SVG.BBox = SVG.invent({
  // Initialize
  create: function(element) {
    // get values if element is given
    if (element) {
      var box

      // yes this is ugly, but Firefox can be a bitch when it comes to elements that are not yet rendered
      try {
        // find native bbox
        box = element.node.getBBox()
      } catch(e) {
        if(element instanceof SVG.Shape){
          var clone = element.clone().addTo(SVG.parser.draw)
          box = clone.bbox()
          clone.remove()
        }else{
          box = {
            x:      element.node.clientLeft
          , y:      element.node.clientTop
          , width:  element.node.clientWidth
          , height: element.node.clientHeight
          }
        }
      }
      
      // plain x and y
      this.x = box.x
      this.y = box.y

      // plain width and height
      this.width  = box.width
      this.height = box.height
    }

    // add center, right and bottom
    fullBox(this)
  }

  // Define Parent
, parent: SVG.Element

  // Constructor
, construct: {
    // Get bounding box
    bbox: function() {
      return new SVG.BBox(this)
    }
  }

})

SVG.TBox = SVG.invent({
  // Initialize
  create: function(element) {
    // get values if element is given
    if (element) {
      var t   = element.ctm().extract()
        , box = element.bbox()
      
      // width and height including transformations
      this.width  = box.width  * t.scaleX
      this.height = box.height * t.scaleY

      // x and y including transformations
      this.x = box.x + t.x
      this.y = box.y + t.y
    }

    // add center, right and bottom
    fullBox(this)
  }

  // Define Parent
, parent: SVG.Element

  // Constructor
, construct: {
    // Get transformed bounding box
    tbox: function() {
      return new SVG.TBox(this)
    }
  }

})


SVG.RBox = SVG.invent({
  // Initialize
  create: function(element) {
    if (element) {
      var e    = element.doc().parent()
        , box  = element.node.getBoundingClientRect()
        , zoom = 1
      
      // get screen offset
      this.x = box.left
      this.y = box.top
      
      // subtract parent offset
      this.x -= e.offsetLeft
      this.y -= e.offsetTop
      
      while (e = e.offsetParent) {
        this.x -= e.offsetLeft
        this.y -= e.offsetTop
      }
      
      // calculate cumulative zoom from svg documents
      e = element
      while (e.parent && (e = e.parent())) {
        if (e.viewbox) {
          zoom *= e.viewbox().zoom
          this.x -= e.x() || 0
          this.y -= e.y() || 0
        }
      }

      // recalculate viewbox distortion
      this.width  = box.width  /= zoom
      this.height = box.height /= zoom
    }
    
    // add center, right and bottom
    fullBox(this)

    // offset by window scroll position, because getBoundingClientRect changes when window is scrolled
    this.x += window.pageXOffset
    this.y += window.pageYOffset
  }

  // define Parent
, parent: SVG.Element

  // Constructor
, construct: {
    // Get rect box
    rbox: function() {
      return new SVG.RBox(this)
    }
  }

})

// Add universal merge method
;[SVG.BBox, SVG.TBox, SVG.RBox].forEach(function(c) {

  SVG.extend(c, {
    // Merge rect box with another, return a new instance
    merge: function(box) {
      var b = new c()

      // merge boxes
      b.x      = Math.min(this.x, box.x)
      b.y      = Math.min(this.y, box.y)
      b.width  = Math.max(this.x + this.width,  box.x + box.width)  - b.x
      b.height = Math.max(this.y + this.height, box.y + box.height) - b.y
      
      return fullBox(b)
    }

  })

})