gecko-dev/modules/libimg/mng/libmng_read.c

694 строки
29 KiB
C

/* ************************************************************************** */
/* * For conditions of distribution and use, * */
/* * see copyright notice in libmng.h * */
/* ************************************************************************** */
/* * * */
/* * project : libmng * */
/* * file : libmng_read.c copyright (c) 2000 G.Juyn * */
/* * version : 1.0.0 * */
/* * * */
/* * purpose : Read logic (implementation) * */
/* * * */
/* * author : G.Juyn * */
/* * web : http://www.3-t.com * */
/* * email : mailto:info@3-t.com * */
/* * * */
/* * comment : implementation of the high-level read logic * */
/* * * */
/* * changes : 0.5.1 - 05/08/2000 - G.Juyn * */
/* * - changed strict-ANSI stuff * */
/* * 0.5.1 - 05/11/2000 - G.Juyn * */
/* * - added callback error-reporting support * */
/* * 0.5.1 - 05/12/2000 - G.Juyn * */
/* * - changed trace to macro for callback error-reporting * */
/* * * */
/* * 0.5.2 - 05/19/2000 - G.Juyn * */
/* * - cleaned up some code regarding mixed support * */
/* * 0.5.2 - 05/20/2000 - G.Juyn * */
/* * - added support for JNG * */
/* * 0.5.2 - 05/31/2000 - G.Juyn * */
/* * - fixed up punctuation (contribution by Tim Rowley) * */
/* * * */
/* * 0.5.3 - 06/16/2000 - G.Juyn * */
/* * - changed progressive-display processing * */
/* * * */
/* * 0.9.1 - 07/08/2000 - G.Juyn * */
/* * - changed read-processing for improved I/O-suspension * */
/* * 0.9.1 - 07/14/2000 - G.Juyn * */
/* * - changed EOF processing behavior * */
/* * 0.9.1 - 07/14/2000 - G.Juyn * */
/* * - changed default readbuffer size from 1024 to 4200 * */
/* * * */
/* * 0.9.2 - 07/27/2000 - G.Juyn * */
/* * - B110320 - fixed GCC warning about mix-sized pointer math * */
/* * 0.9.2 - 07/31/2000 - G.Juyn * */
/* * - B110546 - fixed for improperly returning UNEXPECTEDEOF * */
/* * 0.9.2 - 08/04/2000 - G.Juyn * */
/* * - B111096 - fixed large-buffer read-suspension * */
/* * 0.9.2 - 08/05/2000 - G.Juyn * */
/* * - changed file-prefixes * */
/* * * */
/* * 0.9.3 - 08/26/2000 - G.Juyn * */
/* * - added MAGN chunk * */
/* * 0.9.3 - 10/11/2000 - G.Juyn * */
/* * - removed test-MaGN * */
/* * 0.9.3 - 10/16/2000 - G.Juyn * */
/* * - added support for JDAA * */
/* * * */
/* * 0.9.5 - 1/23/2001 - G.Juyn * */
/* * - fixed timing-problem with switching framing_modes * */
/* * * */
/* ************************************************************************** */
#include "libmng.h"
#include "libmng_data.h"
#include "libmng_error.h"
#include "libmng_trace.h"
#ifdef __BORLANDC__
#pragma hdrstop
#endif
#include "libmng_memory.h"
#include "libmng_objects.h"
#include "libmng_object_prc.h"
#include "libmng_chunks.h"
#include "libmng_chunk_prc.h"
#include "libmng_chunk_io.h"
#include "libmng_display.h"
#include "libmng_read.h"
#if defined(__BORLANDC__) && defined(MNG_STRICT_ANSI)
#pragma option -A /* force ANSI-C */
#endif
/* ************************************************************************** */
#ifdef MNG_INCLUDE_READ_PROCS
/* ************************************************************************** */
mng_retcode process_eof (mng_datap pData)
{
if (!pData->bEOF) /* haven't closed the stream yet ? */
{
pData->bEOF = MNG_TRUE; /* now we do! */
if (!pData->fClosestream ((mng_handle)pData))
MNG_ERROR (pData, MNG_APPIOERROR)
}
return MNG_NOERROR;
}
/* ************************************************************************** */
mng_retcode read_databuffer (mng_datap pData,
mng_uint8p pBuf,
mng_uint32 iSize,
mng_uint32 * iRead)
{
#ifdef MNG_SUPPORT_TRACE
MNG_TRACE (pData, MNG_FN_READ_DATABUFFER, MNG_LC_START)
#endif
if (pData->bSuspensionmode)
{
mng_uint8p pTemp;
mng_uint32 iTemp;
*iRead = 0; /* let's be negative about the outcome */
if (!pData->pSuspendbuf) /* need to create a suspension buffer ? */
{
pData->iSuspendbufsize = MNG_SUSPENDBUFFERSIZE;
/* so, create it */
MNG_ALLOC (pData, pData->pSuspendbuf, pData->iSuspendbufsize)
pData->iSuspendbufleft = 0; /* make sure to fill it first time */
pData->pSuspendbufnext = pData->pSuspendbuf;
}
/* more than our buffer can hold ? */
if (iSize > pData->iSuspendbufsize)
{
mng_uint32 iRemain;
if (!pData->pReadbufnext) /* first time ? */
{
if (pData->iSuspendbufleft) /* do we have some data left ? */
{ /* then copy it */
MNG_COPY (pBuf, pData->pSuspendbufnext, pData->iSuspendbufleft)
/* fixup variables */
pData->pReadbufnext = pBuf + pData->iSuspendbufleft;
pData->pSuspendbufnext = pData->pSuspendbuf;
pData->iSuspendbufleft = 0;
}
else
{
pData->pReadbufnext = pBuf;
}
}
/* calculate how much to get */
iRemain = iSize - (mng_uint32)(pData->pReadbufnext - pBuf);
/* let's go get it */
if (!pData->fReaddata (((mng_handle)pData), pData->pReadbufnext, iRemain, &iTemp))
MNG_ERROR (pData, MNG_APPIOERROR);
/* first read after suspension return 0 means EOF */
if ((pData->iSuspendpoint) && (iTemp == 0))
{ /* that makes it final */
mng_retcode iRetcode = process_eof (pData);
if (iRetcode) /* on error bail out */
return iRetcode;
/* indicate the source is depleted */
*iRead = iSize - iRemain + iTemp;
}
else
{
if (iTemp < iRemain) /* suspension required ? */
{
pData->pReadbufnext = pData->pReadbufnext + iTemp;
pData->bSuspended = MNG_TRUE;
}
else
{
*iRead = iSize; /* got it all now ! */
}
}
}
else
{ /* need to read some more ? */
while ((!pData->bSuspended) && (!pData->bEOF) && (iSize > pData->iSuspendbufleft))
{ /* not enough space left in buffer ? */
if (pData->iSuspendbufsize - pData->iSuspendbufleft -
(mng_uint32)(pData->pSuspendbufnext - pData->pSuspendbuf) <
MNG_SUSPENDREQUESTSIZE)
{
if (pData->iSuspendbufleft) /* then lets shift (if there's anything left) */
MNG_COPY (pData->pSuspendbuf, pData->pSuspendbufnext, pData->iSuspendbufleft)
/* adjust running pointer */
pData->pSuspendbufnext = pData->pSuspendbuf;
}
/* still not enough room ? */
if (pData->iSuspendbufsize - pData->iSuspendbufleft < MNG_SUSPENDREQUESTSIZE)
MNG_ERROR (pData, MNG_INTERNALERROR)
/* now read some more data */
pTemp = pData->pSuspendbufnext + pData->iSuspendbufleft;
if (!pData->fReaddata (((mng_handle)pData), pTemp, MNG_SUSPENDREQUESTSIZE, &iTemp))
MNG_ERROR (pData, MNG_APPIOERROR);
/* adjust fill-counter */
pData->iSuspendbufleft += iTemp;
/* first read after suspension returning 0 means EOF */
if ((pData->iSuspendpoint) && (iTemp == 0))
{ /* that makes it final */
mng_retcode iRetcode = process_eof (pData);
if (iRetcode) /* on error bail out */
return iRetcode;
if (pData->iSuspendbufleft) /* return the leftover scraps */
MNG_COPY (pBuf, pData->pSuspendbufnext, pData->iSuspendbufleft)
/* and indicate so */
*iRead = pData->iSuspendbufleft;
pData->pSuspendbufnext = pData->pSuspendbuf;
pData->iSuspendbufleft = 0;
}
else
{ /* suspension required ? */
if ((iSize > pData->iSuspendbufleft) && (iTemp < MNG_SUSPENDREQUESTSIZE))
pData->bSuspended = MNG_TRUE;
}
pData->iSuspendpoint = 0; /* reset it here in case we loop back */
}
if ((!pData->bSuspended) && (!pData->bEOF))
{ /* return the data ! */
MNG_COPY (pBuf, pData->pSuspendbufnext, iSize)
*iRead = iSize; /* returned it all */
/* adjust suspension-buffer variables */
pData->pSuspendbufnext += iSize;
pData->iSuspendbufleft -= iSize;
}
}
}
else
{
if (!pData->fReaddata (((mng_handle)pData), (mng_ptr)pBuf, iSize, iRead))
{
if (iRead == 0) /* suspension required ? */
pData->bSuspended = MNG_TRUE;
else
MNG_ERROR (pData, MNG_APPIOERROR);
}
}
pData->iSuspendpoint = 0; /* safely reset it here ! */
#ifdef MNG_SUPPORT_TRACE
MNG_TRACE (pData, MNG_FN_READ_DATABUFFER, MNG_LC_END)
#endif
return MNG_NOERROR;
}
/* ************************************************************************** */
mng_retcode process_raw_chunk (mng_datap pData,
mng_uint8p pBuf,
mng_uint32 iBuflen)
{
/* the table-idea & binary search code was adapted from
libpng 1.1.0 (pngread.c) */
/* NOTE1: the table must remain sorted by chunkname, otherwise the binary
search will break !!! */
/* NOTE2: the layout must remain equal to the header part of all the
chunk-structures (yes, that means even the pNext and pPrev fields;
it's wasting a bit of space, but hey, the code is a lot easier) */
mng_chunk_header chunk_unknown = {MNG_UINT_HUH, init_unknown, free_unknown,
read_unknown, write_unknown, 0, 0};
mng_chunk_header chunk_table [] =
{
{MNG_UINT_BACK, init_back, free_back, read_back, write_back, 0, 0},
{MNG_UINT_BASI, init_basi, free_basi, read_basi, write_basi, 0, 0},
{MNG_UINT_CLIP, init_clip, free_clip, read_clip, write_clip, 0, 0},
{MNG_UINT_CLON, init_clon, free_clon, read_clon, write_clon, 0, 0},
{MNG_UINT_DBYK, init_dbyk, free_dbyk, read_dbyk, write_dbyk, 0, 0},
{MNG_UINT_DEFI, init_defi, free_defi, read_defi, write_defi, 0, 0},
{MNG_UINT_DHDR, init_dhdr, free_dhdr, read_dhdr, write_dhdr, 0, 0},
{MNG_UINT_DISC, init_disc, free_disc, read_disc, write_disc, 0, 0},
{MNG_UINT_DROP, init_drop, free_drop, read_drop, write_drop, 0, 0},
{MNG_UINT_ENDL, init_endl, free_endl, read_endl, write_endl, 0, 0},
{MNG_UINT_FRAM, init_fram, free_fram, read_fram, write_fram, 0, 0},
{MNG_UINT_IDAT, init_idat, free_idat, read_idat, write_idat, 0, 0}, /* 12-th element! */
{MNG_UINT_IEND, init_iend, free_iend, read_iend, write_iend, 0, 0},
{MNG_UINT_IHDR, init_ihdr, free_ihdr, read_ihdr, write_ihdr, 0, 0},
{MNG_UINT_IJNG, init_ijng, free_ijng, read_ijng, write_ijng, 0, 0},
{MNG_UINT_IPNG, init_ipng, free_ipng, read_ipng, write_ipng, 0, 0},
#ifdef MNG_INCLUDE_JNG
{MNG_UINT_JDAA, init_jdaa, free_jdaa, read_jdaa, write_jdaa, 0, 0},
{MNG_UINT_JDAT, init_jdat, free_jdat, read_jdat, write_jdat, 0, 0},
{MNG_UINT_JHDR, init_jhdr, free_jhdr, read_jhdr, write_jhdr, 0, 0},
{MNG_UINT_JSEP, init_jsep, free_jsep, read_jsep, write_jsep, 0, 0},
{MNG_UINT_JdAA, init_jdaa, free_jdaa, read_jdaa, write_jdaa, 0, 0},
#endif
{MNG_UINT_LOOP, init_loop, free_loop, read_loop, write_loop, 0, 0},
{MNG_UINT_MAGN, init_magn, free_magn, read_magn, write_magn, 0, 0},
{MNG_UINT_MEND, init_mend, free_mend, read_mend, write_mend, 0, 0},
{MNG_UINT_MHDR, init_mhdr, free_mhdr, read_mhdr, write_mhdr, 0, 0},
{MNG_UINT_MOVE, init_move, free_move, read_move, write_move, 0, 0},
{MNG_UINT_ORDR, init_ordr, free_ordr, read_ordr, write_ordr, 0, 0},
{MNG_UINT_PAST, init_past, free_past, read_past, write_past, 0, 0},
{MNG_UINT_PLTE, init_plte, free_plte, read_plte, write_plte, 0, 0},
{MNG_UINT_PPLT, init_pplt, free_pplt, read_pplt, write_pplt, 0, 0},
{MNG_UINT_PROM, init_prom, free_prom, read_prom, write_prom, 0, 0},
{MNG_UINT_SAVE, init_save, free_save, read_save, write_save, 0, 0},
{MNG_UINT_SEEK, init_seek, free_seek, read_seek, write_seek, 0, 0},
{MNG_UINT_SHOW, init_show, free_show, read_show, write_show, 0, 0},
{MNG_UINT_TERM, init_term, free_term, read_term, write_term, 0, 0},
{MNG_UINT_bKGD, init_bkgd, free_bkgd, read_bkgd, write_bkgd, 0, 0},
{MNG_UINT_cHRM, init_chrm, free_chrm, read_chrm, write_chrm, 0, 0},
{MNG_UINT_eXPI, init_expi, free_expi, read_expi, write_expi, 0, 0},
{MNG_UINT_fPRI, init_fpri, free_fpri, read_fpri, write_fpri, 0, 0},
{MNG_UINT_gAMA, init_gama, free_gama, read_gama, write_gama, 0, 0},
{MNG_UINT_hIST, init_hist, free_hist, read_hist, write_hist, 0, 0},
{MNG_UINT_iCCP, init_iccp, free_iccp, read_iccp, write_iccp, 0, 0},
{MNG_UINT_iTXt, init_itxt, free_itxt, read_itxt, write_itxt, 0, 0},
{MNG_UINT_nEED, init_need, free_need, read_need, write_need, 0, 0},
/* TODO: {MNG_UINT_oFFs, 0, 0, 0, 0, 0, 0}, */
/* TODO: {MNG_UINT_pCAL, 0, 0, 0, 0, 0, 0}, */
{MNG_UINT_pHYg, init_phyg, free_phyg, read_phyg, write_phyg, 0, 0},
{MNG_UINT_pHYs, init_phys, free_phys, read_phys, write_phys, 0, 0},
{MNG_UINT_sBIT, init_sbit, free_sbit, read_sbit, write_sbit, 0, 0},
/* TODO: {MNG_UINT_sCAL, 0, 0, 0, 0, 0, 0}, */
{MNG_UINT_sPLT, init_splt, free_splt, read_splt, write_splt, 0, 0},
{MNG_UINT_sRGB, init_srgb, free_srgb, read_srgb, write_srgb, 0, 0},
{MNG_UINT_tEXt, init_text, free_text, read_text, write_text, 0, 0},
{MNG_UINT_tIME, init_time, free_time, read_time, write_time, 0, 0},
{MNG_UINT_tRNS, init_trns, free_trns, read_trns, write_trns, 0, 0},
{MNG_UINT_zTXt, init_ztxt, free_ztxt, read_ztxt, write_ztxt, 0, 0},
};
/* binary search variables */
mng_int32 iTop, iLower, iUpper, iMiddle;
mng_chunk_headerp pEntry; /* pointer to found entry */
mng_chunkid iChunkname; /* the chunk's tag */
mng_chunkp pChunk; /* chunk structure (if #define MNG_STORE_CHUNKS) */
mng_retcode iRetcode; /* temporary error-code */
#ifdef MNG_SUPPORT_TRACE
MNG_TRACE (pData, MNG_FN_PROCESS_RAW_CHUNK, MNG_LC_START)
#endif
/* get the chunkname */
iChunkname = (mng_chunkid)(mng_get_uint32 (pBuf));
pBuf += sizeof (mng_chunkid); /* adjust the buffer */
iBuflen -= sizeof (mng_chunkid);
/* determine max index of table */
iTop = (sizeof (chunk_table) / sizeof (chunk_table [0])) - 1;
/* binary search; with 52 chunks, worst-case is 7 comparisons */
iLower = 0;
iMiddle = 11; /* start with the IDAT entry */
iUpper = iTop;
pEntry = 0; /* no goods yet! */
pChunk = 0;
do /* the binary search itself */
{
if (chunk_table [iMiddle].iChunkname < iChunkname)
iLower = iMiddle + 1;
else if (chunk_table [iMiddle].iChunkname > iChunkname)
iUpper = iMiddle - 1;
else
{
pEntry = &chunk_table [iMiddle];
break;
}
iMiddle = (iLower + iUpper) >> 1;
}
while (iLower <= iUpper);
if (!pEntry) /* unknown chunk ? */
pEntry = &chunk_unknown; /* make it so! */
pData->iChunkname = iChunkname; /* keep track of where we are */
pData->iChunkseq++;
if (pEntry->fRead) /* read-callback available ? */
{
iRetcode = pEntry->fRead (pData, pEntry, iBuflen, (mng_ptr)pBuf, &pChunk);
if (!iRetcode) /* everything oke ? */
{ /* remember unknown chunk's id */
if ((pChunk) && (pEntry == &chunk_unknown))
((mng_chunk_headerp)pChunk)->iChunkname = iChunkname;
}
}
else
iRetcode = MNG_NOERROR;
if (pChunk) /* store this chunk ? */
add_chunk (pData, pChunk); /* do it */
#ifdef MNG_INCLUDE_JNG /* implicit EOF ? */
if ((!pData->bHasMHDR) && (!pData->bHasIHDR) && (!pData->bHasJHDR))
#else
if ((!pData->bHasMHDR) && (!pData->bHasIHDR))
#endif
iRetcode = process_eof (pData); /* then do some EOF processing */
if (iRetcode) /* on error bail out */
return iRetcode;
#ifdef MNG_SUPPORT_TRACE
MNG_TRACE (pData, MNG_FN_PROCESS_RAW_CHUNK, MNG_LC_END)
#endif
return MNG_NOERROR;
}
/* ************************************************************************** */
mng_retcode read_chunk (mng_datap pData)
{
mng_uint32 iBufmax = pData->iReadbufsize;
mng_uint8p pBuf = pData->pReadbuf;
mng_uint32 iBuflen = 0; /* number of bytes requested */
mng_uint32 iRead = 0; /* number of bytes read */
mng_uint32 iCrc; /* calculated CRC */
mng_retcode iRetcode = MNG_NOERROR;
#ifdef MNG_SUPPORT_TRACE
MNG_TRACE (pData, MNG_FN_READ_CHUNK, MNG_LC_START)
#endif
#ifdef MNG_SUPPORT_DISPLAY
if (pData->pCurraniobj) /* processing an animation object ? */
{
do /* process it then */
{
iRetcode = ((mng_object_headerp)pData->pCurraniobj)->fProcess (pData, pData->pCurraniobj);
/* refresh needed ? */
/* if ((!iRetcode) && (!pData->bTimerset) && (pData->bNeedrefresh))
iRetcode = display_progressive_refresh (pData, 1); */
/* can we advance to next object ? */
if ((!iRetcode) && (pData->pCurraniobj) &&
(!pData->bTimerset) && (!pData->bSectionwait))
{
pData->pCurraniobj = ((mng_object_headerp)pData->pCurraniobj)->pNext;
/* TERM processing to be done ? */
if ((!pData->pCurraniobj) && (pData->bHasTERM) && (!pData->bHasMHDR))
iRetcode = process_display_mend (pData);
}
} /* until error or a break or no more objects */
while ((!iRetcode) && (pData->pCurraniobj) &&
(!pData->bTimerset) && (!pData->bSectionwait) && (!pData->bFreezing));
}
else
{
if (pData->iBreakpoint) /* do we need to finish something first ? */
{
switch (pData->iBreakpoint) /* return to broken display routine */
{
case 1 : { iRetcode = process_display_fram2 (pData); break; }
case 2 : { iRetcode = process_display_ihdr (pData); break; }
case 3 : ; /* same as 4 !!! */
case 4 : { iRetcode = process_display_show (pData); break; }
case 5 : { iRetcode = process_display_clon2 (pData); break; }
#ifdef MNG_INCLUDE_JNG
case 7 : { iRetcode = process_display_jhdr (pData); break; }
#endif
case 6 : ; /* same as 8 !!! */
case 8 : { iRetcode = process_display_iend (pData); break; }
case 9 : { iRetcode = process_display_magn2 (pData); break; }
}
}
}
if (iRetcode) /* on error bail out */
return iRetcode;
#endif /* MNG_SUPPORT_DISPLAY */
/* can we continue processing now, or do we */
/* need to wait for the timer to finish (again) ? */
#ifdef MNG_SUPPORT_DISPLAY
if ((!pData->bTimerset) && (!pData->bSectionwait) && (!pData->bEOF))
#else
if (!pData->bEOF)
#endif
{ /* freezing in progress ? */
if ((pData->bFreezing) && (pData->iSuspendpoint == 0))
pData->bRunning = MNG_FALSE; /* then this is the right moment to do it */
if (pData->iSuspendpoint <= 2)
{
iBuflen = sizeof (mng_uint32); /* read length */
iRetcode = read_databuffer (pData, pBuf, iBuflen, &iRead);
if (iRetcode) /* bail on errors */
return iRetcode;
if (pData->bSuspended) /* suspended ? */
pData->iSuspendpoint = 2;
else /* save the length */
pData->iChunklen = mng_get_uint32 (pBuf);
}
if (!pData->bSuspended) /* still going ? */
{ /* previously suspended or not eof ? */
if ((pData->iSuspendpoint > 2) || (iRead == iBuflen))
{ /* determine length chunkname + data + crc */
iBuflen = pData->iChunklen + (mng_uint32)(sizeof (mng_chunkid) + sizeof (iCrc));
if (iBuflen < iBufmax) /* does it fit in default buffer ? */
{ /* note that we don't use the full size
so there's always a zero-byte at the
very end !!! */
iRetcode = read_databuffer (pData, pBuf, iBuflen, &iRead);
if (iRetcode) /* bail on errors */
return iRetcode;
if (pData->bSuspended) /* suspended ? */
pData->iSuspendpoint = 3;
else
{
if (iRead != iBuflen) /* did we get all the data ? */
iRetcode = MNG_UNEXPECTEDEOF;
else
{
mng_uint32 iL = iBuflen - (mng_uint32)(sizeof (iCrc));
/* calculate the crc */
iCrc = crc (pData, pBuf, iL);
/* and check it */
if (!(iCrc == mng_get_uint32 (pBuf + iL)))
iRetcode = MNG_INVALIDCRC;
else
iRetcode = process_raw_chunk (pData, pBuf, iL);
}
}
}
else
{
if (!pData->iSuspendpoint) /* create additional large buffer ? */
{ /* again reserve space for the last zero-byte */
pData->iLargebufsize = iBuflen + 1;
MNG_ALLOC (pData, pData->pLargebuf, pData->iLargebufsize)
}
iRetcode = read_databuffer (pData, pData->pLargebuf, iBuflen, &iRead);
if (iRetcode)
return iRetcode;
if (pData->bSuspended) /* suspended ? */
pData->iSuspendpoint = 4;
else
{
if (iRead != iBuflen) /* did we get all the data ? */
iRetcode = MNG_UNEXPECTEDEOF;
else
{
mng_uint32 iL = iBuflen - (mng_uint32)(sizeof (iCrc));
/* calculate the crc */
iCrc = crc (pData, pData->pLargebuf, iL);
/* and check it */
if (!(iCrc == mng_get_uint32 (pData->pLargebuf + iL)))
iRetcode = MNG_INVALIDCRC;
else
iRetcode = process_raw_chunk (pData, pData->pLargebuf, iL);
}
/* cleanup additional large buffer */
MNG_FREE (pData, pData->pLargebuf, pData->iLargebufsize)
}
}
if (iRetcode) /* on error bail out */
return iRetcode;
}
else
{ /* that's final */
iRetcode = process_eof (pData);
if (iRetcode) /* on error bail out */
return iRetcode;
if ((iRead != 0) || /* did we get an unexpected eof ? */
#ifdef MNG_INCLUDE_JNG
(pData->bHasIHDR || pData->bHasMHDR || pData->bHasJHDR))
#else
(pData->bHasIHDR || pData->bHasMHDR))
#endif
MNG_ERROR (pData, MNG_UNEXPECTEDEOF);
}
}
}
#ifdef MNG_SUPPORT_DISPLAY /* refresh needed ? */
if ((!pData->bTimerset) && (!pData->bSuspended) && (pData->bNeedrefresh))
{
iRetcode = display_progressive_refresh (pData, 1);
if (iRetcode) /* on error bail out */
return iRetcode;
}
#endif
#ifdef MNG_SUPPORT_TRACE
MNG_TRACE (pData, MNG_FN_READ_CHUNK, MNG_LC_END)
#endif
return MNG_NOERROR;
}
/* ************************************************************************** */
mng_retcode read_graphic (mng_datap pData)
{
mng_uint32 iBuflen; /* number of bytes requested */
mng_uint32 iRead; /* number of bytes read */
mng_retcode iRetcode; /* temporary error-code */
#ifdef MNG_SUPPORT_TRACE
MNG_TRACE (pData, MNG_FN_READ_GRAPHIC, MNG_LC_START)
#endif
if (!pData->pReadbuf) /* buffer allocated ? */
{
pData->iReadbufsize = 4200; /* allocate a default read buffer */
MNG_ALLOC (pData, pData->pReadbuf, pData->iReadbufsize)
}
/* haven't processed the signature ? */
if ((!pData->bHavesig) || (pData->iSuspendpoint == 1))
{
iBuflen = 2 * sizeof (mng_uint32); /* read signature */
iRetcode = read_databuffer (pData, pData->pReadbuf, iBuflen, &iRead);
if (iRetcode)
return iRetcode;
if (pData->bSuspended) /* input suspension ? */
pData->iSuspendpoint = 1;
else
{
if (iRead != iBuflen) /* full signature received ? */
MNG_ERROR (pData, MNG_UNEXPECTEDEOF);
/* is it a valid signature ? */
if (mng_get_uint32 (pData->pReadbuf) == PNG_SIG)
pData->eSigtype = mng_it_png;
else
if (mng_get_uint32 (pData->pReadbuf) == JNG_SIG)
pData->eSigtype = mng_it_jng;
else
if (mng_get_uint32 (pData->pReadbuf) == MNG_SIG)
pData->eSigtype = mng_it_mng;
else
MNG_ERROR (pData, MNG_INVALIDSIG);
/* all of it ? */
if (mng_get_uint32 (pData->pReadbuf+4) != POST_SIG)
MNG_ERROR (pData, MNG_INVALIDSIG);
pData->bHavesig = MNG_TRUE;
}
}
if (!pData->bSuspended) /* still going ? */
{
do
{
iRetcode = read_chunk (pData); /* process a chunk */
if (iRetcode) /* on error bail out */
return iRetcode;
}
#ifdef MNG_SUPPORT_DISPLAY /* until EOF or a break-request */
while (((!pData->bEOF) || (pData->pCurraniobj)) && (!pData->bSuspended) &&
(!pData->bTimerset) && (!pData->bSectionwait));
#else
while ((!pData->bEOF) && (!pData->bSuspended));
#endif
}
#ifdef MNG_SUPPORT_TRACE
MNG_TRACE (pData, MNG_FN_READ_GRAPHIC, MNG_LC_END)
#endif
return MNG_NOERROR;
}
/* ************************************************************************** */
#endif /* MNG_INCLUDE_READ_PROCS */
/* ************************************************************************** */
/* * end of file * */
/* ************************************************************************** */