/* $Id: tif_predict.c,v 1.32 2010-03-10 18:56:49 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.

 *

 * Predictor Tag Support (used by multiple codecs).

 */

#include "tiffiop.h"

#include "tif_predict.h"

#define	PredictorState(tif)	((TIFFPredictorState*) (tif)->tif_data)

static void horAcc8(TIFF* tif, uint8* cp0, tmsize_t cc);

static void horAcc16(TIFF* tif, uint8* cp0, tmsize_t cc);

static void horAcc32(TIFF* tif, uint8* cp0, tmsize_t cc);

static void swabHorAcc16(TIFF* tif, uint8* cp0, tmsize_t cc);

static void swabHorAcc32(TIFF* tif, uint8* cp0, tmsize_t cc);

static void horDiff8(TIFF* tif, uint8* cp0, tmsize_t cc);

static void horDiff16(TIFF* tif, uint8* cp0, tmsize_t cc);

static void horDiff32(TIFF* tif, uint8* cp0, tmsize_t cc);

static void fpAcc(TIFF* tif, uint8* cp0, tmsize_t cc);

static void fpDiff(TIFF* tif, uint8* cp0, tmsize_t cc);

static int PredictorDecodeRow(TIFF* tif, uint8* op0, tmsize_t occ0, uint16 s);

static int PredictorDecodeTile(TIFF* tif, uint8* op0, tmsize_t occ0, uint16 s);

static int PredictorEncodeRow(TIFF* tif, uint8* bp, tmsize_t cc, uint16 s);

static int PredictorEncodeTile(TIFF* tif, uint8* bp0, tmsize_t cc0, uint16 s);

static int

PredictorSetup(TIFF* tif)

{

	static const char module[] = "PredictorSetup";

	TIFFPredictorState* sp = PredictorState(tif);

	TIFFDirectory* td = &tif->tif_dir;

	switch (sp->predictor)		/* no differencing */

	{

		case PREDICTOR_NONE:

			return 1;

		case PREDICTOR_HORIZONTAL:

			if (td->td_bitspersample != 8

			    && td->td_bitspersample != 16

			    && td->td_bitspersample != 32) {

				TIFFErrorExt(tif->tif_clientdata, module,

				    "Horizontal differencing \"Predictor\" not supported with %d-bit samples",

				    td->td_bitspersample);

				return 0;

			}

			break;

		case PREDICTOR_FLOATINGPOINT:

			if (td->td_sampleformat != SAMPLEFORMAT_IEEEFP) {

				TIFFErrorExt(tif->tif_clientdata, module,

				    "Floating point \"Predictor\" not supported with %d data format",

				    td->td_sampleformat);

				return 0;

			}

			break;

		default:

			TIFFErrorExt(tif->tif_clientdata, module,

			    "\"Predictor\" value %d not supported",

			    sp->predictor);

			return 0;

	}

	sp->stride = (td->td_planarconfig == PLANARCONFIG_CONTIG ?

	    td->td_samplesperpixel : 1);

	/*

	 * Calculate the scanline/tile-width size in bytes.

	 */

	if (isTiled(tif))

		sp->rowsize = TIFFTileRowSize(tif);

	else

		sp->rowsize = TIFFScanlineSize(tif);

	if (sp->rowsize == 0)

		return 0;

	return 1;

}

static int

PredictorSetupDecode(TIFF* tif)

{

	TIFFPredictorState* sp = PredictorState(tif);

	TIFFDirectory* td = &tif->tif_dir;

	if (!(*sp->setupdecode)(tif) || !PredictorSetup(tif))

		return 0;

	if (sp->predictor == 2) {

		switch (td->td_bitspersample) {

			case 8:  sp->decodepfunc = horAcc8; break;

			case 16: sp->decodepfunc = horAcc16; break;

			case 32: sp->decodepfunc = horAcc32; break;

		}

		/*

		 * Override default decoding method with one that does the

		 * predictor stuff.

		 */

                if( tif->tif_decoderow != PredictorDecodeRow )

                {

                    sp->decoderow = tif->tif_decoderow;

                    tif->tif_decoderow = PredictorDecodeRow;

                    sp->decodestrip = tif->tif_decodestrip;

                    tif->tif_decodestrip = PredictorDecodeTile;

                    sp->decodetile = tif->tif_decodetile;

                    tif->tif_decodetile = PredictorDecodeTile;

                }

		/*

		 * If the data is horizontally differenced 16-bit data that

		 * requires byte-swapping, then it must be byte swapped before

		 * the accumulation step.  We do this with a special-purpose

		 * routine and override the normal post decoding logic that

		 * the library setup when the directory was read.

		 */

		if (tif->tif_flags & TIFF_SWAB) {

			if (sp->decodepfunc == horAcc16) {

				sp->decodepfunc = swabHorAcc16;

				tif->tif_postdecode = _TIFFNoPostDecode;

            } else if (sp->decodepfunc == horAcc32) {

				sp->decodepfunc = swabHorAcc32;

				tif->tif_postdecode = _TIFFNoPostDecode;

            }

		}

	}

	else if (sp->predictor == 3) {

		sp->decodepfunc = fpAcc;

		/*

		 * Override default decoding method with one that does the

		 * predictor stuff.

		 */

                if( tif->tif_decoderow != PredictorDecodeRow )

                {

                    sp->decoderow = tif->tif_decoderow;

                    tif->tif_decoderow = PredictorDecodeRow;

                    sp->decodestrip = tif->tif_decodestrip;

                    tif->tif_decodestrip = PredictorDecodeTile;

                    sp->decodetile = tif->tif_decodetile;

                    tif->tif_decodetile = PredictorDecodeTile;

                }

		/*

		 * The data should not be swapped outside of the floating

		 * point predictor, the accumulation routine should return

		 * byres in the native order.

		 */

		if (tif->tif_flags & TIFF_SWAB) {

			tif->tif_postdecode = _TIFFNoPostDecode;

		}

		/*

		 * Allocate buffer to keep the decoded bytes before

		 * rearranging in the ight order

		 */

	}

	return 1;

}

static int

PredictorSetupEncode(TIFF* tif)

{

	TIFFPredictorState* sp = PredictorState(tif);

	TIFFDirectory* td = &tif->tif_dir;

	if (!(*sp->setupencode)(tif) || !PredictorSetup(tif))

		return 0;

	if (sp->predictor == 2) {

		switch (td->td_bitspersample) {

			case 8:  sp->encodepfunc = horDiff8; break;

			case 16: sp->encodepfunc = horDiff16; break;

			case 32: sp->encodepfunc = horDiff32; break;

		}

		/*

		 * Override default encoding method with one that does the

		 * predictor stuff.

		 */

                if( tif->tif_encoderow != PredictorEncodeRow )

                {

                    sp->encoderow = tif->tif_encoderow;

                    tif->tif_encoderow = PredictorEncodeRow;

                    sp->encodestrip = tif->tif_encodestrip;

                    tif->tif_encodestrip = PredictorEncodeTile;

                    sp->encodetile = tif->tif_encodetile;

                    tif->tif_encodetile = PredictorEncodeTile;

                }

	}

	else if (sp->predictor == 3) {

		sp->encodepfunc = fpDiff;

		/*

		 * Override default encoding method with one that does the

		 * predictor stuff.

		 */

                if( tif->tif_encoderow != PredictorEncodeRow )

                {

                    sp->encoderow = tif->tif_encoderow;

                    tif->tif_encoderow = PredictorEncodeRow;

                    sp->encodestrip = tif->tif_encodestrip;

                    tif->tif_encodestrip = PredictorEncodeTile;

                    sp->encodetile = tif->tif_encodetile;

                    tif->tif_encodetile = PredictorEncodeTile;

                }

	}

	return 1;

}

#define REPEAT4(n, op)		\

    switch (n) {		\

    default: { tmsize_t i; for (i = n-4; i > 0; i--) { op; } } \

    case 4:  op;		\

    case 3:  op;		\

    case 2:  op;		\

    case 1:  op;		\

    case 0:  ;			\

    }

static void

horAcc8(TIFF* tif, uint8* cp0, tmsize_t cc)

{

	tmsize_t stride = PredictorState(tif)->stride;

	char* cp = (char*) cp0;

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

	if (cc > stride) {

		/*

		 * Pipeline the most common cases.

		 */

		if (stride == 3)  {

			unsigned int cr = cp[0];

			unsigned int cg = cp[1];

			unsigned int cb = cp[2];

			cc -= 3;

			cp += 3;

			while (cc>0) {

				cp[0] = (char) (cr += cp[0]);

				cp[1] = (char) (cg += cp[1]);

				cp[2] = (char) (cb += cp[2]);

				cc -= 3;

				cp += 3;

			}

		} else if (stride == 4)  {

			unsigned int cr = cp[0];

			unsigned int cg = cp[1];

			unsigned int cb = cp[2];

			unsigned int ca = cp[3];

			cc -= 4;

			cp += 4;

			while (cc>0) {

				cp[0] = (char) (cr += cp[0]);

				cp[1] = (char) (cg += cp[1]);

				cp[2] = (char) (cb += cp[2]);

				cp[3] = (char) (ca += cp[3]);

				cc -= 4;

				cp += 4;

			}

		} else  {

			cc -= stride;

			do {

				REPEAT4(stride, cp[stride] =

					(char) (cp[stride] + *cp); cp++)

				cc -= stride;

			} while (cc>0);

		}

	}

}

static void

swabHorAcc16(TIFF* tif, uint8* cp0, tmsize_t cc)

{

	tmsize_t stride = PredictorState(tif)->stride;

	uint16* wp = (uint16*) cp0;

	tmsize_t wc = cc / 2;

	assert((cc%(2*stride))==0);

	if (wc > stride) {

		TIFFSwabArrayOfShort(wp, wc);

		wc -= stride;

		do {

			REPEAT4(stride, wp[stride] += wp[0]; wp++)

			wc -= stride;

		} while (wc > 0);

	}

}

static void

horAcc16(TIFF* tif, uint8* cp0, tmsize_t cc)

{

	tmsize_t stride = PredictorState(tif)->stride;

	uint16* wp = (uint16*) cp0;

	tmsize_t wc = cc / 2;

	assert((cc%(2*stride))==0);

	if (wc > stride) {

		wc -= stride;

		do {

			REPEAT4(stride, wp[stride] += wp[0]; wp++)

			wc -= stride;

		} while (wc > 0);

	}

}

static void

swabHorAcc32(TIFF* tif, uint8* cp0, tmsize_t cc)

{

	tmsize_t stride = PredictorState(tif)->stride;

	uint32* wp = (uint32*) cp0;

	tmsize_t wc = cc / 4;

	assert((cc%(4*stride))==0);

	if (wc > stride) {

		TIFFSwabArrayOfLong(wp, wc);

		wc -= stride;

		do {

			REPEAT4(stride, wp[stride] += wp[0]; wp++)

			wc -= stride;

		} while (wc > 0);

	}

}

static void

horAcc32(TIFF* tif, uint8* cp0, tmsize_t cc)

{

	tmsize_t stride = PredictorState(tif)->stride;

	uint32* wp = (uint32*) cp0;

	tmsize_t wc = cc / 4;

	assert((cc%(4*stride))==0);

	if (wc > stride) {

		wc -= stride;

		do {

			REPEAT4(stride, wp[stride] += wp[0]; wp++)

			wc -= stride;

		} while (wc > 0);

	}

}

/*

 * Floating point predictor accumulation routine.

 */

static void

fpAcc(TIFF* tif, uint8* cp0, tmsize_t cc)

{

	tmsize_t stride = PredictorState(tif)->stride;

	uint32 bps = tif->tif_dir.td_bitspersample / 8;

	tmsize_t wc = cc / bps;

	tmsize_t count = cc;

	uint8 *cp = (uint8 *) cp0;

	uint8 *tmp = (uint8 *)_TIFFmalloc(cc);

	assert((cc%(bps*stride))==0);

	if (!tmp)

		return;

	while (count > stride) {

		REPEAT4(stride, cp[stride] += cp[0]; cp++)

		count -= stride;

	}

	_TIFFmemcpy(tmp, cp0, cc);

	cp = (uint8 *) cp0;

	for (count = 0; count < wc; count++) {

		uint32 byte;

		for (byte = 0; byte < bps; byte++) {

			#if WORDS_BIGENDIAN

			cp[bps * count + byte] = tmp[byte * wc + count];

			#else

			cp[bps * count + byte] =

				tmp[(bps - byte - 1) * wc + count];

			#endif

		}

	}

	_TIFFfree(tmp);

}

/*

 * Decode a scanline and apply the predictor routine.

 */

static int

PredictorDecodeRow(TIFF* tif, uint8* op0, tmsize_t occ0, uint16 s)

{

	TIFFPredictorState *sp = PredictorState(tif);

	assert(sp != NULL);

	assert(sp->decoderow != NULL);

	assert(sp->decodepfunc != NULL);  

	if ((*sp->decoderow)(tif, op0, occ0, s)) {

		(*sp->decodepfunc)(tif, op0, occ0);

		return 1;

	} else

		return 0;

}

/*

 * Decode a tile/strip and apply the predictor routine.

 * Note that horizontal differencing must be done on a

 * row-by-row basis.  The width of a "row" has already

 * been calculated at pre-decode time according to the

 * strip/tile dimensions.

 */

static int

PredictorDecodeTile(TIFF* tif, uint8* op0, tmsize_t occ0, uint16 s)

{

	TIFFPredictorState *sp = PredictorState(tif);

	assert(sp != NULL);

	assert(sp->decodetile != NULL);

	if ((*sp->decodetile)(tif, op0, occ0, s)) {

		tmsize_t rowsize = sp->rowsize;

		assert(rowsize > 0);

		assert((occ0%rowsize)==0);

		assert(sp->decodepfunc != NULL);

		while (occ0 > 0) {

			(*sp->decodepfunc)(tif, op0, rowsize);

			occ0 -= rowsize;

			op0 += rowsize;

		}

		return 1;

	} else

		return 0;

}

static void

horDiff8(TIFF* tif, uint8* cp0, tmsize_t cc)

{

	TIFFPredictorState* sp = PredictorState(tif);

	tmsize_t stride = sp->stride;

	char* cp = (char*) cp0;

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

	if (cc > stride) {

		cc -= stride;

		/*

		 * Pipeline the most common cases.

		 */

		if (stride == 3) {

			int r1, g1, b1;

			int r2 = cp[0];

			int g2 = cp[1];

			int b2 = cp[2];

			do {

				r1 = cp[3]; cp[3] = r1-r2; r2 = r1;

				g1 = cp[4]; cp[4] = g1-g2; g2 = g1;

				b1 = cp[5]; cp[5] = b1-b2; b2 = b1;

				cp += 3;

			} while ((cc -= 3) > 0);

		} else if (stride == 4) {

			int r1, g1, b1, a1;

			int r2 = cp[0];

			int g2 = cp[1];

			int b2 = cp[2];

			int a2 = cp[3];

			do {

				r1 = cp[4]; cp[4] = r1-r2; r2 = r1;

				g1 = cp[5]; cp[5] = g1-g2; g2 = g1;

				b1 = cp[6]; cp[6] = b1-b2; b2 = b1;

				a1 = cp[7]; cp[7] = a1-a2; a2 = a1;

				cp += 4;

			} while ((cc -= 4) > 0);

		} else {

			cp += cc - 1;

			do {

				REPEAT4(stride, cp[stride] -= cp[0]; cp--)

			} while ((cc -= stride) > 0);

		}

	}

}

static void

horDiff16(TIFF* tif, uint8* cp0, tmsize_t cc)

{

	TIFFPredictorState* sp = PredictorState(tif);

	tmsize_t stride = sp->stride;

	int16 *wp = (int16*) cp0;

	tmsize_t wc = cc/2;

	assert((cc%(2*stride))==0);

	if (wc > stride) {

		wc -= stride;

		wp += wc - 1;

		do {

			REPEAT4(stride, wp[stride] -= wp[0]; wp--)

			wc -= stride;

		} while (wc > 0);

	}

}

static void

horDiff32(TIFF* tif, uint8* cp0, tmsize_t cc)

{

	TIFFPredictorState* sp = PredictorState(tif);

	tmsize_t stride = sp->stride;

	int32 *wp = (int32*) cp0;

	tmsize_t wc = cc/4;

	assert((cc%(4*stride))==0);

	if (wc > stride) {

		wc -= stride;

		wp += wc - 1;

		do {

			REPEAT4(stride, wp[stride] -= wp[0]; wp--)

			wc -= stride;

		} while (wc > 0);

	}

}

/*

 * Floating point predictor differencing routine.

 */

static void

fpDiff(TIFF* tif, uint8* cp0, tmsize_t cc)

{

	tmsize_t stride = PredictorState(tif)->stride;

	uint32 bps = tif->tif_dir.td_bitspersample / 8;

	tmsize_t wc = cc / bps;

	tmsize_t count;

	uint8 *cp = (uint8 *) cp0;

	uint8 *tmp = (uint8 *)_TIFFmalloc(cc);

	assert((cc%(bps*stride))==0);

	if (!tmp)

		return;

	_TIFFmemcpy(tmp, cp0, cc);

	for (count = 0; count < wc; count++) {

		uint32 byte;

		for (byte = 0; byte < bps; byte++) {

			#if WORDS_BIGENDIAN

			cp[byte * wc + count] = tmp[bps * count + byte];

			#else

			cp[(bps - byte - 1) * wc + count] =

				tmp[bps * count + byte];

			#endif

		}

	}

	_TIFFfree(tmp);

	cp = (uint8 *) cp0;

	cp += cc - stride - 1;

	for (count = cc; count > stride; count -= stride)

		REPEAT4(stride, cp[stride] -= cp[0]; cp--)

}

static int

PredictorEncodeRow(TIFF* tif, uint8* bp, tmsize_t cc, uint16 s)

{

	TIFFPredictorState *sp = PredictorState(tif);

	assert(sp != NULL);

	assert(sp->encodepfunc != NULL);

	assert(sp->encoderow != NULL);

	/* XXX horizontal differencing alters user's data XXX */

	(*sp->encodepfunc)(tif, bp, cc);

	return (*sp->encoderow)(tif, bp, cc, s);

}

static int

PredictorEncodeTile(TIFF* tif, uint8* bp0, tmsize_t cc0, uint16 s)

{

	static const char module[] = "PredictorEncodeTile";

	TIFFPredictorState *sp = PredictorState(tif);

        uint8 *working_copy;

	tmsize_t cc = cc0, rowsize;

	unsigned char* bp;

        int result_code;

	assert(sp != NULL);

	assert(sp->encodepfunc != NULL);

	assert(sp->encodetile != NULL);

        /* 

         * Do predictor manipulation in a working buffer to avoid altering

         * the callers buffer. http://trac.osgeo.org/gdal/ticket/1965

         */

        working_copy = (uint8*) _TIFFmalloc(cc0);

        if( working_copy == NULL )

        {

            TIFFErrorExt(tif->tif_clientdata, module, 

                         "Out of memory allocating " TIFF_SSIZE_FORMAT " byte temp buffer.",

                         cc0 );

            return 0;

        }

        memcpy( working_copy, bp0, cc0 );

        bp = working_copy;

	rowsize = sp->rowsize;

	assert(rowsize > 0);

	assert((cc0%rowsize)==0);

	while (cc > 0) {

		(*sp->encodepfunc)(tif, bp, rowsize);

		cc -= rowsize;

		bp += rowsize;

	}

	result_code = (*sp->encodetile)(tif, working_copy, cc0, s);

        _TIFFfree( working_copy );

        return result_code;

}

#define	FIELD_PREDICTOR	(FIELD_CODEC+0)		/* XXX */

static const TIFFField predictFields[] = {

    { TIFFTAG_PREDICTOR, 1, 1, TIFF_SHORT, 0, TIFF_SETGET_UINT16, TIFF_SETGET_UINT16, FIELD_PREDICTOR, FALSE, FALSE, "Predictor", NULL },

};

static int

PredictorVSetField(TIFF* tif, uint32 tag, va_list ap)

{

	TIFFPredictorState *sp = PredictorState(tif);

	assert(sp != NULL);

	assert(sp->vsetparent != NULL);

	switch (tag) {

	case TIFFTAG_PREDICTOR:

		sp->predictor = (uint16) va_arg(ap, uint16_vap);

		TIFFSetFieldBit(tif, FIELD_PREDICTOR);

		break;

	default:

		return (*sp->vsetparent)(tif, tag, ap);

	}

	tif->tif_flags |= TIFF_DIRTYDIRECT;

	return 1;

}

static int

PredictorVGetField(TIFF* tif, uint32 tag, va_list ap)

{

	TIFFPredictorState *sp = PredictorState(tif);

	assert(sp != NULL);

	assert(sp->vgetparent != NULL);

	switch (tag) {

	case TIFFTAG_PREDICTOR:

		*va_arg(ap, uint16*) = sp->predictor;

		break;

	default:

		return (*sp->vgetparent)(tif, tag, ap);

	}

	return 1;

}

static void

PredictorPrintDir(TIFF* tif, FILE* fd, long flags)

{

	TIFFPredictorState* sp = PredictorState(tif);

	(void) flags;

	if (TIFFFieldSet(tif,FIELD_PREDICTOR)) {

		fprintf(fd, "  Predictor: ");

		switch (sp->predictor) {

			case 1: fprintf(fd, "none "); break;

			case 2: fprintf(fd, "horizontal differencing "); break;

			case 3: fprintf(fd, "floating point predictor "); break;

		}

		fprintf(fd, "%u (0x%x)\n", sp->predictor, sp->predictor);

	}

	if (sp->printdir)

		(*sp->printdir)(tif, fd, flags);

}

int

TIFFPredictorInit(TIFF* tif)

{

	TIFFPredictorState* sp = PredictorState(tif);

	assert(sp != 0);

	/*

	 * Merge codec-specific tag information.

	 */

	if (!_TIFFMergeFields(tif, predictFields,

			      TIFFArrayCount(predictFields))) {

		TIFFErrorExt(tif->tif_clientdata, "TIFFPredictorInit",

		    "Merging Predictor codec-specific tags failed");

		return 0;

	}

	/*

	 * Override parent get/set field methods.

	 */

	sp->vgetparent = tif->tif_tagmethods.vgetfield;

	tif->tif_tagmethods.vgetfield =

            PredictorVGetField;/* hook for predictor tag */

	sp->vsetparent = tif->tif_tagmethods.vsetfield;

	tif->tif_tagmethods.vsetfield =

	    PredictorVSetField;/* hook for predictor tag */

	sp->printdir = tif->tif_tagmethods.printdir;

	tif->tif_tagmethods.printdir =

            PredictorPrintDir;	/* hook for predictor tag */

	sp->setupdecode = tif->tif_setupdecode;

	tif->tif_setupdecode = PredictorSetupDecode;

	sp->setupencode = tif->tif_setupencode;

	tif->tif_setupencode = PredictorSetupEncode;

	sp->predictor = 1;			/* default value */

	sp->encodepfunc = NULL;			/* no predictor routine */

	sp->decodepfunc = NULL;			/* no predictor routine */

	return 1;

}

int

TIFFPredictorCleanup(TIFF* tif)

{

	TIFFPredictorState* sp = PredictorState(tif);

	assert(sp != 0);

	tif->tif_tagmethods.vgetfield = sp->vgetparent;

	tif->tif_tagmethods.vsetfield = sp->vsetparent;

	tif->tif_tagmethods.printdir = sp->printdir;

	tif->tif_setupdecode = sp->setupdecode;

	tif->tif_setupencode = sp->setupencode;

	return 1;

}

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

/*

 * Local Variables:

 * mode: c

 * c-basic-offset: 8

 * fill-column: 78

 * End:

 */