# T_RIDSMTN -- Semicode for the IDS mountain format tape reader.  IDS
# records in raw or mountain reduced format can be read into a series of
# one dimensional IRAF images.  The first record on each mtn tape is a
# dummy record and is ignored.  Each IDS header is read and compared
# against the "record_numbers" list.  Depending on the user's request,
# the header can be printed in long or short form, an IRAF image can
# be written and the pixel values listed.  All IDS records are in a 
# single file; an EOF implies EOT.  Procedure terminates when EOF is
# encountered or all requested records havs been read.

procedure t_ridsmtn (ids_file, iraf_file)

begin
	get control parameters from cl
	if (output image is to be made)
	    get root output name
	
	fd = open input file

	while (all requested records haven't been read) {

	    # Code has been revised to accomodate the apparent fact that
	    # the data matrix is imbedded in the header information.  The
	    # entire record (header + data) is now read in at one time.

	    if (read (fd, ids_record, length_of_record) == EOF) 
	        quit
	    else {
		current_record = unpack current record from buffer
	        if (current_record is to be read) 
		    call idsm_read_record (ids_record, header_struct, cp_struct)
	    }
	}
end


# IDSM_READ_RECORD -- is called once for each IDS record that appears in
# the "record_numbers" range.   The header is printed and the IDS pixels
# converted, printed or skipped depending on user request.

procedure idsm_read_record (ids_record, header_struct, control_param)

begin
	stat = idsm_read_header  (ids_record, header_struct)
	if (stat == DUMMY) {
	    report dummy record encountered
	    return
	}
	call idsm_print_header (header_struct, long_header)

	if (make_image or print_pixels == YES)  {
	    # First unpack pixels into a pixel buffer
	    if (reduced data)
	        call red_ids_unpk (fd, pixels)
	    else
	        call raw_ids_unpk (fd, pixels)

	    if (output image is to be written) {
	        generate output filename
	        call idsm_write_image (pixels, data_type, out_fname, 
		    header_struct)
	    }

	    if (pixels values are to be listed)
	        call isdm_print_pixels (pixels)

end


# IDSM_READ_HEADER -- Read an IDS header and fill the program data
# structure with header values.  Returns DUMMY or OK.

int procedure idsm_read_header (ids_buffer, header_structure)

begin
	unpack header words into header structure
	if record is DUMMY record
	    return (DUMMY)
	else
	    return (OK)
end


# IDSM_WRITE_IMAGE -- Write a one dimensional IRAF image of an IDS record.

procedure idsm_write_image (pixels, data_type, out_fname, header_struct)

begin
	map output image

	move pixel_buffer into row vector

	store IDS header values in image user area
end