third_party/libtiff/tif_aux.c - pdfium - Git at Google

 /* $Id: tif_aux.c,v 1.26 2010-07-01 15:33:28 dron Exp $ */

 /*
  * Copyright (c) 1991-1997 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.
  *
  * Auxiliary Support Routines.
  */
 #include "tiffiop.h"
 #include "tif_predict.h"
 #include <math.h>

 uint32
 _TIFFMultiply32(TIFF* tif, uint32 first, uint32 second, const char* where)
 {
 	uint32 bytes = first * second;

 	if (second && bytes / second != first) {
 		TIFFErrorExt(tif->tif_clientdata, where, "Integer overflow in %s", where);
 		bytes = 0;
 	}

 	return bytes;
 }

 uint64
 _TIFFMultiply64(TIFF* tif, uint64 first, uint64 second, const char* where)
 {
 	uint64 bytes = first * second;

 	if (second && bytes / second != first) {
 		TIFFErrorExt(tif->tif_clientdata, where, "Integer overflow in %s", where);
 		bytes = 0;
 	}

 	return bytes;
 }

 void*
 _TIFFCheckRealloc(TIFF* tif, void* buffer,
 		  tmsize_t nmemb, tmsize_t elem_size, const char* what)
 {
 	void* cp = NULL;
 	tmsize_t bytes = nmemb * elem_size;

 	/*
 	 * XXX: Check for integer overflow.
 	 */
 	if (nmemb && elem_size && bytes / elem_size == nmemb)
 		cp = _TIFFrealloc(buffer, bytes);

 	if (cp == NULL) {
 		TIFFErrorExt(tif->tif_clientdata, tif->tif_name,
 			     "Failed to allocate memory for %s "
 			     "(%ld elements of %ld bytes each)",
 			     what,(long) nmemb, (long) elem_size);
 	}

 	return cp;
 }

 void*
 _TIFFCheckMalloc(TIFF* tif, tmsize_t nmemb, tmsize_t elem_size, const char* what)
 {
 	return _TIFFCheckRealloc(tif, NULL, nmemb, elem_size, what);
 }

 static int
 TIFFDefaultTransferFunction(TIFFDirectory* td)
 {
 	uint16 **tf = td->td_transferfunction;
 	tmsize_t i, n, nbytes;

 	tf[0] = tf[1] = tf[2] = 0;
 	if (td->td_bitspersample >= sizeof(tmsize_t) * 8 - 2)
 		return 0;

 	n = ((tmsize_t)1)<<td->td_bitspersample;
 	nbytes = n * sizeof (uint16);
 	if (!(tf[0] = (uint16 *)_TIFFmalloc(nbytes)))
 		return 0;
 	tf[0][0] = 0;
 	for (i = 1; i < n; i++) {
 		double t = (double)i/((double) n-1.);
 		tf[0][i] = (uint16)floor(65535.*pow(t, 2.2) + .5);
 	}

 	if (td->td_samplesperpixel - td->td_extrasamples > 1) {
 		if (!(tf[1] = (uint16 *)_TIFFmalloc(nbytes)))
 			goto bad;
 		_TIFFmemcpy(tf[1], tf[0], nbytes);
 		if (!(tf[2] = (uint16 *)_TIFFmalloc(nbytes)))
 			goto bad;
 		_TIFFmemcpy(tf[2], tf[0], nbytes);
 	}
 	return 1;

 bad:
 	if (tf[0])
 		_TIFFfree(tf[0]);
 	if (tf[1])
 		_TIFFfree(tf[1]);
 	if (tf[2])
 		_TIFFfree(tf[2]);
 	tf[0] = tf[1] = tf[2] = 0;
 	return 0;
 }

 static int
 TIFFDefaultRefBlackWhite(TIFFDirectory* td)
 {
 	int i;

 	if (!(td->td_refblackwhite = (float *)_TIFFmalloc(6*sizeof (float))))
 		return 0;
         if (td->td_photometric == PHOTOMETRIC_YCBCR) {
 		/*
 		 * YCbCr (Class Y) images must have the ReferenceBlackWhite
 		 * tag set. Fix the broken images, which lacks that tag.
 		 */
 		td->td_refblackwhite[0] = 0.0F;
 		td->td_refblackwhite[1] = td->td_refblackwhite[3] =
 			td->td_refblackwhite[5] = 255.0F;
 		td->td_refblackwhite[2] = td->td_refblackwhite[4] = 128.0F;
 	} else {
 		/*
 		 * Assume RGB (Class R)
 		 */
 		for (i = 0; i < 3; i++) {
 		    td->td_refblackwhite[2*i+0] = 0;
 		    td->td_refblackwhite[2*i+1] =
 			    (float)((1L<<td->td_bitspersample)-1L);
 		}
 	}
 	return 1;
 }

 /*
  * Like TIFFGetField, but return any default
  * value if the tag is not present in the directory.
  *
  * NB:	We use the value in the directory, rather than
  *	explcit values so that defaults exist only one
  *	place in the library -- in TIFFDefaultDirectory.
  */
 int
 TIFFVGetFieldDefaulted(TIFF* tif, uint32 tag, va_list ap)
 {
 	TIFFDirectory *td = &tif->tif_dir;

 	if (TIFFVGetField(tif, tag, ap))
 		return (1);
 	switch (tag) {
 	case TIFFTAG_SUBFILETYPE:
 		*va_arg(ap, uint32 *) = td->td_subfiletype;
 		return (1);
 	case TIFFTAG_BITSPERSAMPLE:
 		*va_arg(ap, uint16 *) = td->td_bitspersample;
 		return (1);
 	case TIFFTAG_THRESHHOLDING:
 		*va_arg(ap, uint16 *) = td->td_threshholding;
 		return (1);
 	case TIFFTAG_FILLORDER:
 		*va_arg(ap, uint16 *) = td->td_fillorder;
 		return (1);
 	case TIFFTAG_ORIENTATION:
 		*va_arg(ap, uint16 *) = td->td_orientation;
 		return (1);
 	case TIFFTAG_SAMPLESPERPIXEL:
 		*va_arg(ap, uint16 *) = td->td_samplesperpixel;
 		return (1);
 	case TIFFTAG_ROWSPERSTRIP:
 		*va_arg(ap, uint32 *) = td->td_rowsperstrip;
 		return (1);
 	case TIFFTAG_MINSAMPLEVALUE:
 		*va_arg(ap, uint16 *) = td->td_minsamplevalue;
 		return (1);
 	case TIFFTAG_MAXSAMPLEVALUE:
 		*va_arg(ap, uint16 *) = td->td_maxsamplevalue;
 		return (1);
 	case TIFFTAG_PLANARCONFIG:
 		*va_arg(ap, uint16 *) = td->td_planarconfig;
 		return (1);
 	case TIFFTAG_RESOLUTIONUNIT:
 		*va_arg(ap, uint16 *) = td->td_resolutionunit;
 		return (1);
 	case TIFFTAG_PREDICTOR:
                 {
 			TIFFPredictorState* sp = (TIFFPredictorState*) tif->tif_data;
 			*va_arg(ap, uint16*) = (uint16) sp->predictor;
 			return 1;
                 }
 	case TIFFTAG_DOTRANGE:
 		*va_arg(ap, uint16 *) = 0;
 		*va_arg(ap, uint16 *) = (1<<td->td_bitspersample)-1;
 		return (1);
 	case TIFFTAG_INKSET:
 		*va_arg(ap, uint16 *) = INKSET_CMYK;
 		return 1;
 	case TIFFTAG_NUMBEROFINKS:
 		*va_arg(ap, uint16 *) = 4;
 		return (1);
 	case TIFFTAG_EXTRASAMPLES:
 		*va_arg(ap, uint16 *) = td->td_extrasamples;
 		*va_arg(ap, uint16 **) = td->td_sampleinfo;
 		return (1);
 	case TIFFTAG_MATTEING:
 		*va_arg(ap, uint16 *) =
 		    (td->td_extrasamples == 1 &&
 		     td->td_sampleinfo[0] == EXTRASAMPLE_ASSOCALPHA);
 		return (1);
 	case TIFFTAG_TILEDEPTH:
 		*va_arg(ap, uint32 *) = td->td_tiledepth;
 		return (1);
 	case TIFFTAG_DATATYPE:
 		*va_arg(ap, uint16 *) = td->td_sampleformat-1;
 		return (1);
 	case TIFFTAG_SAMPLEFORMAT:
 		*va_arg(ap, uint16 *) = td->td_sampleformat;
                 return(1);
 	case TIFFTAG_IMAGEDEPTH:
 		*va_arg(ap, uint32 *) = td->td_imagedepth;
 		return (1);
 	case TIFFTAG_YCBCRCOEFFICIENTS:
 		{
 			/* defaults are from CCIR Recommendation 601-1 */
 			static float ycbcrcoeffs[] = { 0.299f, 0.587f, 0.114f };
 			*va_arg(ap, float **) = ycbcrcoeffs;
 			return 1;
 		}
 	case TIFFTAG_YCBCRSUBSAMPLING:
 		*va_arg(ap, uint16 *) = td->td_ycbcrsubsampling[0];
 		*va_arg(ap, uint16 *) = td->td_ycbcrsubsampling[1];
 		return (1);
 	case TIFFTAG_YCBCRPOSITIONING:
 		*va_arg(ap, uint16 *) = td->td_ycbcrpositioning;
 		return (1);
 	case TIFFTAG_WHITEPOINT:
 		{
 			static float whitepoint[2];

 			/* TIFF 6.0 specification tells that it is no default
 			   value for the WhitePoint, but AdobePhotoshop TIFF
 			   Technical Note tells that it should be CIE D50. */
 			whitepoint[0] =	D50_X0 / (D50_X0 + D50_Y0 + D50_Z0);
 			whitepoint[1] =	D50_Y0 / (D50_X0 + D50_Y0 + D50_Z0);
 			*va_arg(ap, float **) = whitepoint;
 			return 1;
 		}
 	case TIFFTAG_TRANSFERFUNCTION:
 		if (!td->td_transferfunction[0] &&
 		    !TIFFDefaultTransferFunction(td)) {
 			TIFFErrorExt(tif->tif_clientdata, tif->tif_name, "No space for \"TransferFunction\" tag");
 			return (0);
 		}
 		*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];
 		}
 		return (1);
 	case TIFFTAG_REFERENCEBLACKWHITE:
 		if (!td->td_refblackwhite && !TIFFDefaultRefBlackWhite(td))
 			return (0);
 		*va_arg(ap, float **) = td->td_refblackwhite;
 		return (1);
 	}
 	return 0;
 }

 /*
  * Like TIFFGetField, but return any default
  * value if the tag is not present in the directory.
  */
 int
 TIFFGetFieldDefaulted(TIFF* tif, uint32 tag, ...)
 {
 	int ok;
 	va_list ap;

 	va_start(ap, tag);
 	ok =  TIFFVGetFieldDefaulted(tif, tag, ap);
 	va_end(ap);
 	return (ok);
 }

 struct _Int64Parts {
 	int32 low, high;
 };

 typedef union {
 	struct _Int64Parts part;
 	int64 value;
 } _Int64;

 float
 _TIFFUInt64ToFloat(uint64 ui64)
 {
 	_Int64 i;

 	i.value = ui64;
 	if (i.part.high >= 0) {
 		return (float)i.value;
 	} else {
 		long double df;
 		df = (long double)i.value;
 		df += 18446744073709551616.0; /* adding 2**64 */
 		return (float)df;
 	}
 }

 double
 _TIFFUInt64ToDouble(uint64 ui64)
 {
 	_Int64 i;

 	i.value = ui64;
 	if (i.part.high >= 0) {
 		return (double)i.value;
 	} else {
 		long double df;
 		df = (long double)i.value;
 		df += 18446744073709551616.0; /* adding 2**64 */
 		return (double)df;
 	}
 }

 /* vim: set ts=8 sts=8 sw=8 noet: */
 /*
  * Local Variables:
  * mode: c
  * c-basic-offset: 8
  * fill-column: 78
  * End:
  */
	/* $Id: tif_aux.c,v 1.26 2010-07-01 15:33:28 dron Exp $ */

	/*
	* Copyright (c) 1991-1997 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.
	*
	* Auxiliary Support Routines.
	*/
	#include "tiffiop.h"
	#include "tif_predict.h"
	#include <math.h>

	uint32
	_TIFFMultiply32(TIFF* tif, uint32 first, uint32 second, const char* where)
	{
	uint32 bytes = first * second;

	if (second && bytes / second != first) {
	TIFFErrorExt(tif->tif_clientdata, where, "Integer overflow in %s", where);
	bytes = 0;
	}

	return bytes;
	}

	uint64
	_TIFFMultiply64(TIFF* tif, uint64 first, uint64 second, const char* where)
	{
	uint64 bytes = first * second;

	if (second && bytes / second != first) {
	TIFFErrorExt(tif->tif_clientdata, where, "Integer overflow in %s", where);
	bytes = 0;
	}

	return bytes;
	}

	void*
	_TIFFCheckRealloc(TIFF* tif, void* buffer,
	tmsize_t nmemb, tmsize_t elem_size, const char* what)
	{
	void* cp = NULL;
	tmsize_t bytes = nmemb * elem_size;

	/*
	* XXX: Check for integer overflow.
	*/
	if (nmemb && elem_size && bytes / elem_size == nmemb)
	cp = _TIFFrealloc(buffer, bytes);

	if (cp == NULL) {
	TIFFErrorExt(tif->tif_clientdata, tif->tif_name,
	"Failed to allocate memory for %s "
	"(%ld elements of %ld bytes each)",
	what,(long) nmemb, (long) elem_size);
	}

	return cp;
	}

	void*
	_TIFFCheckMalloc(TIFF* tif, tmsize_t nmemb, tmsize_t elem_size, const char* what)
	{
	return _TIFFCheckRealloc(tif, NULL, nmemb, elem_size, what);
	}

	static int
	TIFFDefaultTransferFunction(TIFFDirectory* td)
	{
	uint16 **tf = td->td_transferfunction;
	tmsize_t i, n, nbytes;

	tf[0] = tf[1] = tf[2] = 0;
	if (td->td_bitspersample >= sizeof(tmsize_t) * 8 - 2)
	return 0;

	n = ((tmsize_t)1)<<td->td_bitspersample;
	nbytes = n * sizeof (uint16);
	if (!(tf[0] = (uint16 *)_TIFFmalloc(nbytes)))
	return 0;
	tf[0][0] = 0;
	for (i = 1; i < n; i++) {
	double t = (double)i/((double) n-1.);
	tf[0][i] = (uint16)floor(65535.*pow(t, 2.2) + .5);
	}

	if (td->td_samplesperpixel - td->td_extrasamples > 1) {
	if (!(tf[1] = (uint16 *)_TIFFmalloc(nbytes)))
	goto bad;
	_TIFFmemcpy(tf[1], tf[0], nbytes);
	if (!(tf[2] = (uint16 *)_TIFFmalloc(nbytes)))
	goto bad;
	_TIFFmemcpy(tf[2], tf[0], nbytes);
	}
	return 1;

	bad:
	if (tf[0])
	_TIFFfree(tf[0]);
	if (tf[1])
	_TIFFfree(tf[1]);
	if (tf[2])
	_TIFFfree(tf[2]);
	tf[0] = tf[1] = tf[2] = 0;
	return 0;
	}

	static int
	TIFFDefaultRefBlackWhite(TIFFDirectory* td)
	{
	int i;

	if (!(td->td_refblackwhite = (float )_TIFFmalloc(6sizeof (float))))
	return 0;
	if (td->td_photometric == PHOTOMETRIC_YCBCR) {
	/*
	* YCbCr (Class Y) images must have the ReferenceBlackWhite
	* tag set. Fix the broken images, which lacks that tag.
	*/
	td->td_refblackwhite[0] = 0.0F;
	td->td_refblackwhite[1] = td->td_refblackwhite[3] =
	td->td_refblackwhite[5] = 255.0F;
	td->td_refblackwhite[2] = td->td_refblackwhite[4] = 128.0F;
	} else {
	/*
	* Assume RGB (Class R)
	*/
	for (i = 0; i < 3; i++) {
	td->td_refblackwhite[2*i+0] = 0;
	td->td_refblackwhite[2*i+1] =
	(float)((1L<<td->td_bitspersample)-1L);
	}
	}
	return 1;
	}

	/*
	* Like TIFFGetField, but return any default
	* value if the tag is not present in the directory.
	*
	* NB: We use the value in the directory, rather than
	* explcit values so that defaults exist only one
	* place in the library -- in TIFFDefaultDirectory.
	*/
	int
	TIFFVGetFieldDefaulted(TIFF* tif, uint32 tag, va_list ap)
	{
	TIFFDirectory *td = &tif->tif_dir;

	if (TIFFVGetField(tif, tag, ap))
	return (1);
	switch (tag) {
	case TIFFTAG_SUBFILETYPE:
	va_arg(ap, uint32 ) = td->td_subfiletype;
	return (1);
	case TIFFTAG_BITSPERSAMPLE:
	va_arg(ap, uint16 ) = td->td_bitspersample;
	return (1);
	case TIFFTAG_THRESHHOLDING:
	va_arg(ap, uint16 ) = td->td_threshholding;
	return (1);
	case TIFFTAG_FILLORDER:
	va_arg(ap, uint16 ) = td->td_fillorder;
	return (1);
	case TIFFTAG_ORIENTATION:
	va_arg(ap, uint16 ) = td->td_orientation;
	return (1);
	case TIFFTAG_SAMPLESPERPIXEL:
	va_arg(ap, uint16 ) = td->td_samplesperpixel;
	return (1);
	case TIFFTAG_ROWSPERSTRIP:
	va_arg(ap, uint32 ) = td->td_rowsperstrip;
	return (1);
	case TIFFTAG_MINSAMPLEVALUE:
	va_arg(ap, uint16 ) = td->td_minsamplevalue;
	return (1);
	case TIFFTAG_MAXSAMPLEVALUE:
	va_arg(ap, uint16 ) = td->td_maxsamplevalue;
	return (1);
	case TIFFTAG_PLANARCONFIG:
	va_arg(ap, uint16 ) = td->td_planarconfig;
	return (1);
	case TIFFTAG_RESOLUTIONUNIT:
	va_arg(ap, uint16 ) = td->td_resolutionunit;
	return (1);
	case TIFFTAG_PREDICTOR:
	{
	TIFFPredictorState* sp = (TIFFPredictorState*) tif->tif_data;
	va_arg(ap, uint16) = (uint16) sp->predictor;
	return 1;
	}
	case TIFFTAG_DOTRANGE:
	va_arg(ap, uint16 ) = 0;
	va_arg(ap, uint16 ) = (1<<td->td_bitspersample)-1;
	return (1);
	case TIFFTAG_INKSET:
	va_arg(ap, uint16 ) = INKSET_CMYK;
	return 1;
	case TIFFTAG_NUMBEROFINKS:
	va_arg(ap, uint16 ) = 4;
	return (1);
	case TIFFTAG_EXTRASAMPLES:
	va_arg(ap, uint16 ) = td->td_extrasamples;
	va_arg(ap, uint16 *) = td->td_sampleinfo;
	return (1);
	case TIFFTAG_MATTEING:
	va_arg(ap, uint16 ) =
	(td->td_extrasamples == 1 &&
	td->td_sampleinfo[0] == EXTRASAMPLE_ASSOCALPHA);
	return (1);
	case TIFFTAG_TILEDEPTH:
	va_arg(ap, uint32 ) = td->td_tiledepth;
	return (1);
	case TIFFTAG_DATATYPE:
	va_arg(ap, uint16 ) = td->td_sampleformat-1;
	return (1);
	case TIFFTAG_SAMPLEFORMAT:
	va_arg(ap, uint16 ) = td->td_sampleformat;
	return(1);
	case TIFFTAG_IMAGEDEPTH:
	va_arg(ap, uint32 ) = td->td_imagedepth;
	return (1);
	case TIFFTAG_YCBCRCOEFFICIENTS:
	{
	/* defaults are from CCIR Recommendation 601-1 */
	static float ycbcrcoeffs[] = { 0.299f, 0.587f, 0.114f };
	va_arg(ap, float *) = ycbcrcoeffs;
	return 1;
	}
	case TIFFTAG_YCBCRSUBSAMPLING:
	va_arg(ap, uint16 ) = td->td_ycbcrsubsampling[0];
	va_arg(ap, uint16 ) = td->td_ycbcrsubsampling[1];
	return (1);
	case TIFFTAG_YCBCRPOSITIONING:
	va_arg(ap, uint16 ) = td->td_ycbcrpositioning;
	return (1);
	case TIFFTAG_WHITEPOINT:
	{
	static float whitepoint[2];

	/* TIFF 6.0 specification tells that it is no default
	value for the WhitePoint, but AdobePhotoshop TIFF
	Technical Note tells that it should be CIE D50. */
	whitepoint[0] = D50_X0 / (D50_X0 + D50_Y0 + D50_Z0);
	whitepoint[1] = D50_Y0 / (D50_X0 + D50_Y0 + D50_Z0);
	va_arg(ap, float *) = whitepoint;
	return 1;
	}
	case TIFFTAG_TRANSFERFUNCTION:
	if (!td->td_transferfunction[0] &&
	!TIFFDefaultTransferFunction(td)) {
	TIFFErrorExt(tif->tif_clientdata, tif->tif_name, "No space for \"TransferFunction\" tag");
	return (0);
	}
	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];
	}
	return (1);
	case TIFFTAG_REFERENCEBLACKWHITE:
	if (!td->td_refblackwhite && !TIFFDefaultRefBlackWhite(td))
	return (0);
	va_arg(ap, float *) = td->td_refblackwhite;
	return (1);
	}
	return 0;
	}

	/*
	* Like TIFFGetField, but return any default
	* value if the tag is not present in the directory.
	*/
	int
	TIFFGetFieldDefaulted(TIFF* tif, uint32 tag, ...)
	{
	int ok;
	va_list ap;

	va_start(ap, tag);
	ok = TIFFVGetFieldDefaulted(tif, tag, ap);
	va_end(ap);
	return (ok);
	}

	struct _Int64Parts {
	int32 low, high;
	};

	typedef union {
	struct _Int64Parts part;
	int64 value;
	} _Int64;

	float
	_TIFFUInt64ToFloat(uint64 ui64)
	{
	_Int64 i;

	i.value = ui64;
	if (i.part.high >= 0) {
	return (float)i.value;
	} else {
	long double df;
	df = (long double)i.value;
	df += 18446744073709551616.0; /* adding 2*64 /
	return (float)df;
	}
	}

	double
	_TIFFUInt64ToDouble(uint64 ui64)
	{
	_Int64 i;

	i.value = ui64;
	if (i.part.high >= 0) {
	return (double)i.value;
	} else {
	long double df;
	df = (long double)i.value;
	df += 18446744073709551616.0; /* adding 2*64 /
	return (double)df;
	}
	}

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