/* $Header: /usr/people/sam/tiff/libtiff/RCS/tif_compress.c,v 1.51 1996/01/10 19:32:57 sam Rel $ */

/*
 * Copyright (c) 1988-1996 Sam Leffler
 * Copyright (c) 1991-1996 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
 *
 * Compression Scheme Configuration Support.
 */
#include "tiffiop.h"

static int TIFFAPI
TIFFNoEncode(TIFF* tif, char* method)
{
    const TIFFCodec* c = TIFFFindCODEC(tif->tif_dir.td_compression);

    if (c)
    TIFFError(tif->tif_name, "%s %s encoding is not implemented",
        c->name, method);
    else
    TIFFError(tif->tif_name,
        "Compression scheme %u %s encoding is not implemented",
        tif->tif_dir.td_compression, method);
    return (-1);
}

int TIFFAPI
_TIFFNoRowEncode(TIFF* tif, tidata_t pp, tsize_t cc, tsample_t s)
{
    (void) pp; (void) cc; (void) s;
    return (TIFFNoEncode(tif, "scanline"));
}

int TIFFAPI
_TIFFNoStripEncode(TIFF* tif, tidata_t pp, tsize_t cc, tsample_t s)
{
    (void) pp; (void) cc; (void) s;
    return (TIFFNoEncode(tif, "strip"));
}

int TIFFAPI
_TIFFNoTileEncode(TIFF* tif, tidata_t pp, tsize_t cc, tsample_t s)
{
    (void) pp; (void) cc; (void) s;
    return (TIFFNoEncode(tif, "tile"));
}

static int TIFFAPI
TIFFNoDecode(TIFF* tif, char* method)
{
    const TIFFCodec* c = TIFFFindCODEC(tif->tif_dir.td_compression);

    if (c)
    TIFFError(tif->tif_name, "%s %s decoding is not implemented",
        c->name, method);
    else
    TIFFError(tif->tif_name,
        "Compression scheme %u %s decoding is not implemented",
        tif->tif_dir.td_compression, method);
    return (-1);
}

int TIFFAPI
_TIFFNoRowDecode(TIFF* tif, tidata_t pp, tsize_t cc, tsample_t s)
{
    (void) pp; (void) cc; (void) s;
    return (TIFFNoDecode(tif, "scanline"));
}

int TIFFAPI
_TIFFNoStripDecode(TIFF* tif, tidata_t pp, tsize_t cc, tsample_t s)
{
    (void) pp; (void) cc; (void) s;
    return (TIFFNoDecode(tif, "strip"));
}

int TIFFAPI
_TIFFNoTileDecode(TIFF* tif, tidata_t pp, tsize_t cc, tsample_t s)
{
    (void) pp; (void) cc; (void) s;
    return (TIFFNoDecode(tif, "tile"));
}

int TIFFAPI
_TIFFNoSeek(TIFF* tif, uint32 off)
{
    (void) off;
    TIFFError(tif->tif_name,
    "Compression algorithm does not support random access");
    return (0);
}

int TIFFAPI
_TIFFNoPreCode(TIFF* tif, tsample_t s)
{
    (void) tif; (void) s;
    return (1);
}

static int TIFFAPI _TIFFtrue(TIFF* tif) { (void) tif; return (1); }
static void TIFFAPI _TIFFvoid(TIFF* tif) { (void) tif; }

int
TIFFSetCompressionScheme(TIFF* tif, int scheme)
{
    const TIFFCodec *c = TIFFFindCODEC(scheme);

    tif->tif_setupdecode = _TIFFtrue;
    tif->tif_predecode = _TIFFNoPreCode;
    tif->tif_decoderow = _TIFFNoRowDecode;
    tif->tif_decodestrip = _TIFFNoStripDecode;
    tif->tif_decodetile = _TIFFNoTileDecode;
    tif->tif_setupencode = _TIFFtrue;
    tif->tif_preencode = _TIFFNoPreCode;
    tif->tif_postencode = _TIFFtrue;
    tif->tif_encoderow = _TIFFNoRowEncode;
    tif->tif_encodestrip = _TIFFNoStripEncode;
    tif->tif_encodetile = _TIFFNoTileEncode;
    tif->tif_close = _TIFFvoid;
    tif->tif_seek = _TIFFNoSeek;
    tif->tif_cleanup = _TIFFvoid;
    tif->tif_defstripsize = _TIFFDefaultStripSize;
    tif->tif_deftilesize = _TIFFDefaultTileSize;
    tif->tif_flags &= ~TIFF_NOBITREV;
    /*
     * Don't treat an unknown compression scheme as an error.
     * This permits applications to open files with data that
     * the library does not have builtin support for, but which
     * may still be meaningful.
     */
    return (c ? (*c->init)(tif, scheme) : 1);
}

/*
 * Other compression schemes may be registered.  Registered
 * schemes can also override the builtin versions provided
 * by this library.
 */
typedef struct _codec {
    struct _codec*  next;
    TIFFCodec*  info;
} codec_t;
static  codec_t* registeredCODECS = NULL;

const TIFFCodec*
TIFFFindCODEC(uint16 scheme)
{
    const TIFFCodec* c;
    codec_t* cd;

    for (cd = registeredCODECS; cd; cd = cd->next)
    if (cd->info->scheme == scheme)
        return ((const TIFFCodec*) cd->info);
    for (c = _TIFFBuiltinCODECS; c->name; c++)
    if (c->scheme == scheme)
        return (c);
    return ((const TIFFCodec*) 0);
}

TIFFCodec*
TIFFRegisterCODEC(uint16 scheme, const char* name, TIFFInitMethod init)
{
    codec_t* cd = (codec_t*)
    _TIFFmalloc(sizeof (codec_t) + sizeof (TIFFCodec) + strlen(name)+1);

    if (cd != NULL) {
    cd->info = (TIFFCodec*) ((tidata_t) cd + sizeof (codec_t));
    cd->info->name = (char*)
        ((tidata_t) cd->info + sizeof (TIFFCodec));
    strcpy(cd->info->name, name);
    cd->info->scheme = scheme;
    cd->info->init = init;
    cd->next = registeredCODECS;
    registeredCODECS = cd;
    } else
    TIFFError("TIFFRegisterCODEC",
        "No space to register compression scheme %s", name);
    return (cd->info);
}

void
TIFFUnRegisterCODEC(TIFFCodec* c)
{
    codec_t* cd;
    codec_t** pcd;

    for (pcd = &registeredCODECS; (cd = *pcd); pcd = &cd->next)
    if (cd->info == c) {
        *pcd = cd->next;
        _TIFFfree(cd);
        return;
    }
    TIFFError("TIFFUnRegisterCODEC",
    "Cannot remove compression scheme %s; not registered", c->name);
}
