src/main/scala/li/cil/oc/util/PseudoMarkdown.scala - minecraft/opencomputers - Rivoreo Source Code Repositories

 package li.cil.oc.util

 import java.io.InputStream
 import javax.imageio.ImageIO

 import com.google.common.base.Strings
 import li.cil.oc.Settings
 import net.minecraft.block.Block
 import net.minecraft.client.Minecraft
 import net.minecraft.client.gui.FontRenderer
 import net.minecraft.client.renderer.OpenGlHelper
 import net.minecraft.client.renderer.RenderHelper
 import net.minecraft.client.renderer.entity.RenderItem
 import net.minecraft.client.renderer.texture.AbstractTexture
 import net.minecraft.client.renderer.texture.TextureUtil
 import net.minecraft.client.resources.IResourceManager
 import net.minecraft.item.Item
 import net.minecraft.item.ItemStack
 import net.minecraft.util.EnumChatFormatting
 import net.minecraft.util.ResourceLocation
 import net.minecraftforge.oredict.OreDictionary
 import org.lwjgl.opengl.GL11
 import org.lwjgl.opengl.GL12

 import scala.annotation.tailrec
 import scala.collection.convert.WrapAsScala._
 import scala.collection.mutable
 import scala.util.matching.Regex

 /**
  * Primitive Markdown parser, only supports a very small subset. Used for
  * parsing documentation into segments, to be displayed in a GUI somewhere.
  */
 object PseudoMarkdown {
   /**
    * Parses a plain text document into a list of segments.
    */
   def parse(document: Iterator[String]): Iterable[Segment] = {
     var segments = document.flatMap(line => Iterable(new TextSegment(null, line), new NewLineSegment())).toArray
     for ((pattern, factory) <- segmentTypes) {
       segments = segments.flatMap(_.refine(pattern, factory))
     }
     for (Array(s1, s2) <- segments.sliding(2)) {
       s2.previous = s1
     }
     segments
   }

   /**
    * Renders a list of segments and tooltips if a segment with a tooltip is hovered.
    * Returns a link address if a link is hovered.
    */
   def render(document: Iterable[Segment], x: Int, y: Int, maxWidth: Int, maxHeight: Int, yOffset: Int, renderer: FontRenderer, mouseX: Int, mouseY: Int): Option[InteractiveSegment] = {
     // Create a flat area in the depth buffer.
     GL11.glPushMatrix()
     GL11.glTranslatef(0, 0, 1)
     GL11.glDepthMask(true)
     GL11.glColor4f(0.01f, 0.01f, 0.01f, 1)
     GL11.glBegin(GL11.GL_QUADS)
     GL11.glVertex2f(x - 1, y - 1)
     GL11.glVertex2f(x - 1, y + 1 + maxHeight)
     GL11.glVertex2f(x + 1 + maxWidth, y + 1 + maxHeight)
     GL11.glVertex2f(x + 1 + maxWidth, y - 1)
     GL11.glEnd()

     // Use that flat area to mask the output area.
     GL11.glDepthMask(false)
     GL11.glDepthFunc(GL11.GL_EQUAL)

     // Actual rendering.
     var hovered: Option[InteractiveSegment] = None
     var currentX = 0
     var currentY = 0
     for (segment <- document) {
       val result = segment.render(x, y + currentY - yOffset, currentX, maxWidth, y, maxHeight - (currentY - yOffset), renderer, mouseX, mouseY)
       hovered = hovered.orElse(result)
       currentY += segment.height(currentX, maxWidth, renderer)
       currentX = segment.width(currentX, maxWidth, renderer)
     }
     if (mouseX < x || mouseX > x + maxWidth || mouseY < y || mouseY > y + maxHeight) hovered = None
     hovered.foreach(_.notifyHover())

     // Restore all the things.
     GL11.glDepthFunc(GL11.GL_LEQUAL)
     GL11.glPopMatrix()

     hovered
   }

   /**
    * Compute the overall height of a document, for computation of scroll offsets.
    */
   def height(document: Iterable[Segment], maxWidth: Int, renderer: FontRenderer): Int = {
     var currentX = 0
     var currentY = 0
     for (segment <- document) {
       currentY += segment.height(currentX, maxWidth, renderer)
       currentX = segment.width(currentX, maxWidth, renderer)
     }
     currentY
   }

   def lineHeight(renderer: FontRenderer): Int = renderer.FONT_HEIGHT + 1

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

   trait Segment {
     // Set after construction of document, used for formatting (e.g. newline height).
     private[PseudoMarkdown] var previous: Segment = null

     // Used when rendering, to compute the style of a nested segment.
     protected def parent: Segment

     // Used during construction, checks a segment for inner segments.
     private[PseudoMarkdown] def refine(pattern: Regex, factory: (Segment, Regex.Match) => Segment): Iterable[Segment] = Iterable(this)

     /**
      * Computes the height of this segment, in pixels, given it starts at the
      * specified indent into the current line, with the specified maximum
      * allowed width.
      */
     def height(indent: Int, maxWidth: Int, renderer: FontRenderer): Int = 0

     /**
      * Computes the width of the last line of this segment, given it starts
      * at the specified indent into the current line, with the specified
      * maximum allowed width.
      * If the segment remains on the same line, returns the new end of the
      * line (i.e. indent plus width of the segment).
      */
     def width(indent: Int, maxWidth: Int, renderer: FontRenderer): Int = 0

     def render(x: Int, y: Int, indent: Int, maxWidth: Int, minY: Int, maxY: Int, renderer: FontRenderer, mouseX: Int, mouseY: Int): Option[InteractiveSegment] = None
   }

   trait InteractiveSegment extends Segment {
     def tooltip: Option[String] = None

     def link: Option[String] = None

     private[PseudoMarkdown] def notifyHover(): Unit = {}

     private[PseudoMarkdown] def checkHovered(mouseX: Int, mouseY: Int, x: Int, y: Int, w: Int, h: Int): Option[InteractiveSegment] = if (mouseX >= x && mouseY >= y && mouseX <= x + w && mouseY <= y + h) Some(this) else None
   }

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

   private class TextSegment(protected val parent: Segment, val text: String) extends Segment {
     override def refine(pattern: Regex, factory: (Segment, Regex.Match) => Segment): Iterable[Segment] = {
       val result = mutable.Buffer.empty[Segment]

       // Keep track of last matches end, to generate plain text segments.
       var textStart = 0
       for (m <- pattern.findAllMatchIn(text)) {
         // Create segment for leading plain text.
         if (m.start > textStart) {
           result += new TextSegment(this, text.substring(textStart, m.start))
         }
         textStart = m.end

         // Create segment for formatted text.
         result += factory(this, m)
       }

       // Create segment for remaining plain text.
       if (textStart == 0) {
         result += this
       }
       else if (textStart < text.length) {
         result += new TextSegment(this, text.substring(textStart))
       }
       result
     }

     override def height(indent: Int, maxWidth: Int, renderer: FontRenderer): Int = {
       var lines = 0
       var chars = text
       var lineChars = maxChars(chars, maxWidth - indent, renderer)
       while (chars.length > lineChars) {
         lines += 1
         chars = chars.drop(lineChars)
         lineChars = maxChars(chars, maxWidth, renderer)
       }
       (lines * lineHeight(renderer) * resolvedScale).toInt
     }

     override def width(indent: Int, maxWidth: Int, renderer: FontRenderer): Int = {
       var currentX = indent
       var chars = text
       var lineChars = maxChars(chars, maxWidth - indent, renderer)
       while (chars.length > lineChars) {
         chars = chars.drop(lineChars)
         lineChars = maxChars(chars, maxWidth, renderer)
         currentX = 0
       }
       currentX + (stringWidth(chars, renderer) * resolvedScale).toInt
     }

     override def render(x: Int, y: Int, indent: Int, maxWidth: Int, minY: Int, maxY: Int, renderer: FontRenderer, mouseX: Int, mouseY: Int): Option[InteractiveSegment] = {
       val fontScale = resolvedScale
       var currentX = x + indent
       var currentY = y
       var chars = text
       var numChars = maxChars(chars, maxWidth - indent, renderer)
       val interactive = findInteractive()
       var hovered: Option[InteractiveSegment] = None
       while (chars.length > 0 && (currentY - y) < maxY) {
         val part = chars.take(numChars)
         hovered = hovered.orElse(interactive.fold(None: Option[InteractiveSegment])(_.checkHovered(mouseX, mouseY, currentX, currentY, (stringWidth(part, renderer) * fontScale).toInt, (lineHeight(renderer) * fontScale).toInt)))
         GL11.glPushMatrix()
         GL11.glTranslatef(currentX, currentY, 0)
         GL11.glScalef(fontScale, fontScale, fontScale)
         GL11.glTranslatef(-currentX, -currentY, 0)
         renderer.drawString(resolvedFormat + part, currentX, currentY, resolvedColor)
         GL11.glPopMatrix()
         currentX = x
         currentY += (lineHeight(renderer) * fontScale).toInt
         chars = chars.drop(numChars)
         numChars = maxChars(chars, maxWidth, renderer)
       }

       hovered
     }

     protected def color = None: Option[Int]

     protected def scale = None: Option[Float]

     protected def format = ""

     protected def stringWidth(s: String, renderer: FontRenderer): Int = renderer.getStringWidth(resolvedFormat + s)

     def resolvedColor: Int = parent match {
       case segment: TextSegment => color.getOrElse(segment.resolvedColor)
       case _ => color.getOrElse(0xDDDDDD)
     }

     def resolvedScale: Float = parent match {
       case segment: TextSegment => scale.getOrElse(segment.resolvedScale)
       case _ => scale.getOrElse(1f)
     }

     def resolvedFormat: String = parent match {
       case segment: TextSegment => segment.resolvedFormat + format
       case _ => format
     }

     @tailrec private def findInteractive(): Option[InteractiveSegment] = this match {
       case segment: InteractiveSegment => Some(segment)
       case _ => parent match {
         case segment: TextSegment => segment.findInteractive()
         case _ => None
       }
     }

     private def maxChars(s: String, maxWidth: Int, renderer: FontRenderer): Int = {
       val fontScale = resolvedScale
       val breaks = Set(' ', '-', '.', '+', '*', '_', '/')
       var pos = 0
       var lastBreak = -1
       while (pos < s.length) {
         pos += 1
         val width = (stringWidth(s.take(pos), renderer) * fontScale).toInt
         if (width >= maxWidth) return lastBreak + 1
         if (pos < s.length && breaks.contains(s.charAt(pos))) lastBreak = pos
       }
       pos
     }

     override def toString: String = s"{TextSegment: text = $text}"
   }

   private class HeaderSegment(parent: Segment, text: String, val level: Int) extends TextSegment(parent, text) {
     private val fontScale = math.max(2, 5 - level) / 2f

     override protected def scale = Some(fontScale)

     override protected def format = EnumChatFormatting.UNDERLINE.toString

     override def toString: String = s"{HeaderSegment: text = $text, level = $level}"
   }

   private class LinkSegment(parent: Segment, text: String, val url: String) extends TextSegment(parent, text) with InteractiveSegment {
     private final val normalColor = 0x66FF66
     private final val hoverColor = 0xAAFFAA
     private final val fadeTime = 500
     private var lastHovered = System.currentTimeMillis() - fadeTime

     override protected def color: Option[Int] = {
       val timeSinceHover = (System.currentTimeMillis() - lastHovered).toInt
       if (timeSinceHover > fadeTime) Some(normalColor)
       else Some(fadeColor(hoverColor, normalColor, timeSinceHover / fadeTime.toFloat))
     }

     override def tooltip: Option[String] = Option(url)

     override def link: Option[String] = Option(url)

     override private[PseudoMarkdown] def notifyHover(): Unit = lastHovered = System.currentTimeMillis()

     private def fadeColor(c1: Int, c2: Int, t: Float): Int = {
       val (r1, g1, b1) = ((c1 >>> 16) & 0xFF, (c1 >>> 8) & 0xFF, c1 & 0xFF)
       val (r2, g2, b2) = ((c2 >>> 16) & 0xFF, (c2 >>> 8) & 0xFF, c2 & 0xFF)
       val (r, g, b) = ((r1 + (r2 - r1) * t).toInt, (g1 + (g2 - g1) * t).toInt, (b1 + (b2 - b1) * t).toInt)
       (r << 16) | (g << 8) | b
     }

     override def toString: String = s"{LinkSegment: text = $text, url = $url}"
   }

   private class BoldSegment(parent: Segment, text: String) extends TextSegment(parent, text) {
     override protected def format = EnumChatFormatting.BOLD.toString

     override def toString: String = s"{BoldSegment: text = $text}"
   }

   private class ItalicSegment(parent: Segment, text: String) extends TextSegment(parent, text) {
     override protected def format = EnumChatFormatting.ITALIC.toString

     override def toString: String = s"{ItalicSegment: text = $text}"
   }

   private class StrikethroughSegment(parent: Segment, text: String) extends TextSegment(parent, text) {
     override protected def format = EnumChatFormatting.STRIKETHROUGH.toString

     override def toString: String = s"{StrikethroughSegment: text = $text}"
   }

   private class ItemStackSegment(val parent: Segment, val title: String, val stacks: Array[ItemStack]) extends InteractiveSegment {
     final val renderWidth = 32
     final val renderHeight = 32
     final val cycleSpeed = 1000

     override def tooltip: Option[String] = Option(title)

     override def height(indent: Int, maxWidth: Int, renderer: FontRenderer): Int = math.max(lineHeight(renderer), renderHeight + 10 - lineHeight(renderer))

     override def width(indent: Int, maxWidth: Int, renderer: FontRenderer): Int = maxWidth

     override def render(x: Int, y: Int, indent: Int, maxWidth: Int, minY: Int, maxY: Int, renderer: FontRenderer, mouseX: Int, mouseY: Int): Option[InteractiveSegment] = {
       val xOffset = (maxWidth - renderWidth) / 2
       val yOffset = 4 + (if (indent > 0) lineHeight(renderer) else 0)
       val maskLow = math.max(minY - y - yOffset - 1, 0)
       val maskHigh = math.max(maskLow, math.min(renderHeight, maxY - 3))
       val mc = Minecraft.getMinecraft
       val index = (System.currentTimeMillis() % (cycleSpeed * stacks.length)).toInt / cycleSpeed
       val stack = stacks(index)

       GL11.glPushMatrix()
       GL11.glTranslatef(x + xOffset, y + yOffset, 0)

       GL11.glColor4f(0.1f, 0.1f, 0.1f, 1)
       GL11.glTranslatef(0, 0, 400)
       GL11.glDepthFunc(GL11.GL_LEQUAL)
       GL11.glDisable(GL11.GL_TEXTURE_2D)
       GL11.glColorMaterial(GL11.GL_FRONT_AND_BACK, GL11.GL_AMBIENT_AND_DIFFUSE)
       GL11.glEnable(GL11.GL_COLOR_MATERIAL)
       GL11.glDepthMask(true)
       GL11.glColorMask(false, false, false, false)
       GL11.glBegin(GL11.GL_QUADS)
       GL11.glVertex2f(0, maskLow)
       GL11.glVertex2f(0, maskHigh)
       GL11.glVertex2f(renderWidth, maskHigh)
       GL11.glVertex2f(renderWidth, maskLow)
       GL11.glEnd()
       GL11.glTranslatef(0, 0, -400)
       GL11.glDepthFunc(GL11.GL_GEQUAL)
       GL11.glEnable(GL11.GL_TEXTURE_2D)
       GL11.glDisable(GL11.GL_COLOR_MATERIAL)
       GL11.glDepthMask(false)
       GL11.glColorMask(true, true, true, true)

       GL11.glColor4f(1, 1, 1, 1)
       GL11.glScalef(renderWidth / 16, renderHeight / 16, renderWidth / 16)
       GL11.glEnable(GL12.GL_RESCALE_NORMAL)
       RenderHelper.enableGUIStandardItemLighting()
       OpenGlHelper.setLightmapTextureCoords(OpenGlHelper.lightmapTexUnit, 240, 240)
       RenderItem.getInstance.renderItemAndEffectIntoGUI(renderer, mc.getTextureManager, stack, 0, 0)
       RenderHelper.disableStandardItemLighting()

       GL11.glPopMatrix()
       GL11.glDepthFunc(GL11.GL_EQUAL)

       checkHovered(mouseX, mouseY, x + xOffset, y + yOffset, renderWidth, renderHeight)
     }

     override def toString: String = s"{ItemStackSegment: stacks = $stacks}"
   }

   private class ImageSegment(val parent: Segment, val title: String, val url: String) extends InteractiveSegment {
     val path = if (url.startsWith("/")) url else "doc/img/" + url
     val location = new ResourceLocation(Settings.resourceDomain, path)
     val texture = {
       val manager = Minecraft.getMinecraft.getTextureManager
       manager.getTexture(location) match {
         case image: ImageTexture => image
         case _ =>
           val image = new ImageTexture(location)
           manager.loadTexture(location, image)
           image
       }
     }

     override def tooltip: Option[String] = Option(title)

     override def height(indent: Int, maxWidth: Int, renderer: FontRenderer): Int = math.max(lineHeight(renderer), texture.height + 10 - lineHeight(renderer))

     override def width(indent: Int, maxWidth: Int, renderer: FontRenderer): Int = maxWidth

     override def render(x: Int, y: Int, indent: Int, maxWidth: Int, minY: Int, maxY: Int, renderer: FontRenderer, mouseX: Int, mouseY: Int): Option[InteractiveSegment] = {
       val xOffset = (maxWidth - texture.width) / 2
       val yOffset = 4 + (if (indent > 0) lineHeight(renderer) else 0)
       Minecraft.getMinecraft.getTextureManager.bindTexture(location)
       GL11.glColor4f(1, 1, 1, 1)
       GL11.glBegin(GL11.GL_QUADS)
       GL11.glTexCoord2f(0, 0)
       GL11.glVertex2f(x + xOffset, y + yOffset)
       GL11.glTexCoord2f(0, 1)
       GL11.glVertex2f(x + xOffset, y + yOffset + texture.height)
       GL11.glTexCoord2f(1, 1)
       GL11.glVertex2f(x + xOffset + texture.width, y + yOffset + texture.height)
       GL11.glTexCoord2f(1, 0)
       GL11.glVertex2f(x + xOffset + texture.width, y + yOffset)
       GL11.glEnd()

       checkHovered(mouseX, mouseY, x + xOffset, y + yOffset, texture.width, texture.height)
     }

     override def toString: String = s"{ImageSegment: tooltip = $tooltip, url = $url}"
   }

   private class NewLineSegment extends Segment {
     override protected def parent: Segment = null

     override def height(indent: Int, maxWidth: Int, renderer: FontRenderer): Int = previous match {
       case segment: TextSegment => (lineHeight(renderer) * segment.resolvedScale).toInt
       case _ => lineHeight(renderer)
     }

     override def toString: String = s"{NewLineSegment}"
   }

   private class ImageTexture(val location: ResourceLocation) extends AbstractTexture {
     var width = 0
     var height = 0

     override def loadTexture(manager: IResourceManager): Unit = {
       deleteGlTexture()

       var is: InputStream = null
       try {
         val resource = manager.getResource(location)
         is = resource.getInputStream
         val bi = ImageIO.read(is)
         TextureUtil.uploadTextureImageAllocate(getGlTextureId, bi, false, false)
         width = bi.getWidth
         height = bi.getHeight
       }
       finally {
         Option(is).foreach(_.close())
       }
     }
   }

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

   private def HeaderSegment(s: Segment, m: Regex.Match) = new HeaderSegment(s, m.group(2), m.group(1).length)

   private def LinkSegment(s: Segment, m: Regex.Match) = new LinkSegment(s, m.group(1), m.group(2))

   private def BoldSegment(s: Segment, m: Regex.Match) = new BoldSegment(s, m.group(2))

   private def ItalicSegment(s: Segment, m: Regex.Match) = new ItalicSegment(s, m.group(2))

   private def StrikethroughSegment(s: Segment, m: Regex.Match) = new StrikethroughSegment(s, m.group(1))

   private def ImageSegment(s: Segment, m: Regex.Match) = {
     try {
       if (m.group(2).startsWith("item:")) {
         val desc = m.group(2).stripPrefix("item:")
         val (name, optMeta) = desc.splitAt(desc.lastIndexOf('@'))
         val meta = if (Strings.isNullOrEmpty(optMeta)) 0 else Integer.parseInt(optMeta.drop(1))
         Item.itemRegistry.getObject(name) match {
           case item: Item => new ItemStackSegment(s, m.group(1), Array(new ItemStack(item, 1, meta)))
           case _ => new TextSegment(s, m.group(1))
         }
       }
       else if (m.group(2).startsWith("block:")) {
         val desc = m.group(2).stripPrefix("block:")
         val (name, optMeta) = desc.splitAt(desc.lastIndexOf('@'))
         val meta = if (Strings.isNullOrEmpty(optMeta)) 0 else Integer.parseInt(optMeta.drop(1))
         Block.blockRegistry.getObject(name) match {
           case block: Block => new ItemStackSegment(s, m.group(1), Array(new ItemStack(block, 1, meta)))
           case _ => new TextSegment(s, m.group(1))
         }
       }
       else if (m.group(2).startsWith("oredict:")) {
         val name = m.group(2).stripPrefix("oredict:")
         val stacks = OreDictionary.getOres(name)
         if (stacks != null && stacks.nonEmpty) new ItemStackSegment(s, m.group(1), stacks.toArray(new Array[ItemStack](stacks.size())))
         else new TextSegment(s, m.group(1))
       }
       else new ImageSegment(s, m.group(1), m.group(2))
     }
     catch {
       case t: Throwable => new TextSegment(s, t.getMessage)
     }
   }

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

   private val segmentTypes = Array(
     """^(#+)\s(.*)""".r -> HeaderSegment _, // headers: # ...
     """!\[([^\[]*)\]\(([^\)]+)\)""".r -> ImageSegment _, // images: ![...](...)
     """\[([^\[]+)\]\(([^\)]+)\)""".r -> LinkSegment _, // links: [...](...)
     """(\*\*|__)(\S.*?\S|$)\1""".r -> BoldSegment _, // bold: **...** | __...__
     """(\*|_)(\S.*?\S|$)\1""".r -> ItalicSegment _, // italic: *...* | _..._
     """~~(\S.*?\S|$)~~""".r -> StrikethroughSegment _ // strikethrough: ~~...~~
   )
 }
	package li.cil.oc.util

	import java.io.InputStream
	import javax.imageio.ImageIO

	import com.google.common.base.Strings
	import li.cil.oc.Settings
	import net.minecraft.block.Block
	import net.minecraft.client.Minecraft
	import net.minecraft.client.gui.FontRenderer
	import net.minecraft.client.renderer.OpenGlHelper
	import net.minecraft.client.renderer.RenderHelper
	import net.minecraft.client.renderer.entity.RenderItem
	import net.minecraft.client.renderer.texture.AbstractTexture
	import net.minecraft.client.renderer.texture.TextureUtil
	import net.minecraft.client.resources.IResourceManager
	import net.minecraft.item.Item
	import net.minecraft.item.ItemStack
	import net.minecraft.util.EnumChatFormatting
	import net.minecraft.util.ResourceLocation
	import net.minecraftforge.oredict.OreDictionary
	import org.lwjgl.opengl.GL11
	import org.lwjgl.opengl.GL12

	import scala.annotation.tailrec
	import scala.collection.convert.WrapAsScala._
	import scala.collection.mutable
	import scala.util.matching.Regex

	/**
	* Primitive Markdown parser, only supports a very small subset. Used for
	* parsing documentation into segments, to be displayed in a GUI somewhere.
	*/
	object PseudoMarkdown {
	/**
	* Parses a plain text document into a list of segments.
	*/
	def parse(document: Iterator[String]): Iterable[Segment] = {
	var segments = document.flatMap(line => Iterable(new TextSegment(null, line), new NewLineSegment())).toArray
	for ((pattern, factory) <- segmentTypes) {
	segments = segments.flatMap(_.refine(pattern, factory))
	}
	for (Array(s1, s2) <- segments.sliding(2)) {
	s2.previous = s1
	}
	segments
	}

	/**
	* Renders a list of segments and tooltips if a segment with a tooltip is hovered.
	* Returns a link address if a link is hovered.
	*/
	def render(document: Iterable[Segment], x: Int, y: Int, maxWidth: Int, maxHeight: Int, yOffset: Int, renderer: FontRenderer, mouseX: Int, mouseY: Int): Option[InteractiveSegment] = {
	// Create a flat area in the depth buffer.
	GL11.glPushMatrix()
	GL11.glTranslatef(0, 0, 1)
	GL11.glDepthMask(true)
	GL11.glColor4f(0.01f, 0.01f, 0.01f, 1)
	GL11.glBegin(GL11.GL_QUADS)
	GL11.glVertex2f(x - 1, y - 1)
	GL11.glVertex2f(x - 1, y + 1 + maxHeight)
	GL11.glVertex2f(x + 1 + maxWidth, y + 1 + maxHeight)
	GL11.glVertex2f(x + 1 + maxWidth, y - 1)
	GL11.glEnd()

	// Use that flat area to mask the output area.
	GL11.glDepthMask(false)
	GL11.glDepthFunc(GL11.GL_EQUAL)

	// Actual rendering.
	var hovered: Option[InteractiveSegment] = None
	var currentX = 0
	var currentY = 0
	for (segment <- document) {
	val result = segment.render(x, y + currentY - yOffset, currentX, maxWidth, y, maxHeight - (currentY - yOffset), renderer, mouseX, mouseY)
	hovered = hovered.orElse(result)
	currentY += segment.height(currentX, maxWidth, renderer)
	currentX = segment.width(currentX, maxWidth, renderer)
	}
	if (mouseX < x \|\| mouseX > x + maxWidth \|\| mouseY < y \|\| mouseY > y + maxHeight) hovered = None
	hovered.foreach(_.notifyHover())

	// Restore all the things.
	GL11.glDepthFunc(GL11.GL_LEQUAL)
	GL11.glPopMatrix()

	hovered
	}

	/**
	* Compute the overall height of a document, for computation of scroll offsets.
	*/
	def height(document: Iterable[Segment], maxWidth: Int, renderer: FontRenderer): Int = {
	var currentX = 0
	var currentY = 0
	for (segment <- document) {
	currentY += segment.height(currentX, maxWidth, renderer)
	currentX = segment.width(currentX, maxWidth, renderer)
	}
	currentY
	}

	def lineHeight(renderer: FontRenderer): Int = renderer.FONT_HEIGHT + 1

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

	trait Segment {
	// Set after construction of document, used for formatting (e.g. newline height).
	private[PseudoMarkdown] var previous: Segment = null

	// Used when rendering, to compute the style of a nested segment.
	protected def parent: Segment

	// Used during construction, checks a segment for inner segments.
	private[PseudoMarkdown] def refine(pattern: Regex, factory: (Segment, Regex.Match) => Segment): Iterable[Segment] = Iterable(this)

	/**
	* Computes the height of this segment, in pixels, given it starts at the
	* specified indent into the current line, with the specified maximum
	* allowed width.
	*/
	def height(indent: Int, maxWidth: Int, renderer: FontRenderer): Int = 0

	/**
	* Computes the width of the last line of this segment, given it starts
	* at the specified indent into the current line, with the specified
	* maximum allowed width.
	* If the segment remains on the same line, returns the new end of the
	* line (i.e. indent plus width of the segment).
	*/
	def width(indent: Int, maxWidth: Int, renderer: FontRenderer): Int = 0

	def render(x: Int, y: Int, indent: Int, maxWidth: Int, minY: Int, maxY: Int, renderer: FontRenderer, mouseX: Int, mouseY: Int): Option[InteractiveSegment] = None
	}

	trait InteractiveSegment extends Segment {
	def tooltip: Option[String] = None

	def link: Option[String] = None

	private[PseudoMarkdown] def notifyHover(): Unit = {}

	private[PseudoMarkdown] def checkHovered(mouseX: Int, mouseY: Int, x: Int, y: Int, w: Int, h: Int): Option[InteractiveSegment] = if (mouseX >= x && mouseY >= y && mouseX <= x + w && mouseY <= y + h) Some(this) else None
	}

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

	private class TextSegment(protected val parent: Segment, val text: String) extends Segment {
	override def refine(pattern: Regex, factory: (Segment, Regex.Match) => Segment): Iterable[Segment] = {
	val result = mutable.Buffer.empty[Segment]

	// Keep track of last matches end, to generate plain text segments.
	var textStart = 0
	for (m <- pattern.findAllMatchIn(text)) {
	// Create segment for leading plain text.
	if (m.start > textStart) {
	result += new TextSegment(this, text.substring(textStart, m.start))
	}
	textStart = m.end

	// Create segment for formatted text.
	result += factory(this, m)
	}

	// Create segment for remaining plain text.
	if (textStart == 0) {
	result += this
	}
	else if (textStart < text.length) {
	result += new TextSegment(this, text.substring(textStart))
	}
	result
	}

	override def height(indent: Int, maxWidth: Int, renderer: FontRenderer): Int = {
	var lines = 0
	var chars = text
	var lineChars = maxChars(chars, maxWidth - indent, renderer)
	while (chars.length > lineChars) {
	lines += 1
	chars = chars.drop(lineChars)
	lineChars = maxChars(chars, maxWidth, renderer)
	}
	(lines * lineHeight(renderer) * resolvedScale).toInt
	}

	override def width(indent: Int, maxWidth: Int, renderer: FontRenderer): Int = {
	var currentX = indent
	var chars = text
	var lineChars = maxChars(chars, maxWidth - indent, renderer)
	while (chars.length > lineChars) {
	chars = chars.drop(lineChars)
	lineChars = maxChars(chars, maxWidth, renderer)
	currentX = 0
	}
	currentX + (stringWidth(chars, renderer) * resolvedScale).toInt
	}

	override def render(x: Int, y: Int, indent: Int, maxWidth: Int, minY: Int, maxY: Int, renderer: FontRenderer, mouseX: Int, mouseY: Int): Option[InteractiveSegment] = {
	val fontScale = resolvedScale
	var currentX = x + indent
	var currentY = y
	var chars = text
	var numChars = maxChars(chars, maxWidth - indent, renderer)
	val interactive = findInteractive()
	var hovered: Option[InteractiveSegment] = None
	while (chars.length > 0 && (currentY - y) < maxY) {
	val part = chars.take(numChars)
	hovered = hovered.orElse(interactive.fold(None: Option[InteractiveSegment])(_.checkHovered(mouseX, mouseY, currentX, currentY, (stringWidth(part, renderer) * fontScale).toInt, (lineHeight(renderer) * fontScale).toInt)))
	GL11.glPushMatrix()
	GL11.glTranslatef(currentX, currentY, 0)
	GL11.glScalef(fontScale, fontScale, fontScale)
	GL11.glTranslatef(-currentX, -currentY, 0)
	renderer.drawString(resolvedFormat + part, currentX, currentY, resolvedColor)
	GL11.glPopMatrix()
	currentX = x
	currentY += (lineHeight(renderer) * fontScale).toInt
	chars = chars.drop(numChars)
	numChars = maxChars(chars, maxWidth, renderer)
	}

	hovered
	}

	protected def color = None: Option[Int]

	protected def scale = None: Option[Float]

	protected def format = ""

	protected def stringWidth(s: String, renderer: FontRenderer): Int = renderer.getStringWidth(resolvedFormat + s)

	def resolvedColor: Int = parent match {
	case segment: TextSegment => color.getOrElse(segment.resolvedColor)
	case _ => color.getOrElse(0xDDDDDD)
	}

	def resolvedScale: Float = parent match {
	case segment: TextSegment => scale.getOrElse(segment.resolvedScale)
	case _ => scale.getOrElse(1f)
	}

	def resolvedFormat: String = parent match {
	case segment: TextSegment => segment.resolvedFormat + format
	case _ => format
	}

	@tailrec private def findInteractive(): Option[InteractiveSegment] = this match {
	case segment: InteractiveSegment => Some(segment)
	case _ => parent match {
	case segment: TextSegment => segment.findInteractive()
	case _ => None
	}
	}

	private def maxChars(s: String, maxWidth: Int, renderer: FontRenderer): Int = {
	val fontScale = resolvedScale
	val breaks = Set(' ', '-', '.', '+', '*', '_', '/')
	var pos = 0
	var lastBreak = -1
	while (pos < s.length) {
	pos += 1
	val width = (stringWidth(s.take(pos), renderer) * fontScale).toInt
	if (width >= maxWidth) return lastBreak + 1
	if (pos < s.length && breaks.contains(s.charAt(pos))) lastBreak = pos
	}
	pos
	}

	override def toString: String = s"{TextSegment: text = $text}"
	}

	private class HeaderSegment(parent: Segment, text: String, val level: Int) extends TextSegment(parent, text) {
	private val fontScale = math.max(2, 5 - level) / 2f

	override protected def scale = Some(fontScale)

	override protected def format = EnumChatFormatting.UNDERLINE.toString

	override def toString: String = s"{HeaderSegment: text = $text, level = $level}"
	}

	private class LinkSegment(parent: Segment, text: String, val url: String) extends TextSegment(parent, text) with InteractiveSegment {
	private final val normalColor = 0x66FF66
	private final val hoverColor = 0xAAFFAA
	private final val fadeTime = 500
	private var lastHovered = System.currentTimeMillis() - fadeTime

	override protected def color: Option[Int] = {
	val timeSinceHover = (System.currentTimeMillis() - lastHovered).toInt
	if (timeSinceHover > fadeTime) Some(normalColor)
	else Some(fadeColor(hoverColor, normalColor, timeSinceHover / fadeTime.toFloat))
	}

	override def tooltip: Option[String] = Option(url)

	override def link: Option[String] = Option(url)

	override private[PseudoMarkdown] def notifyHover(): Unit = lastHovered = System.currentTimeMillis()

	private def fadeColor(c1: Int, c2: Int, t: Float): Int = {
	val (r1, g1, b1) = ((c1 >>> 16) & 0xFF, (c1 >>> 8) & 0xFF, c1 & 0xFF)
	val (r2, g2, b2) = ((c2 >>> 16) & 0xFF, (c2 >>> 8) & 0xFF, c2 & 0xFF)
	val (r, g, b) = ((r1 + (r2 - r1) * t).toInt, (g1 + (g2 - g1) * t).toInt, (b1 + (b2 - b1) * t).toInt)
	(r << 16) \| (g << 8) \| b
	}

	override def toString: String = s"{LinkSegment: text = $text, url = $url}"
	}

	private class BoldSegment(parent: Segment, text: String) extends TextSegment(parent, text) {
	override protected def format = EnumChatFormatting.BOLD.toString

	override def toString: String = s"{BoldSegment: text = $text}"
	}

	private class ItalicSegment(parent: Segment, text: String) extends TextSegment(parent, text) {
	override protected def format = EnumChatFormatting.ITALIC.toString

	override def toString: String = s"{ItalicSegment: text = $text}"
	}

	private class StrikethroughSegment(parent: Segment, text: String) extends TextSegment(parent, text) {
	override protected def format = EnumChatFormatting.STRIKETHROUGH.toString

	override def toString: String = s"{StrikethroughSegment: text = $text}"
	}

	private class ItemStackSegment(val parent: Segment, val title: String, val stacks: Array[ItemStack]) extends InteractiveSegment {
	final val renderWidth = 32
	final val renderHeight = 32
	final val cycleSpeed = 1000

	override def tooltip: Option[String] = Option(title)

	override def height(indent: Int, maxWidth: Int, renderer: FontRenderer): Int = math.max(lineHeight(renderer), renderHeight + 10 - lineHeight(renderer))

	override def width(indent: Int, maxWidth: Int, renderer: FontRenderer): Int = maxWidth

	override def render(x: Int, y: Int, indent: Int, maxWidth: Int, minY: Int, maxY: Int, renderer: FontRenderer, mouseX: Int, mouseY: Int): Option[InteractiveSegment] = {
	val xOffset = (maxWidth - renderWidth) / 2
	val yOffset = 4 + (if (indent > 0) lineHeight(renderer) else 0)
	val maskLow = math.max(minY - y - yOffset - 1, 0)
	val maskHigh = math.max(maskLow, math.min(renderHeight, maxY - 3))
	val mc = Minecraft.getMinecraft
	val index = (System.currentTimeMillis() % (cycleSpeed * stacks.length)).toInt / cycleSpeed
	val stack = stacks(index)

	GL11.glPushMatrix()
	GL11.glTranslatef(x + xOffset, y + yOffset, 0)

	GL11.glColor4f(0.1f, 0.1f, 0.1f, 1)
	GL11.glTranslatef(0, 0, 400)
	GL11.glDepthFunc(GL11.GL_LEQUAL)
	GL11.glDisable(GL11.GL_TEXTURE_2D)
	GL11.glColorMaterial(GL11.GL_FRONT_AND_BACK, GL11.GL_AMBIENT_AND_DIFFUSE)
	GL11.glEnable(GL11.GL_COLOR_MATERIAL)
	GL11.glDepthMask(true)
	GL11.glColorMask(false, false, false, false)
	GL11.glBegin(GL11.GL_QUADS)
	GL11.glVertex2f(0, maskLow)
	GL11.glVertex2f(0, maskHigh)
	GL11.glVertex2f(renderWidth, maskHigh)
	GL11.glVertex2f(renderWidth, maskLow)
	GL11.glEnd()
	GL11.glTranslatef(0, 0, -400)
	GL11.glDepthFunc(GL11.GL_GEQUAL)
	GL11.glEnable(GL11.GL_TEXTURE_2D)
	GL11.glDisable(GL11.GL_COLOR_MATERIAL)
	GL11.glDepthMask(false)
	GL11.glColorMask(true, true, true, true)

	GL11.glColor4f(1, 1, 1, 1)
	GL11.glScalef(renderWidth / 16, renderHeight / 16, renderWidth / 16)
	GL11.glEnable(GL12.GL_RESCALE_NORMAL)
	RenderHelper.enableGUIStandardItemLighting()
	OpenGlHelper.setLightmapTextureCoords(OpenGlHelper.lightmapTexUnit, 240, 240)
	RenderItem.getInstance.renderItemAndEffectIntoGUI(renderer, mc.getTextureManager, stack, 0, 0)
	RenderHelper.disableStandardItemLighting()

	GL11.glPopMatrix()
	GL11.glDepthFunc(GL11.GL_EQUAL)

	checkHovered(mouseX, mouseY, x + xOffset, y + yOffset, renderWidth, renderHeight)
	}

	override def toString: String = s"{ItemStackSegment: stacks = $stacks}"
	}

	private class ImageSegment(val parent: Segment, val title: String, val url: String) extends InteractiveSegment {
	val path = if (url.startsWith("/")) url else "doc/img/" + url
	val location = new ResourceLocation(Settings.resourceDomain, path)
	val texture = {
	val manager = Minecraft.getMinecraft.getTextureManager
	manager.getTexture(location) match {
	case image: ImageTexture => image
	case _ =>
	val image = new ImageTexture(location)
	manager.loadTexture(location, image)
	image
	}
	}

	override def tooltip: Option[String] = Option(title)

	override def height(indent: Int, maxWidth: Int, renderer: FontRenderer): Int = math.max(lineHeight(renderer), texture.height + 10 - lineHeight(renderer))

	override def width(indent: Int, maxWidth: Int, renderer: FontRenderer): Int = maxWidth

	override def render(x: Int, y: Int, indent: Int, maxWidth: Int, minY: Int, maxY: Int, renderer: FontRenderer, mouseX: Int, mouseY: Int): Option[InteractiveSegment] = {
	val xOffset = (maxWidth - texture.width) / 2
	val yOffset = 4 + (if (indent > 0) lineHeight(renderer) else 0)
	Minecraft.getMinecraft.getTextureManager.bindTexture(location)
	GL11.glColor4f(1, 1, 1, 1)
	GL11.glBegin(GL11.GL_QUADS)
	GL11.glTexCoord2f(0, 0)
	GL11.glVertex2f(x + xOffset, y + yOffset)
	GL11.glTexCoord2f(0, 1)
	GL11.glVertex2f(x + xOffset, y + yOffset + texture.height)
	GL11.glTexCoord2f(1, 1)
	GL11.glVertex2f(x + xOffset + texture.width, y + yOffset + texture.height)
	GL11.glTexCoord2f(1, 0)
	GL11.glVertex2f(x + xOffset + texture.width, y + yOffset)
	GL11.glEnd()

	checkHovered(mouseX, mouseY, x + xOffset, y + yOffset, texture.width, texture.height)
	}

	override def toString: String = s"{ImageSegment: tooltip = $tooltip, url = $url}"
	}

	private class NewLineSegment extends Segment {
	override protected def parent: Segment = null

	override def height(indent: Int, maxWidth: Int, renderer: FontRenderer): Int = previous match {
	case segment: TextSegment => (lineHeight(renderer) * segment.resolvedScale).toInt
	case _ => lineHeight(renderer)
	}

	override def toString: String = s"{NewLineSegment}"
	}

	private class ImageTexture(val location: ResourceLocation) extends AbstractTexture {
	var width = 0
	var height = 0

	override def loadTexture(manager: IResourceManager): Unit = {
	deleteGlTexture()

	var is: InputStream = null
	try {
	val resource = manager.getResource(location)
	is = resource.getInputStream
	val bi = ImageIO.read(is)
	TextureUtil.uploadTextureImageAllocate(getGlTextureId, bi, false, false)
	width = bi.getWidth
	height = bi.getHeight
	}
	finally {
	Option(is).foreach(_.close())
	}
	}
	}

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

	private def HeaderSegment(s: Segment, m: Regex.Match) = new HeaderSegment(s, m.group(2), m.group(1).length)

	private def LinkSegment(s: Segment, m: Regex.Match) = new LinkSegment(s, m.group(1), m.group(2))

	private def BoldSegment(s: Segment, m: Regex.Match) = new BoldSegment(s, m.group(2))

	private def ItalicSegment(s: Segment, m: Regex.Match) = new ItalicSegment(s, m.group(2))

	private def StrikethroughSegment(s: Segment, m: Regex.Match) = new StrikethroughSegment(s, m.group(1))

	private def ImageSegment(s: Segment, m: Regex.Match) = {
	try {
	if (m.group(2).startsWith("item:")) {
	val desc = m.group(2).stripPrefix("item:")
	val (name, optMeta) = desc.splitAt(desc.lastIndexOf('@'))
	val meta = if (Strings.isNullOrEmpty(optMeta)) 0 else Integer.parseInt(optMeta.drop(1))
	Item.itemRegistry.getObject(name) match {
	case item: Item => new ItemStackSegment(s, m.group(1), Array(new ItemStack(item, 1, meta)))
	case _ => new TextSegment(s, m.group(1))
	}
	}
	else if (m.group(2).startsWith("block:")) {
	val desc = m.group(2).stripPrefix("block:")
	val (name, optMeta) = desc.splitAt(desc.lastIndexOf('@'))
	val meta = if (Strings.isNullOrEmpty(optMeta)) 0 else Integer.parseInt(optMeta.drop(1))
	Block.blockRegistry.getObject(name) match {
	case block: Block => new ItemStackSegment(s, m.group(1), Array(new ItemStack(block, 1, meta)))
	case _ => new TextSegment(s, m.group(1))
	}
	}
	else if (m.group(2).startsWith("oredict:")) {
	val name = m.group(2).stripPrefix("oredict:")
	val stacks = OreDictionary.getOres(name)
	if (stacks != null && stacks.nonEmpty) new ItemStackSegment(s, m.group(1), stacks.toArray(new Array[ItemStack](stacks.size())))
	else new TextSegment(s, m.group(1))
	}
	else new ImageSegment(s, m.group(1), m.group(2))
	}
	catch {
	case t: Throwable => new TextSegment(s, t.getMessage)
	}
	}

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

	private val segmentTypes = Array(
	"""^(#+)\s(.*)""".r -> HeaderSegment _, // headers: # ...
	"""!\[([^\[]*)\]\(([^\)]+)\)""".r -> ImageSegment _, // images: ![...](...)
	"""\[([^\[]+)\]\(([^\)]+)\)""".r -> LinkSegment _, // links: [...](...)
	"""(\\\|__)(\S.?\S\|$)\1""".r -> BoldSegment _, // bold: ...* \| __...__
	"""(\\|_)(\S.?\S\|$)\1""".r -> ItalicSegment _, // italic: ... \| _..._
	"""~~(\S.*?\S\|$)~~""".r -> StrikethroughSegment _ // strikethrough: ~~...~~
	)
	}