/* $Id: tif_read.c,v 1.16.2.3 2010-06-09 14:32:47 bfriesen 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.

 */

/*

 * TIFF Library.

 * Scanline-oriented Read Support

 */

#include "tiffiop.h"

#include <stdio.h>

	int TIFFFillStrip(TIFF*, tstrip_t);

	int TIFFFillTile(TIFF*, ttile_t);

static	int TIFFStartStrip(TIFF*, tstrip_t);

static	int TIFFStartTile(TIFF*, ttile_t);

static	int TIFFCheckRead(TIFF*, int);

#define	NOSTRIP	((tstrip_t) -1)			/* undefined state */

#define	NOTILE	((ttile_t) -1)			/* undefined state */

/*

 * Seek to a random row+sample in a file.

 */

static int

TIFFSeek(TIFF* tif, uint32 row, tsample_t sample)

{

	register TIFFDirectory *td = &tif->tif_dir;

	tstrip_t strip;

	if (row >= td->td_imagelength) {	/* out of range */

		TIFFErrorExt(tif->tif_clientdata, tif->tif_name,

			     "%lu: Row out of range, max %lu",

			     (unsigned long) row,

			     (unsigned long) td->td_imagelength);

		return (0);

	}

	if (td->td_planarconfig == PLANARCONFIG_SEPARATE) {

		if (sample >= td->td_samplesperpixel) {

			TIFFErrorExt(tif->tif_clientdata, tif->tif_name,

			    "%lu: Sample out of range, max %lu",

			    (unsigned long) sample, (unsigned long) td->td_samplesperpixel);

			return (0);

		}

		strip = sample*td->td_stripsperimage + row/td->td_rowsperstrip;

	} else

		strip = row / td->td_rowsperstrip;

	if (strip != tif->tif_curstrip) {	/* different strip, refill */

		if (!TIFFFillStrip(tif, strip))

			return (0);

	} else if (row < tif->tif_row) {

		/*

		 * Moving backwards within the same strip: backup

		 * to the start and then decode forward (below).

		 *

		 * NB: If you're planning on lots of random access within a

		 * strip, it's better to just read and decode the entire

		 * strip, and then access the decoded data in a random fashion.

		 */

		if (!TIFFStartStrip(tif, strip))

			return (0);

	}

	if (row != tif->tif_row) {

		/*

		 * Seek forward to the desired row.

		 */

		if (!(*tif->tif_seek)(tif, row - tif->tif_row))

			return (0);

		tif->tif_row = row;

	}

	return (1);

}

int

TIFFReadScanline(TIFF* tif, tdata_t buf, uint32 row, tsample_t sample)

{

	int e;

	if (!TIFFCheckRead(tif, 0))

		return (-1);

	if( (e = TIFFSeek(tif, row, sample)) != 0) {

		/*

		 * Decompress desired row into user buffer.

		 */

		e = (*tif->tif_decoderow)

		    (tif, (tidata_t) buf, tif->tif_scanlinesize, sample);

		/* we are now poised at the beginning of the next row */

		tif->tif_row = row + 1;

		if (e)

			(*tif->tif_postdecode)(tif, (tidata_t) buf,

			    tif->tif_scanlinesize);

	}

	return (e > 0 ? 1 : -1);

}

/*

 * Read a strip of data and decompress the specified

 * amount into the user-supplied buffer.

 */

tsize_t

TIFFReadEncodedStrip(TIFF* tif, tstrip_t strip, tdata_t buf, tsize_t size)

{

	TIFFDirectory *td = &tif->tif_dir;

	uint32 nrows;

	tsize_t stripsize;

        tstrip_t sep_strip, strips_per_sep;

	if (!TIFFCheckRead(tif, 0))

		return (-1);

	if (strip >= td->td_nstrips) {

		TIFFErrorExt(tif->tif_clientdata, tif->tif_name,

			     "%ld: Strip out of range, max %ld",

			     (long) strip, (long) td->td_nstrips);

		return (-1);

	}

	/*

	 * Calculate the strip size according to the number of

	 * rows in the strip (check for truncated last strip on any

	 * of the separations).

	 */

	if( td->td_rowsperstrip >= td->td_imagelength )

		strips_per_sep = 1;

	else

		strips_per_sep = (td->td_imagelength+td->td_rowsperstrip-1)

		    / td->td_rowsperstrip;

	sep_strip = strip % strips_per_sep;

	if (sep_strip != strips_per_sep-1 ||

	    (nrows = td->td_imagelength % td->td_rowsperstrip) == 0)

		nrows = td->td_rowsperstrip;

	stripsize = TIFFVStripSize(tif, nrows);

	if (size == (tsize_t) -1)

		size = stripsize;

	else if (size > stripsize)

		size = stripsize;

	if (TIFFFillStrip(tif, strip)

	    && (*tif->tif_decodestrip)(tif, (tidata_t) buf, size,   

	    (tsample_t)(strip / td->td_stripsperimage)) > 0 ) {

		(*tif->tif_postdecode)(tif, (tidata_t) buf, size);

		return (size);

	} else

		return ((tsize_t) -1);

}

static tsize_t

TIFFReadRawStrip1(TIFF* tif,

    tstrip_t strip, tdata_t buf, tsize_t size, const char* module)

{

	TIFFDirectory *td = &tif->tif_dir;

	assert((tif->tif_flags&TIFF_NOREADRAW)==0);

	if (!isMapped(tif)) {

		tsize_t cc;

		if (!SeekOK(tif, td->td_stripoffset[strip])) {

			TIFFErrorExt(tif->tif_clientdata, module,

			    "%s: Seek error at scanline %lu, strip %lu",

			    tif->tif_name,

			    (unsigned long) tif->tif_row, (unsigned long) strip);

			return (-1);

		}

		cc = TIFFReadFile(tif, buf, size);

		if (cc != size) {

			TIFFErrorExt(tif->tif_clientdata, module,

		"%s: Read error at scanline %lu; got %lu bytes, expected %lu",

			    tif->tif_name,

			    (unsigned long) tif->tif_row,

			    (unsigned long) cc,

			    (unsigned long) size);

			return (-1);

		}

	} else {

		if (td->td_stripoffset[strip] + size > tif->tif_size) {

			TIFFErrorExt(tif->tif_clientdata, module,

    "%s: Read error at scanline %lu, strip %lu; got %lu bytes, expected %lu",

			    tif->tif_name,

			    (unsigned long) tif->tif_row,

			    (unsigned long) strip,

			    (unsigned long) tif->tif_size - td->td_stripoffset[strip],

			    (unsigned long) size);

			return (-1);

		}

		_TIFFmemcpy(buf, tif->tif_base + td->td_stripoffset[strip],

                            size);

	}

	return (size);

}

/*

 * Read a strip of data from the file.

 */

tsize_t

TIFFReadRawStrip(TIFF* tif, tstrip_t strip, tdata_t buf, tsize_t size)

{

	static const char module[] = "TIFFReadRawStrip";

	TIFFDirectory *td = &tif->tif_dir;

	/*

	 * FIXME: butecount should have tsize_t type, but for now libtiff

	 * defines tsize_t as a signed 32-bit integer and we are losing

	 * ability to read arrays larger than 2^31 bytes. So we are using

	 * uint32 instead of tsize_t here.

	 */

	uint32 bytecount;

	if (!TIFFCheckRead(tif, 0))

		return ((tsize_t) -1);

	if (strip >= td->td_nstrips) {

		TIFFErrorExt(tif->tif_clientdata, tif->tif_name,

			     "%lu: Strip out of range, max %lu",

			     (unsigned long) strip,

			     (unsigned long) td->td_nstrips);

		return ((tsize_t) -1);

	}

	if (tif->tif_flags&TIFF_NOREADRAW)

	{

		TIFFErrorExt(tif->tif_clientdata, tif->tif_name,

	"Compression scheme does not support access to raw uncompressed data");

		return ((tsize_t) -1);

	}

	bytecount = td->td_stripbytecount[strip];

	if (bytecount <= 0) {

		TIFFErrorExt(tif->tif_clientdata, tif->tif_name,

		    "%lu: Invalid strip byte count, strip %lu",

		    (unsigned long) bytecount, (unsigned long) strip);

		return ((tsize_t) -1);

	}

	if (size != (tsize_t)-1 && (uint32)size < bytecount)

		bytecount = size;

	return (TIFFReadRawStrip1(tif, strip, buf, bytecount, module));

}

/*

 * Read the specified strip and setup for decoding. The data buffer is

 * expanded, as necessary, to hold the strip's data.

 */

int

TIFFFillStrip(TIFF* tif, tstrip_t strip)

{

	static const char module[] = "TIFFFillStrip";

	TIFFDirectory *td = &tif->tif_dir;

	if ((tif->tif_flags&TIFF_NOREADRAW)==0)

	{

		/*

		 * FIXME: butecount should have tsize_t type, but for now

		 * libtiff defines tsize_t as a signed 32-bit integer and we

		 * are losing ability to read arrays larger than 2^31 bytes.

		 * So we are using uint32 instead of tsize_t here.

		 */

		uint32 bytecount = td->td_stripbytecount[strip];

		if (bytecount <= 0) {

			TIFFErrorExt(tif->tif_clientdata, module,

			    "%s: Invalid strip byte count %lu, strip %lu",

			    tif->tif_name, (unsigned long) bytecount,

			    (unsigned long) strip);

			return (0);

		}

		if (isMapped(tif) &&

		    (isFillOrder(tif, td->td_fillorder)

		    || (tif->tif_flags & TIFF_NOBITREV))) {

			/*

			 * The image is mapped into memory and we either don't

			 * need to flip bits or the compression routine is

			 * going to handle this operation itself.  In this

			 * case, avoid copying the raw data and instead just

			 * reference the data from the memory mapped file

			 * image.  This assumes that the decompression

			 * routines do not modify the contents of the raw data

			 * buffer (if they try to, the application will get a

			 * fault since the file is mapped read-only).

			 */

			if ((tif->tif_flags & TIFF_MYBUFFER) && tif->tif_rawdata)

				_TIFFfree(tif->tif_rawdata);

			tif->tif_flags &= ~TIFF_MYBUFFER;

			/*

			 * We must check for overflow, potentially causing

			 * an OOB read. Instead of simple

			 *

			 *  td->td_stripoffset[strip]+bytecount > tif->tif_size

			 *

			 * comparison (which can overflow) we do the following

			 * two comparisons:

			 */

			if (bytecount > tif->tif_size ||

			    td->td_stripoffset[strip] > tif->tif_size - bytecount) {

				/*

				 * This error message might seem strange, but

				 * it's what would happen if a read were done

				 * instead.

				 */

				TIFFErrorExt(tif->tif_clientdata, module,

					"%s: Read error on strip %lu; "

					"got %lu bytes, expected %lu",

					tif->tif_name, (unsigned long) strip,

					(unsigned long) tif->tif_size - td->td_stripoffset[strip],

					(unsigned long) bytecount);

				tif->tif_curstrip = NOSTRIP;

				return (0);

			}

			tif->tif_rawdatasize = bytecount;

			tif->tif_rawdata = tif->tif_base + td->td_stripoffset[strip];

		} else {

			/*

			 * Expand raw data buffer, if needed, to hold data

			 * strip coming from file (perhaps should set upper

			 * bound on the size of a buffer we'll use?).

			 */

			if (bytecount > (uint32)tif->tif_rawdatasize) {

				tif->tif_curstrip = NOSTRIP;

				if ((tif->tif_flags & TIFF_MYBUFFER) == 0) {

					TIFFErrorExt(tif->tif_clientdata,

						     module,

				"%s: Data buffer too small to hold strip %lu",

						     tif->tif_name,

						     (unsigned long) strip);

					return (0);

				}

				if (!TIFFReadBufferSetup(tif, 0,

				    TIFFroundup(bytecount, 1024)))

					return (0);

			}

			if ((uint32)TIFFReadRawStrip1(tif, strip,

				(unsigned char *)tif->tif_rawdata,

				bytecount, module) != bytecount)

				return (0);

			if (!isFillOrder(tif, td->td_fillorder) &&

			    (tif->tif_flags & TIFF_NOBITREV) == 0)

				TIFFReverseBits(tif->tif_rawdata, bytecount);

		}

	}

	return (TIFFStartStrip(tif, strip));

}

/*

 * Tile-oriented Read Support

 * Contributed by Nancy Cam (Silicon Graphics).

 */

/*

 * Read and decompress a tile of data.  The

 * tile is selected by the (x,y,z,s) coordinates.

 */

tsize_t

TIFFReadTile(TIFF* tif,

    tdata_t buf, uint32 x, uint32 y, uint32 z, tsample_t s)

{

	if (!TIFFCheckRead(tif, 1) || !TIFFCheckTile(tif, x, y, z, s))

		return (-1);

	return (TIFFReadEncodedTile(tif,

	    TIFFComputeTile(tif, x, y, z, s), buf, (tsize_t) -1));

}

/*

 * Read a tile of data and decompress the specified

 * amount into the user-supplied buffer.

 */

tsize_t

TIFFReadEncodedTile(TIFF* tif, ttile_t tile, tdata_t buf, tsize_t size)

{

	TIFFDirectory *td = &tif->tif_dir;

	tsize_t tilesize = tif->tif_tilesize;

	if (!TIFFCheckRead(tif, 1))

		return (-1);

	if (tile >= td->td_nstrips) {

		TIFFErrorExt(tif->tif_clientdata, tif->tif_name,

			     "%ld: Tile out of range, max %ld",

			     (long) tile, (unsigned long) td->td_nstrips);

		return (-1);

	}

	if (size == (tsize_t) -1)

		size = tilesize;

	else if (size > tilesize)

		size = tilesize;

	if (TIFFFillTile(tif, tile) && (*tif->tif_decodetile)(tif,

	    (tidata_t) buf, size, (tsample_t)(tile/td->td_stripsperimage))) {

		(*tif->tif_postdecode)(tif, (tidata_t) buf, size);

		return (size);

	} else

		return (-1);

}

static tsize_t

TIFFReadRawTile1(TIFF* tif,

    ttile_t tile, tdata_t buf, tsize_t size, const char* module)

{

	TIFFDirectory *td = &tif->tif_dir;

	assert((tif->tif_flags&TIFF_NOREADRAW)==0);

	if (!isMapped(tif)) {

		tsize_t cc;

		if (!SeekOK(tif, td->td_stripoffset[tile])) {

			TIFFErrorExt(tif->tif_clientdata, module,

			    "%s: Seek error at row %ld, col %ld, tile %ld",

			    tif->tif_name,

			    (long) tif->tif_row,

			    (long) tif->tif_col,

			    (long) tile);

			return ((tsize_t) -1);

		}

		cc = TIFFReadFile(tif, buf, size);

		if (cc != size) {

			TIFFErrorExt(tif->tif_clientdata, module,

	    "%s: Read error at row %ld, col %ld; got %lu bytes, expected %lu",

			    tif->tif_name,

			    (long) tif->tif_row,

			    (long) tif->tif_col,

			    (unsigned long) cc,

			    (unsigned long) size);

			return ((tsize_t) -1);

		}

	} else {

		if (td->td_stripoffset[tile] + size > tif->tif_size) {

			TIFFErrorExt(tif->tif_clientdata, module,

    "%s: Read error at row %ld, col %ld, tile %ld; got %lu bytes, expected %lu",

			    tif->tif_name,

			    (long) tif->tif_row,

			    (long) tif->tif_col,

			    (long) tile,

			    (unsigned long) tif->tif_size - td->td_stripoffset[tile],

			    (unsigned long) size);

			return ((tsize_t) -1);

		}

		_TIFFmemcpy(buf, tif->tif_base + td->td_stripoffset[tile], size);

	}

	return (size);

}

/*

 * Read a tile of data from the file.

 */

tsize_t

TIFFReadRawTile(TIFF* tif, ttile_t tile, tdata_t buf, tsize_t size)

{

	static const char module[] = "TIFFReadRawTile";

	TIFFDirectory *td = &tif->tif_dir;

	/*

	 * FIXME: butecount should have tsize_t type, but for now libtiff

	 * defines tsize_t as a signed 32-bit integer and we are losing

	 * ability to read arrays larger than 2^31 bytes. So we are using

	 * uint32 instead of tsize_t here.

	 */

	uint32 bytecount;

	if (!TIFFCheckRead(tif, 1))

		return ((tsize_t) -1);

	if (tile >= td->td_nstrips) {

		TIFFErrorExt(tif->tif_clientdata, tif->tif_name,

			     "%lu: Tile out of range, max %lu",

		    (unsigned long) tile, (unsigned long) td->td_nstrips);

		return ((tsize_t) -1);

	}

	if (tif->tif_flags&TIFF_NOREADRAW)

	{

		TIFFErrorExt(tif->tif_clientdata, tif->tif_name,

	"Compression scheme does not support access to raw uncompressed data");

		return ((tsize_t) -1);

	}

	bytecount = td->td_stripbytecount[tile];

	if (size != (tsize_t) -1 && (uint32)size < bytecount)

		bytecount = size;

	return (TIFFReadRawTile1(tif, tile, buf, bytecount, module));

}

/*

 * Read the specified tile and setup for decoding. The data buffer is

 * expanded, as necessary, to hold the tile's data.

 */

int

TIFFFillTile(TIFF* tif, ttile_t tile)

{

	static const char module[] = "TIFFFillTile";

	TIFFDirectory *td = &tif->tif_dir;

	if ((tif->tif_flags&TIFF_NOREADRAW)==0)

	{

		/*

		 * FIXME: butecount should have tsize_t type, but for now

		 * libtiff defines tsize_t as a signed 32-bit integer and we

		 * are losing ability to read arrays larger than 2^31 bytes.

		 * So we are using uint32 instead of tsize_t here.

		 */

		uint32 bytecount = td->td_stripbytecount[tile];

		if (bytecount <= 0) {

			TIFFErrorExt(tif->tif_clientdata, tif->tif_name,

			    "%lu: Invalid tile byte count, tile %lu",

			    (unsigned long) bytecount, (unsigned long) tile);

			return (0);

		}

		if (isMapped(tif) &&

		    (isFillOrder(tif, td->td_fillorder)

		     || (tif->tif_flags & TIFF_NOBITREV))) {

			/*

			 * The image is mapped into memory and we either don't

			 * need to flip bits or the compression routine is

			 * going to handle this operation itself.  In this

			 * case, avoid copying the raw data and instead just

			 * reference the data from the memory mapped file

			 * image.  This assumes that the decompression

			 * routines do not modify the contents of the raw data

			 * buffer (if they try to, the application will get a

			 * fault since the file is mapped read-only).

			 */

			if ((tif->tif_flags & TIFF_MYBUFFER) && tif->tif_rawdata)

				_TIFFfree(tif->tif_rawdata);

			tif->tif_flags &= ~TIFF_MYBUFFER;

			/*

			 * We must check for overflow, potentially causing

			 * an OOB read. Instead of simple

			 *

			 *  td->td_stripoffset[tile]+bytecount > tif->tif_size

			 *

			 * comparison (which can overflow) we do the following

			 * two comparisons:

			 */

			if (bytecount > tif->tif_size ||

			    td->td_stripoffset[tile] > tif->tif_size - bytecount) {

				tif->tif_curtile = NOTILE;

				return (0);

			}

			tif->tif_rawdatasize = bytecount;

			tif->tif_rawdata =

				tif->tif_base + td->td_stripoffset[tile];

		} else {

			/*

			 * Expand raw data buffer, if needed, to hold data

			 * tile coming from file (perhaps should set upper

			 * bound on the size of a buffer we'll use?).

			 */

			if (bytecount > (uint32)tif->tif_rawdatasize) {

				tif->tif_curtile = NOTILE;

				if ((tif->tif_flags & TIFF_MYBUFFER) == 0) {

					TIFFErrorExt(tif->tif_clientdata,

						     module,

				"%s: Data buffer too small to hold tile %ld",

						     tif->tif_name,

						     (long) tile);

					return (0);

				}

				if (!TIFFReadBufferSetup(tif, 0,

				    TIFFroundup(bytecount, 1024)))

					return (0);

			}

			if ((uint32)TIFFReadRawTile1(tif, tile,

				(unsigned char *)tif->tif_rawdata,

				bytecount, module) != bytecount)

				return (0);

			if (!isFillOrder(tif, td->td_fillorder) &&

			    (tif->tif_flags & TIFF_NOBITREV) == 0)

				TIFFReverseBits(tif->tif_rawdata, bytecount);

		}

	}

	return (TIFFStartTile(tif, tile));

}

/*

 * Setup the raw data buffer in preparation for

 * reading a strip of raw data.  If the buffer

 * is specified as zero, then a buffer of appropriate

 * size is allocated by the library.  Otherwise,

 * the client must guarantee that the buffer is

 * large enough to hold any individual strip of

 * raw data.

 */

int

TIFFReadBufferSetup(TIFF* tif, tdata_t bp, tsize_t size)

{

	static const char module[] = "TIFFReadBufferSetup";

	assert((tif->tif_flags&TIFF_NOREADRAW)==0);

	if (tif->tif_rawdata) {

		if (tif->tif_flags & TIFF_MYBUFFER)

			_TIFFfree(tif->tif_rawdata);

		tif->tif_rawdata = NULL;

	}

	if (bp) {

		tif->tif_rawdatasize = size;

		tif->tif_rawdata = (tidata_t) bp;

		tif->tif_flags &= ~TIFF_MYBUFFER;

	} else {

		tif->tif_rawdatasize = TIFFroundup(size, 1024);

		if (tif->tif_rawdatasize > 0)

			tif->tif_rawdata = (tidata_t) _TIFFmalloc(tif->tif_rawdatasize);

		tif->tif_flags |= TIFF_MYBUFFER;

	}

	if ((tif->tif_rawdata == NULL) || (tif->tif_rawdatasize == 0)) {

		TIFFErrorExt(tif->tif_clientdata, module,

		    "%s: No space for data buffer at scanline %ld",

		    tif->tif_name, (long) tif->tif_row);

		tif->tif_rawdatasize = 0;

		return (0);

	}

	return (1);

}

/*

 * Set state to appear as if a

 * strip has just been read in.

 */

static int

TIFFStartStrip(TIFF* tif, tstrip_t strip)

{

	TIFFDirectory *td = &tif->tif_dir;

	if ((tif->tif_flags & TIFF_CODERSETUP) == 0) {

		if (!(*tif->tif_setupdecode)(tif))

			return (0);

		tif->tif_flags |= TIFF_CODERSETUP;

	}

	tif->tif_curstrip = strip;

	tif->tif_row = (strip % td->td_stripsperimage) * td->td_rowsperstrip;

	if (tif->tif_flags&TIFF_NOREADRAW)

	{

		tif->tif_rawcp = NULL;

		tif->tif_rawcc = 0;

	}

	else

	{

		tif->tif_rawcp = tif->tif_rawdata;

		tif->tif_rawcc = td->td_stripbytecount[strip];

	}

	return ((*tif->tif_predecode)(tif,

			(tsample_t)(strip / td->td_stripsperimage)));

}

/*

 * Set state to appear as if a

 * tile has just been read in.

 */

static int

TIFFStartTile(TIFF* tif, ttile_t tile)

{

	TIFFDirectory *td = &tif->tif_dir;

	if ((tif->tif_flags & TIFF_CODERSETUP) == 0) {

		if (!(*tif->tif_setupdecode)(tif))

			return (0);

		tif->tif_flags |= TIFF_CODERSETUP;

	}

	tif->tif_curtile = tile;

	tif->tif_row =

	    (tile % TIFFhowmany(td->td_imagewidth, td->td_tilewidth)) *

		td->td_tilelength;

	tif->tif_col =

	    (tile % TIFFhowmany(td->td_imagelength, td->td_tilelength)) *

		td->td_tilewidth;

	if (tif->tif_flags&TIFF_NOREADRAW)

	{

		tif->tif_rawcp = NULL;

		tif->tif_rawcc = 0;

	}

	else

	{

		tif->tif_rawcp = tif->tif_rawdata;

		tif->tif_rawcc = td->td_stripbytecount[tile];

	}

	return ((*tif->tif_predecode)(tif,

			(tsample_t)(tile/td->td_stripsperimage)));

}

static int

TIFFCheckRead(TIFF* tif, int tiles)

{

	if (tif->tif_mode == O_WRONLY) {

		TIFFErrorExt(tif->tif_clientdata, tif->tif_name, "File not open for reading");

		return (0);

	}

	if (tiles ^ isTiled(tif)) {

		TIFFErrorExt(tif->tif_clientdata, tif->tif_name, tiles ?

		    "Can not read tiles from a stripped image" :

		    "Can not read scanlines from a tiled image");

		return (0);

	}

	return (1);

}

void

_TIFFNoPostDecode(TIFF* tif, tidata_t buf, tsize_t cc)

{

    (void) tif; (void) buf; (void) cc;

}

void

_TIFFSwab16BitData(TIFF* tif, tidata_t buf, tsize_t cc)

{

    (void) tif;

    assert((cc & 1) == 0);

    TIFFSwabArrayOfShort((uint16*) buf, cc/2);

}

void

_TIFFSwab24BitData(TIFF* tif, tidata_t buf, tsize_t cc)

{

    (void) tif;

    assert((cc % 3) == 0);

    TIFFSwabArrayOfTriples((uint8*) buf, cc/3);

}

void

_TIFFSwab32BitData(TIFF* tif, tidata_t buf, tsize_t cc)

{

    (void) tif;

    assert((cc & 3) == 0);

    TIFFSwabArrayOfLong((uint32*) buf, cc/4);

}

void

_TIFFSwab64BitData(TIFF* tif, tidata_t buf, tsize_t cc)

{

    (void) tif;

    assert((cc & 7) == 0);

    TIFFSwabArrayOfDouble((double*) buf, cc/8);

}

/* vim: set ts=8 sts=8 sw=8 noet: */

/*

 * Local Variables:

 * mode: c

 * c-basic-offset: 8

 * fill-column: 78

 * End:

 */