home
***
CD-ROM
|
disk
|
FTP
|
other
***
search
/
Almathera Ten Pack 3: CDPD 3
/
Almathera Ten on Ten - Disc 3: CDPD3.iso
/
fish
/
001-100
/
001-025
/
016
/
source.files
/
ilbmr.c
< prev
next >
Wrap
C/C++ Source or Header
|
1995-03-17
|
5KB
|
148 lines
/*----------------------------------------------------------------------*
* ILBMR.C Support routines for reading ILBM files. 11/27/85
* (IFF is Interchange Format File.)
*
* By Jerry Morrison and Steve Shaw, Electronic Arts.
* This software is in the public domain.
*
* This version for the Commodore-Amiga computer.
*----------------------------------------------------------------------*/
#include "iff/packer.h"
#include "iff/ilbm.h"
/* ---------- GetCMAP ------------------------------------------------*/
/* pNColorRegs is passed in as a pointer to the number of ColorRegisters
* caller has space to hold. GetCMAP sets to the number actually read.*/
IFFP GetCMAP(ilbmContext, colorMap, pNColorRegs)
GroupContext *ilbmContext; WORD *colorMap; UBYTE *pNColorRegs;
{
register int nColorRegs;
register IFFP iffp;
ColorRegister colorReg;
nColorRegs = ilbmContext->ckHdr.ckSize / sizeofColorRegister;
if (*pNColorRegs < nColorRegs) nColorRegs = *pNColorRegs;
*pNColorRegs = nColorRegs; /* Set to the number actually there.*/
for ( ; nColorRegs > 0; --nColorRegs) {
iffp = IFFReadBytes(ilbmContext, (BYTE *)&colorReg,sizeofColorRegister);
CheckIFFP();
*colorMap++ = ( ( colorReg.red >> 4 ) << 8 ) |
( ( colorReg.green >> 4 ) << 4 ) |
( ( colorReg.blue >> 4 ) );
}
return(IFF_OKAY);
}
/*---------- GetBODY ---------------------------------------------------*/
/* NOTE: This implementation could be a LOT faster if it used more of the
* supplied buffer. It would make far fewer calls to IFFReadBytes (and
* therefore to DOS Read) and to movemem. */
IFFP GetBODY(context, bitmap, mask, bmHdr, buffer, bufsize)
GroupContext *context; struct BitMap *bitmap; BYTE *mask;
BitMapHeader *bmHdr; BYTE *buffer; LONG bufsize;
{
register IFFP iffp;
UBYTE srcPlaneCnt = bmHdr->nPlanes; /* Haven't counted for mask plane yet*/
WORD srcRowBytes = RowBytes(bmHdr->w);
LONG bufRowBytes = MaxPackedSize(srcRowBytes);
int nRows = bmHdr->h;
Compression compression = bmHdr->compression;
register int iPlane, iRow, nEmpty;
register WORD nFilled;
BYTE *buf, *nullDest, *nullBuf, **pDest;
BYTE *planes[MaxSrcPlanes]; /* array of ptrs to planes & mask */
if (compression > cmpByteRun1)
return(CLIENT_ERROR);
/* Complain if client asked for a conversion GetBODY doesn't handle.*/
if ( srcRowBytes != bitmap->BytesPerRow ||
bufsize < bufRowBytes * 2 ||
srcPlaneCnt > MaxSrcPlanes )
return(CLIENT_ERROR);
if (nRows > bitmap->Rows)
nRows = bitmap->Rows;
/* Initialize array "planes" with bitmap ptrs; NULL in empty slots.*/
for (iPlane = 0; iPlane < bitmap->Depth; iPlane++)
planes[iPlane] = (BYTE *)bitmap->Planes[iPlane];
for ( ; iPlane < MaxSrcPlanes; iPlane++)
planes[iPlane] = NULL;
/* Copy any mask plane ptr into corresponding "planes" slot.*/
if (bmHdr->masking == mskHasMask) {
if (mask != NULL)
planes[srcPlaneCnt] = mask; /* If there are more srcPlanes than
* dstPlanes, there will be NULL plane-pointers before this.*/
else
planes[srcPlaneCnt] = NULL; /* In case more dstPlanes than src.*/
srcPlaneCnt += 1; /* Include mask plane in count.*/
}
/* Setup a sink for dummy destination of rows from unwanted planes.*/
nullDest = buffer;
buffer += srcRowBytes;
bufsize -= srcRowBytes;
/* Read the BODY contents into client's bitmap.
* De-interleave planes and decompress rows.
* MODIFIES: Last iteration modifies bufsize.*/
buf = buffer + bufsize; /* Buffer is currently empty.*/
for (iRow = nRows; iRow > 0; iRow--) {
for (iPlane = 0; iPlane < srcPlaneCnt; iPlane++) {
pDest = &planes[iPlane];
/* Establish a sink for any unwanted plane.*/
if (*pDest == NULL) {
nullBuf = nullDest;
pDest = &nullBuf;
}
/* Read in at least enough bytes to uncompress next row.*/
nEmpty = buf - buffer; /* size of empty part of buffer.*/
nFilled = bufsize - nEmpty; /* this part has data.*/
if (nFilled < bufRowBytes) {
/* Need to read more.*/
/* Move the existing data to the front of the buffer.*/
/* Now covers range buffer[0]..buffer[nFilled-1].*/
movmem(buf, buffer, nFilled); /* Could be moving 0 bytes.*/
if (nEmpty > ChunkMoreBytes(context)) {
/* There aren't enough bytes left to fill the buffer.*/
nEmpty = ChunkMoreBytes(context);
bufsize = nFilled + nEmpty; /* heh-heh */
}
/* Append new data to the existing data.*/
iffp = IFFReadBytes(context, &buffer[nFilled], nEmpty);
CheckIFFP();
buf = buffer;
nFilled = bufsize;
nEmpty = 0;
}
/* Copy uncompressed row to destination plane.*/
if (compression == cmpNone) {
if (nFilled < srcRowBytes) return(BAD_FORM);
movmem(buf, *pDest, srcRowBytes);
buf += srcRowBytes;
*pDest += srcRowBytes;
}
else
/* Decompress row to destination plane.*/
if ( UnPackRow(&buf, pDest, nFilled, srcRowBytes) )
/* pSource, pDest, srcBytes, dstBytes */
return(BAD_FORM);
}
}
return(IFF_OKAY);
}