#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;

}