(t)
   }
 
   def sendScreenFill(t: Buffer, col: Int, row: Int, w: Int, h: Int, c: Char) {
@@ -192,7 +192,7 @@ object PacketSender {
     pb.writeInt(h)
     pb.writeChar(c)
 
-    pb.sendToAllPlayers()
+    pb.sendToNearbyPlayers(t)
   }
 
   def sendScreenPowerChange(t: Buffer, hasPower: Boolean) {
@@ -201,7 +201,7 @@ object PacketSender {
     pb.writeTileEntity(t)
     pb.writeBoolean(hasPower)
 
-    pb.sendToAllPlayers()
+    pb.sendToNearbyPlayers(t)
   }
 
   def sendScreenResolutionChange(t: Buffer, w: Int, h: Int) {
@@ -211,7 +211,7 @@ object PacketSender {
     pb.writeInt(w)
     pb.writeInt(h)
 
-    pb.sendToAllPlayers()
+    pb.sendToNearbyPlayers(t)
   }
 
   def sendScreenSet(t: Buffer, col: Int, row: Int, s: String) {
@@ -222,6 +222,6 @@ object PacketSender {
     pb.writeInt(row)
     pb.writeUTF(s)
 
-    pb.sendToAllPlayers()
+    pb.sendToNearbyPlayers(t)
   }
 }