RDict
RDict is a stripped-down version of PrePress, produced by Lyle Ramshaw
(PARC, CSL) in late 1979 for the special purpose of rotating all of the
fonts in a large dictionary. Suppose that you are the proud owner of a
dictionary of orbitized rasters, say the Spruce.Fonts of your local
Dover printer. You would like to produce a new dictionary of orbitized
rasters, in which each font has been rotated through 90 degrees. To do
this job with PrePress, you would have to Extract, DeOrbitize, Rotate,
Orbitize, and then Merge each font individually. With the RDict
program, you can eliminate the Extract and Merge portions of this
scenario, and save yourself the production of a large sea of command
lines as well.
The input to RDict is a dictionary of rasters, all of which must be
either of type OrbitChars or type MultiChars. RDict will simply throw
away the extra width information included in the MultiChars segments,
and produce an output dictionary in which all of the segments are of
type OrbitChars.
RDict is controlled via the command line. Invoke RDict by saying
RDict <InputFileName> <Angle> <OutputFileName>
where the three parameters are as follows. If you have trouble
remembering the order of the three arguments, you may invoke RDict with
the command line "RDict", and it will prompt you for each of the
arguments in turn.
The <InputFileName> is a regular file name, optionally preceded by a
disk specifier. To refer to a file on the standard system disk, you
may use the disk specifier "dp0:", or just omit the disk specifier
entirely. Upper and lower case are equivalent in disk specifiers, so
"DP0:" or "Dp0:" or "dP0:" mean the same as "dp0:". The specifier
"dp1:" refers to the other Diablo Model 31 drive, should your Alto be
so equipped. Trident T-80 drives are referred to as "tp0:" through
"tp7:". Trident T-300 drives contain up to three entirely distinct
Alto file systems; the three file systems on physical T-300 drive 3 are
referred to as "tp3:", "tp403:", and "tp1003:" (for arcane reasons
that, if you have a T-300, you probably already know).
The <OutputFileName> is a regular file name preceded by an optional
disk specifier in an analogous fashion. If the output file already
exists, RDict will overwrite it.
The <Angle> field specifies the amount of additional rotation that is
desired, as a signed, decimal quantity expressed in degrees (rather
than minutes). The <Angle> must be a multiple of 90 degrees, of
course. The rotation specified by <Angle> is incremental, not
absolute. For example, suppose that you use RDict to rotate an input
dictionary by 90 degrees; a font in the input whose Rotation is x
minutes of arc will be written into the output with a Rotation of
(x+5400) minutes, since 5400 minutes is 90 degrees.
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Copyright Xerox Corporation 1979
RDict January 10, 1980 2
RDict first scans the input file, and prints out for you how many fonts
of what types it contains, pausing for 5 seconds to let you read this
display. Next, RDict writes a blank output file of roughly the correct
total length. This guarantees that the disk containing the output file
will overflow right away if it will overflow at all, instead of waiting
until the program has run for several hours. Having written this blank
output file, RDict next writes at the beginning of that output file a
PrePress-style index that describes the desired output fonts; one bit
in each index entry, however, specifies that the corresponding font
data has not yet been rotated. Then, RDict takes each font in turn,
and, for each character in that font, calls the standard PrePress code
to DeOrbitize, Rotate, and then Orbitize that character. [RDict could
be made to run more rapidly if a special Rotate were written that went
from OrbitChars to OrbitChars directly; but I'm lazy, and I didn't want
to introduce any new bugs in the rasters themselves.] When the rotated
font data has been completely entered in the output file, the
corresponding index entry is changed to mark that font as processed.
Since RDict runs tend to take a long time, there is a high probability
that you might want to interrupt one someday. Once the output file has
been set up, and actual rotations of fonts have begun, you may
interrupt RDict at any time by merely typing <shift>-<swat>. To resume
the computation at some later time, repeat the earlier command line,
except type "RDict/R" instead of simply "RDict" (the "R" stands for
"Restart"). RDict will scan the input and output files to check for
consistency, and then resume processing by starting to rotate the first
font that is not yet marked as complete.
Note that RDict can be used to throw away all but the most recent width
information in the MultiChars fonts of a dictionary, without doing
anything else. To convert all of the MultiChars segments in a
dictionary to the equivalent OrbitChars segments, just run RDict over
the dictionary and specify "0" as the <Angle>. To make this use of
RDict more convenient, the program makes a special check for an <Angle>
of 0, and, in this case, simply copies each character from the input to
the output, without bothering to DeOrbitize, Rotate by zero, and
Orbitize again.
RDict is unforgiving about errors, and solves most of its problems by
calling Swat with some flavor of message. Errors generated inside of
the code that Rotates, Orbitizes, and DeOrbitizes will also call Swat.
For example, I hit a "Character height inconsistancy" after more than
four hours of rotating my Spruce.Fonts: life is hard.