Function boxIntersectIter

stackgl_modules/index.js:6754–7079

(
  d, visit, initFull,
  xSize, xBoxes, xIndex,
  ySize, yBoxes, yIndex)

//The main box intersection routine
function boxIntersectIter(
  d, visit, initFull,
  xSize, xBoxes, xIndex,
  ySize, yBoxes, yIndex) {

  //Reserve memory for stack
  iterInit(d, xSize + ySize)

  var top  = 0
  var elemSize = 2 * d
  var retval

  iterPush(top++,
      0,
      0, xSize,
      0, ySize,
      initFull ? 16 : 0,
      -Infinity, Infinity)
  if(!initFull) {
    iterPush(top++,
      0,
      0, ySize,
      0, xSize,
      1,
      -Infinity, Infinity)
  }

  while(top > 0) {
    top  -= 1

    var iptr = top * IFRAME_SIZE
    var axis      = BOX_ISTACK[iptr]
    var redStart  = BOX_ISTACK[iptr+1]
    var redEnd    = BOX_ISTACK[iptr+2]
    var blueStart = BOX_ISTACK[iptr+3]
    var blueEnd   = BOX_ISTACK[iptr+4]
    var state     = BOX_ISTACK[iptr+5]

    var dptr = top * DFRAME_SIZE
    var lo        = BOX_DSTACK[dptr]
    var hi        = BOX_DSTACK[dptr+1]

    //Unpack state info
    var flip      = (state & 1)
    var full      = !!(state & 16)

    //Unpack indices
    var red       = xBoxes
    var redIndex  = xIndex
    var blue      = yBoxes
    var blueIndex = yIndex
    if(flip) {
      red         = yBoxes
      redIndex    = yIndex
      blue        = xBoxes
      blueIndex   = xIndex
    }