[wxWidgets.git] / src / tiff / tif_open.c

/* $Header$ */

/*
 * 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.
 */
#include "tiffiop.h"

void _TIFFSetDefaultCompressionState(TIFF* tif);

static const long typemask[13] = {
	0L,		/* TIFF_NOTYPE */
	0x000000ffL,	/* TIFF_BYTE */
	0xffffffffL,	/* TIFF_ASCII */
	0x0000ffffL,	/* TIFF_SHORT */
	0xffffffffL,	/* TIFF_LONG */
	0xffffffffL,	/* TIFF_RATIONAL */
	0x000000ffL,	/* TIFF_SBYTE */
	0x000000ffL,	/* TIFF_UNDEFINED */
	0x0000ffffL,	/* TIFF_SSHORT */
	0xffffffffL,	/* TIFF_SLONG */
	0xffffffffL,	/* TIFF_SRATIONAL */
	0xffffffffL,	/* TIFF_FLOAT */
	0xffffffffL,	/* TIFF_DOUBLE */
};
static const int bigTypeshift[13] = {
	0,		/* TIFF_NOTYPE */
	24,		/* TIFF_BYTE */
	0,		/* TIFF_ASCII */
	16,		/* TIFF_SHORT */
	0,		/* TIFF_LONG */
	0,		/* TIFF_RATIONAL */
	24,		/* TIFF_SBYTE */
	24,		/* TIFF_UNDEFINED */
	16,		/* TIFF_SSHORT */
	0,		/* TIFF_SLONG */
	0,		/* TIFF_SRATIONAL */
	0,		/* TIFF_FLOAT */
	0,		/* TIFF_DOUBLE */
};
static const int litTypeshift[13] = {
	0,		/* TIFF_NOTYPE */
	0,		/* TIFF_BYTE */
	0,		/* TIFF_ASCII */
	0,		/* TIFF_SHORT */
	0,		/* TIFF_LONG */
	0,		/* TIFF_RATIONAL */
	0,		/* TIFF_SBYTE */
	0,		/* TIFF_UNDEFINED */
	0,		/* TIFF_SSHORT */
	0,		/* TIFF_SLONG */
	0,		/* TIFF_SRATIONAL */
	0,		/* TIFF_FLOAT */
	0,		/* TIFF_DOUBLE */
};

/*
 * Initialize the shift & mask tables, and the
 * byte swapping state according to the file
 * contents and the machine architecture.
 */
static void
TIFFInitOrder(TIFF* tif, int magic, int bigendian)
{
	tif->tif_typemask = typemask;
	if (magic == TIFF_BIGENDIAN) {
		tif->tif_typeshift = bigTypeshift;
		if (!bigendian)
			tif->tif_flags |= TIFF_SWAB;
	} else {
		tif->tif_typeshift = litTypeshift;
		if (bigendian)
			tif->tif_flags |= TIFF_SWAB;
	}
}

int
_TIFFgetMode(const char* mode, const char* module)
{
	int m = -1;

	switch (mode[0]) {
	case 'r':
		m = O_RDONLY;
		if (mode[1] == '+')
			m = O_RDWR;
		break;
	case 'w':
	case 'a':
		m = O_RDWR|O_CREAT;
		if (mode[0] == 'w')
			m |= O_TRUNC;
		break;
	default:
		TIFFError(module, "\"%s\": Bad mode", mode);
		break;
	}
	return (m);
}

TIFF*
TIFFClientOpen(
	const char* name, const char* mode,
	thandle_t clientdata,
	TIFFReadWriteProc readproc,
	TIFFReadWriteProc writeproc,
	TIFFSeekProc seekproc,
	TIFFCloseProc closeproc,
	TIFFSizeProc sizeproc,
	TIFFMapFileProc mapproc,
	TIFFUnmapFileProc unmapproc
)
{
	static const char module[] = "TIFFClientOpen";
	TIFF *tif;
	int m, bigendian;
	const char* cp;

	m = _TIFFgetMode(mode, module);
	if (m == -1)
		goto bad2;
	tif = (TIFF *)_TIFFmalloc(sizeof (TIFF) + strlen(name) + 1);
	if (tif == NULL) {
		TIFFError(module, "%s: Out of memory (TIFF structure)", name);
		goto bad2;
	}
	_TIFFmemset(tif, 0, sizeof (*tif));
	tif->tif_name = (char *)tif + sizeof (TIFF);
	strcpy(tif->tif_name, name);
	tif->tif_mode = m &~ (O_CREAT|O_TRUNC);
	tif->tif_curdir = (tdir_t) -1;		/* non-existent directory */
	tif->tif_curoff = 0;
	tif->tif_curstrip = (tstrip_t) -1;	/* invalid strip */
	tif->tif_row = (uint32) -1;		/* read/write pre-increment */
	tif->tif_clientdata = clientdata;
	tif->tif_readproc = readproc;
	tif->tif_writeproc = writeproc;
	tif->tif_seekproc = seekproc;
	tif->tif_closeproc = closeproc;
	tif->tif_sizeproc = sizeproc;
	tif->tif_mapproc = mapproc;
	tif->tif_unmapproc = unmapproc;
	_TIFFSetDefaultCompressionState(tif);	/* setup default state */
	/*
	 * Default is to return data MSB2LSB and enable the
	 * use of memory-mapped files and strip chopping when
	 * a file is opened read-only.
	 */
	tif->tif_flags = FILLORDER_MSB2LSB;
	if (m == O_RDONLY)
#ifdef STRIPCHOP_DEFAULT
		tif->tif_flags |= TIFF_MAPPED|STRIPCHOP_DEFAULT;
#else
		tif->tif_flags |= TIFF_MAPPED;
#endif

	{ union { int32 i; char c[4]; } u; u.i = 1; bigendian = u.c[0] == 0; }
	/*
	 * Process library-specific flags in the open mode string.
	 * The following flags may be used to control intrinsic library
	 * behaviour that may or may not be desirable (usually for
	 * compatibility with some application that claims to support
	 * TIFF but only supports some braindead idea of what the
	 * vendor thinks TIFF is):
	 *
	 * 'l'		use little-endian byte order for creating a file
	 * 'b'		use big-endian byte order for creating a file
	 * 'L'		read/write information using LSB2MSB bit order
	 * 'B'		read/write information using MSB2LSB bit order
	 * 'H'		read/write information using host bit order
	 * 'M'		enable use of memory-mapped files when supported
	 * 'm'		disable use of memory-mapped files
	 * 'C'		enable strip chopping support when reading
	 * 'c'		disable strip chopping support
	 *
	 * The use of the 'l' and 'b' flags is strongly discouraged.
	 * These flags are provided solely because numerous vendors,
	 * typically on the PC, do not correctly support TIFF; they
	 * only support the Intel little-endian byte order.  This
	 * support is not configured by default because it supports
	 * the violation of the TIFF spec that says that readers *MUST*
	 * support both byte orders.  It is strongly recommended that
	 * you not use this feature except to deal with busted apps
	 * that write invalid TIFF.  And even in those cases you should
	 * bang on the vendors to fix their software.
	 *
	 * The 'L', 'B', and 'H' flags are intended for applications
	 * that can optimize operations on data by using a particular
	 * bit order.  By default the library returns data in MSB2LSB
	 * bit order for compatibiltiy with older versions of this
	 * library.  Returning data in the bit order of the native cpu
	 * makes the most sense but also requires applications to check
	 * the value of the FillOrder tag; something they probabyl do
	 * not do right now.
	 *
	 * The 'M' and 'm' flags are provided because some virtual memory
	 * systems exhibit poor behaviour when large images are mapped.
	 * These options permit clients to control the use of memory-mapped
	 * files on a per-file basis.
	 *
	 * The 'C' and 'c' flags are provided because the library support
	 * for chopping up large strips into multiple smaller strips is not
	 * application-transparent and as such can cause problems.  The 'c'
	 * option permits applications that only want to look at the tags,
	 * for example, to get the unadulterated TIFF tag information.
	 */
	for (cp = mode; *cp; cp++)
		switch (*cp) {
		case 'b':
			if ((m&O_CREAT) && !bigendian)
				tif->tif_flags |= TIFF_SWAB;
			break;
		case 'l':
			if ((m&O_CREAT) && bigendian)
				tif->tif_flags |= TIFF_SWAB;
			break;
		case 'B':
			tif->tif_flags = (tif->tif_flags &~ TIFF_FILLORDER) |
			    FILLORDER_MSB2LSB;
			break;
		case 'L':
			tif->tif_flags = (tif->tif_flags &~ TIFF_FILLORDER) |
			    FILLORDER_LSB2MSB;
			break;
		case 'H':
			tif->tif_flags = (tif->tif_flags &~ TIFF_FILLORDER) |
			    HOST_FILLORDER;
			break;
		case 'M':
			if (m == O_RDONLY)
				tif->tif_flags |= TIFF_MAPPED;
			break;
		case 'm':
			if (m == O_RDONLY)
				tif->tif_flags &= ~TIFF_MAPPED;
			break;
		case 'C':
			if (m == O_RDONLY)
				tif->tif_flags |= TIFF_STRIPCHOP;
			break;
		case 'c':
			if (m == O_RDONLY)
				tif->tif_flags &= ~TIFF_STRIPCHOP;
			break;
		}
	/*
	 * Read in TIFF header.
	 */
	if (!ReadOK(tif, &tif->tif_header, sizeof (TIFFHeader))) {
		if (tif->tif_mode == O_RDONLY) {
			TIFFError(name, "Cannot read TIFF header");
			goto bad;
		}
		/*
		 * Setup header and write.
		 */
		tif->tif_header.tiff_magic = tif->tif_flags & TIFF_SWAB
		    ? (bigendian ? TIFF_LITTLEENDIAN : TIFF_BIGENDIAN)
		    : (bigendian ? TIFF_BIGENDIAN : TIFF_LITTLEENDIAN);
		tif->tif_header.tiff_version = TIFF_VERSION;
		if (tif->tif_flags & TIFF_SWAB)
			TIFFSwabShort(&tif->tif_header.tiff_version);
		tif->tif_header.tiff_diroff = 0;	/* filled in later */
		if (!WriteOK(tif, &tif->tif_header, sizeof (TIFFHeader))) {
			TIFFError(name, "Error writing TIFF header");
			goto bad;
		}
		/*
		 * Setup the byte order handling.
		 */
		TIFFInitOrder(tif, tif->tif_header.tiff_magic, bigendian);
		/*
		 * Setup default directory.
		 */
		if (!TIFFDefaultDirectory(tif))
			goto bad;
		tif->tif_diroff = 0;
		return (tif);
	}
	/*
	 * Setup the byte order handling.
	 */
	if (tif->tif_header.tiff_magic != TIFF_BIGENDIAN &&
	    tif->tif_header.tiff_magic != TIFF_LITTLEENDIAN) {
		TIFFError(name,  "Not a TIFF file, bad magic number %d (0x%x)",
		    tif->tif_header.tiff_magic,
		    tif->tif_header.tiff_magic);
		goto bad;
	}
	TIFFInitOrder(tif, tif->tif_header.tiff_magic, bigendian);
	/*
	 * Swap header if required.
	 */
	if (tif->tif_flags & TIFF_SWAB) {
		TIFFSwabShort(&tif->tif_header.tiff_version);
		TIFFSwabLong(&tif->tif_header.tiff_diroff);
	}
	/*
	 * Now check version (if needed, it's been byte-swapped).
	 * Note that this isn't actually a version number, it's a
	 * magic number that doesn't change (stupid).
	 */
	if (tif->tif_header.tiff_version != TIFF_VERSION) {
		TIFFError(name,
		    "Not a TIFF file, bad version number %d (0x%x)",
		    tif->tif_header.tiff_version,
		    tif->tif_header.tiff_version); 
		goto bad;
	}
	tif->tif_flags |= TIFF_MYBUFFER;
	tif->tif_rawcp = tif->tif_rawdata = 0;
	tif->tif_rawdatasize = 0;
	/*
	 * Setup initial directory.
	 */
	switch (mode[0]) {
	case 'r':
		tif->tif_nextdiroff = tif->tif_header.tiff_diroff;
		/*
		 * Try to use a memory-mapped file if the client
		 * has not explicitly suppressed usage with the
		 * 'm' flag in the open mode (see above).
		 */
		if ((tif->tif_flags & TIFF_MAPPED) &&
	!TIFFMapFileContents(tif, (tdata_t*) &tif->tif_base, &tif->tif_size))
			tif->tif_flags &= ~TIFF_MAPPED;
		if (TIFFReadDirectory(tif)) {
			tif->tif_rawcc = -1;
			tif->tif_flags |= TIFF_BUFFERSETUP;
			return (tif);
		}
		break;
	case 'a':
		/*
		 * New directories are automatically append
		 * to the end of the directory chain when they
		 * are written out (see TIFFWriteDirectory).
		 */
		if (!TIFFDefaultDirectory(tif))
			goto bad;
		return (tif);
	}
bad:
	tif->tif_mode = O_RDONLY;	/* XXX avoid flush */
	TIFFClose(tif);
	return ((TIFF*)0);
bad2:
	(void) (*closeproc)(clientdata);
	return ((TIFF*)0);
}

/*
 * Query functions to access private data.
 */

/*
 * Return open file's name.
 */
const char *
TIFFFileName(TIFF* tif)
{
	return (tif->tif_name);
}

/*
 * Return open file's I/O descriptor.
 */
int
TIFFFileno(TIFF* tif)
{
	return (tif->tif_fd);
}

/*
 * Return read/write mode.
 */
int
TIFFGetMode(TIFF* tif)
{
	return (tif->tif_mode);
}

/*
 * Return nonzero if file is organized in
 * tiles; zero if organized as strips.
 */
int
TIFFIsTiled(TIFF* tif)
{
	return (isTiled(tif));
}

/*
 * Return current row being read/written.
 */
uint32
TIFFCurrentRow(TIFF* tif)
{
	return (tif->tif_row);
}

/*
 * Return index of the current directory.
 */
tdir_t
TIFFCurrentDirectory(TIFF* tif)
{
	return (tif->tif_curdir);
}

/*
 * Return current strip.
 */
tstrip_t
TIFFCurrentStrip(TIFF* tif)
{
	return (tif->tif_curstrip);
}

/*
 * Return current tile.
 */
ttile_t
TIFFCurrentTile(TIFF* tif)
{
	return (tif->tif_curtile);
}

/*
 * Return nonzero if the file has byte-swapped data.
 */
int
TIFFIsByteSwapped(TIFF* tif)
{
	return ((tif->tif_flags & TIFF_SWAB) != 0);
}

/*
 * Return nonzero if the data is returned up-sampled.
 */
int
TIFFIsUpSampled(TIFF* tif)
{
	return (isUpSampled(tif));
}

/*
 * Return nonzero if the data is returned in MSB-to-LSB bit order.
 */
int
TIFFIsMSB2LSB(TIFF* tif)
{
	return (isFillOrder(tif, FILLORDER_MSB2LSB));
}
Commit	Line	Data
b47c832e RR	1	/* $Header$ */
	2
	3	/*
	4	* Copyright (c) 1988-1997 Sam Leffler
	5	* Copyright (c) 1991-1997 Silicon Graphics, Inc.
	6	*
	7	* Permission to use, copy, modify, distribute, and sell this software and
	8	* its documentation for any purpose is hereby granted without fee, provided
	9	* that (i) the above copyright notices and this permission notice appear in
	10	* all copies of the software and related documentation, and (ii) the names of
	11	* Sam Leffler and Silicon Graphics may not be used in any advertising or
	12	* publicity relating to the software without the specific, prior written
	13	* permission of Sam Leffler and Silicon Graphics.
	14	*
	15	* THE SOFTWARE IS PROVIDED "AS-IS" AND WITHOUT WARRANTY OF ANY KIND,
	16	* EXPRESS, IMPLIED OR OTHERWISE, INCLUDING WITHOUT LIMITATION, ANY
	17	* WARRANTY OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.
	18	*
	19	* IN NO EVENT SHALL SAM LEFFLER OR SILICON GRAPHICS BE LIABLE FOR
	20	* ANY SPECIAL, INCIDENTAL, INDIRECT OR CONSEQUENTIAL DAMAGES OF ANY KIND,
	21	* OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS,
	22	* WHETHER OR NOT ADVISED OF THE POSSIBILITY OF DAMAGE, AND ON ANY THEORY OF
	23	* LIABILITY, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE
	24	* OF THIS SOFTWARE.
	25	*/
	26
	27	/*
	28	* TIFF Library.
	29	*/
	30	#include "tiffiop.h"
	31
	32	void _TIFFSetDefaultCompressionState(TIFF* tif);
	33
	34	static const long typemask[13] = {
	35	0L, /* TIFF_NOTYPE */
	36	0x000000ffL, /* TIFF_BYTE */
	37	0xffffffffL, /* TIFF_ASCII */
	38	0x0000ffffL, /* TIFF_SHORT */
	39	0xffffffffL, /* TIFF_LONG */
	40	0xffffffffL, /* TIFF_RATIONAL */
	41	0x000000ffL, /* TIFF_SBYTE */
	42	0x000000ffL, /* TIFF_UNDEFINED */
	43	0x0000ffffL, /* TIFF_SSHORT */
	44	0xffffffffL, /* TIFF_SLONG */
	45	0xffffffffL, /* TIFF_SRATIONAL */
	46	0xffffffffL, /* TIFF_FLOAT */
	47	0xffffffffL, /* TIFF_DOUBLE */
	48	};
	49	static const int bigTypeshift[13] = {
	50	0, /* TIFF_NOTYPE */
	51	24, /* TIFF_BYTE */
	52	0, /* TIFF_ASCII */
	53	16, /* TIFF_SHORT */
	54	0, /* TIFF_LONG */
	55	0, /* TIFF_RATIONAL */
	56	24, /* TIFF_SBYTE */
	57	24, /* TIFF_UNDEFINED */
	58	16, /* TIFF_SSHORT */
	59	0, /* TIFF_SLONG */
	60	0, /* TIFF_SRATIONAL */
	61	0, /* TIFF_FLOAT */
	62	0, /* TIFF_DOUBLE */
	63	};
	64	static const int litTypeshift[13] = {
65	0, /* TIFF_NOTYPE */
66	0, /* TIFF_BYTE */
67	0, /* TIFF_ASCII */
68	0, /* TIFF_SHORT */
69	0, /* TIFF_LONG */
70	0, /* TIFF_RATIONAL */
71	0, /* TIFF_SBYTE */
72	0, /* TIFF_UNDEFINED */
73	0, /* TIFF_SSHORT */
74	0, /* TIFF_SLONG */
75	0, /* TIFF_SRATIONAL */
76	0, /* TIFF_FLOAT */
77	0, /* TIFF_DOUBLE */
78	};
79
80	/*
81	* Initialize the shift & mask tables, and the
82	* byte swapping state according to the file
83	* contents and the machine architecture.
84	*/
85	static void
86	TIFFInitOrder(TIFF* tif, int magic, int bigendian)
87	{
88	tif->tif_typemask = typemask;
89	if (magic == TIFF_BIGENDIAN) {
90	tif->tif_typeshift = bigTypeshift;
91	if (!bigendian)
92	tif->tif_flags \|= TIFF_SWAB;
93	} else {
94	tif->tif_typeshift = litTypeshift;
95	if (bigendian)
96	tif->tif_flags \|= TIFF_SWAB;
97	}
98	}
99
100	int
101	_TIFFgetMode(const char* mode, const char* module)
102	{
103	int m = -1;
104
105	switch (mode[0]) {
106	case 'r':
107	m = O_RDONLY;
108	if (mode[1] == '+')
109	m = O_RDWR;
110	break;
111	case 'w':
112	case 'a':
113	m = O_RDWR\|O_CREAT;
114	if (mode[0] == 'w')
115	m \|= O_TRUNC;
116	break;
117	default:
118	TIFFError(module, "\"%s\": Bad mode", mode);
119	break;
120	}
121	return (m);
122	}
123
124	TIFF*
125	TIFFClientOpen(
126	const char* name, const char* mode,
127	thandle_t clientdata,
128	TIFFReadWriteProc readproc,
129	TIFFReadWriteProc writeproc,
130	TIFFSeekProc seekproc,
131	TIFFCloseProc closeproc,
132	TIFFSizeProc sizeproc,
133	TIFFMapFileProc mapproc,
134	TIFFUnmapFileProc unmapproc
135	)
136	{
137	static const char module[] = "TIFFClientOpen";
138	TIFF *tif;
139	int m, bigendian;
140	const char* cp;
141
142	m = _TIFFgetMode(mode, module);
143	if (m == -1)
144	goto bad2;
145	tif = (TIFF *)_TIFFmalloc(sizeof (TIFF) + strlen(name) + 1);
146	if (tif == NULL) {
147	TIFFError(module, "%s: Out of memory (TIFF structure)", name);
148	goto bad2;
149	}
150	_TIFFmemset(tif, 0, sizeof (*tif));
151	tif->tif_name = (char *)tif + sizeof (TIFF);
152	strcpy(tif->tif_name, name);
153	tif->tif_mode = m &~ (O_CREAT\|O_TRUNC);
154	tif->tif_curdir = (tdir_t) -1; /* non-existent directory */
155	tif->tif_curoff = 0;
156	tif->tif_curstrip = (tstrip_t) -1; /* invalid strip */
157	tif->tif_row = (uint32) -1; /* read/write pre-increment */
158	tif->tif_clientdata = clientdata;
159	tif->tif_readproc = readproc;
160	tif->tif_writeproc = writeproc;
161	tif->tif_seekproc = seekproc;
162	tif->tif_closeproc = closeproc;
163	tif->tif_sizeproc = sizeproc;
164	tif->tif_mapproc = mapproc;
165	tif->tif_unmapproc = unmapproc;
166	_TIFFSetDefaultCompressionState(tif); /* setup default state */
167	/*
168	* Default is to return data MSB2LSB and enable the
169	* use of memory-mapped files and strip chopping when
170	* a file is opened read-only.
171	*/
172	tif->tif_flags = FILLORDER_MSB2LSB;
173	if (m == O_RDONLY)
174	#ifdef STRIPCHOP_DEFAULT
175	tif->tif_flags \|= TIFF_MAPPED\|STRIPCHOP_DEFAULT;
176	#else
177	tif->tif_flags \|= TIFF_MAPPED;
178	#endif
179
180	{ union { int32 i; char c[4]; } u; u.i = 1; bigendian = u.c[0] == 0; }
181	/*
182	* Process library-specific flags in the open mode string.
183	* The following flags may be used to control intrinsic library
184	* behaviour that may or may not be desirable (usually for
185	* compatibility with some application that claims to support
186	* TIFF but only supports some braindead idea of what the
187	* vendor thinks TIFF is):
188	*
189	* 'l' use little-endian byte order for creating a file
190	* 'b' use big-endian byte order for creating a file
191	* 'L' read/write information using LSB2MSB bit order
192	* 'B' read/write information using MSB2LSB bit order
193	* 'H' read/write information using host bit order
194	* 'M' enable use of memory-mapped files when supported
195	* 'm' disable use of memory-mapped files
196	* 'C' enable strip chopping support when reading
197	* 'c' disable strip chopping support
198	*
199	* The use of the 'l' and 'b' flags is strongly discouraged.
200	* These flags are provided solely because numerous vendors,
201	* typically on the PC, do not correctly support TIFF; they
202	* only support the Intel little-endian byte order. This
203	* support is not configured by default because it supports
204	* the violation of the TIFF spec that says that readers MUST
205	* support both byte orders. It is strongly recommended that
206	* you not use this feature except to deal with busted apps
207	* that write invalid TIFF. And even in those cases you should
208	* bang on the vendors to fix their software.
209	*
210	* The 'L', 'B', and 'H' flags are intended for applications
211	* that can optimize operations on data by using a particular
212	* bit order. By default the library returns data in MSB2LSB
213	* bit order for compatibiltiy with older versions of this
214	* library. Returning data in the bit order of the native cpu
215	* makes the most sense but also requires applications to check
216	* the value of the FillOrder tag; something they probabyl do
217	* not do right now.
218	*
219	* The 'M' and 'm' flags are provided because some virtual memory
220	* systems exhibit poor behaviour when large images are mapped.
221	* These options permit clients to control the use of memory-mapped
222	* files on a per-file basis.
223	*
224	* The 'C' and 'c' flags are provided because the library support
225	* for chopping up large strips into multiple smaller strips is not
226	* application-transparent and as such can cause problems. The 'c'
227	* option permits applications that only want to look at the tags,
228	* for example, to get the unadulterated TIFF tag information.
229	*/
230	for (cp = mode; *cp; cp++)
231	switch (*cp) {
232	case 'b':
233	if ((m&O_CREAT) && !bigendian)
234	tif->tif_flags \|= TIFF_SWAB;
235	break;
236	case 'l':
237	if ((m&O_CREAT) && bigendian)
238	tif->tif_flags \|= TIFF_SWAB;
239	break;
240	case 'B':
241	tif->tif_flags = (tif->tif_flags &~ TIFF_FILLORDER) \|
242	FILLORDER_MSB2LSB;
243	break;
244	case 'L':
245	tif->tif_flags = (tif->tif_flags &~ TIFF_FILLORDER) \|
246	FILLORDER_LSB2MSB;
247	break;
248	case 'H':
249	tif->tif_flags = (tif->tif_flags &~ TIFF_FILLORDER) \|
250	HOST_FILLORDER;
251	break;
252	case 'M':
253	if (m == O_RDONLY)
254	tif->tif_flags \|= TIFF_MAPPED;
255	break;
256	case 'm':
257	if (m == O_RDONLY)
258	tif->tif_flags &= ~TIFF_MAPPED;
259	break;
260	case 'C':
261	if (m == O_RDONLY)
262	tif->tif_flags \|= TIFF_STRIPCHOP;
263	break;
264	case 'c':
265	if (m == O_RDONLY)
266	tif->tif_flags &= ~TIFF_STRIPCHOP;
267	break;
268	}
269	/*
270	* Read in TIFF header.
271	*/
272	if (!ReadOK(tif, &tif->tif_header, sizeof (TIFFHeader))) {
273	if (tif->tif_mode == O_RDONLY) {
274	TIFFError(name, "Cannot read TIFF header");
275	goto bad;
276	}
277	/*
278	* Setup header and write.
279	*/
280	tif->tif_header.tiff_magic = tif->tif_flags & TIFF_SWAB
281	? (bigendian ? TIFF_LITTLEENDIAN : TIFF_BIGENDIAN)
282	: (bigendian ? TIFF_BIGENDIAN : TIFF_LITTLEENDIAN);
283	tif->tif_header.tiff_version = TIFF_VERSION;
284	if (tif->tif_flags & TIFF_SWAB)
285	TIFFSwabShort(&tif->tif_header.tiff_version);
286	tif->tif_header.tiff_diroff = 0; /* filled in later */
287	if (!WriteOK(tif, &tif->tif_header, sizeof (TIFFHeader))) {
288	TIFFError(name, "Error writing TIFF header");
289	goto bad;
290	}
291	/*
292	* Setup the byte order handling.
293	*/
294	TIFFInitOrder(tif, tif->tif_header.tiff_magic, bigendian);
295	/*
296	* Setup default directory.
297	*/
298	if (!TIFFDefaultDirectory(tif))
299	goto bad;
300	tif->tif_diroff = 0;
301	return (tif);
302	}
303	/*
304	* Setup the byte order handling.
305	*/
306	if (tif->tif_header.tiff_magic != TIFF_BIGENDIAN &&
307	tif->tif_header.tiff_magic != TIFF_LITTLEENDIAN) {
308	TIFFError(name, "Not a TIFF file, bad magic number %d (0x%x)",
309	tif->tif_header.tiff_magic,
310	tif->tif_header.tiff_magic);
311	goto bad;
312	}
313	TIFFInitOrder(tif, tif->tif_header.tiff_magic, bigendian);
314	/*
315	* Swap header if required.
316	*/
317	if (tif->tif_flags & TIFF_SWAB) {
318	TIFFSwabShort(&tif->tif_header.tiff_version);
319	TIFFSwabLong(&tif->tif_header.tiff_diroff);
320	}
321	/*
322	* Now check version (if needed, it's been byte-swapped).
323	* Note that this isn't actually a version number, it's a
324	* magic number that doesn't change (stupid).
325	*/
326	if (tif->tif_header.tiff_version != TIFF_VERSION) {
327	TIFFError(name,
328	"Not a TIFF file, bad version number %d (0x%x)",
329	tif->tif_header.tiff_version,
330	tif->tif_header.tiff_version);
331	goto bad;
332	}
333	tif->tif_flags \|= TIFF_MYBUFFER;
334	tif->tif_rawcp = tif->tif_rawdata = 0;
335	tif->tif_rawdatasize = 0;
336	/*
337	* Setup initial directory.
338	*/
339	switch (mode[0]) {
340	case 'r':
341	tif->tif_nextdiroff = tif->tif_header.tiff_diroff;
342	/*
343	* Try to use a memory-mapped file if the client
344	* has not explicitly suppressed usage with the
345	* 'm' flag in the open mode (see above).
346	*/
347	if ((tif->tif_flags & TIFF_MAPPED) &&
348	!TIFFMapFileContents(tif, (tdata_t*) &tif->tif_base, &tif->tif_size))
349	tif->tif_flags &= ~TIFF_MAPPED;
350	if (TIFFReadDirectory(tif)) {
351	tif->tif_rawcc = -1;
352	tif->tif_flags \|= TIFF_BUFFERSETUP;
353	return (tif);
354	}
355	break;
356	case 'a':
357	/*
358	* New directories are automatically append
359	* to the end of the directory chain when they
360	* are written out (see TIFFWriteDirectory).
361	*/
362	if (!TIFFDefaultDirectory(tif))
363	goto bad;
364	return (tif);
365	}
366	bad:
367	tif->tif_mode = O_RDONLY; /* XXX avoid flush */
368	TIFFClose(tif);
369	return ((TIFF*)0);
370	bad2:
371	(void) (*closeproc)(clientdata);
372	return ((TIFF*)0);
373	}
374
375	/*
376	* Query functions to access private data.
377	*/
378
379	/*
380	* Return open file's name.
381	*/
382	const char *
383	TIFFFileName(TIFF* tif)
384	{
385	return (tif->tif_name);
386	}
387
388	/*
389	* Return open file's I/O descriptor.
390	*/
391	int
392	TIFFFileno(TIFF* tif)
393	{
394	return (tif->tif_fd);
395	}
396
397	/*
398	* Return read/write mode.
399	*/
400	int
401	TIFFGetMode(TIFF* tif)
402	{
403	return (tif->tif_mode);
404	}
405
406	/*
407	* Return nonzero if file is organized in
408	* tiles; zero if organized as strips.
409	*/
410	int
411	TIFFIsTiled(TIFF* tif)
412	{
413	return (isTiled(tif));
414	}
415
416	/*
417	* Return current row being read/written.
418	*/
419	uint32
420	TIFFCurrentRow(TIFF* tif)
421	{
422	return (tif->tif_row);
423	}
424
425	/*
426	* Return index of the current directory.
427	*/
428	tdir_t
429	TIFFCurrentDirectory(TIFF* tif)
430	{
431	return (tif->tif_curdir);
432	}
433
434	/*
435	* Return current strip.
436	*/
437	tstrip_t
438	TIFFCurrentStrip(TIFF* tif)
439	{
440	return (tif->tif_curstrip);
441	}
442
443	/*
444	* Return current tile.
445	*/
446	ttile_t
447	TIFFCurrentTile(TIFF* tif)
448	{
449	return (tif->tif_curtile);
450	}
451
452	/*
453	* Return nonzero if the file has byte-swapped data.
454	*/
455	int
456	TIFFIsByteSwapped(TIFF* tif)
457	{
458	return ((tif->tif_flags & TIFF_SWAB) != 0);
459	}
460
461	/*
462	* Return nonzero if the data is returned up-sampled.
463	*/
464	int
465	TIFFIsUpSampled(TIFF* tif)
466	{
467	return (isUpSampled(tif));
468	}
469
470	/*
471	* Return nonzero if the data is returned in MSB-to-LSB bit order.
472	*/
473	int
474	TIFFIsMSB2LSB(TIFF* tif)
475	{
476	return (isFillOrder(tif, FILLORDER_MSB2LSB));
477	}