64 bit SI type
Joris van der Hoeven <[email protected]> Thu, 31 Jul 2025 13:12:21 +0200
| Newsgroups | gmane.editors.texmacs.devel |
|---|---|
| Message-ID | <[email protected]> |
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Dear all,
I just completed a fairly large amount of work in order to
make it possible to use a 64 bit integer type for SI instead of
the current 32 bit type.
I recall that the SI type corresponds to graphical coordinates or lengths,
with a sign bit, a 23 bit integer part and an 8 bit fractional part.
It turns that the 32 bit integer type is more and more often insufficient
for very large documents, like books with >= 500 pages.
Indeed, the current SI type has a span of 2^23 / 5 ~ 1.6M pixels
(after application of the shrinking factor 5). On retina screens,
the height of a line is quickly about 50 pixels, which yields a limit
of about 32000 lines of text.
For this reason, I wish to switch to a 64 bit format,
but this is a somewhat dangerous change of a fundamental data type.
Before doing the final commit, it would be nice if some of you could
test on particularly challenging documents. In order to enable
the 64 bit SI type, you should change '#define SI_32' in basic.hpp
into '#define SI_64' and recompile.
Best wishes, --Joris
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<p>Dear all,</p>
<p>I just completed a fairly large amount of work in order to<br>
make it possible to use a 64 bit integer type for SI instead of<br>
the current 32 bit type.<br>
</p>
<p>I recall that the SI type corresponds to graphical coordinates or
lengths,<br>
with a sign bit, a 23 bit integer part and an 8 bit fractional
part.<br>
It turns that the 32 bit integer type is more and more often
insufficient<br>
for very large documents, like books with >= 500 pages.<br>
Indeed, the current SI type has a span of 2^23 / 5 ~ 1.6M pixels<br>
(after application of the shrinking factor 5). On retina screens,<br>
the height of a line is quickly about 50 pixels, which yields a
limit<br>
of about 32000 lines of text.</p>
<p>For this reason, I wish to switch to a 64 bit format,<br>
but this is a somewhat dangerous change of a fundamental data
type.<br>
Before doing the final commit, it would be nice if some of you
could<br>
test on particularly challenging documents. In order to enable<br>
the 64 bit SI type, you should change '#define SI_32' in basic.hpp<br>
into '#define SI_64' and recompile.</p>
<p>Best wishes, --Joris</p>
<p><br>
</p>
</body>
</html>
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