/* $Header: /d1/sam/tiff/libtiff/RCS/tif_dir.c,v 1.162 1997/08/29 21:45:47 sam 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.
 *
 * Directory Tag Get & Set Routines.
 * (and also some miscellaneous stuff)
 */
#include "tiffiop.h"

/*
 * These are used in the backwards compatibility code...
 */
#define DATATYPE_VOID		0       /* !untyped data */
#define DATATYPE_INT		1       /* !signed integer data */
#define DATATYPE_UINT		2       /* !unsigned integer data */
#define DATATYPE_IEEEFP		3       /* !IEEE floating point data */

void
_TIFFsetByteArray(void** vpp, void* vp, long n)
{
	if (*vpp)
		_TIFFfree(*vpp), *vpp = 0;
	if (vp && (*vpp = (void*) _TIFFmalloc(n)))
		_TIFFmemcpy(*vpp, vp, n);
}
void _TIFFsetString(char** cpp, char* cp)
    { _TIFFsetByteArray((void**) cpp, (void*) cp, (long) (strlen(cp)+1)); }
void _TIFFsetNString(char** cpp, char* cp, long n)
    { _TIFFsetByteArray((void**) cpp, (void*) cp, n); }
void _TIFFsetShortArray(uint16** wpp, uint16* wp, long n)
    { _TIFFsetByteArray((void**) wpp, (void*) wp, n*sizeof (uint16)); }
void _TIFFsetLongArray(uint32** lpp, uint32* lp, long n)
    { _TIFFsetByteArray((void**) lpp, (void*) lp, n*sizeof (uint32)); }
void _TIFFsetFloatArray(float** fpp, float* fp, long n)
    { _TIFFsetByteArray((void**) fpp, (void*) fp, n*sizeof (float)); }
void _TIFFsetDoubleArray(double** dpp, double* dp, long n)
    { _TIFFsetByteArray((void**) dpp, (void*) dp, n*sizeof (double)); }

/*
 * Install extra samples information.
 */
static int
setExtraSamples(TIFFDirectory* td, va_list ap, int* v)
{
	uint16* va;
	int i;

	*v = va_arg(ap, int);
	if ((uint16) *v > td->td_samplesperpixel)
		return (0);
	va = va_arg(ap, uint16*);
	if (*v > 0 && va == NULL)		/* typically missing param */
		return (0);
	for (i = 0; i < *v; i++)
		if (va[i] > EXTRASAMPLE_UNASSALPHA)
			return (0);
	td->td_extrasamples = (uint16) *v;
	_TIFFsetShortArray(&td->td_sampleinfo, va, td->td_extrasamples);
	return (1);
}

#ifdef CMYK_SUPPORT
static int
checkInkNamesString(TIFF* tif, int slen, const char* s)
{
	TIFFDirectory* td = &tif->tif_dir;
	int i = td->td_samplesperpixel;

	if (slen > 0) {
		const char* ep = s+slen;
		const char* cp = s;
		for (; i > 0; i--) {
			for (; *cp != '\0'; cp++)
				if (cp >= ep)
					goto bad;
			cp++;				/* skip \0 */
		}
		return (cp-s);
	}
bad:
	TIFFError("TIFFSetField",
	    "%s: Invalid InkNames value; expecting %d names, found %d",
	    tif->tif_name,
	    td->td_samplesperpixel,
	    td->td_samplesperpixel-i);
	return (0);
}
#endif

static int
_TIFFVSetField(TIFF* tif, ttag_t tag, va_list ap)
{
	TIFFDirectory* td = &tif->tif_dir;
	int status = 1;
	uint32 v32;
	int i, v;
	double d;
	char* s;

	switch (tag) {
	case TIFFTAG_SUBFILETYPE:
		td->td_subfiletype = va_arg(ap, uint32);
		break;
	case TIFFTAG_IMAGEWIDTH:
		td->td_imagewidth = va_arg(ap, uint32);
		break;
	case TIFFTAG_IMAGELENGTH:
		td->td_imagelength = va_arg(ap, uint32);
		break;
	case TIFFTAG_BITSPERSAMPLE:
		td->td_bitspersample = (uint16) va_arg(ap, int);
		/*
		 * If the data require post-decoding processing
		 * to byte-swap samples, set it up here.  Note
		 * that since tags are required to be ordered,
		 * compression code can override this behaviour
		 * in the setup method if it wants to roll the
		 * post decoding work in with its normal work.
		 */
		if (tif->tif_flags & TIFF_SWAB) {
			if (td->td_bitspersample == 16)
				tif->tif_postdecode = _TIFFSwab16BitData;
			else if (td->td_bitspersample == 32)
				tif->tif_postdecode = _TIFFSwab32BitData;
			else if (td->td_bitspersample == 64)
				tif->tif_postdecode = _TIFFSwab64BitData;
		}
		break;
	case TIFFTAG_COMPRESSION:
		v = va_arg(ap, int) & 0xffff;
		/*
		 * If we're changing the compression scheme,
		 * the notify the previous module so that it
		 * can cleanup any state it's setup.
		 */
		if (TIFFFieldSet(tif, FIELD_COMPRESSION)) {
			if (td->td_compression == v)
				break;
			(*tif->tif_cleanup)(tif);
			tif->tif_flags &= ~TIFF_CODERSETUP;
		}
		/*
		 * Setup new compression routine state.
		 */
		if (status = TIFFSetCompressionScheme(tif, v))
			td->td_compression = v;
		break;
	case TIFFTAG_PHOTOMETRIC:
		td->td_photometric = (uint16) va_arg(ap, int);
		break;
	case TIFFTAG_THRESHHOLDING:
		td->td_threshholding = (uint16) va_arg(ap, int);
		break;
	case TIFFTAG_FILLORDER:
		v = va_arg(ap, int);
		if (v != FILLORDER_LSB2MSB && v != FILLORDER_MSB2LSB)
			goto badvalue;
		td->td_fillorder = (uint16) v;
		break;
	case TIFFTAG_DOCUMENTNAME:
		_TIFFsetString(&td->td_documentname, va_arg(ap, char*));
		break;
	case TIFFTAG_ARTIST:
		_TIFFsetString(&td->td_artist, va_arg(ap, char*));
		break;
	case TIFFTAG_DATETIME:
		_TIFFsetString(&td->td_datetime, va_arg(ap, char*));
		break;
	case TIFFTAG_HOSTCOMPUTER:
		_TIFFsetString(&td->td_hostcomputer, va_arg(ap, char*));
		break;
	case TIFFTAG_IMAGEDESCRIPTION:
		_TIFFsetString(&td->td_imagedescription, va_arg(ap, char*));
		break;
	case TIFFTAG_MAKE:
		_TIFFsetString(&td->td_make, va_arg(ap, char*));
		break;
	case TIFFTAG_MODEL:
		_TIFFsetString(&td->td_model, va_arg(ap, char*));
		break;
	case TIFFTAG_SOFTWARE:
		_TIFFsetString(&td->td_software, va_arg(ap, char*));
		break;
	case TIFFTAG_ORIENTATION:
		v = va_arg(ap, int);
		if (v < ORIENTATION_TOPLEFT || ORIENTATION_LEFTBOT < v) {
			TIFFWarning(tif->tif_name,
			    "Bad value %ld for \"%s\" tag ignored",
			    v, _TIFFFieldWithTag(tif, tag)->field_name);
		} else
			td->td_orientation = (uint16) v;
		break;
	case TIFFTAG_SAMPLESPERPIXEL:
		/* XXX should cross check -- e.g. if pallette, then 1 */
		v = va_arg(ap, int);
		if (v == 0)
			goto badvalue;
		td->td_samplesperpixel = (uint16) v;
		break;
	case TIFFTAG_ROWSPERSTRIP:
		v32 = va_arg(ap, uint32);
		if (v32 == 0)
			goto badvalue32;
		td->td_rowsperstrip = v32;
		if (!TIFFFieldSet(tif, FIELD_TILEDIMENSIONS)) {
			td->td_tilelength = v32;
			td->td_tilewidth = td->td_imagewidth;
		}
		break;
	case TIFFTAG_MINSAMPLEVALUE:
		td->td_minsamplevalue = (uint16) va_arg(ap, int);
		break;
	case TIFFTAG_MAXSAMPLEVALUE:
		td->td_maxsamplevalue = (uint16) va_arg(ap, int);
		break;
	case TIFFTAG_SMINSAMPLEVALUE:
		td->td_sminsamplevalue = (double) va_arg(ap, dblparam_t);
		break;
	case TIFFTAG_SMAXSAMPLEVALUE:
		td->td_smaxsamplevalue = (double) va_arg(ap, dblparam_t);
		break;
	case TIFFTAG_XRESOLUTION:
		td->td_xresolution = (float) va_arg(ap, dblparam_t);
		break;
	case TIFFTAG_YRESOLUTION:
		td->td_yresolution = (float) va_arg(ap, dblparam_t);
		break;
	case TIFFTAG_PLANARCONFIG:
		v = va_arg(ap, int);
		if (v != PLANARCONFIG_CONTIG && v != PLANARCONFIG_SEPARATE)
			goto badvalue;
		td->td_planarconfig = (uint16) v;
		break;
	case TIFFTAG_PAGENAME:
		_TIFFsetString(&td->td_pagename, va_arg(ap, char*));
		break;
	case TIFFTAG_XPOSITION:
		td->td_xposition = (float) va_arg(ap, dblparam_t);
		break;
	case TIFFTAG_YPOSITION:
		td->td_yposition = (float) va_arg(ap, dblparam_t);
		break;
	case TIFFTAG_RESOLUTIONUNIT:
		v = va_arg(ap, int);
		if (v < RESUNIT_NONE || RESUNIT_CENTIMETER < v)
			goto badvalue;
		td->td_resolutionunit = (uint16) v;
		break;
	case TIFFTAG_PAGENUMBER:
		td->td_pagenumber[0] = (uint16) va_arg(ap, int);
		td->td_pagenumber[1] = (uint16) va_arg(ap, int);
		break;
	case TIFFTAG_HALFTONEHINTS:
		td->td_halftonehints[0] = (uint16) va_arg(ap, int);
		td->td_halftonehints[1] = (uint16) va_arg(ap, int);
		break;
	case TIFFTAG_COLORMAP:
		v32 = (uint32)(1L<<td->td_bitspersample);
		_TIFFsetShortArray(&td->td_colormap[0], va_arg(ap, uint16*), v32);
		_TIFFsetShortArray(&td->td_colormap[1], va_arg(ap, uint16*), v32);
		_TIFFsetShortArray(&td->td_colormap[2], va_arg(ap, uint16*), v32);
		break;
	case TIFFTAG_EXTRASAMPLES:
		if (!setExtraSamples(td, ap, &v))
			goto badvalue;
		break;
	case TIFFTAG_MATTEING:
		td->td_extrasamples = (uint16) (va_arg(ap, int) != 0);
		if (td->td_extrasamples) {
			uint16 sv = EXTRASAMPLE_ASSOCALPHA;
			_TIFFsetShortArray(&td->td_sampleinfo, &sv, 1);
		}
		break;
	case TIFFTAG_TILEWIDTH:
		v32 = va_arg(ap, uint32);
		if (v32 % 16) {
			if (tif->tif_mode != O_RDONLY)
				goto badvalue32;
			TIFFWarning(tif->tif_name,
			    "Nonstandard tile width %d, convert file", v32);
		}
		td->td_tilewidth = v32;
		tif->tif_flags |= TIFF_ISTILED;
		break;
	case TIFFTAG_TILELENGTH:
		v32 = va_arg(ap, uint32);
		if (v32 % 16) {
			if (tif->tif_mode != O_RDONLY)
				goto badvalue32;
			TIFFWarning(tif->tif_name,
			    "Nonstandard tile length %d, convert file", v32);
		}
		td->td_tilelength = v32;
		tif->tif_flags |= TIFF_ISTILED;
		break;
	case TIFFTAG_TILEDEPTH:
		v32 = va_arg(ap, uint32);
		if (v32 == 0)
			goto badvalue32;
		td->td_tiledepth = v32;
		break;
	case TIFFTAG_DATATYPE:
		v = va_arg(ap, int);
		switch (v) {
		case DATATYPE_VOID:	v = SAMPLEFORMAT_VOID;	break;
		case DATATYPE_INT:	v = SAMPLEFORMAT_INT;	break;
		case DATATYPE_UINT:	v = SAMPLEFORMAT_UINT;	break;
		case DATATYPE_IEEEFP:	v = SAMPLEFORMAT_IEEEFP;break;
		default:		goto badvalue;
		}
		td->td_sampleformat = (uint16) v;
		break;
	case TIFFTAG_SAMPLEFORMAT:
		v = va_arg(ap, int);
		if (v < SAMPLEFORMAT_UINT || SAMPLEFORMAT_VOID < v)
			goto badvalue;
		td->td_sampleformat = (uint16) v;
		break;
	case TIFFTAG_IMAGEDEPTH:
		td->td_imagedepth = va_arg(ap, uint32);
		break;
	case TIFFTAG_STONITS:
		d = va_arg(ap, dblparam_t);
		if (d <= 0.)
			goto badvaluedbl;
		td->td_stonits = d;
		break;
#if SUBIFD_SUPPORT
	case TIFFTAG_SUBIFD:
		if ((tif->tif_flags & TIFF_INSUBIFD) == 0) {
			td->td_nsubifd = (uint16) va_arg(ap, int);
			_TIFFsetLongArray(&td->td_subifd, va_arg(ap, uint32*),
			    (long) td->td_nsubifd);
		} else {
			TIFFError(tif->tif_name, "Sorry, cannot nest SubIFDs");
			status = 0;
		}
		break;
#endif
#ifdef YCBCR_SUPPORT
	case TIFFTAG_YCBCRCOEFFICIENTS:
		_TIFFsetFloatArray(&td->td_ycbcrcoeffs, va_arg(ap, float*), 3);
		break;
	case TIFFTAG_YCBCRPOSITIONING:
		td->td_ycbcrpositioning = (uint16) va_arg(ap, int);
		break;
	case TIFFTAG_YCBCRSUBSAMPLING:
		td->td_ycbcrsubsampling[0] = (uint16) va_arg(ap, int);
		td->td_ycbcrsubsampling[1] = (uint16) va_arg(ap, int);
		break;
#endif
#ifdef COLORIMETRY_SUPPORT
	case TIFFTAG_WHITEPOINT:
		_TIFFsetFloatArray(&td->td_whitepoint, va_arg(ap, float*), 2);
		break;
	case TIFFTAG_PRIMARYCHROMATICITIES:
		_TIFFsetFloatArray(&td->td_primarychromas, va_arg(ap, float*), 6);
		break;
	case TIFFTAG_TRANSFERFUNCTION:
		v = (td->td_samplesperpixel - td->td_extrasamples) > 1 ? 3 : 1;
		for (i = 0; i < v; i++)
			_TIFFsetShortArray(&td->td_transferfunction[i],
			    va_arg(ap, uint16*), 1L<<td->td_bitspersample);
		break;
	case TIFFTAG_REFERENCEBLACKWHITE:
		/* XXX should check for null range */
		_TIFFsetFloatArray(&td->td_refblackwhite, va_arg(ap, float*), 6);
		break;
#endif
#ifdef CMYK_SUPPORT
	case TIFFTAG_INKSET:
		td->td_inkset = (uint16) va_arg(ap, int);
		break;
	case TIFFTAG_DOTRANGE:
		/* XXX should check for null range */
		td->td_dotrange[0] = (uint16) va_arg(ap, int);
		td->td_dotrange[1] = (uint16) va_arg(ap, int);
		break;
	case TIFFTAG_INKNAMES:
		i = va_arg(ap, int);
		s = va_arg(ap, char*);
		i = checkInkNamesString(tif, i, s);
		if (status = (i > 0)) {
			_TIFFsetNString(&td->td_inknames, s, i);
			td->td_inknameslen = i;
		}
		break;
	case TIFFTAG_NUMBEROFINKS:
		td->td_ninks = (uint16) va_arg(ap, int);
		break;
	case TIFFTAG_TARGETPRINTER:
		_TIFFsetString(&td->td_targetprinter, va_arg(ap, char*));
		break;
#endif
#ifdef ICC_SUPPORT
	case TIFFTAG_ICCPROFILE:
		td->td_profileLength = (uint32) va_arg(ap, uint32);
		_TIFFsetByteArray(&td->td_profileData, va_arg(ap, void*),
		    td->td_profileLength);
		break;
#endif
	default:
		/*
		 * This can happen if multiple images are open with
		 * different codecs which have private tags.  The
		 * global tag information table may then have tags
		 * that are valid for one file but not the other. 
		 * If the client tries to set a tag that is not valid
		 * for the image's codec then we'll arrive here.  This
		 * happens, for example, when tiffcp is used to convert
		 * between compression schemes and codec-specific tags
		 * are blindly copied.
		 */
		TIFFError("TIFFSetField",
		    "%s: Invalid %stag \"%s\" (not supported by codec)",
		    tif->tif_name, isPseudoTag(tag) ? "pseduo-" : "",
		    _TIFFFieldWithTag(tif, tag)->field_name);
		status = 0;
		break;
	}
	if (status) {
		TIFFSetFieldBit(tif, _TIFFFieldWithTag(tif, tag)->field_bit);
		tif->tif_flags |= TIFF_DIRTYDIRECT;
	}
	va_end(ap);
	return (status);
badvalue:
	TIFFError(tif->tif_name, "%d: Bad value for \"%s\"", v,
	    _TIFFFieldWithTag(tif, tag)->field_name);
	va_end(ap);
	return (0);
badvalue32:
	TIFFError(tif->tif_name, "%ld: Bad value for \"%s\"", v32,
	    _TIFFFieldWithTag(tif, tag)->field_name);
	va_end(ap);
	return (0);
badvaluedbl:
	TIFFError(tif->tif_name, "%f: Bad value for \"%s\"", d,
	    _TIFFFieldWithTag(tif, tag)->field_name);
	va_end(ap);
	return (0);
}

/*
 * Return 1/0 according to whether or not
 * it is permissible to set the tag's value.
 * Note that we allow ImageLength to be changed
 * so that we can append and extend to images.
 * Any other tag may not be altered once writing
 * has commenced, unless its value has no effect
 * on the format of the data that is written.
 */
static int
OkToChangeTag(TIFF* tif, ttag_t tag)
{
	const TIFFFieldInfo* fip = _TIFFFindFieldInfo(tif, tag, TIFF_ANY);
	if (!fip) {			/* unknown tag */
		TIFFError("TIFFSetField", "%s: Unknown %stag %u",
		    tif->tif_name, isPseudoTag(tag) ? "pseudo-" : "", tag);
		return (0);
	}
	if (tag != TIFFTAG_IMAGELENGTH && (tif->tif_flags & TIFF_BEENWRITING) &&
	    !fip->field_oktochange) {
		/*
		 * Consult info table to see if tag can be changed
		 * after we've started writing.  We only allow changes
		 * to those tags that don't/shouldn't affect the
		 * compression and/or format of the data.
		 */
		TIFFError("TIFFSetField",
		    "%s: Cannot modify tag \"%s\" while writing",
		    tif->tif_name, fip->field_name);
		return (0);
	}
	return (1);
}

/*
 * Record the value of a field in the
 * internal directory structure.  The
 * field will be written to the file
 * when/if the directory structure is
 * updated.
 */
int
TIFFSetField(TIFF* tif, ttag_t tag, ...)
{
	va_list ap;
	int status;

	va_start(ap, tag);
	status = TIFFVSetField(tif, tag, ap);
	va_end(ap);
	return (status);
}

/*
 * Like TIFFSetField, but taking a varargs
 * parameter list.  This routine is useful
 * for building higher-level interfaces on
 * top of the library.
 */
int
TIFFVSetField(TIFF* tif, ttag_t tag, va_list ap)
{
	return OkToChangeTag(tif, tag) ?
	    (*tif->tif_vsetfield)(tif, tag, ap) : 0;
}

static int
_TIFFVGetField(TIFF* tif, ttag_t tag, va_list ap)
{
	TIFFDirectory* td = &tif->tif_dir;

	switch (tag) {
	case TIFFTAG_SUBFILETYPE:
		*va_arg(ap, uint32*) = td->td_subfiletype;
		break;
	case TIFFTAG_IMAGEWIDTH:
		*va_arg(ap, uint32*) = td->td_imagewidth;
		break;
	case TIFFTAG_IMAGELENGTH:
		*va_arg(ap, uint32*) = td->td_imagelength;
		break;
	case TIFFTAG_BITSPERSAMPLE:
		*va_arg(ap, uint16*) = td->td_bitspersample;
		break;
	case TIFFTAG_COMPRESSION:
		*va_arg(ap, uint16*) = td->td_compression;
		break;
	case TIFFTAG_PHOTOMETRIC:
		*va_arg(ap, uint16*) = td->td_photometric;
		break;
	case TIFFTAG_THRESHHOLDING:
		*va_arg(ap, uint16*) = td->td_threshholding;
		break;
	case TIFFTAG_FILLORDER:
		*va_arg(ap, uint16*) = td->td_fillorder;
		break;
	case TIFFTAG_DOCUMENTNAME:
		*va_arg(ap, char**) = td->td_documentname;
		break;
	case TIFFTAG_ARTIST:
		*va_arg(ap, char**) = td->td_artist;
		break;
	case TIFFTAG_DATETIME:
		*va_arg(ap, char**) = td->td_datetime;
		break;
	case TIFFTAG_HOSTCOMPUTER:
		*va_arg(ap, char**) = td->td_hostcomputer;
		break;
	case TIFFTAG_IMAGEDESCRIPTION:
		*va_arg(ap, char**) = td->td_imagedescription;
		break;
	case TIFFTAG_MAKE:
		*va_arg(ap, char**) = td->td_make;
		break;
	case TIFFTAG_MODEL:
		*va_arg(ap, char**) = td->td_model;
		break;
	case TIFFTAG_SOFTWARE:
		*va_arg(ap, char**) = td->td_software;
		break;
	case TIFFTAG_ORIENTATION:
		*va_arg(ap, uint16*) = td->td_orientation;
		break;
	case TIFFTAG_SAMPLESPERPIXEL:
		*va_arg(ap, uint16*) = td->td_samplesperpixel;
		break;
	case TIFFTAG_ROWSPERSTRIP:
		*va_arg(ap, uint32*) = td->td_rowsperstrip;
		break;
	case TIFFTAG_MINSAMPLEVALUE:
		*va_arg(ap, uint16*) = td->td_minsamplevalue;
		break;
	case TIFFTAG_MAXSAMPLEVALUE:
		*va_arg(ap, uint16*) = td->td_maxsamplevalue;
		break;
	case TIFFTAG_SMINSAMPLEVALUE:
		*va_arg(ap, double*) = td->td_sminsamplevalue;
		break;
	case TIFFTAG_SMAXSAMPLEVALUE:
		*va_arg(ap, double*) = td->td_smaxsamplevalue;
		break;
	case TIFFTAG_XRESOLUTION:
		*va_arg(ap, float*) = td->td_xresolution;
		break;
	case TIFFTAG_YRESOLUTION:
		*va_arg(ap, float*) = td->td_yresolution;
		break;
	case TIFFTAG_PLANARCONFIG:
		*va_arg(ap, uint16*) = td->td_planarconfig;
		break;
	case TIFFTAG_XPOSITION:
		*va_arg(ap, float*) = td->td_xposition;
		break;
	case TIFFTAG_YPOSITION:
		*va_arg(ap, float*) = td->td_yposition;
		break;
	case TIFFTAG_PAGENAME:
		*va_arg(ap, char**) = td->td_pagename;
		break;
	case TIFFTAG_RESOLUTIONUNIT:
		*va_arg(ap, uint16*) = td->td_resolutionunit;
		break;
	case TIFFTAG_PAGENUMBER:
		*va_arg(ap, uint16*) = td->td_pagenumber[0];
		*va_arg(ap, uint16*) = td->td_pagenumber[1];
		break;
	case TIFFTAG_HALFTONEHINTS:
		*va_arg(ap, uint16*) = td->td_halftonehints[0];
		*va_arg(ap, uint16*) = td->td_halftonehints[1];
		break;
	case TIFFTAG_COLORMAP:
		*va_arg(ap, uint16**) = td->td_colormap[0];
		*va_arg(ap, uint16**) = td->td_colormap[1];
		*va_arg(ap, uint16**) = td->td_colormap[2];
		break;
	case TIFFTAG_STRIPOFFSETS:
	case TIFFTAG_TILEOFFSETS:
		*va_arg(ap, uint32**) = td->td_stripoffset;
		break;
	case TIFFTAG_STRIPBYTECOUNTS:
	case TIFFTAG_TILEBYTECOUNTS:
		*va_arg(ap, uint32**) = td->td_stripbytecount;
		break;
	case TIFFTAG_MATTEING:
		*va_arg(ap, uint16*) =
		    (td->td_extrasamples == 1 &&
		     td->td_sampleinfo[0] == EXTRASAMPLE_ASSOCALPHA);
		break;
	case TIFFTAG_EXTRASAMPLES:
		*va_arg(ap, uint16*) = td->td_extrasamples;
		*va_arg(ap, uint16**) = td->td_sampleinfo;
		break;
	case TIFFTAG_TILEWIDTH:
		*va_arg(ap, uint32*) = td->td_tilewidth;
		break;
	case TIFFTAG_TILELENGTH:
		*va_arg(ap, uint32*) = td->td_tilelength;
		break;
	case TIFFTAG_TILEDEPTH:
		*va_arg(ap, uint32*) = td->td_tiledepth;
		break;
	case TIFFTAG_DATATYPE:
		switch (td->td_sampleformat) {
		case SAMPLEFORMAT_UINT:
			*va_arg(ap, uint16*) = DATATYPE_UINT;
			break;
		case SAMPLEFORMAT_INT:
			*va_arg(ap, uint16*) = DATATYPE_INT;
			break;
		case SAMPLEFORMAT_IEEEFP:
			*va_arg(ap, uint16*) = DATATYPE_IEEEFP;
			break;
		case SAMPLEFORMAT_VOID:
			*va_arg(ap, uint16*) = DATATYPE_VOID;
			break;
		}
		break;
	case TIFFTAG_SAMPLEFORMAT:
		*va_arg(ap, uint16*) = td->td_sampleformat;
		break;
	case TIFFTAG_IMAGEDEPTH:
		*va_arg(ap, uint32*) = td->td_imagedepth;
		break;
	case TIFFTAG_STONITS:
		*va_arg(ap, double*) = td->td_stonits;
		break;
#if SUBIFD_SUPPORT
	case TIFFTAG_SUBIFD:
		*va_arg(ap, uint16*) = td->td_nsubifd;
		*va_arg(ap, uint32**) = td->td_subifd;
		break;
#endif
#ifdef YCBCR_SUPPORT
	case TIFFTAG_YCBCRCOEFFICIENTS:
		*va_arg(ap, float**) = td->td_ycbcrcoeffs;
		break;
	case TIFFTAG_YCBCRPOSITIONING:
		*va_arg(ap, uint16*) = td->td_ycbcrpositioning;
		break;
	case TIFFTAG_YCBCRSUBSAMPLING:
		*va_arg(ap, uint16*) = td->td_ycbcrsubsampling[0];
		*va_arg(ap, uint16*) = td->td_ycbcrsubsampling[1];
		break;
#endif
#ifdef COLORIMETRY_SUPPORT
	case TIFFTAG_WHITEPOINT:
		*va_arg(ap, float**) = td->td_whitepoint;
		break;
	case TIFFTAG_PRIMARYCHROMATICITIES:
		*va_arg(ap, float**) = td->td_primarychromas;
		break;
	case TIFFTAG_TRANSFERFUNCTION:
		*va_arg(ap, uint16**) = td->td_transferfunction[0];
		if (td->td_samplesperpixel - td->td_extrasamples > 1) {
			*va_arg(ap, uint16**) = td->td_transferfunction[1];
			*va_arg(ap, uint16**) = td->td_transferfunction[2];
		}
		break;
	case TIFFTAG_REFERENCEBLACKWHITE:
		*va_arg(ap, float**) = td->td_refblackwhite;
		break;
#endif
#ifdef CMYK_SUPPORT
	case TIFFTAG_INKSET:
		*va_arg(ap, uint16*) = td->td_inkset;
		break;
	case TIFFTAG_DOTRANGE:
		*va_arg(ap, uint16*) = td->td_dotrange[0];
		*va_arg(ap, uint16*) = td->td_dotrange[1];
		break;
	case TIFFTAG_INKNAMES:
		*va_arg(ap, char**) = td->td_inknames;
		break;
	case TIFFTAG_NUMBEROFINKS:
		*va_arg(ap, uint16*) = td->td_ninks;
		break;
	case TIFFTAG_TARGETPRINTER:
		*va_arg(ap, char**) = td->td_targetprinter;
		break;
#endif
#ifdef ICC_SUPPORT
	case TIFFTAG_ICCPROFILE:
		*va_arg(ap, uint32*) = td->td_profileLength;
		*va_arg(ap, void**) = td->td_profileData;
		break;
#endif
	default:
		/*
		 * This can happen if multiple images are open with
		 * different codecs which have private tags.  The
		 * global tag information table may then have tags
		 * that are valid for one file but not the other. 
		 * If the client tries to get a tag that is not valid
		 * for the image's codec then we'll arrive here.
		 */
		TIFFError("TIFFGetField",
		    "%s: Invalid %stag \"%s\" (not supported by codec)",
		    tif->tif_name, isPseudoTag(tag) ? "pseudo-" : "",
		    _TIFFFieldWithTag(tif, tag)->field_name);
		break;
	}
	return (1);
}

/*
 * Return the value of a field in the
 * internal directory structure.
 */
int
TIFFGetField(TIFF* tif, ttag_t tag, ...)
{
	int status;
	va_list ap;

	va_start(ap, tag);
	status = TIFFVGetField(tif, tag, ap);
	va_end(ap);
	return (status);
}

/*
 * Like TIFFGetField, but taking a varargs
 * parameter list.  This routine is useful
 * for building higher-level interfaces on
 * top of the library.
 */
int
TIFFVGetField(TIFF* tif, ttag_t tag, va_list ap)
{
	const TIFFFieldInfo* fip = _TIFFFindFieldInfo(tif, tag, TIFF_ANY);
	return (fip && (isPseudoTag(tag) || TIFFFieldSet(tif, fip->field_bit)) ?
	    (*tif->tif_vgetfield)(tif, tag, ap) : 0);
}

#define	CleanupField(member) {		\
    if (td->member) {			\
	_TIFFfree(td->member);		\
	td->member = 0;			\
    }					\
}

/*
 * Release storage associated with a directory.
 */
void
TIFFFreeDirectory(TIFF* tif)
{
	register TIFFDirectory *td = &tif->tif_dir;

	CleanupField(td_colormap[0]);
	CleanupField(td_colormap[1]);
	CleanupField(td_colormap[2]);
	CleanupField(td_documentname);
	CleanupField(td_artist);
	CleanupField(td_datetime);
	CleanupField(td_hostcomputer);
	CleanupField(td_imagedescription);
	CleanupField(td_make);
	CleanupField(td_model);
	CleanupField(td_software);
	CleanupField(td_pagename);
	CleanupField(td_sampleinfo);
#if SUBIFD_SUPPORT
	CleanupField(td_subifd);
#endif
#ifdef YCBCR_SUPPORT
	CleanupField(td_ycbcrcoeffs);
#endif
#ifdef CMYK_SUPPORT
	CleanupField(td_inknames);
	CleanupField(td_targetprinter);
#endif
#ifdef COLORIMETRY_SUPPORT
	CleanupField(td_whitepoint);
	CleanupField(td_primarychromas);
	CleanupField(td_refblackwhite);
	CleanupField(td_transferfunction[0]);
	CleanupField(td_transferfunction[1]);
	CleanupField(td_transferfunction[2]);
#endif
#ifdef ICC_SUPPORT
	CleanupField(td_profileData);
#endif
	CleanupField(td_stripoffset);
	CleanupField(td_stripbytecount);
}
#undef CleanupField

/*
 * Client Tag extension support (from Niles Ritter).
 */
static TIFFExtendProc _TIFFextender = (TIFFExtendProc) NULL;

TIFFExtendProc
TIFFSetTagExtender(TIFFExtendProc extender)
{
	TIFFExtendProc prev = _TIFFextender;
	_TIFFextender = extender;
	return (prev);
}

/*
 * Setup a default directory structure.
 */
int
TIFFDefaultDirectory(TIFF* tif)
{
	register TIFFDirectory* td = &tif->tif_dir;

	_TIFFSetupFieldInfo(tif);
	_TIFFmemset(td, 0, sizeof (*td));
	td->td_fillorder = FILLORDER_MSB2LSB;
	td->td_bitspersample = 1;
	td->td_threshholding = THRESHHOLD_BILEVEL;
	td->td_orientation = ORIENTATION_TOPLEFT;
	td->td_samplesperpixel = 1;
	td->td_rowsperstrip = (uint32) -1;
	td->td_tilewidth = (uint32) -1;
	td->td_tilelength = (uint32) -1;
	td->td_tiledepth = 1;
	td->td_resolutionunit = RESUNIT_INCH;
	td->td_sampleformat = SAMPLEFORMAT_VOID;
	td->td_imagedepth = 1;
#ifdef YCBCR_SUPPORT
	td->td_ycbcrsubsampling[0] = 2;
	td->td_ycbcrsubsampling[1] = 2;
	td->td_ycbcrpositioning = YCBCRPOSITION_CENTERED;
#endif
#ifdef CMYK_SUPPORT
	td->td_inkset = INKSET_CMYK;
	td->td_ninks = 4;
#endif
	tif->tif_postdecode = _TIFFNoPostDecode;
	tif->tif_vsetfield = _TIFFVSetField;
	tif->tif_vgetfield = _TIFFVGetField;
	tif->tif_printdir = NULL;
	/*
	 *  Give client code a chance to install their own
	 *  tag extensions & methods, prior to compression overloads.
	 */
	if (_TIFFextender)
		(*_TIFFextender)(tif);
	(void) TIFFSetField(tif, TIFFTAG_COMPRESSION, COMPRESSION_NONE);
	/*
	 * NB: The directory is marked dirty as a result of setting
	 * up the default compression scheme.  However, this really
	 * isn't correct -- we want TIFF_DIRTYDIRECT to be set only
	 * if the user does something.  We could just do the setup
	 * by hand, but it seems better to use the normal mechanism
	 * (i.e. TIFFSetField).
	 */
	tif->tif_flags &= ~TIFF_DIRTYDIRECT;
	return (1);
}

static int
TIFFAdvanceDirectory(TIFF* tif, uint32* nextdir, toff_t* off)
{
	static const char module[] = "TIFFAdvanceDirectory";
	uint16 dircount;

	if (!SeekOK(tif, *nextdir) ||
	    !ReadOK(tif, &dircount, sizeof (uint16))) {
		TIFFError(module, "%s: Error fetching directory count",
		    tif->tif_name);
		return (0);
	}
	if (tif->tif_flags & TIFF_SWAB)
		TIFFSwabShort(&dircount);
	if (off != NULL)
		*off = TIFFSeekFile(tif,
		    dircount*sizeof (TIFFDirEntry), SEEK_CUR);
	else
		(void) TIFFSeekFile(tif,
		    dircount*sizeof (TIFFDirEntry), SEEK_CUR);
	if (!ReadOK(tif, nextdir, sizeof (uint32))) {
		TIFFError(module, "%s: Error fetching directory link",
		    tif->tif_name);
		return (0);
	}
	if (tif->tif_flags & TIFF_SWAB)
		TIFFSwabLong(nextdir);
	return (1);
}

/*
 * Count the number of directories in a file.
 */
tdir_t
TIFFNumberOfDirectories(TIFF* tif)
{
	uint32 nextdir = tif->tif_header.tiff_diroff;
	tdir_t n = 0;

	while (nextdir != 0 && TIFFAdvanceDirectory(tif, &nextdir, NULL))
		n++;
	return (n);
}

/*
 * Set the n-th directory as the current directory.
 * NB: Directories are numbered starting at 0.
 */
int
TIFFSetDirectory(TIFF* tif, tdir_t dirn)
{
	uint32 nextdir;
	tdir_t n;

	nextdir = tif->tif_header.tiff_diroff;
	for (n = dirn; n > 0 && nextdir != 0; n--)
		if (!TIFFAdvanceDirectory(tif, &nextdir, NULL))
			return (0);
	tif->tif_nextdiroff = nextdir;
	/*
	 * Set curdir to the actual directory index.  The
	 * -1 is because TIFFReadDirectory will increment
	 * tif_curdir after successfully reading the directory.
	 */
	tif->tif_curdir = (dirn - n) - 1;
	return (TIFFReadDirectory(tif));
}

/*
 * Set the current directory to be the directory
 * located at the specified file offset.  This interface
 * is used mainly to access directories linked with
 * the SubIFD tag (e.g. thumbnail images).
 */
int
TIFFSetSubDirectory(TIFF* tif, uint32 diroff)
{
	tif->tif_nextdiroff = diroff;
	return (TIFFReadDirectory(tif));
}

/*
 * Return file offset of the current directory.
 */
uint32
TIFFCurrentDirOffset(TIFF* tif)
{
	return (tif->tif_diroff);
}

/*
 * Return an indication of whether or not we are
 * at the last directory in the file.
 */
int
TIFFLastDirectory(TIFF* tif)
{
	return (tif->tif_nextdiroff == 0);
}

/*
 * Unlink the specified directory from the directory chain.
 */
int
TIFFUnlinkDirectory(TIFF* tif, tdir_t dirn)
{
	static const char module[] = "TIFFUnlinkDirectory";
	uint32 nextdir;
	toff_t off;
	tdir_t n;

	if (tif->tif_mode == O_RDONLY) {
		TIFFError(module, "Can not unlink directory in read-only file");
		return (0);
	}
	/*
	 * Go to the directory before the one we want
	 * to unlink and nab the offset of the link
	 * field we'll need to patch.
	 */
	nextdir = tif->tif_header.tiff_diroff;
	off = sizeof (uint16) + sizeof (uint16);
	for (n = dirn-1; n > 0; n--) {
		if (nextdir == 0) {
			TIFFError(module, "Directory %d does not exist", dirn);
			return (0);
		}
		if (!TIFFAdvanceDirectory(tif, &nextdir, &off))
			return (0);
	}
	/*
	 * Advance to the directory to be unlinked and fetch
	 * the offset of the directory that follows.
	 */
	if (!TIFFAdvanceDirectory(tif, &nextdir, NULL))
		return (0);
	/*
	 * Go back and patch the link field of the preceding
	 * directory to point to the offset of the directory
	 * that follows.
	 */
	(void) TIFFSeekFile(tif, off, SEEK_SET);
	if (tif->tif_flags & TIFF_SWAB)
		TIFFSwabLong(&nextdir);
	if (!WriteOK(tif, &nextdir, sizeof (uint32))) {
		TIFFError(module, "Error writing directory link");
		return (0);
	}
	/*
	 * Leave directory state setup safely.  We don't have
	 * facilities for doing inserting and removing directories,
	 * so it's safest to just invalidate everything.  This
	 * means that the caller can only append to the directory
	 * chain.
	 */
	(*tif->tif_cleanup)(tif);
	if ((tif->tif_flags & TIFF_MYBUFFER) && tif->tif_rawdata) {
		_TIFFfree(tif->tif_rawdata);
		tif->tif_rawdata = NULL;
		tif->tif_rawcc = 0;
	}
	tif->tif_flags &= ~(TIFF_BEENWRITING|TIFF_BUFFERSETUP|TIFF_POSTENCODE);
	TIFFFreeDirectory(tif);
	TIFFDefaultDirectory(tif);
	tif->tif_diroff = 0;			/* force link on next write */
	tif->tif_nextdiroff = 0;		/* next write must be at end */
	tif->tif_curoff = 0;
	tif->tif_row = (uint32) -1;
	tif->tif_curstrip = (tstrip_t) -1;
	return (1);
}
