/* $Header: /cvsroot/VTK/VTK/Utilities/tiff/tif_open.c,v 1.2 2002/01/30 14:16:09 andy 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.
 */
#include "tiffiop.h"

void _TIFFSetDefaultCompressionState(TIFF* tif);

static const unsigned 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 )
            tif->tif_flags |= TIFF_MAPPED;

#ifdef STRIPCHOP_DEFAULT
        if (m == O_RDONLY || m == O_RDWR)
                tif->tif_flags |= STRIPCHOP_DEFAULT;
#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 */

                /*
                 * This seek shouldn't be necessary, but I have had some
                 * crazy problems with a failed fseek() on Solaris leaving
                 * the current file pointer out of whack when an fwrite()
                 * is done. 
                 */
                TIFFSeekFile( tif, 0, SEEK_SET );

                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)) {
                        if( m != O_RDONLY 
                          && tif->tif_dir.td_compression != COMPRESSION_NONE )
                        {
                            TIFFError( name, 
                                       "Can't open a compressed TIFF file"
                                       " with compression for update." );
                            goto bad;
                        }
                        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));
}
