[groff] 05/20: [docs]: Explain how to get the device resolution.

[G. Branden Robinson]

gbranden pushed a commit to branch master
in repository groff.

commit 0fdcc60b9a8c498aaf9380b7cf4b737fd1275daa
Author: G. Branden Robinson <g.branden.robinson@gmail.com>
AuthorDate: Sat Nov 19 16:19:27 2022 -0600

    [docs]: Explain how to get the device resolution.
    
    ...from within the formatter.
---
 doc/groff.texi  | 8 ++++++--
 man/groff.7.man | 4 ++++
 2 files changed, 10 insertions(+), 2 deletions(-)

diff --git a/doc/groff.texi b/doc/groff.texi
index 1a8e4dc71..eab61fbb4 100644
--- a/doc/groff.texi
+++ b/doc/groff.texi
@@ -5799,8 +5799,12 @@ after the decimal point are optional.  Measurement 
expressions include
 @cindex units, basic, converstion to
 @cindex conversion to basic units
 Measurements are scaled by the scaling unit and stored internally (with
-any fractional part discarded) in basic units.  The only constraint
-on the basic unit is that it is at least as small as any other unit.
+any fractional part discarded) in basic units.
+@cindex device resolution, obtaining in the formatter
+@cindex resolution, device, obtaining in the formatter
+The device resolution can therefore be obtained by storing a value of
+@samp{1i} to a register.  The only constraint on the basic unit is that
+it is at least as small as any other unit.
 @c That's a fib.  A device resolution of around 2^31 would surely also
 @c cause problems.  But nobody does that.
 
diff --git a/man/groff.7.man b/man/groff.7.man
index 1c323602f..1ec89c1b0 100644
--- a/man/groff.7.man
+++ b/man/groff.7.man
@@ -752,6 +752,10 @@ Measurements are scaled by the scaling unit and stored 
internally
 (with any fractional part discarded)
 in basic units.
 .
+The device resolution can therefore be obtained by storing a value of
+.RB \[lq] 1i \[rq]
+to a register.
+.
 The only constraint on the basic unit is that it is at least as small as
 any other unit.
 .\" That's a fib.  A device resolution of around 2^31 would surely also