/* $Id: tif_next.c,v 1.8 2006/10/12 15:00:49 dron Exp $ *//* * 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 intNeXTDecode(TIFF* tif, tidata_t buf, tsize_t occ, tsample_t s){	unsigned char *bp, *op;	tsize_t cc;	tidata_t row;	tsize_t scanline, n;	(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; 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: {			tsize_t 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: {			uint32 npixels = 0, grey;			uint32 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;				/*				 * Ensure the run does not exceed the scanline				 * bounds, potentially resulting in a security				 * issue.				 */				while (n-- > 0 && npixels < imagewidth)					SETPIXEL(op, grey);				if (npixels >= 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);}intTIFFInitNeXT(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: */