src/tiff/libtiff/tif_next.c

/* $Id$ */

/*
 * Copyright (c) 1988-1997 Sam Leffler
 * Copyright (c) 1991-1997 Silicon Graphics, Inc.
 *
 * Permission to use, copy, modify, distribute, and sell this software and
 * its documentation for any purpose is hereby granted without fee, provided
 * that (i) the above copyright notices and this permission notice appear in
 * all copies of the software and related documentation, and (ii) the names of
 * Sam Leffler and Silicon Graphics may not be used in any advertising or
 * publicity relating to the software without the specific, prior written
 * permission of Sam Leffler and Silicon Graphics.
 *
 * THE SOFTWARE IS PROVIDED "AS-IS" AND WITHOUT WARRANTY OF ANY KIND,
 * EXPRESS, IMPLIED OR OTHERWISE, INCLUDING WITHOUT LIMITATION, ANY
 * WARRANTY OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.
 *
 * IN NO EVENT SHALL SAM LEFFLER OR SILICON GRAPHICS BE LIABLE FOR
 * ANY SPECIAL, INCIDENTAL, INDIRECT OR CONSEQUENTIAL DAMAGES OF ANY KIND,
 * OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS,
 * WHETHER OR NOT ADVISED OF THE POSSIBILITY OF DAMAGE, AND ON ANY THEORY OF
 * LIABILITY, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE
 * OF THIS SOFTWARE.
 */

#include "tiffiop.h"
#ifdef NEXT_SUPPORT
/*
 * TIFF Library.
 *
 * NeXT 2-bit Grey Scale Compression Algorithm Support
 */

#define SETPIXEL(op, v) {			\
	switch (npixels++ & 3) {		\
	case 0:	op[0]  = (unsigned char) ((v) << 6); break;	\
	case 1:	op[0] |= (v) << 4; break;	\
	case 2:	op[0] |= (v) << 2; break;	\
	case 3:	*op++ |= (v);	   break;	\
	}					\
}

#define LITERALROW	0x00
#define LITERALSPAN	0x40
#define WHITE   	((1<<2)-1)

static int
NeXTDecode(TIFF* tif, tidata_t buf, tsize_t occ, tsample_t s)
{
	register unsigned char *bp, *op;
	register tsize_t cc;
	register int n;
	tidata_t row;
	tsize_t scanline;

	(void) s;
	/*
	 * Each scanline is assumed to start off as all
	 * white (we assume a PhotometricInterpretation
	 * of ``min-is-black'').
	 */
	for (op = buf, cc = occ; cc-- > 0;)
		*op++ = 0xff;

	bp = (unsigned char *)tif->tif_rawcp;
	cc = tif->tif_rawcc;
	scanline = tif->tif_scanlinesize;
	for (row = buf; (long)occ > 0; occ -= scanline, row += scanline) {
		n = *bp++, cc--;
		switch (n) {
		case LITERALROW:
			/*
			 * The entire scanline is given as literal values.
			 */
			if (cc < scanline)
				goto bad;
			_TIFFmemcpy(row, bp, scanline);
			bp += scanline;
			cc -= scanline;
			break;
		case LITERALSPAN: {
			int off;
			/*
			 * The scanline has a literal span
			 * that begins at some offset.
			 */
			off = (bp[0] * 256) + bp[1];
			n = (bp[2] * 256) + bp[3];
			if (cc < 4+n || off+n > scanline)
				goto bad;
			_TIFFmemcpy(row+off, bp+4, n);
			bp += 4+n;
			cc -= 4+n;
			break;
		}
		default: {
			register int npixels = 0, grey;
			unsigned long imagewidth = tif->tif_dir.td_imagewidth;

			/*
			 * The scanline is composed of a sequence
			 * of constant color ``runs''.  We shift
			 * into ``run mode'' and interpret bytes
			 * as codes of the form <color><npixels>
			 * until we've filled the scanline.
			 */
			op = row;
			for (;;) {
				grey = (n>>6) & 0x3;
				n &= 0x3f;
				while (n-- > 0)
					SETPIXEL(op, grey);
				if (npixels >= (int) imagewidth)
					break;
				if (cc == 0)
					goto bad;
				n = *bp++, cc--;
			}
			break;
		}
		}
	}
	tif->tif_rawcp = (tidata_t) bp;
	tif->tif_rawcc = cc;
	return (1);
bad:
	TIFFErrorExt(tif->tif_clientdata, tif->tif_name, "NeXTDecode: Not enough data for scanline %ld",
	    (long) tif->tif_row);
	return (0);
}

int
TIFFInitNeXT(TIFF* tif, int scheme)
{
	(void) scheme;
	tif->tif_decoderow = NeXTDecode;
	tif->tif_decodestrip = NeXTDecode;
	tif->tif_decodetile = NeXTDecode;
	return (1);
}
#endif /* NEXT_SUPPORT */

/* vim: set ts=8 sts=8 sw=8 noet: */
Commit	Line	Data
	1	/* $Id$ */
	2
	3	/*
	4	* Copyright (c) 1988-1997 Sam Leffler
	5	* Copyright (c) 1991-1997 Silicon Graphics, Inc.
	6	*
	7	* Permission to use, copy, modify, distribute, and sell this software and
	8	* its documentation for any purpose is hereby granted without fee, provided
	9	* that (i) the above copyright notices and this permission notice appear in
	10	* all copies of the software and related documentation, and (ii) the names of
	11	* Sam Leffler and Silicon Graphics may not be used in any advertising or
	12	* publicity relating to the software without the specific, prior written
	13	* permission of Sam Leffler and Silicon Graphics.
	14	*
	15	* THE SOFTWARE IS PROVIDED "AS-IS" AND WITHOUT WARRANTY OF ANY KIND,
	16	* EXPRESS, IMPLIED OR OTHERWISE, INCLUDING WITHOUT LIMITATION, ANY
	17	* WARRANTY OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.
	18	*
	19	* IN NO EVENT SHALL SAM LEFFLER OR SILICON GRAPHICS BE LIABLE FOR
	20	* ANY SPECIAL, INCIDENTAL, INDIRECT OR CONSEQUENTIAL DAMAGES OF ANY KIND,
	21	* OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS,
	22	* WHETHER OR NOT ADVISED OF THE POSSIBILITY OF DAMAGE, AND ON ANY THEORY OF
	23	* LIABILITY, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE
	24	* OF THIS SOFTWARE.
	25	*/
	26
	27	#include "tiffiop.h"
	28	#ifdef NEXT_SUPPORT
	29	/*
	30	* TIFF Library.
	31	*
	32	* NeXT 2-bit Grey Scale Compression Algorithm Support
	33	*/
	34
	35	#define SETPIXEL(op, v) { \
	36	switch (npixels++ & 3) { \
	37	case 0: op[0] = (unsigned char) ((v) << 6); break; \
	38	case 1: op[0] \|= (v) << 4; break; \
	39	case 2: op[0] \|= (v) << 2; break; \
	40	case 3: *op++ \|= (v); break; \
	41	} \
	42	}
	43
	44	#define LITERALROW 0x00
	45	#define LITERALSPAN 0x40
	46	#define WHITE ((1<<2)-1)
	47
	48	static int
	49	NeXTDecode(TIFF* tif, tidata_t buf, tsize_t occ, tsample_t s)
	50	{
	51	register unsigned char bp, op;
	52	register tsize_t cc;
	53	register int n;
	54	tidata_t row;
	55	tsize_t scanline;
	56
	57	(void) s;
	58	/*
	59	* Each scanline is assumed to start off as all
	60	* white (we assume a PhotometricInterpretation
	61	* of ``min-is-black'').
	62	*/
	63	for (op = buf, cc = occ; cc-- > 0;)
	64	*op++ = 0xff;
	65
	66	bp = (unsigned char *)tif->tif_rawcp;
	67	cc = tif->tif_rawcc;
	68	scanline = tif->tif_scanlinesize;
	69	for (row = buf; (long)occ > 0; occ -= scanline, row += scanline) {
	70	n = *bp++, cc--;
	71	switch (n) {
	72	case LITERALROW:
	73	/*
	74	* The entire scanline is given as literal values.
	75	*/
	76	if (cc < scanline)
	77	goto bad;
	78	_TIFFmemcpy(row, bp, scanline);
	79	bp += scanline;
	80	cc -= scanline;
	81	break;
	82	case LITERALSPAN: {
	83	int off;
	84	/*
	85	* The scanline has a literal span
	86	* that begins at some offset.
	87	*/
	88	off = (bp[0] * 256) + bp[1];
	89	n = (bp[2] * 256) + bp[3];
	90	if (cc < 4+n \|\| off+n > scanline)
	91	goto bad;
	92	_TIFFmemcpy(row+off, bp+4, n);
	93	bp += 4+n;
	94	cc -= 4+n;
	95	break;
	96	}
	97	default: {
	98	register int npixels = 0, grey;
	99	unsigned long imagewidth = tif->tif_dir.td_imagewidth;
	100
	101	/*
	102	* The scanline is composed of a sequence
	103	* of constant color ``runs''. We shift
	104	* into ``run mode'' and interpret bytes
	105	* as codes of the form <color><npixels>
	106	* until we've filled the scanline.
	107	*/
	108	op = row;
	109	for (;;) {
	110	grey = (n>>6) & 0x3;
	111	n &= 0x3f;
	112	while (n-- > 0)
	113	SETPIXEL(op, grey);
	114	if (npixels >= (int) imagewidth)
	115	break;
	116	if (cc == 0)
	117	goto bad;
	118	n = *bp++, cc--;
	119	}
	120	break;
	121	}
	122	}
	123	}
	124	tif->tif_rawcp = (tidata_t) bp;
	125	tif->tif_rawcc = cc;
	126	return (1);
	127	bad:
	128	TIFFErrorExt(tif->tif_clientdata, tif->tif_name, "NeXTDecode: Not enough data for scanline %ld",
	129	(long) tif->tif_row);
	130	return (0);
	131	}
	132
	133	int
	134	TIFFInitNeXT(TIFF* tif, int scheme)
	135	{
	136	(void) scheme;
	137	tif->tif_decoderow = NeXTDecode;
	138	tif->tif_decodestrip = NeXTDecode;
	139	tif->tif_decodetile = NeXTDecode;
	140	return (1);
	141	}
	142	#endif /* NEXT_SUPPORT */
	143
	144	/* vim: set ts=8 sts=8 sw=8 noet: */