src/main/scala/li/cil/oc/common/component/TextBuffer.scala - minecraft/opencomputers - Rivoreo Source Code Repositories

 package li.cil.oc.common.component

 import cpw.mods.fml.common.FMLCommonHandler
 import cpw.mods.fml.common.eventhandler.SubscribeEvent
 import cpw.mods.fml.relauncher.{SideOnly, Side}
 import li.cil.oc.{api, Settings}
 import li.cil.oc.api.component.TextBuffer.ColorDepth
 import li.cil.oc.api.driver.Container
 import li.cil.oc.api.network._
 import li.cil.oc.client.{PacketSender => ClientPacketSender, ComponentTracker => ClientComponentTracker}
 import li.cil.oc.client.renderer.{MonospaceFontRenderer, TextBufferRenderCache}
 import li.cil.oc.common.tileentity
 import li.cil.oc.server.{PacketSender => ServerPacketSender, ComponentTracker => ServerComponentTracker}
 import li.cil.oc.server.component.Keyboard
 import li.cil.oc.util
 import li.cil.oc.util.ExtendedNBT._
 import li.cil.oc.util.PackedColor
 import net.minecraft.entity.player.EntityPlayer
 import net.minecraft.nbt.NBTTagCompound
 import scala.collection.convert.WrapAsScala._
 import scala.collection.mutable
 import net.minecraftforge.event.world.{WorldEvent, ChunkEvent}

 class TextBuffer(val owner: Container) extends ManagedComponent with api.component.TextBuffer {
   val node = api.Network.newNode(this, Visibility.Network).
     withComponent("screen").
     withConnector().
     create()

   private var maxResolution = Settings.screenResolutionsByTier(0)

   private var maxDepth = Settings.screenDepthsByTier(0)

   private var aspectRatio = (1.0, 1.0)

   private var powerConsumptionPerTick = Settings.get.screenCost

   // For client side only.
   private var isRendering = true

   private var isDisplaying = true

   private var hasPower = true

   private var relativeLitArea = -1.0

   var fullyLitCost = computeFullyLitCost()

   // This computes the energy cost (per tick) to keep the screen running if
   // every single "pixel" is lit. This cost increases with higher tiers as
   // their maximum resolution (pixel density) increases. For a basic screen
   // this is simply the configured cost.
   def computeFullyLitCost() = {
     val (w, h) = Settings.screenResolutionsByTier(0)
     val mw = getMaximumWidth
     val mh = getMaximumHeight
     powerConsumptionPerTick * (mw * mh) / (w * h)
   }

   val proxy =
     if (FMLCommonHandler.instance.getEffectiveSide.isClient) new TextBuffer.ClientProxy(this)
     else new TextBuffer.ServerProxy(this)

   val data = new util.TextBuffer(maxResolution, PackedColor.Depth.format(maxDepth))

   // ----------------------------------------------------------------------- //

   override val canUpdate = true

   override def update() {
     super.update()
     if (isDisplaying && owner.world.getWorldTime % Settings.get.tickFrequency == 0) {
       if (relativeLitArea < 0) {
         // The relative lit area is the number of pixels that are not blank
         // versus the number of pixels in the *current* resolution. This is
         // scaled to multi-block screens, since we only compute this for the
         // origin.
         val w = getWidth
         val h = getHeight
         relativeLitArea = (data.buffer, data.color).zipped.foldLeft(0) {
           case (acc, (line, colors)) => acc + (line, colors).zipped.foldLeft(0) {
             case (acc2, (char, color)) =>
               val bg = PackedColor.unpackBackground(color, data.format)
               val fg = PackedColor.unpackForeground(color, data.format)
               acc2 + (if (char == ' ') if (bg == 0) 0 else 1
               else if (char == 0x2588) if (fg == 0) 0 else 1
               else if (fg == 0 && bg == 0) 0 else 1)
           }
         } / (w * h).toDouble
       }
       if (node != null) {
         val hadPower = hasPower
         val neededPower = relativeLitArea * fullyLitCost * Settings.get.tickFrequency
         hasPower = node.tryChangeBuffer(-neededPower)
         if (hasPower != hadPower) {
           ServerPacketSender.sendTextBufferPowerChange(node.address, isDisplaying && hasPower, owner)
         }
       }
     }
   }

   // ----------------------------------------------------------------------- //

   @Callback(doc = """function():boolean -- Returns whether the screen is currently on.""")
   def isOn(computer: Context, args: Arguments): Array[AnyRef] = result(isDisplaying)

   @Callback(doc = """function():boolean -- Turns the screen on. Returns true if it was off.""")
   def turnOn(computer: Context, args: Arguments): Array[AnyRef] = {
     val oldPowerState = isDisplaying
     setPowerState(value = true)
     result(isDisplaying != oldPowerState, isDisplaying)
   }

   @Callback(doc = """function():boolean -- Turns off the screen. Returns true if it was on.""")
   def turnOff(computer: Context, args: Arguments): Array[AnyRef] = {
     val oldPowerState = isDisplaying
     setPowerState(value = false)
     result(isDisplaying != oldPowerState, isDisplaying)
   }

   @Callback(doc = """function():number, number -- The aspect ratio of the screen. For multi-block screens this is the number of blocks, horizontal and vertical.""")
   def getAspectRatio(context: Context, args: Arguments): Array[AnyRef] = {
     result(aspectRatio._1, aspectRatio._2)
   }

   @Callback(doc = """function():table -- The list of keyboards attached to the screen.""")
   def getKeyboards(context: Context, args: Arguments): Array[AnyRef] = {
     context.pause(0.25)
     Array(node.neighbors.filter(_.host.isInstanceOf[Keyboard]).map(_.address).toArray)
   }

   // ----------------------------------------------------------------------- //

   override def setEnergyCostPerTick(value: Double) {
     powerConsumptionPerTick = value
     fullyLitCost = computeFullyLitCost()
   }

   override def getEnergyCostPerTick = powerConsumptionPerTick

   override def setPowerState(value: Boolean) {
     if (isDisplaying != value) {
       isDisplaying = value
       if (isDisplaying) {
         val neededPower = fullyLitCost * Settings.get.tickFrequency
         hasPower = node.changeBuffer(-neededPower) == 0
       }
       ServerPacketSender.sendTextBufferPowerChange(node.address, isDisplaying && hasPower, owner)
     }
   }

   override def getPowerState = isDisplaying

   override def setMaximumResolution(width: Int, height: Int) {
     if (width < 1) throw new IllegalArgumentException("width must be larger or equal to one")
     if (height < 1) throw new IllegalArgumentException("height must be larger or equal to one")
     maxResolution = (width, height)
     fullyLitCost = computeFullyLitCost()
   }

   override def getMaximumWidth = maxResolution._1

   override def getMaximumHeight = maxResolution._2

   override def setAspectRatio(width: Double, height: Double) = aspectRatio = (width, height)

   override def getAspectRatio = aspectRatio._1 / aspectRatio._2

   override def setResolution(w: Int, h: Int) = {
     val (mw, mh) = maxResolution
     if (w < 1 || h < 1 || w > mw || h > mw || h * w > mw * mh)
       throw new IllegalArgumentException("unsupported resolution")
     if (data.size = (w, h)) {
       if (node != null) {
         node.sendToReachable("computer.signal", "screen_resized", Int.box(w), Int.box(h))
       }
       proxy.onScreenResolutionChange(w, h)
       true
     }
     else false
   }

   override def getWidth = data.width

   override def getHeight = data.height

   override def setMaximumColorDepth(depth: ColorDepth) = maxDepth = depth

   override def getMaximumColorDepth = maxDepth

   override def setColorDepth(depth: ColorDepth) = {
     if (depth.ordinal > maxDepth.ordinal)
       throw new IllegalArgumentException("unsupported depth")
     if (data.format = PackedColor.Depth.format(depth)) {
       proxy.onScreenDepthChange(depth)
       true
     }
     else false
   }

   override def getColorDepth = data.format.depth

   override def setPaletteColor(index: Int, color: Int) = data.format match {
     case palette: PackedColor.MutablePaletteFormat =>
       palette(index) = color
       proxy.onScreenPaletteChange(index)
     case _ => throw new Exception("palette not available")
   }

   override def getPaletteColor(index: Int) = data.format match {
     case palette: PackedColor.MutablePaletteFormat => palette(index)
     case _ => throw new Exception("palette not available")
   }

   override def setForegroundColor(color: Int) = setForegroundColor(color, isFromPalette = false)

   override def setForegroundColor(color: Int, isFromPalette: Boolean) {
     val value = PackedColor.Color(color, isFromPalette)
     if (data.foreground != value) {
       data.foreground = value
       proxy.onScreenColorChange()
     }
   }

   override def getForegroundColor = data.foreground.value

   override def isForegroundFromPalette = data.foreground.isPalette

   override def setBackgroundColor(color: Int) = setBackgroundColor(color, isFromPalette = false)

   override def setBackgroundColor(color: Int, isFromPalette: Boolean) {
     val value = PackedColor.Color(color, isFromPalette)
     if (data.background != value) {
       data.background = value
       proxy.onScreenColorChange()
     }
   }

   override def getBackgroundColor = data.background.value

   override def isBackgroundFromPalette = data.background.isPalette

   def copy(col: Int, row: Int, w: Int, h: Int, tx: Int, ty: Int) =
     if (data.copy(col, row, w, h, tx, ty))
       proxy.onScreenCopy(col, row, w, h, tx, ty)

   def fill(col: Int, row: Int, w: Int, h: Int, c: Char) =
     if (data.fill(col, row, w, h, c))
       proxy.onScreenFill(col, row, w, h, c)

   def set(col: Int, row: Int, s: String, vertical: Boolean) = if (col < data.width && (col >= 0 || -col < s.length)) {
     // Make sure the string isn't longer than it needs to be, in particular to
     // avoid sending too much data to our clients.
     val (x, y, truncated) =
       if (vertical) {
         if (row < 0) (col, 0, s.substring(-row))
         else (col, row, s.substring(0, math.min(s.length, data.height - row)))
       }
       else {
         if (col < 0) (0, row, s.substring(-col))
         else (col, row, s.substring(0, math.min(s.length, data.width - col)))
       }
     if (data.set(x, y, truncated, vertical))
       proxy.onScreenSet(x, row, truncated, vertical)
   }

   def get(col: Int, row: Int) = data.get(col, row)

   override def getForegroundColor(column: Int, row: Int) =
     if (isForegroundFromPalette(column, row)) {
       PackedColor.extractForeground(data.color(row)(column))
     }
     else {
       PackedColor.unpackForeground(data.color(row)(column), data.format)
     }

   override def isForegroundFromPalette(column: Int, row: Int) =
     data.format.isFromPalette(PackedColor.extractForeground(data.color(row)(column)))

   override def getBackgroundColor(column: Int, row: Int) =
     if (isBackgroundFromPalette(column, row)) {
       PackedColor.extractBackground(data.color(row)(column))
     }
     else {
       PackedColor.unpackBackground(data.color(row)(column), data.format)
     }

   override def isBackgroundFromPalette(column: Int, row: Int) =
     data.format.isFromPalette(PackedColor.extractBackground(data.color(row)(column)))

   @SideOnly(Side.CLIENT)
   override def renderText() = relativeLitArea != 0 && proxy.render()

   @SideOnly(Side.CLIENT)
   override def renderWidth = MonospaceFontRenderer.fontWidth * data.width

   @SideOnly(Side.CLIENT)
   override def renderHeight = MonospaceFontRenderer.fontHeight * data.height

   @SideOnly(Side.CLIENT)
   override def setRenderingEnabled(enabled: Boolean) = isRendering = enabled

   @SideOnly(Side.CLIENT)
   override def isRenderingEnabled = isRendering

   override def keyDown(character: Char, code: Int, player: EntityPlayer) =
     proxy.keyDown(character, code, player)

   override def keyUp(character: Char, code: Int, player: EntityPlayer) =
     proxy.keyUp(character, code, player)

   override def clipboard(value: String, player: EntityPlayer) =
     proxy.clipboard(value, player)

   override def mouseDown(x: Int, y: Int, button: Int, player: EntityPlayer) =
     proxy.mouseDown(x, y, button, player)

   override def mouseDrag(x: Int, y: Int, button: Int, player: EntityPlayer) =
     proxy.mouseDrag(x, y, button, player)

   override def mouseUp(x: Int, y: Int, button: Int, player: EntityPlayer) =
     proxy.mouseUp(x, y, button, player)

   override def mouseScroll(x: Int, y: Int, delta: Int, player: EntityPlayer) =
     proxy.mouseScroll(x, y, delta, player)

   // ----------------------------------------------------------------------- //

   override def onConnect(node: Node) {
     super.onConnect(node)
     if (node == this.node) {
       ServerComponentTracker.add(node.address, this)
     }
   }

   override def onDisconnect(node: Node) {
     super.onDisconnect(node)
     if (node == this.node) {
       ServerComponentTracker.remove(node.address)
     }
   }

   // ----------------------------------------------------------------------- //

   override def load(nbt: NBTTagCompound) = {
     super.load(nbt)
     data.load(nbt.getCompoundTag("buffer"))
     if (FMLCommonHandler.instance.getEffectiveSide.isClient) {
       proxy.nodeAddress = nbt.getCompoundTag("node").getString("address")
       TextBuffer.registerClientBuffer(this)
     }

     if (nbt.hasKey(Settings.namespace + "isOn")) {
       isDisplaying = nbt.getBoolean(Settings.namespace + "isOn")
     }
     if (nbt.hasKey(Settings.namespace + "hasPower")) {
       hasPower = nbt.getBoolean(Settings.namespace + "hasPower")
     }
   }

   // Null check for Waila (and other mods that may call this client side).
   override def save(nbt: NBTTagCompound) = if (node != null) {
     super.save(nbt)
     // Happy thread synchronization hack! Here's the problem: GPUs allow direct
     // calls for modifying screens to give a more responsive experience. This
     // causes the following problem: when saving, if the screen is saved first,
     // then the executor runs in parallel and changes the screen *before* the
     // server thread begins saving that computer, the saved computer will think
     // it changed the screen, although the saved screen wasn't. To avoid that we
     // wait for all computers the screen is connected to to finish their current
     // execution and pausing them (which will make them resume in the next tick
     // when their update() runs).
     if (node.network != null) {
       for (node <- node.reachableNodes) node.host match {
         case host: tileentity.traits.Computer if !host.isPaused =>
           host.pause(0.1)
         case _ =>
       }
     }

     nbt.setNewCompoundTag("buffer", data.save)
     nbt.setBoolean(Settings.namespace + "isOn", isDisplaying)
     nbt.setBoolean(Settings.namespace + "hasPower", hasPower)
   }
 }

 object TextBuffer {
   var clientBuffers = mutable.LinkedList.empty[TextBuffer]

   @SubscribeEvent
   def onChunkUnload(e: ChunkEvent.Unload) {
     val chunk = e.getChunk
     clientBuffers = clientBuffers.filter(t => {
       val keep = t.owner.world != e.world || !chunk.isAtLocation(t.owner.xPosition.toInt << 4, t.owner.zPosition.toInt << 4)
       if (!keep) {
         ClientComponentTracker.remove(t.proxy.nodeAddress)
       }
       keep
     })
   }

   @SubscribeEvent
   def onWorldUnload(e: WorldEvent.Unload) {
     clientBuffers = clientBuffers.filter(t => {
       val keep = t.owner.world != e.world
       if (!keep) {
         ClientComponentTracker.remove(t.proxy.nodeAddress)
       }
       keep
     })
   }

   def registerClientBuffer(t: TextBuffer) {
     ClientComponentTracker.add(t.proxy.nodeAddress, t)
     clientBuffers ++= mutable.LinkedList(t)
   }

   abstract class Proxy {
     def owner: TextBuffer

     var dirty = false

     var lastChange = 0L

     var nodeAddress = ""

     def markDirty() {
       dirty = true
       lastChange = owner.owner.world.getWorldTime
     }

     def render() = false

     def onScreenColorChange()

     def onScreenCopy(col: Int, row: Int, w: Int, h: Int, tx: Int, ty: Int) {
       owner.relativeLitArea = -1
     }

     def onScreenDepthChange(depth: ColorDepth)

     def onScreenFill(col: Int, row: Int, w: Int, h: Int, c: Char) {
       owner.relativeLitArea = -1
     }

     def onScreenPaletteChange(index: Int)

     def onScreenResolutionChange(w: Int, h: Int) {
       owner.relativeLitArea = -1
     }

     def onScreenSet(col: Int, row: Int, s: String, vertical: Boolean) {
       owner.relativeLitArea = -1
     }

     def keyDown(character: Char, code: Int, player: EntityPlayer)

     def keyUp(character: Char, code: Int, player: EntityPlayer)

     def clipboard(value: String, player: EntityPlayer)

     def mouseDown(x: Int, y: Int, button: Int, player: EntityPlayer)

     def mouseDrag(x: Int, y: Int, button: Int, player: EntityPlayer)

     def mouseUp(x: Int, y: Int, button: Int, player: EntityPlayer)

     def mouseScroll(x: Int, y: Int, delta: Int, player: EntityPlayer)
   }

   class ClientProxy(val owner: TextBuffer) extends Proxy {
     override def render() = {
       TextBufferRenderCache.render(owner)
       lastChange == owner.owner.world.getWorldTime
     }

     override def onScreenColorChange() {
       markDirty()
     }

     override def onScreenCopy(col: Int, row: Int, w: Int, h: Int, tx: Int, ty: Int) {
       super.onScreenCopy(col, row, w, h, tx, ty)
       markDirty()
     }

     override def onScreenDepthChange(depth: ColorDepth) {
       markDirty()
     }

     override def onScreenFill(col: Int, row: Int, w: Int, h: Int, c: Char) {
       super.onScreenFill(col, row, w, h, c)
       markDirty()
     }

     override def onScreenPaletteChange(index: Int) {
       markDirty()
     }

     override def onScreenResolutionChange(w: Int, h: Int) {
       super.onScreenResolutionChange(w, h)
       markDirty()
     }

     override def onScreenSet(col: Int, row: Int, s: String, vertical: Boolean) {
       super.onScreenSet(col, row, s, vertical)
       dirty = true
     }

     override def keyDown(character: Char, code: Int, player: EntityPlayer) =
       ClientPacketSender.sendKeyDown(nodeAddress, character, code)

     override def keyUp(character: Char, code: Int, player: EntityPlayer) =
       ClientPacketSender.sendKeyUp(nodeAddress, character, code)

     override def clipboard(value: String, player: EntityPlayer) =
       ClientPacketSender.sendClipboard(nodeAddress, value)

     override def mouseDown(x: Int, y: Int, button: Int, player: EntityPlayer) =
       ClientPacketSender.sendMouseClick(nodeAddress, x, y, drag = false, button)

     override def mouseDrag(x: Int, y: Int, button: Int, player: EntityPlayer) =
       ClientPacketSender.sendMouseClick(nodeAddress, x, y, drag = true, button)

     override def mouseUp(x: Int, y: Int, button: Int, player: EntityPlayer) =
       ClientPacketSender.sendMouseUp(nodeAddress, x, y, button)

     override def mouseScroll(x: Int, y: Int, delta: Int, player: EntityPlayer) =
       ClientPacketSender.sendMouseScroll(nodeAddress, x, y, delta)
   }

   class ServerProxy(val owner: TextBuffer) extends Proxy {
     override def onScreenColorChange() {
       owner.owner.markChanged()
       ServerPacketSender.sendTextBufferColorChange(owner.node.address, owner.data.foreground, owner.data.background, owner.owner)
     }

     override def onScreenCopy(col: Int, row: Int, w: Int, h: Int, tx: Int, ty: Int) {
       super.onScreenCopy(col, row, w, h, tx, ty)
       owner.owner.markChanged()
       ServerPacketSender.sendTextBufferCopy(owner.node.address, col, row, w, h, tx, ty, owner.owner)
     }

     override def onScreenDepthChange(depth: ColorDepth) {
       owner.owner.markChanged()
       ServerPacketSender.sendTextBufferDepthChange(owner.node.address, depth, owner.owner)
     }

     override def onScreenFill(col: Int, row: Int, w: Int, h: Int, c: Char) {
       super.onScreenFill(col, row, w, h, c)
       owner.owner.markChanged()
       ServerPacketSender.sendTextBufferFill(owner.node.address, col, row, w, h, c, owner.owner)
     }

     override def onScreenPaletteChange(index: Int) {
       owner.owner.markChanged()
       ServerPacketSender.sendTextBufferPaletteChange(owner.node.address, index, owner.getPaletteColor(index), owner.owner)
     }

     override def onScreenResolutionChange(w: Int, h: Int) {
       super.onScreenResolutionChange(w, h)
       owner.owner.markChanged()
       ServerPacketSender.sendTextBufferResolutionChange(owner.node.address, w, h, owner.owner)
     }

     override def onScreenSet(col: Int, row: Int, s: String, vertical: Boolean) {
       super.onScreenSet(col, row, s, vertical)
       owner.owner.markChanged()
       ServerPacketSender.sendTextBufferSet(owner.node.address, col, row, s, vertical, owner.owner)
     }

     override def keyDown(character: Char, code: Int, player: EntityPlayer) {
       owner.node.sendToVisible("keyboard.keyDown", player, Char.box(character), Int.box(code))
     }

     override def keyUp(character: Char, code: Int, player: EntityPlayer) {
       owner.node.sendToVisible("keyboard.keyUp", player, Char.box(character), Int.box(code))
     }

     override def clipboard(value: String, player: EntityPlayer) {
       owner.node.sendToVisible("keyboard.clipboard", player, value)
     }

     override def mouseDown(x: Int, y: Int, button: Int, player: EntityPlayer) {
       if (Settings.get.inputUsername) owner.node.sendToReachable("computer.checked_signal", player, "touch", Int.box(x), Int.box(y), Int.box(button), player.getCommandSenderName)
       else owner.node.sendToReachable("computer.checked_signal", player, "touch", Int.box(x), Int.box(y), Int.box(button))
     }

     override def mouseDrag(x: Int, y: Int, button: Int, player: EntityPlayer) {
       if (Settings.get.inputUsername) owner.node.sendToReachable("computer.checked_signal", player, "drag", Int.box(x), Int.box(y), Int.box(button), player.getCommandSenderName)
       else owner.node.sendToReachable("computer.checked_signal", player, "drag", Int.box(x), Int.box(y), Int.box(button))
     }

     override def mouseUp(x: Int, y: Int, button: Int, player: EntityPlayer) {
       if (Settings.get.inputUsername) owner.node.sendToReachable("computer.checked_signal", player, "drop", Int.box(x), Int.box(y), Int.box(button), player.getCommandSenderName)
       else owner.node.sendToReachable("computer.checked_signal", player, "drop", Int.box(x), Int.box(y), Int.box(button))
     }

     override def mouseScroll(x: Int, y: Int, delta: Int, player: EntityPlayer) {
       if (Settings.get.inputUsername) owner.node.sendToReachable("computer.checked_signal", player, "scroll", Int.box(x), Int.box(y), Int.box(delta), player.getCommandSenderName)
       else owner.node.sendToReachable("computer.checked_signal", player, "scroll", Int.box(x), Int.box(y), Int.box(delta))
     }
   }

 }
	package li.cil.oc.common.component

	import cpw.mods.fml.common.FMLCommonHandler
	import cpw.mods.fml.common.eventhandler.SubscribeEvent
	import cpw.mods.fml.relauncher.{SideOnly, Side}
	import li.cil.oc.{api, Settings}
	import li.cil.oc.api.component.TextBuffer.ColorDepth
	import li.cil.oc.api.driver.Container
	import li.cil.oc.api.network._
	import li.cil.oc.client.{PacketSender => ClientPacketSender, ComponentTracker => ClientComponentTracker}
	import li.cil.oc.client.renderer.{MonospaceFontRenderer, TextBufferRenderCache}
	import li.cil.oc.common.tileentity
	import li.cil.oc.server.{PacketSender => ServerPacketSender, ComponentTracker => ServerComponentTracker}
	import li.cil.oc.server.component.Keyboard
	import li.cil.oc.util
	import li.cil.oc.util.ExtendedNBT._
	import li.cil.oc.util.PackedColor
	import net.minecraft.entity.player.EntityPlayer
	import net.minecraft.nbt.NBTTagCompound
	import scala.collection.convert.WrapAsScala._
	import scala.collection.mutable
	import net.minecraftforge.event.world.{WorldEvent, ChunkEvent}

	class TextBuffer(val owner: Container) extends ManagedComponent with api.component.TextBuffer {
	val node = api.Network.newNode(this, Visibility.Network).
	withComponent("screen").
	withConnector().
	create()

	private var maxResolution = Settings.screenResolutionsByTier(0)

	private var maxDepth = Settings.screenDepthsByTier(0)

	private var aspectRatio = (1.0, 1.0)

	private var powerConsumptionPerTick = Settings.get.screenCost

	// For client side only.
	private var isRendering = true

	private var isDisplaying = true

	private var hasPower = true

	private var relativeLitArea = -1.0

	var fullyLitCost = computeFullyLitCost()

	// This computes the energy cost (per tick) to keep the screen running if
	// every single "pixel" is lit. This cost increases with higher tiers as
	// their maximum resolution (pixel density) increases. For a basic screen
	// this is simply the configured cost.
	def computeFullyLitCost() = {
	val (w, h) = Settings.screenResolutionsByTier(0)
	val mw = getMaximumWidth
	val mh = getMaximumHeight
	powerConsumptionPerTick * (mw * mh) / (w * h)
	}

	val proxy =
	if (FMLCommonHandler.instance.getEffectiveSide.isClient) new TextBuffer.ClientProxy(this)
	else new TextBuffer.ServerProxy(this)

	val data = new util.TextBuffer(maxResolution, PackedColor.Depth.format(maxDepth))

	// ----------------------------------------------------------------------- //

	override val canUpdate = true

	override def update() {
	super.update()
	if (isDisplaying && owner.world.getWorldTime % Settings.get.tickFrequency == 0) {
	if (relativeLitArea < 0) {
	// The relative lit area is the number of pixels that are not blank
	// versus the number of pixels in the current resolution. This is
	// scaled to multi-block screens, since we only compute this for the
	// origin.
	val w = getWidth
	val h = getHeight
	relativeLitArea = (data.buffer, data.color).zipped.foldLeft(0) {
	case (acc, (line, colors)) => acc + (line, colors).zipped.foldLeft(0) {
	case (acc2, (char, color)) =>
	val bg = PackedColor.unpackBackground(color, data.format)
	val fg = PackedColor.unpackForeground(color, data.format)
	acc2 + (if (char == ' ') if (bg == 0) 0 else 1
	else if (char == 0x2588) if (fg == 0) 0 else 1
	else if (fg == 0 && bg == 0) 0 else 1)
	}
	} / (w * h).toDouble
	}
	if (node != null) {
	val hadPower = hasPower
	val neededPower = relativeLitArea * fullyLitCost * Settings.get.tickFrequency
	hasPower = node.tryChangeBuffer(-neededPower)
	if (hasPower != hadPower) {
	ServerPacketSender.sendTextBufferPowerChange(node.address, isDisplaying && hasPower, owner)
	}
	}
	}
	}

	// ----------------------------------------------------------------------- //

	@Callback(doc = """function():boolean -- Returns whether the screen is currently on.""")
	def isOn(computer: Context, args: Arguments): Array[AnyRef] = result(isDisplaying)

	@Callback(doc = """function():boolean -- Turns the screen on. Returns true if it was off.""")
	def turnOn(computer: Context, args: Arguments): Array[AnyRef] = {
	val oldPowerState = isDisplaying
	setPowerState(value = true)
	result(isDisplaying != oldPowerState, isDisplaying)
	}

	@Callback(doc = """function():boolean -- Turns off the screen. Returns true if it was on.""")
	def turnOff(computer: Context, args: Arguments): Array[AnyRef] = {
	val oldPowerState = isDisplaying
	setPowerState(value = false)
	result(isDisplaying != oldPowerState, isDisplaying)
	}

	@Callback(doc = """function():number, number -- The aspect ratio of the screen. For multi-block screens this is the number of blocks, horizontal and vertical.""")
	def getAspectRatio(context: Context, args: Arguments): Array[AnyRef] = {
	result(aspectRatio._1, aspectRatio._2)
	}

	@Callback(doc = """function():table -- The list of keyboards attached to the screen.""")
	def getKeyboards(context: Context, args: Arguments): Array[AnyRef] = {
	context.pause(0.25)
	Array(node.neighbors.filter(_.host.isInstanceOf[Keyboard]).map(_.address).toArray)
	}

	// ----------------------------------------------------------------------- //

	override def setEnergyCostPerTick(value: Double) {
	powerConsumptionPerTick = value
	fullyLitCost = computeFullyLitCost()
	}

	override def getEnergyCostPerTick = powerConsumptionPerTick

	override def setPowerState(value: Boolean) {
	if (isDisplaying != value) {
	isDisplaying = value
	if (isDisplaying) {
	val neededPower = fullyLitCost * Settings.get.tickFrequency
	hasPower = node.changeBuffer(-neededPower) == 0
	}
	ServerPacketSender.sendTextBufferPowerChange(node.address, isDisplaying && hasPower, owner)
	}
	}

	override def getPowerState = isDisplaying

	override def setMaximumResolution(width: Int, height: Int) {
	if (width < 1) throw new IllegalArgumentException("width must be larger or equal to one")
	if (height < 1) throw new IllegalArgumentException("height must be larger or equal to one")
	maxResolution = (width, height)
	fullyLitCost = computeFullyLitCost()
	}

	override def getMaximumWidth = maxResolution._1

	override def getMaximumHeight = maxResolution._2

	override def setAspectRatio(width: Double, height: Double) = aspectRatio = (width, height)

	override def getAspectRatio = aspectRatio._1 / aspectRatio._2

	override def setResolution(w: Int, h: Int) = {
	val (mw, mh) = maxResolution
	if (w < 1 \|\| h < 1 \|\| w > mw \|\| h > mw \|\| h * w > mw * mh)
	throw new IllegalArgumentException("unsupported resolution")
	if (data.size = (w, h)) {
	if (node != null) {
	node.sendToReachable("computer.signal", "screen_resized", Int.box(w), Int.box(h))
	}
	proxy.onScreenResolutionChange(w, h)
	true
	}
	else false
	}

	override def getWidth = data.width

	override def getHeight = data.height

	override def setMaximumColorDepth(depth: ColorDepth) = maxDepth = depth

	override def getMaximumColorDepth = maxDepth

	override def setColorDepth(depth: ColorDepth) = {
	if (depth.ordinal > maxDepth.ordinal)
	throw new IllegalArgumentException("unsupported depth")
	if (data.format = PackedColor.Depth.format(depth)) {
	proxy.onScreenDepthChange(depth)
	true
	}
	else false
	}

	override def getColorDepth = data.format.depth

	override def setPaletteColor(index: Int, color: Int) = data.format match {
	case palette: PackedColor.MutablePaletteFormat =>
	palette(index) = color
	proxy.onScreenPaletteChange(index)
	case _ => throw new Exception("palette not available")
	}

	override def getPaletteColor(index: Int) = data.format match {
	case palette: PackedColor.MutablePaletteFormat => palette(index)
	case _ => throw new Exception("palette not available")
	}

	override def setForegroundColor(color: Int) = setForegroundColor(color, isFromPalette = false)

	override def setForegroundColor(color: Int, isFromPalette: Boolean) {
	val value = PackedColor.Color(color, isFromPalette)
	if (data.foreground != value) {
	data.foreground = value
	proxy.onScreenColorChange()
	}
	}

	override def getForegroundColor = data.foreground.value

	override def isForegroundFromPalette = data.foreground.isPalette

	override def setBackgroundColor(color: Int) = setBackgroundColor(color, isFromPalette = false)

	override def setBackgroundColor(color: Int, isFromPalette: Boolean) {
	val value = PackedColor.Color(color, isFromPalette)
	if (data.background != value) {
	data.background = value
	proxy.onScreenColorChange()
	}
	}

	override def getBackgroundColor = data.background.value

	override def isBackgroundFromPalette = data.background.isPalette

	def copy(col: Int, row: Int, w: Int, h: Int, tx: Int, ty: Int) =
	if (data.copy(col, row, w, h, tx, ty))
	proxy.onScreenCopy(col, row, w, h, tx, ty)

	def fill(col: Int, row: Int, w: Int, h: Int, c: Char) =
	if (data.fill(col, row, w, h, c))
	proxy.onScreenFill(col, row, w, h, c)

	def set(col: Int, row: Int, s: String, vertical: Boolean) = if (col < data.width && (col >= 0 \|\| -col < s.length)) {
	// Make sure the string isn't longer than it needs to be, in particular to
	// avoid sending too much data to our clients.
	val (x, y, truncated) =
	if (vertical) {
	if (row < 0) (col, 0, s.substring(-row))
	else (col, row, s.substring(0, math.min(s.length, data.height - row)))
	}
	else {
	if (col < 0) (0, row, s.substring(-col))
	else (col, row, s.substring(0, math.min(s.length, data.width - col)))
	}
	if (data.set(x, y, truncated, vertical))
	proxy.onScreenSet(x, row, truncated, vertical)
	}

	def get(col: Int, row: Int) = data.get(col, row)

	override def getForegroundColor(column: Int, row: Int) =
	if (isForegroundFromPalette(column, row)) {
	PackedColor.extractForeground(data.color(row)(column))
	}
	else {
	PackedColor.unpackForeground(data.color(row)(column), data.format)
	}

	override def isForegroundFromPalette(column: Int, row: Int) =
	data.format.isFromPalette(PackedColor.extractForeground(data.color(row)(column)))

	override def getBackgroundColor(column: Int, row: Int) =
	if (isBackgroundFromPalette(column, row)) {
	PackedColor.extractBackground(data.color(row)(column))
	}
	else {
	PackedColor.unpackBackground(data.color(row)(column), data.format)
	}

	override def isBackgroundFromPalette(column: Int, row: Int) =
	data.format.isFromPalette(PackedColor.extractBackground(data.color(row)(column)))

	@SideOnly(Side.CLIENT)
	override def renderText() = relativeLitArea != 0 && proxy.render()

	@SideOnly(Side.CLIENT)
	override def renderWidth = MonospaceFontRenderer.fontWidth * data.width

	@SideOnly(Side.CLIENT)
	override def renderHeight = MonospaceFontRenderer.fontHeight * data.height

	@SideOnly(Side.CLIENT)
	override def setRenderingEnabled(enabled: Boolean) = isRendering = enabled

	@SideOnly(Side.CLIENT)
	override def isRenderingEnabled = isRendering

	override def keyDown(character: Char, code: Int, player: EntityPlayer) =
	proxy.keyDown(character, code, player)

	override def keyUp(character: Char, code: Int, player: EntityPlayer) =
	proxy.keyUp(character, code, player)

	override def clipboard(value: String, player: EntityPlayer) =
	proxy.clipboard(value, player)

	override def mouseDown(x: Int, y: Int, button: Int, player: EntityPlayer) =
	proxy.mouseDown(x, y, button, player)

	override def mouseDrag(x: Int, y: Int, button: Int, player: EntityPlayer) =
	proxy.mouseDrag(x, y, button, player)

	override def mouseUp(x: Int, y: Int, button: Int, player: EntityPlayer) =
	proxy.mouseUp(x, y, button, player)

	override def mouseScroll(x: Int, y: Int, delta: Int, player: EntityPlayer) =
	proxy.mouseScroll(x, y, delta, player)

	// ----------------------------------------------------------------------- //

	override def onConnect(node: Node) {
	super.onConnect(node)
	if (node == this.node) {
	ServerComponentTracker.add(node.address, this)
	}
	}

	override def onDisconnect(node: Node) {
	super.onDisconnect(node)
	if (node == this.node) {
	ServerComponentTracker.remove(node.address)
	}
	}

	// ----------------------------------------------------------------------- //

	override def load(nbt: NBTTagCompound) = {
	super.load(nbt)
	data.load(nbt.getCompoundTag("buffer"))
	if (FMLCommonHandler.instance.getEffectiveSide.isClient) {
	proxy.nodeAddress = nbt.getCompoundTag("node").getString("address")
	TextBuffer.registerClientBuffer(this)
	}

	if (nbt.hasKey(Settings.namespace + "isOn")) {
	isDisplaying = nbt.getBoolean(Settings.namespace + "isOn")
	}
	if (nbt.hasKey(Settings.namespace + "hasPower")) {
	hasPower = nbt.getBoolean(Settings.namespace + "hasPower")
	}
	}

	// Null check for Waila (and other mods that may call this client side).
	override def save(nbt: NBTTagCompound) = if (node != null) {
	super.save(nbt)
	// Happy thread synchronization hack! Here's the problem: GPUs allow direct
	// calls for modifying screens to give a more responsive experience. This
	// causes the following problem: when saving, if the screen is saved first,
	// then the executor runs in parallel and changes the screen before the
	// server thread begins saving that computer, the saved computer will think
	// it changed the screen, although the saved screen wasn't. To avoid that we
	// wait for all computers the screen is connected to to finish their current
	// execution and pausing them (which will make them resume in the next tick
	// when their update() runs).
	if (node.network != null) {
	for (node <- node.reachableNodes) node.host match {
	case host: tileentity.traits.Computer if !host.isPaused =>
	host.pause(0.1)
	case _ =>
	}
	}

	nbt.setNewCompoundTag("buffer", data.save)
	nbt.setBoolean(Settings.namespace + "isOn", isDisplaying)
	nbt.setBoolean(Settings.namespace + "hasPower", hasPower)
	}
	}

	object TextBuffer {
	var clientBuffers = mutable.LinkedList.empty[TextBuffer]

	@SubscribeEvent
	def onChunkUnload(e: ChunkEvent.Unload) {
	val chunk = e.getChunk
	clientBuffers = clientBuffers.filter(t => {
	val keep = t.owner.world != e.world \|\| !chunk.isAtLocation(t.owner.xPosition.toInt << 4, t.owner.zPosition.toInt << 4)
	if (!keep) {
	ClientComponentTracker.remove(t.proxy.nodeAddress)
	}
	keep
	})
	}

	@SubscribeEvent
	def onWorldUnload(e: WorldEvent.Unload) {
	clientBuffers = clientBuffers.filter(t => {
	val keep = t.owner.world != e.world
	if (!keep) {
	ClientComponentTracker.remove(t.proxy.nodeAddress)
	}
	keep
	})
	}

	def registerClientBuffer(t: TextBuffer) {
	ClientComponentTracker.add(t.proxy.nodeAddress, t)
	clientBuffers ++= mutable.LinkedList(t)
	}

	abstract class Proxy {
	def owner: TextBuffer

	var dirty = false

	var lastChange = 0L

	var nodeAddress = ""

	def markDirty() {
	dirty = true
	lastChange = owner.owner.world.getWorldTime
	}

	def render() = false

	def onScreenColorChange()

	def onScreenCopy(col: Int, row: Int, w: Int, h: Int, tx: Int, ty: Int) {
	owner.relativeLitArea = -1
	}

	def onScreenDepthChange(depth: ColorDepth)

	def onScreenFill(col: Int, row: Int, w: Int, h: Int, c: Char) {
	owner.relativeLitArea = -1
	}

	def onScreenPaletteChange(index: Int)

	def onScreenResolutionChange(w: Int, h: Int) {
	owner.relativeLitArea = -1
	}

	def onScreenSet(col: Int, row: Int, s: String, vertical: Boolean) {
	owner.relativeLitArea = -1
	}

	def keyDown(character: Char, code: Int, player: EntityPlayer)

	def keyUp(character: Char, code: Int, player: EntityPlayer)

	def clipboard(value: String, player: EntityPlayer)

	def mouseDown(x: Int, y: Int, button: Int, player: EntityPlayer)

	def mouseDrag(x: Int, y: Int, button: Int, player: EntityPlayer)

	def mouseUp(x: Int, y: Int, button: Int, player: EntityPlayer)

	def mouseScroll(x: Int, y: Int, delta: Int, player: EntityPlayer)
	}

	class ClientProxy(val owner: TextBuffer) extends Proxy {
	override def render() = {
	TextBufferRenderCache.render(owner)
	lastChange == owner.owner.world.getWorldTime
	}

	override def onScreenColorChange() {
	markDirty()
	}

	override def onScreenCopy(col: Int, row: Int, w: Int, h: Int, tx: Int, ty: Int) {
	super.onScreenCopy(col, row, w, h, tx, ty)
	markDirty()
	}

	override def onScreenDepthChange(depth: ColorDepth) {
	markDirty()
	}

	override def onScreenFill(col: Int, row: Int, w: Int, h: Int, c: Char) {
	super.onScreenFill(col, row, w, h, c)
	markDirty()
	}

	override def onScreenPaletteChange(index: Int) {
	markDirty()
	}

	override def onScreenResolutionChange(w: Int, h: Int) {
	super.onScreenResolutionChange(w, h)
	markDirty()
	}

	override def onScreenSet(col: Int, row: Int, s: String, vertical: Boolean) {
	super.onScreenSet(col, row, s, vertical)
	dirty = true
	}

	override def keyDown(character: Char, code: Int, player: EntityPlayer) =
	ClientPacketSender.sendKeyDown(nodeAddress, character, code)

	override def keyUp(character: Char, code: Int, player: EntityPlayer) =
	ClientPacketSender.sendKeyUp(nodeAddress, character, code)

	override def clipboard(value: String, player: EntityPlayer) =
	ClientPacketSender.sendClipboard(nodeAddress, value)

	override def mouseDown(x: Int, y: Int, button: Int, player: EntityPlayer) =
	ClientPacketSender.sendMouseClick(nodeAddress, x, y, drag = false, button)

	override def mouseDrag(x: Int, y: Int, button: Int, player: EntityPlayer) =
	ClientPacketSender.sendMouseClick(nodeAddress, x, y, drag = true, button)

	override def mouseUp(x: Int, y: Int, button: Int, player: EntityPlayer) =
	ClientPacketSender.sendMouseUp(nodeAddress, x, y, button)

	override def mouseScroll(x: Int, y: Int, delta: Int, player: EntityPlayer) =
	ClientPacketSender.sendMouseScroll(nodeAddress, x, y, delta)
	}

	class ServerProxy(val owner: TextBuffer) extends Proxy {
	override def onScreenColorChange() {
	owner.owner.markChanged()
	ServerPacketSender.sendTextBufferColorChange(owner.node.address, owner.data.foreground, owner.data.background, owner.owner)
	}

	override def onScreenCopy(col: Int, row: Int, w: Int, h: Int, tx: Int, ty: Int) {
	super.onScreenCopy(col, row, w, h, tx, ty)
	owner.owner.markChanged()
	ServerPacketSender.sendTextBufferCopy(owner.node.address, col, row, w, h, tx, ty, owner.owner)
	}

	override def onScreenDepthChange(depth: ColorDepth) {
	owner.owner.markChanged()
	ServerPacketSender.sendTextBufferDepthChange(owner.node.address, depth, owner.owner)
	}

	override def onScreenFill(col: Int, row: Int, w: Int, h: Int, c: Char) {
	super.onScreenFill(col, row, w, h, c)
	owner.owner.markChanged()
	ServerPacketSender.sendTextBufferFill(owner.node.address, col, row, w, h, c, owner.owner)
	}

	override def onScreenPaletteChange(index: Int) {
	owner.owner.markChanged()
	ServerPacketSender.sendTextBufferPaletteChange(owner.node.address, index, owner.getPaletteColor(index), owner.owner)
	}

	override def onScreenResolutionChange(w: Int, h: Int) {
	super.onScreenResolutionChange(w, h)
	owner.owner.markChanged()
	ServerPacketSender.sendTextBufferResolutionChange(owner.node.address, w, h, owner.owner)
	}

	override def onScreenSet(col: Int, row: Int, s: String, vertical: Boolean) {
	super.onScreenSet(col, row, s, vertical)
	owner.owner.markChanged()
	ServerPacketSender.sendTextBufferSet(owner.node.address, col, row, s, vertical, owner.owner)
	}

	override def keyDown(character: Char, code: Int, player: EntityPlayer) {
	owner.node.sendToVisible("keyboard.keyDown", player, Char.box(character), Int.box(code))
	}

	override def keyUp(character: Char, code: Int, player: EntityPlayer) {
	owner.node.sendToVisible("keyboard.keyUp", player, Char.box(character), Int.box(code))
	}

	override def clipboard(value: String, player: EntityPlayer) {
	owner.node.sendToVisible("keyboard.clipboard", player, value)
	}

	override def mouseDown(x: Int, y: Int, button: Int, player: EntityPlayer) {
	if (Settings.get.inputUsername) owner.node.sendToReachable("computer.checked_signal", player, "touch", Int.box(x), Int.box(y), Int.box(button), player.getCommandSenderName)
	else owner.node.sendToReachable("computer.checked_signal", player, "touch", Int.box(x), Int.box(y), Int.box(button))
	}

	override def mouseDrag(x: Int, y: Int, button: Int, player: EntityPlayer) {
	if (Settings.get.inputUsername) owner.node.sendToReachable("computer.checked_signal", player, "drag", Int.box(x), Int.box(y), Int.box(button), player.getCommandSenderName)
	else owner.node.sendToReachable("computer.checked_signal", player, "drag", Int.box(x), Int.box(y), Int.box(button))
	}

	override def mouseUp(x: Int, y: Int, button: Int, player: EntityPlayer) {
	if (Settings.get.inputUsername) owner.node.sendToReachable("computer.checked_signal", player, "drop", Int.box(x), Int.box(y), Int.box(button), player.getCommandSenderName)
	else owner.node.sendToReachable("computer.checked_signal", player, "drop", Int.box(x), Int.box(y), Int.box(button))
	}

	override def mouseScroll(x: Int, y: Int, delta: Int, player: EntityPlayer) {
	if (Settings.get.inputUsername) owner.node.sendToReachable("computer.checked_signal", player, "scroll", Int.box(x), Int.box(y), Int.box(delta), player.getCommandSenderName)
	else owner.node.sendToReachable("computer.checked_signal", player, "scroll", Int.box(x), Int.box(y), Int.box(delta))
	}
	}

	}