Summary of responses on desktop-publishing survey

[H.David Scarbro x6608]

In the recent article "Summary of Responses on Desktop Publishing Survey"
by root at helios.ucsc.edu (De Clarke x2630) a printing problem was described
that was caused by the low internal precision of Frame's publishing
software.

In addition to the printing problems caused by truncation of positioning
information to screen resolution there is more serious usage problem.
Here is a simple example:

    Create a rectangle and a diagonal line somewhere within in.  Group these
    objects and size them as small as possible.  Now resize to the original
    dimensions.  Both the size and position of the diagonal line will have
    changed.

Sufficiently high internal precision eliminates the complete loss of
diagram fidelity that this test illustrates, and also of printer fidelity
with respect to various geometric constraints, such as the attachment of
lines to one another.  Interleaf's TPS maintains an internal precision of
approximately 1.25 million dpi.

Also, there is a second-order problem that programs with low internal
precision (like Frame) suffer from.  It is caused by rounding coordinate
values that occurs when an object is scaled.  Visually this is seen as
objects that seem to "float" apart after they are scaled.  In practice,
this problem can be somewhat maddening because the error often cannot be
seen at screen resolution.  It appears only when the objects are printed
on a device with higher resolution.

Interleaf solves this problem in TPS with diagramming gravity.  In TPS,
gravity can be turned on or off.  With it on, the edges of objects attract
one another.  Once attached, they stay attached until a user explicitly
breaks them apart.

Finally, I have a comment about De Clarke's survey.  The opinion of
experienced users and anecdotal evidence can be a useful tool, but there
are several other sources for more thorough evaluations of electronic
publishing software. The Seybold Group does excellent technical reviews.
They have reviewed, I think, all of popular the publishing packages
available for Sun.  Also, the December issue of Unix World has a
comparative review of Interleaf TPS and FrameMaker.

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David Scarbro                          UUCP: ..!{sun!sunne,mit-eddie}!ileaf!hds
Interleaf, Inc.                        Internet: hds at ileaf.com
10 Canal Park, Cambridge, MA 02141     Phone: (617)577-9800 x6608