display lists for screen gui and general performance improvement in monospace font renderer (not rendering spaces, just translate)

li/cil/oc/client/gui/GuiScreen.scala

@@ -5,19 +5,29 @@ import net.minecraft.client.gui.Gui
 import org.lwjgl.opengl.GL11
 import net.minecraft.util.ResourceLocation
 import net.minecraft.client.renderer.Tessellator
+import net.minecraft.client.renderer.GLAllocation
+import net.minecraft.client.renderer.texture.TextureManager
 
+/**
+ * This GUI shows the buffer of a single screen.
+ *
+ * The window is sized to fit the contents of the buffer. If the buffer is
+ * smaller than the overall available space, the window is centered. if it is
+ * larger, the content is scaled down to fit the available space.
+ *
+ * Text and background are cached in display lists, so updateText() must be
+ * called whenever the text actually changes, otherwise there will be no change
+ * in the text displayed in the GUI.
+ */
 class GuiScreen(val tileEntity: TileEntityScreen) extends net.minecraft.client.gui.GuiScreen {
   tileEntity.gui = Some(this)
 
-  private val borders = new ResourceLocation("opencomputers", "textures/gui/borders.png")
-
-  private val margin = 7
-  private val innerMargin = 1
-
   var (x, y, innerWidth, innerHeight, scale) = (0, 0, 0, 0, 0.0)
 
+  /** Must be called when the size of the underlying screen changes */
   def setSize(w: Double, h: Double) = {
-    val totalMargin = (margin + innerMargin) * 2
+    // Re-compute sizes and positions.
+    val totalMargin = (GuiScreen.margin + GuiScreen.innerMargin) * 2
     val bufferWidth = w * MonospaceFontRenderer.fontWidth
     val bufferHeight = h * MonospaceFontRenderer.fontHeight
     val bufferScaleX = ((width - totalMargin) / bufferWidth) min 1
@@ -27,11 +37,19 @@ class GuiScreen(val tileEntity: TileEntityScreen) extends net.minecraft.client.g
     innerHeight = (bufferHeight * scale + 1).ceil.toInt
     x = (width - (innerWidth + totalMargin)) / 2
     y = (height - (innerHeight + totalMargin)) / 2
+
+    // Re-build display lists.
+    GuiScreen.compileBackground(innerWidth, innerHeight)
+    GuiScreen.compileText(scale, tileEntity.component.lines)
   }
 
+  /** Must be called whenever the buffer of the underlying screen changes. */
+  def updateText() = GuiScreen.compileText(scale, tileEntity.component.lines)
+
   override def initGui() = {
     super.initGui()
     MonospaceFontRenderer.init(mc.renderEngine)
+    GuiScreen.init(mc.renderEngine)
     val (w, h) = tileEntity.component.resolution
     setSize(w, h)
   }
@@ -45,57 +63,100 @@ class GuiScreen(val tileEntity: TileEntityScreen) extends net.minecraft.client.g
     GL11.glPushMatrix()
     GL11.glTranslatef(x, y, 0)
     GL11.glColor4f(1.0F, 1.0F, 1.0F, 1.0F)
-    setTexture(borders)
-
-    drawRectangle(
-      0, 0, 7, 7,
-      0, 0, 7, 7)
-    drawRectangle(
-      margin, 0, innerWidth, 7,
-      7, 0, 8, 7)
-    drawRectangle(
-      margin + innerWidth, 0, 7, 7,
-      8, 0, 15, 7)
-
-    drawRectangle(
-      0, margin, 7, innerHeight,
-      0, 7, 7, 8)
-    drawRectangle(
-      margin, margin, innerWidth, innerHeight,
-      7, 7, 8, 8)
-    drawRectangle(
-      margin + innerWidth, margin, 7, innerHeight,
-      8, 7, 15, 8)
-
-    drawRectangle(
-      0, margin + innerHeight, 7, 7,
-      0, 8, 7, 15)
-    drawRectangle(
-      margin, margin + innerHeight, innerWidth, 7,
-      7, 8, 8, 15)
-    drawRectangle(
-      margin + innerWidth, margin + innerHeight, 7, 7,
-      8, 8, 15, 15)
-
-    GL11.glTranslatef(margin + innerMargin, margin + innerMargin, 0)
-    GL11.glScaled(scale, scale, 1)
-
-    tileEntity.component.lines.zipWithIndex.foreach {
-      case (line, i) => MonospaceFontRenderer.drawString(line, 0, i * MonospaceFontRenderer.fontHeight)
-    }
+    GuiScreen.draw()
     GL11.glPopMatrix()
 
     super.drawScreen(mouseX, mouseY, dt);
   }
 
   override def doesGuiPauseGame = false
+}
 
-  private def setTexture(value: ResourceLocation) =
-    mc.renderEngine.func_110577_a(value)
+/** We cache OpenGL stuff in a singleton to avoid having to re-allocate. */
+object GuiScreen {
+  val margin = 7
 
-  private def drawRectangle(x: Double, y: Double, w: Double, h: Double, u1: Int, v1: Int, u2: Int, v2: Int) = {
-    val t = Tessellator.instance
+  val innerMargin = 1
+
+  private val borders = new ResourceLocation("opencomputers", "textures/gui/borders.png")
+
+  private var textureManager: Option[TextureManager] = None
+
+  private var displayLists: Option[Int] = None
+
+  private var buffer: Option[java.nio.IntBuffer] = None
+
+  def init(tm: TextureManager) = if (!textureManager.isDefined) {
+    textureManager = Some(tm)
+    displayLists = Some(GLAllocation.generateDisplayLists(2))
+    buffer = Some(GLAllocation.createDirectIntBuffer(2))
+    buffer.get.put(displayLists.get)
+    buffer.get.put(displayLists.get + 1)
+  }
+
+  def draw() = if (textureManager.isDefined) {
+    buffer.get.rewind()
+    GL11.glCallLists(buffer.get)
+  }
+
+  private[gui] def compileBackground(innerWidth: Int, innerHeight: Int) =
+    if (textureManager.isDefined) {
+      GL11.glNewList(displayLists.get, GL11.GL_COMPILE)
+
+      setTexture(borders)
+
+      // Top border (left corner, middle bar, right corner).
+      drawBorder(
+        0, 0, 7, 7,
+        0, 0, 7, 7)
+      drawBorder(
+        margin, 0, innerWidth, 7,
+        7, 0, 8, 7)
+      drawBorder(
+        margin + innerWidth, 0, 7, 7,
+        8, 0, 15, 7)
+
+      // Middle area (left bar, screen background, right bar).
+      drawBorder(
+        0, margin, 7, innerHeight,
+        0, 7, 7, 8)
+      drawBorder(
+        margin, margin, innerWidth, innerHeight,
+        7, 7, 8, 8)
+      drawBorder(
+        margin + innerWidth, margin, 7, innerHeight,
+        8, 7, 15, 8)
+
+      // Bottom border (left corner, middle bar, right corner).
+      drawBorder(
+        0, margin + innerHeight, 7, 7,
+        0, 8, 7, 15)
+      drawBorder(
+        margin, margin + innerHeight, innerWidth, 7,
+        7, 8, 8, 15)
+      drawBorder(
+        margin + innerWidth, margin + innerHeight, 7, 7,
+        8, 8, 15, 15)
+
+      GL11.glEndList()
+    }
+
+  private[gui] def compileText(scale: Double, lines: Array[Array[Char]]) =
+    if (textureManager.isDefined) {
+      GL11.glNewList(displayLists.get + 1, GL11.GL_COMPILE)
+
+      GL11.glTranslatef(margin + innerMargin, margin + innerMargin, 0)
+      GL11.glScaled(scale, scale, 1)
+      lines.zipWithIndex.foreach {
+        case (line, i) => MonospaceFontRenderer.drawString(line, 0, i * MonospaceFontRenderer.fontHeight)
+      }
+
+      GL11.glEndList()
+    }
+
+  private def drawBorder(x: Double, y: Double, w: Double, h: Double, u1: Int, v1: Int, u2: Int, v2: Int) = {
     val (u1d, u2d, v1d, v2d) = (u1 / 16.0, u2 / 16.0, v1 / 16.0, v2 / 16.0)
+    val t = Tessellator.instance
     t.startDrawingQuads()
     t.addVertexWithUV(x, y + h, 0, u1d, v2d)
     t.addVertexWithUV(x + w, y + h, 0, u2d, v2d)
@@ -103,4 +164,7 @@ class GuiScreen(val tileEntity: TileEntityScreen) extends net.minecraft.client.g
     t.addVertexWithUV(x, y, 0, u1d, v1d)
     t.draw()
   }
+
+  private def setTexture(value: ResourceLocation) =
+    textureManager.get.func_110577_a(value)
 }

li/cil/oc/client/gui/MonospaceFontRenderer.scala

@@ -41,7 +41,12 @@ object MonospaceFontRenderer {
       val vOffset = vStep * 1 / 20
       val vSize = vStep * 18 / 20
       val t = Tessellator.instance
-      for (index <- (32 until 0x7F).union(0x9F until 0xFF)) {
+      // Special case for whitespace: just translate, don't render.
+      GL11.glNewList(charLists + 32, GL11.GL_COMPILE)
+      GL11.glTranslatef(charWidth, 0, 0)
+      GL11.glEndList()
+      // Now create lists for all printable chars.
+      for (index <- (33 until 0x7F).union(0x9F until 0xFF)) {
         // The font texture does not contain the 0-1F range, nor the 0x7F to
         // 0x9F range (control chars as per Character.isISOControl).
         val textureIndex =

li/cil/oc/common/tileentity/TileEntityScreen.scala

@@ -46,19 +46,28 @@ class TileEntityScreen extends TileEntityRotatable with IScreenEnvironment {
     }
 
   def onScreenSet(col: Int, row: Int, s: String) =
-    if (!worldObj.isRemote) {
+    if (worldObj.isRemote) {
+      gui.foreach(_.updateText())
+    }
+    else {
       markAsChanged()
       ServerPacketSender.sendScreenSet(this, col, row, s)
     }
 
   def onScreenFill(col: Int, row: Int, w: Int, h: Int, c: Char) =
-    if (!worldObj.isRemote) {
+    if (worldObj.isRemote) {
+      gui.foreach(_.updateText())
+    }
+    else {
       markAsChanged()
       ServerPacketSender.sendScreenFill(this, col, row, w, h, c)
     }
 
   def onScreenCopy(col: Int, row: Int, w: Int, h: Int, tx: Int, ty: Int) =
-    if (!worldObj.isRemote) {
+    if (worldObj.isRemote) {
+      gui.foreach(_.updateText())
+    }
+    else {
       markAsChanged()
       ServerPacketSender.sendScreenCopy(this, col, row, w, h, tx, ty)
     }