{Specs for Routines for handling IFF plus files.  Full code is in IFFUTILS}
{Full documentation commented in at the end of IFFUTILS.}
{J. Butler 12 Jan 86}

%constinteger %c
    iff not magic=16_81,       iff no file = 16_82,
    iff wrong length = 16_83,  iff header too short = 16_84,
    iff last one = 16_84
%constinteger iff read=0, iff write=1

%conststring (31) %array iff error(iff not magic:iff last one)= %c
   "File has wrong magic number",    "File does not exist",
   "File length inconsistent",       "Header too short"

%recordformat context fm( %c
%integer filstart, filptr, readwrite, imaddr, %byte colour,screen,file,d1,
%integer xoff,yoff)
%constinteger context size = 28

%recordformat iffhdr fm(%integer  hlen, datatype, ht, wid, 
signed, fov ht, fov wid, stereo, baseline, vergence, gaze, id, processed, fstop,
%integer focus, appno, images, subs, xoff, yoff, aspect, mapaddr, mapwid, maplen, 
%record (context fm) %name context, %record (*) %name app,
%string (255) title,
%string (8) date, time)

%externalintegerfnspec IFF OPEN FILE %alias "IFF_OPEN_FILE" %c
(%string (255) filename, %record (iffhdr fm) %name iffh, %integer readwrite)
{opens an IFF file for input or output.  Result=0 if it succeeds #0 otherwise}
{Note uses stream 1 for output}

%externalroutinespec IFF CLOSE FILE %alias "IFF_CLOSE_FILE" %c
(%record (iffhdr fm) iffh)
{closes an IFF OPENed file}

%externalintegerfnspec IFF READ HEADER %alias "IFF_READ_HEADER" %c
(%record (iffhdr fm) %name iffh)
{read header from an IFF OPENed file and puts field values in IFFH}

%externalintegerfnspec IFF WRITE HEADER %alias "IFF_WRITE_HEADER" %c
(%record (iffhdr fm) %name iffh)
{writes a valid IFF header from values supplied in IFFH. Uses sensible defaults}

%externalroutinespec IFF SHOW HEADER %alias "IFF_SHOW_HEADER" %c
(%record (iffhdr fm) iffh, %integer detail)
{Dumps some of the more interesting IFF header values to current o/p stream}

%externalintegerfnspec IFF READ IMAGE %alias "IFF_READ_IMAGE"( %c
%record (iffhdr fm) %name iffh, %integer address)
{reads the image from an IFF OPENed file which has had the header read by}
{IFF READ HEADER (normally).  Will expand the image if compressed}

%externalintegerfnspec IFF WRITE IMAGE %alias "IFF_WRITE_IMAGE"( %c
%record (iffhdr fm) %name iffh, %integer address)
{writes the image to an IFF OPENed file which has had the header written by}
{IFF WRITE HEADER (normally).  Will compress the image if IFFHDR_DATATYPE has}
{the compress bits set}

%externalintegerfnspec iff readin %alias "IFF_READIN" (%string (255) file,
%record (iffhdr fm) %name iffh, %integername ad)

%externalintegerfnspec iff writeout %alias "IFF_WRITEOUT" (%string (255) file,
%record (iffhdr fm) %name iffh, %integer ad)
%endoffile