Wider/wrong? font rendering since v2.0

[r2rien]

Thanks a lot for this great piece of software I've been with for so long now :)

Since upgrade from 1.38 to 2.0, font rendering seems to have changed,
precisely horizontal spacing?/ligatures? between letters has increased,
and seem to be unpar with other gtk app using same font+size
(first noticed as when activating document wrapping, document displaying less lines within viewport)

checked gtk/pango/fontconfig stack against both debian stable/bookworm + unstable/sid,
and without any relevant clue I could report from dbg logs

-- System Information:

Debian Release: trixie/sid
Architecture: amd64 (x86_64)
Kernel: Linux 6.6.11-amd64 (SMP w/4 CPU threads; PREEMPT)
Locale: LANG=en_US.UTF-8, LC_CTYPE=en_US.UTF-8 (charmap=UTF-8), LANGUAGE=en_US:en.UTF-8

Versions of packages geany depends on:
ii  libatk1.0-0          2.50.0-1+b1
ii  libc6                2.37-13
ii  libcairo2            1.18.0-1+b1
ii  libgcc-s1            13.2.0-10
ii  libgdk-pixbuf-2.0-0  2.42.10+dfsg-3
ii  libglib2.0-0         2.78.3-1
ii  libgtk-3-0           3.24.40-1
ii  libpango-1.0-0       1.51.0+ds-4
ii  libpangocairo-1.0-0  1.51.0+ds-4
ii  libstdc++6           13.2.0-10

[elextr]

Looks like Scintilla rounding of fractional positions to integer pixels has changed for your system with [unspecified] font and [unspecified] size on a monitor with [unspecified] DPI with [unspecified] display server and [unspecified] GFX driver.

See also #3738 where that causes extra gaps and misalignment between 1.38 and 2.0, with the fix there (setting pango_context_set_round_glyph_positions to TRUE) both 1.38 and 2.0 produce exactly the same width text for me. But as @nyamatongwe pointed out setting that has other negative effects, YMMV.

The problem in #3738 is reported (by a bleeding edge Suse Tumbleweed user ;-) to go away with Pango 1.51.1, so maybe when that is in Debian you could re-check to see if it fixes this as well.

[r2rien]

Thanks and thanks for pointing me to #3738
Hack regular font 13 at 96 dpi with xorg and i915 here
will try pango_context_set_round_glyph_positions(pcontext, TRUE)
as I should not be affected by #3111 as I don't use chinese
while waiting (or maybe reporting it in debian to push it) for Pango 1.51.1 then recheck

[elextr]

then recheck

Don't forget to take the TRUE out first, at first I didn't ;-P

[r2rien]

just to confirm setting it to TRUE fixed it for me too
hereafter my 99_pango_context_set_round_glyph_positions_true.patch added to debian series

diff -Naur a/scintilla/gtk/PlatGTK.cxx b/scintilla/gtk/PlatGTK.cxx
--- a/scintilla/gtk/PlatGTK.cxx	2023-10-19 18:09:27.000000000 +0200
+++ b/scintilla/gtk/PlatGTK.cxx	2024-01-25 07:08:24.603457827 +0100
@@ -76,7 +76,7 @@
 
 void SetFractionalPositions([[maybe_unused]] PangoContext *pcontext) noexcept {
 #if PANGO_VERSION_CHECK(1,44,3)
-	pango_context_set_round_glyph_positions(pcontext, FALSE);
+	pango_context_set_round_glyph_positions(pcontext, TRUE);
 #endif
 }

thanks again, I will no forget to revert it (re-installing vanilla debian package one) when pango 1.51.1 in