#include "runsmap.h"

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

void RunsMap::setRunLength(TPixelGR8 *pix, TUINT32 length) {

  TPixelGR8 *origPix = pix;

  pix                = origPix;

  TPixelGR8 *pixRev = pix + length - 1;

  --length;

  if (length < 3)

    pix->value = pixRev->value = (length << 6);

  else {

    pix->value = pixRev->value = (3 << 6);

    ++pix, --pixRev;

    if (length < 255)

      pix->value = pixRev->value = length;

    else {

      pix->value = pixRev->value = 255;

      ++pix, pixRev -= 4;

      TUINT32 *l = (TUINT32 *)pix;

      *l         = length;

    }

  }

  assert(runLength(origPix) == (length + 1));

}

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

TUINT32 RunsMap::runLength(const TPixelGR8 *pix, bool reversed) const {

  int length = pix->value >> 6;

  if (length >= 3) {

    pix += (reversed) ? -1 : 1, length = pix->value;

    if (length >= 255) {

      pix += (reversed) ? -4 : 1;

      length = *(TUINT32 *)pix;

    }

  }

  return length + 1;

}