xref: /third_party/backends/backend/plustek-pp_scale.c

/* @file plustek-pp_scale.c
 * @brief Scaling functionality
 *
 * Copyright (C) 2000-2004 Gerhard Jaeger <gerhard@gjaeger.de>
 *
 * History:
 * - 0.32 - initial version
 * - 0.33 - no changes
 * - 0.34 - no changes
 * - 0.35 - no changes
 * - 0.36 - no changes
 * - 0.37 - no changes
 * - 0.38 - no changes
 * - 0.39 - no changes
 * - 0.40 - no changes
 * - 0.41 - no changes
 * - 0.42 - changed include names
 * - 0.43 - cleanup, removed floating point stuff
 * .
 * <hr>
 * This file is part of the SANE package.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License as
 * published by the Free Software Foundation; either version 2 of the
 * License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <https://www.gnu.org/licenses/>.
 *
 * As a special exception, the authors of SANE give permission for
 * additional uses of the libraries contained in this release of SANE.
 *
 * The exception is that, if you link a SANE library with other files
 * to produce an executable, this does not by itself cause the
 * resulting executable to be covered by the GNU General Public
 * License.  Your use of that executable is in no way restricted on
 * account of linking the SANE library code into it.
 *
 * This exception does not, however, invalidate any other reasons why
 * the executable file might be covered by the GNU General Public
 * License.
 *
 * If you submit changes to SANE to the maintainers to be included in
 * a subsequent release, you agree by submitting the changes that
 * those changes may be distributed with this exception intact.
 *
 * If you write modifications of your own for SANE, it is your choice
 * whether to permit this exception to apply to your modifications.
 * If you do not wish that, delete this exception notice.
 * <hr>
 */
#include "plustek-pp_scan.h"

/************************ exported functions *********************************/

/** scaling picture data in x-direction, using a DDA algo
 *  (digital differential analyzer).
 */
_LOC void ScaleX( pScanData ps, pUChar inBuf, pUChar outBuf )
{
	UChar tmp;
	int   step;
	int   izoom;
	int   ddax;
	register ULong i, j, x;

#ifdef DEBUG
	_VAR_NOT_USED( dbg_level );
#endif

	/* scale... */
	izoom = (int)(1000000/ps->DataInf.XYRatio);

	switch( ps->DataInf.wAppDataType ) {

	case COLOR_BW      : step = 0;  break;
	case COLOR_HALFTONE: step = 0;  break;
	case COLOR_256GRAY : step = 1;  break;
	case COLOR_TRUE24  : step = 3;  break; /*NOTE: COLOR_TRUE32 is the same !*/
	case COLOR_TRUE48  : step = 6;  break;
	default            : step = 99; break;
	}

	/* when not supported, only copy the data
	 */
	if( 99 == step ) {
		memcpy( outBuf, inBuf, ps->DataInf.dwAppBytesPerLine );
		return;
	}

	/* now scale...
	 */
	ddax = 0;
	x    = 0;
	if( 0 == step ) {

		/* binary scaling
		 */
		memset( outBuf, 0, ps->DataInf.dwAppBytesPerLine );

		for( i = 0; i < ps->DataInf.dwPhysBytesPerLine*8; i++ ) {

			ddax -= 1000;

			while( ddax < 0 ) {

				tmp = inBuf[(i>>3)];

				if((x>>3) < ps->DataInf.dwAppBytesPerLine ) {
					if( 0 != (tmp &= (1 << ((~(i & 0x7))&0x7))))
						outBuf[x>>3] |= (1 << ((~(x & 0x7))&0x7));
				}
				x++;
				ddax += izoom;
			}
		}

	} else {

		/* color and gray scaling
		 */
		for( i = 0; i < ps->DataInf.dwPhysBytesPerLine*step; i+=step ) {

			ddax -= 1000;

			while( ddax < 0 ) {

				for( j = 0; j < (ULong)step; j++ ) {

					if((x+j) < ps->DataInf.dwAppBytesPerLine ) {
						outBuf[x+j] = inBuf[i+j];
					}
				}
				x    += step;
				ddax += izoom;
			}
		}
	}
}

/* END PLUSTEK-PP_SCALE.C ...................................................*/