tif_write.c

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/* $Id: tif_write.c,v 1.22.2.5 2010-06-08 18:50:43 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 Write Support
 */
#include "tiffiop.h"
#include <stdio.h>

#define STRIPINCR   20      /* expansion factor on strip array */

#define WRITECHECKSTRIPS(tif, module)               \
    (((tif)->tif_flags&TIFF_BEENWRITING) || TIFFWriteCheck((tif),0,module))
#define WRITECHECKTILES(tif, module)                \
    (((tif)->tif_flags&TIFF_BEENWRITING) || TIFFWriteCheck((tif),1,module))
#define BUFFERCHECK(tif)                    \
    ((((tif)->tif_flags & TIFF_BUFFERSETUP) && tif->tif_rawdata) || \
        TIFFWriteBufferSetup((tif), NULL, (tsize_t) -1))

static  int TIFFGrowStrips(TIFF*, int, const char*);
static  int TIFFAppendToStrip(TIFF*, tstrip_t, tidata_t, tsize_t);

int
TIFFWriteScanline(TIFF* tif, tdata_t buf, uint32 row, tsample_t sample)
{
    static const char module[] = "TIFFWriteScanline";
    register TIFFDirectory *td;
    int status, imagegrew = 0;
    tstrip_t strip;

    if (!WRITECHECKSTRIPS(tif, module))
        return (-1);
    /*
     * Handle delayed allocation of data buffer.  This
     * permits it to be sized more intelligently (using
     * directory information).
     */
    if (!BUFFERCHECK(tif))
        return (-1);
    td = &tif->tif_dir;
    /*
     * Extend image length if needed
     * (but only for PlanarConfig=1).
     */
    if (row >= td->td_imagelength) {    /* extend image */
        if (td->td_planarconfig == PLANARCONFIG_SEPARATE) {
            TIFFErrorExt(tif->tif_clientdata, tif->tif_name,
        "Can not change \"ImageLength\" when using separate planes");
            return (-1);
        }
        td->td_imagelength = row+1;
        imagegrew = 1;
    }
    /*
     * Calculate strip and check for crossings.
     */
    if (td->td_planarconfig == PLANARCONFIG_SEPARATE) {
        if (sample >= td->td_samplesperpixel) {
            TIFFErrorExt(tif->tif_clientdata, tif->tif_name,
                "%d: Sample out of range, max %d",
                sample, td->td_samplesperpixel);
            return (-1);
        }
        strip = sample*td->td_stripsperimage + row/td->td_rowsperstrip;
    } else
        strip = row / td->td_rowsperstrip;
    /*
     * Check strip array to make sure there's space. We don't support
     * dynamically growing files that have data organized in separate
     * bitplanes because it's too painful.  In that case we require that
     * the imagelength be set properly before the first write (so that the
     * strips array will be fully allocated above).
     */
    if (strip >= td->td_nstrips && !TIFFGrowStrips(tif, 1, module))
        return (-1);
    if (strip != tif->tif_curstrip) {
        /*
         * Changing strips -- flush any data present.
         */
        if (!TIFFFlushData(tif))
            return (-1);
        tif->tif_curstrip = strip;
        /*
         * Watch out for a growing image.  The value of strips/image
         * will initially be 1 (since it can't be deduced until the
         * imagelength is known).
         */
        if (strip >= td->td_stripsperimage && imagegrew)
            td->td_stripsperimage =
                TIFFhowmany(td->td_imagelength,td->td_rowsperstrip);
        tif->tif_row =
            (strip % td->td_stripsperimage) * td->td_rowsperstrip;
        if ((tif->tif_flags & TIFF_CODERSETUP) == 0) {
            if (!(*tif->tif_setupencode)(tif))
                return (-1);
            tif->tif_flags |= TIFF_CODERSETUP;
        }
        
        tif->tif_rawcc = 0;
        tif->tif_rawcp = tif->tif_rawdata;

        if( td->td_stripbytecount[strip] > 0 )
        {
            /* if we are writing over existing tiles, zero length */
            td->td_stripbytecount[strip] = 0;

            /* this forces TIFFAppendToStrip() to do a seek */
            tif->tif_curoff = 0;
        }

        if (!(*tif->tif_preencode)(tif, sample))
            return (-1);
        tif->tif_flags |= TIFF_POSTENCODE;
    }
    /*
     * Ensure the write is either sequential or at the
     * beginning of a strip (or that we can randomly
     * access the data -- i.e. no encoding).
     */
    if (row != tif->tif_row) {
        if (row < tif->tif_row) {
            /*
             * Moving backwards within the same strip:
             * backup to the start and then decode
             * forward (below).
             */
            tif->tif_row = (strip % td->td_stripsperimage) *
                td->td_rowsperstrip;
            tif->tif_rawcp = tif->tif_rawdata;
        }
        /*
         * Seek forward to the desired row.
         */
        if (!(*tif->tif_seek)(tif, row - tif->tif_row))
            return (-1);
        tif->tif_row = row;
    }

        /* swab if needed - note that source buffer will be altered */
        tif->tif_postdecode( tif, (tidata_t) buf, tif->tif_scanlinesize );

    status = (*tif->tif_encoderow)(tif, (tidata_t) buf,
        tif->tif_scanlinesize, sample);

        /* we are now poised at the beginning of the next row */
    tif->tif_row = row + 1;
    return (status);
}

/*
 * Encode the supplied data and write it to the
 * specified strip.
 *
 * NB: Image length must be setup before writing.
 */
tsize_t
TIFFWriteEncodedStrip(TIFF* tif, tstrip_t strip, tdata_t data, tsize_t cc)
{
    static const char module[] = "TIFFWriteEncodedStrip";
    TIFFDirectory *td = &tif->tif_dir;
    tsample_t sample;

    if (!WRITECHECKSTRIPS(tif, module))
        return ((tsize_t) -1);
    /*
     * Check strip array to make sure there's space.
     * We don't support dynamically growing files that
     * have data organized in separate bitplanes because
     * it's too painful.  In that case we require that
     * the imagelength be set properly before the first
     * write (so that the strips array will be fully
     * allocated above).
     */
    if (strip >= td->td_nstrips) {
        if (td->td_planarconfig == PLANARCONFIG_SEPARATE) {
            TIFFErrorExt(tif->tif_clientdata, tif->tif_name,
        "Can not grow image by strips when using separate planes");
            return ((tsize_t) -1);
        }
        if (!TIFFGrowStrips(tif, 1, module))
            return ((tsize_t) -1);
        td->td_stripsperimage =
            TIFFhowmany(td->td_imagelength, td->td_rowsperstrip);
    }
    /*
     * Handle delayed allocation of data buffer.  This
     * permits it to be sized according to the directory
     * info.
     */
    if (!BUFFERCHECK(tif))
        return ((tsize_t) -1);
    tif->tif_curstrip = strip;
    tif->tif_row = (strip % td->td_stripsperimage) * td->td_rowsperstrip;
    if ((tif->tif_flags & TIFF_CODERSETUP) == 0) {
        if (!(*tif->tif_setupencode)(tif))
            return ((tsize_t) -1);
        tif->tif_flags |= TIFF_CODERSETUP;
    }
        
    tif->tif_rawcc = 0;
    tif->tif_rawcp = tif->tif_rawdata;

        if( td->td_stripbytecount[strip] > 0 )
        {
        /* Force TIFFAppendToStrip() to consider placing data at end
               of file. */
            tif->tif_curoff = 0;
        }
        
    tif->tif_flags &= ~TIFF_POSTENCODE;
    sample = (tsample_t)(strip / td->td_stripsperimage);
    if (!(*tif->tif_preencode)(tif, sample))
        return ((tsize_t) -1);

        /* swab if needed - note that source buffer will be altered */
        tif->tif_postdecode( tif, (tidata_t) data, cc );

    if (!(*tif->tif_encodestrip)(tif, (tidata_t) data, cc, sample))
        return ((tsize_t) 0);
    if (!(*tif->tif_postencode)(tif))
        return ((tsize_t) -1);
    if (!isFillOrder(tif, td->td_fillorder) &&
        (tif->tif_flags & TIFF_NOBITREV) == 0)
        TIFFReverseBits(tif->tif_rawdata, tif->tif_rawcc);
    if (tif->tif_rawcc > 0 &&
        !TIFFAppendToStrip(tif, strip, tif->tif_rawdata, tif->tif_rawcc))
        return ((tsize_t) -1);
    tif->tif_rawcc = 0;
    tif->tif_rawcp = tif->tif_rawdata;
    return (cc);
}

/*
 * Write the supplied data to the specified strip.
 *
 * NB: Image length must be setup before writing.
 */
tsize_t
TIFFWriteRawStrip(TIFF* tif, tstrip_t strip, tdata_t data, tsize_t cc)
{
    static const char module[] = "TIFFWriteRawStrip";
    TIFFDirectory *td = &tif->tif_dir;

    if (!WRITECHECKSTRIPS(tif, module))
        return ((tsize_t) -1);
    /*
     * Check strip array to make sure there's space.
     * We don't support dynamically growing files that
     * have data organized in separate bitplanes because
     * it's too painful.  In that case we require that
     * the imagelength be set properly before the first
     * write (so that the strips array will be fully
     * allocated above).
     */
    if (strip >= td->td_nstrips) {
        if (td->td_planarconfig == PLANARCONFIG_SEPARATE) {
            TIFFErrorExt(tif->tif_clientdata, tif->tif_name,
        "Can not grow image by strips when using separate planes");
            return ((tsize_t) -1);
        }
        /*
         * Watch out for a growing image.  The value of
         * strips/image will initially be 1 (since it
         * can't be deduced until the imagelength is known).
         */
        if (strip >= td->td_stripsperimage)
            td->td_stripsperimage =
                TIFFhowmany(td->td_imagelength,td->td_rowsperstrip);
        if (!TIFFGrowStrips(tif, 1, module))
            return ((tsize_t) -1);
    }
    tif->tif_curstrip = strip;
    tif->tif_row = (strip % td->td_stripsperimage) * td->td_rowsperstrip;
    return (TIFFAppendToStrip(tif, strip, (tidata_t) data, cc) ?
        cc : (tsize_t) -1);
}

/*
 * Write and compress a tile of data.  The
 * tile is selected by the (x,y,z,s) coordinates.
 */
tsize_t
TIFFWriteTile(TIFF* tif,
    tdata_t buf, uint32 x, uint32 y, uint32 z, tsample_t s)
{
    if (!TIFFCheckTile(tif, x, y, z, s))
        return (-1);
    /*
     * NB: A tile size of -1 is used instead of tif_tilesize knowing
     *     that TIFFWriteEncodedTile will clamp this to the tile size.
     *     This is done because the tile size may not be defined until
     *     after the output buffer is setup in TIFFWriteBufferSetup.
     */
    return (TIFFWriteEncodedTile(tif,
        TIFFComputeTile(tif, x, y, z, s), buf, (tsize_t) -1));
}

/*
 * Encode the supplied data and write it to the
 * specified tile.  There must be space for the
 * data.  The function clamps individual writes
 * to a tile to the tile size, but does not (and
 * can not) check that multiple writes to the same
 * tile do not write more than tile size data.
 *
 * NB: Image length must be setup before writing; this
 *     interface does not support automatically growing
 *     the image on each write (as TIFFWriteScanline does).
 */
tsize_t
TIFFWriteEncodedTile(TIFF* tif, ttile_t tile, tdata_t data, tsize_t cc)
{
    static const char module[] = "TIFFWriteEncodedTile";
    TIFFDirectory *td;
    tsample_t sample;

    if (!WRITECHECKTILES(tif, module))
        return ((tsize_t) -1);
    td = &tif->tif_dir;
    if (tile >= td->td_nstrips) {
        TIFFErrorExt(tif->tif_clientdata, module, "%s: Tile %lu out of range, max %lu",
            tif->tif_name, (unsigned long) tile, (unsigned long) td->td_nstrips);
        return ((tsize_t) -1);
    }
    /*
     * Handle delayed allocation of data buffer.  This
     * permits it to be sized more intelligently (using
     * directory information).
     */
    if (!BUFFERCHECK(tif))
        return ((tsize_t) -1);
    tif->tif_curtile = tile;

    tif->tif_rawcc = 0;
    tif->tif_rawcp = tif->tif_rawdata;

        if( td->td_stripbytecount[tile] > 0 )
        {
        /* Force TIFFAppendToStrip() to consider placing data at end
               of file. */
            tif->tif_curoff = 0;
        }
        
    /* 
     * Compute tiles per row & per column to compute
     * current row and column
     */
    tif->tif_row = (tile % TIFFhowmany(td->td_imagelength, td->td_tilelength))
        * td->td_tilelength;
    tif->tif_col = (tile % TIFFhowmany(td->td_imagewidth, td->td_tilewidth))
        * td->td_tilewidth;

    if ((tif->tif_flags & TIFF_CODERSETUP) == 0) {
        if (!(*tif->tif_setupencode)(tif))
            return ((tsize_t) -1);
        tif->tif_flags |= TIFF_CODERSETUP;
    }
    tif->tif_flags &= ~TIFF_POSTENCODE;
    sample = (tsample_t)(tile/td->td_stripsperimage);
    if (!(*tif->tif_preencode)(tif, sample))
        return ((tsize_t) -1);
    /*
     * Clamp write amount to the tile size.  This is mostly
     * done so that callers can pass in some large number
     * (e.g. -1) and have the tile size used instead.
     */
    if ( cc < 1 || cc > tif->tif_tilesize)
        cc = tif->tif_tilesize;

        /* swab if needed - note that source buffer will be altered */
        tif->tif_postdecode( tif, (tidata_t) data, cc );

    if (!(*tif->tif_encodetile)(tif, (tidata_t) data, cc, sample))
        return ((tsize_t) 0);
    if (!(*tif->tif_postencode)(tif))
        return ((tsize_t) -1);
    if (!isFillOrder(tif, td->td_fillorder) &&
        (tif->tif_flags & TIFF_NOBITREV) == 0)
        TIFFReverseBits((unsigned char *)tif->tif_rawdata, tif->tif_rawcc);
    if (tif->tif_rawcc > 0 && !TIFFAppendToStrip(tif, tile,
        tif->tif_rawdata, tif->tif_rawcc))
        return ((tsize_t) -1);
    tif->tif_rawcc = 0;
    tif->tif_rawcp = tif->tif_rawdata;
    return (cc);
}

/*
 * Write the supplied data to the specified strip.
 * There must be space for the data; we don't check
 * if strips overlap!
 *
 * NB: Image length must be setup before writing; this
 *     interface does not support automatically growing
 *     the image on each write (as TIFFWriteScanline does).
 */
tsize_t
TIFFWriteRawTile(TIFF* tif, ttile_t tile, tdata_t data, tsize_t cc)
{
    static const char module[] = "TIFFWriteRawTile";

    if (!WRITECHECKTILES(tif, module))
        return ((tsize_t) -1);
    if (tile >= tif->tif_dir.td_nstrips) {
        TIFFErrorExt(tif->tif_clientdata, module, "%s: Tile %lu out of range, max %lu",
            tif->tif_name, (unsigned long) tile,
            (unsigned long) tif->tif_dir.td_nstrips);
        return ((tsize_t) -1);
    }
    return (TIFFAppendToStrip(tif, tile, (tidata_t) data, cc) ?
        cc : (tsize_t) -1);
}

#define isUnspecified(tif, f) \
    (TIFFFieldSet(tif,f) && (tif)->tif_dir.td_imagelength == 0)

int
TIFFSetupStrips(TIFF* tif)
{
    TIFFDirectory* td = &tif->tif_dir;

    if (isTiled(tif))
        td->td_stripsperimage =
            isUnspecified(tif, FIELD_TILEDIMENSIONS) ?
            td->td_samplesperpixel : TIFFNumberOfTiles(tif);
    else
        td->td_stripsperimage =
            isUnspecified(tif, FIELD_ROWSPERSTRIP) ?
            td->td_samplesperpixel : TIFFNumberOfStrips(tif);
    td->td_nstrips = td->td_stripsperimage;
    if (td->td_planarconfig == PLANARCONFIG_SEPARATE)
        td->td_stripsperimage /= td->td_samplesperpixel;
    td->td_stripoffset = (uint32 *)
        _TIFFmalloc(td->td_nstrips * sizeof (uint32));
    td->td_stripbytecount = (uint32 *)
        _TIFFmalloc(td->td_nstrips * sizeof (uint32));
    if (td->td_stripoffset == NULL || td->td_stripbytecount == NULL)
        return (0);
    /*
     * Place data at the end-of-file
     * (by setting offsets to zero).
     */
    _TIFFmemset(td->td_stripoffset, 0, td->td_nstrips*sizeof (uint32));
    _TIFFmemset(td->td_stripbytecount, 0, td->td_nstrips*sizeof (uint32));
    TIFFSetFieldBit(tif, FIELD_STRIPOFFSETS);
    TIFFSetFieldBit(tif, FIELD_STRIPBYTECOUNTS);
    return (1);
}
#undef isUnspecified

/*
 * Verify file is writable and that the directory
 * information is setup properly.  In doing the latter
 * we also "freeze" the state of the directory so
 * that important information is not changed.
 */
int
TIFFWriteCheck(TIFF* tif, int tiles, const char* module)
{
    if (tif->tif_mode == O_RDONLY) {
        TIFFErrorExt(tif->tif_clientdata, module, "%s: File not open for writing",
            tif->tif_name);
        return (0);
    }
    if (tiles ^ isTiled(tif)) {
        TIFFErrorExt(tif->tif_clientdata, tif->tif_name, tiles ?
            "Can not write tiles to a stripped image" :
            "Can not write scanlines to a tiled image");
        return (0);
    }
        
    /*
     * On the first write verify all the required information
     * has been setup and initialize any data structures that
     * had to wait until directory information was set.
     * Note that a lot of our work is assumed to remain valid
     * because we disallow any of the important parameters
     * from changing after we start writing (i.e. once
     * TIFF_BEENWRITING is set, TIFFSetField will only allow
     * the image's length to be changed).
     */
    if (!TIFFFieldSet(tif, FIELD_IMAGEDIMENSIONS)) {
        TIFFErrorExt(tif->tif_clientdata, module,
            "%s: Must set \"ImageWidth\" before writing data",
            tif->tif_name);
        return (0);
    }
    if (tif->tif_dir.td_samplesperpixel == 1) {
        /* 
         * Planarconfiguration is irrelevant in case of single band
         * images and need not be included. We will set it anyway,
         * because this field is used in other parts of library even
         * in the single band case.
         */
        if (!TIFFFieldSet(tif, FIELD_PLANARCONFIG))
                    tif->tif_dir.td_planarconfig = PLANARCONFIG_CONTIG;
    } else {
        if (!TIFFFieldSet(tif, FIELD_PLANARCONFIG)) {
            TIFFErrorExt(tif->tif_clientdata, module,
            "%s: Must set \"PlanarConfiguration\" before writing data",
                tif->tif_name);
            return (0);
        }
    }
    if (tif->tif_dir.td_stripoffset == NULL && !TIFFSetupStrips(tif)) {
        tif->tif_dir.td_nstrips = 0;
        TIFFErrorExt(tif->tif_clientdata, module, "%s: No space for %s arrays",
            tif->tif_name, isTiled(tif) ? "tile" : "strip");
        return (0);
    }
    tif->tif_tilesize = isTiled(tif) ? TIFFTileSize(tif) : (tsize_t) -1;
    tif->tif_scanlinesize = TIFFScanlineSize(tif);
    tif->tif_flags |= TIFF_BEENWRITING;
    return (1);
}

/*
 * Setup the raw data buffer used for encoding.
 */
int
TIFFWriteBufferSetup(TIFF* tif, tdata_t bp, tsize_t size)
{
    static const char module[] = "TIFFWriteBufferSetup";

    if (tif->tif_rawdata) {
        if (tif->tif_flags & TIFF_MYBUFFER) {
            _TIFFfree(tif->tif_rawdata);
            tif->tif_flags &= ~TIFF_MYBUFFER;
        }
        tif->tif_rawdata = NULL;
    }
    if (size == (tsize_t) -1) {
        size = (isTiled(tif) ?
            tif->tif_tilesize : TIFFStripSize(tif));
        /*
         * Make raw data buffer at least 8K
         */
        if (size < 8*1024)
            size = 8*1024;
        bp = NULL;          /* NB: force malloc */
    }
    if (bp == NULL) {
        bp = _TIFFmalloc(size);
        if (bp == NULL) {
            TIFFErrorExt(tif->tif_clientdata, module, "%s: No space for output buffer",
                tif->tif_name);
            return (0);
        }
        tif->tif_flags |= TIFF_MYBUFFER;
    } else
        tif->tif_flags &= ~TIFF_MYBUFFER;
    tif->tif_rawdata = (tidata_t) bp;
    tif->tif_rawdatasize = size;
    tif->tif_rawcc = 0;
    tif->tif_rawcp = tif->tif_rawdata;
    tif->tif_flags |= TIFF_BUFFERSETUP;
    return (1);
}

/*
 * Grow the strip data structures by delta strips.
 */
static int
TIFFGrowStrips(TIFF* tif, int delta, const char* module)
{
    TIFFDirectory   *td = &tif->tif_dir;
    uint32      *new_stripoffset, *new_stripbytecount;

    assert(td->td_planarconfig == PLANARCONFIG_CONTIG);
    new_stripoffset = (uint32*)_TIFFrealloc(td->td_stripoffset,
        (td->td_nstrips + delta) * sizeof (uint32));
    new_stripbytecount = (uint32*)_TIFFrealloc(td->td_stripbytecount,
        (td->td_nstrips + delta) * sizeof (uint32));
    if (new_stripoffset == NULL || new_stripbytecount == NULL) {
        if (new_stripoffset)
            _TIFFfree(new_stripoffset);
        if (new_stripbytecount)
            _TIFFfree(new_stripbytecount);
        td->td_nstrips = 0;
        TIFFErrorExt(tif->tif_clientdata, module, "%s: No space to expand strip arrays",
              tif->tif_name);
        return (0);
    }
    td->td_stripoffset = new_stripoffset;
    td->td_stripbytecount = new_stripbytecount;
    _TIFFmemset(td->td_stripoffset + td->td_nstrips,
            0, delta*sizeof (uint32));
    _TIFFmemset(td->td_stripbytecount + td->td_nstrips,
            0, delta*sizeof (uint32));
    td->td_nstrips += delta;
    return (1);
}

/*
 * Append the data to the specified strip.
 */
static int
TIFFAppendToStrip(TIFF* tif, tstrip_t strip, tidata_t data, tsize_t cc)
{
    static const char module[] = "TIFFAppendToStrip";
    TIFFDirectory *td = &tif->tif_dir;

    if (td->td_stripoffset[strip] == 0 || tif->tif_curoff == 0) {
            assert(td->td_nstrips > 0);

            if( td->td_stripbytecount[strip] != 0 
                && td->td_stripoffset[strip] != 0 
                && td->td_stripbytecount[strip] >= cc )
            {
                /* 
                 * There is already tile data on disk, and the new tile
                 * data we have to will fit in the same space.  The only 
                 * aspect of this that is risky is that there could be
                 * more data to append to this strip before we are done
                 * depending on how we are getting called.
                 */
                if (!SeekOK(tif, td->td_stripoffset[strip])) {
                    TIFFErrorExt(tif->tif_clientdata, module,
                                 "Seek error at scanline %lu",
                                 (unsigned long)tif->tif_row);
                    return (0);
                }
            }
            else
            {
                /* 
                 * Seek to end of file, and set that as our location to 
                 * write this strip.
                 */
                td->td_stripoffset[strip] = TIFFSeekFile(tif, 0, SEEK_END);
            }

            tif->tif_curoff = td->td_stripoffset[strip];

            /*
             * We are starting a fresh strip/tile, so set the size to zero.
             */
            td->td_stripbytecount[strip] = 0;
    }

    if (!WriteOK(tif, data, cc)) {
        TIFFErrorExt(tif->tif_clientdata, module, "Write error at scanline %lu",
            (unsigned long) tif->tif_row);
            return (0);
    }
    tif->tif_curoff =  tif->tif_curoff+cc;
    td->td_stripbytecount[strip] += cc;
    return (1);
}

/*
 * Internal version of TIFFFlushData that can be
 * called by ``encodestrip routines'' w/o concern
 * for infinite recursion.
 */
int
TIFFFlushData1(TIFF* tif)
{
    if (tif->tif_rawcc > 0) {
        if (!isFillOrder(tif, tif->tif_dir.td_fillorder) &&
            (tif->tif_flags & TIFF_NOBITREV) == 0)
            TIFFReverseBits((unsigned char *)tif->tif_rawdata,
                tif->tif_rawcc);
        if (!TIFFAppendToStrip(tif,
            isTiled(tif) ? tif->tif_curtile : tif->tif_curstrip,
            tif->tif_rawdata, tif->tif_rawcc))
            return (0);
        tif->tif_rawcc = 0;
        tif->tif_rawcp = tif->tif_rawdata;
    }
    return (1);
}

/*
 * Set the current write offset.  This should only be
 * used to set the offset to a known previous location
 * (very carefully), or to 0 so that the next write gets
 * appended to the end of the file.
 */
void
TIFFSetWriteOffset(TIFF* tif, toff_t off)
{
    tif->tif_curoff = off;
}

/* vim: set ts=8 sts=8 sw=8 noet: */
/*
 * Local Variables:
 * mode: c
 * c-basic-offset: 8
 * fill-column: 78
 * End:
 */