Re: [NTG-context] LuaTeX and PDF.js

2021-01-08 Thread Vedran Miletić

08. 01. 2021. u 05:41, Aditya Mahajan piše:

On Fri, 8 Jan 2021, Hans Hagen wrote:


On 1/8/2021 12:39 AM, Vedran Miletić wrote:


It's whatever ConTeXt standalone has. I don't have any extra Lua installed:


--credits should mention the lua version


Should I see it on non-HiDPI as well? Because it seems it's there.


depends on what you consider (non) hdpi ... the positioning of glyphs
depends on font scale, rounding of stems and such (hints in fonts but
these get less relevant with high res displays), caching, inter glyph
corrections (that pdftex/luatex/...) put in the text stream to resync
within certain tolerances, etc ... (often a print is a better reference
as displays are seldom 600+ dpi) .. it's also why often expansion looks
bad on screen because even a sub percentage difference can give such
effects


Another way to see it is just zoom in on the PDF. If the artifacts go away on 
zooming in, then they are due to anti-aliasing.

Aditya

Thanks to both of you for the detailed explanations. Printed page shows 
no artifacts and neither does PDF.js when the text is zoomed. So it is 
an issue with anti-aliasing after all.


I'll report it to PDF.js and see what they tell me.

Regards,
Vedran

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Re: [NTG-context] LuaTeX and PDF.js

2021-01-07 Thread Aditya Mahajan
On Fri, 8 Jan 2021, Hans Hagen wrote:

> On 1/8/2021 12:39 AM, Vedran Miletić wrote:
> 
> > It's whatever ConTeXt standalone has. I don't have any extra Lua installed:
> 
> --credits should mention the lua version
> 
> > Should I see it on non-HiDPI as well? Because it seems it's there.
> 
> depends on what you consider (non) hdpi ... the positioning of glyphs 
> depends on font scale, rounding of stems and such (hints in fonts but 
> these get less relevant with high res displays), caching, inter glyph 
> corrections (that pdftex/luatex/...) put in the text stream to resync 
> within certain tolerances, etc ... (often a print is a better reference 
> as displays are seldom 600+ dpi) .. it's also why often expansion looks 
> bad on screen because even a sub percentage difference can give such 
> effects

Another way to see it is just zoom in on the PDF. If the artifacts go away on 
zooming in, then they are due to anti-aliasing.

Aditya___
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Re: [NTG-context] LuaTeX and PDF.js

2021-01-07 Thread Vedran Miletić

On 07. 01. 2021. 23:01, Hans Hagen wrote:

what lua does your 2.08 have? if it's 5.2. then such small differences 
can be a side effect of lua (different number models), serialization 
of numbers (default accuracy), or maybe rounding in the lua=>tex font 
interface (there were some fixes iir), the number of digist that the 
backend uses, etc



It's whatever ConTeXt standalone has. I don't have any extra Lua installed:

$ luametatex --version
This is LuaMetaTeX, Version 2.08.11

Execute 'luametatex --credits' for credits and version details.

There is NO warranty. Redistribution of this software is covered by the 
terms

of the GNU General Public License, version 2 or (at your option) any later
version. For more information about these matters, see the file named 
COPYING

and the LuaTeX source.

Functionality : level 20210107
Support   : cont...@ntg.nl
Copyright : The Lua(Meta)TeX Team(s) (2005-2020+)

The LuaMetaTeX project is related to ConTeXt development. This macro package
tightly integrates TeX and MetaPost in close cooperation with Lua.

$ luatex --version
This is LuaTeX, Version 1.13.0 (TeX Live 2021/dev)

Execute  'luatex --credits'  for credits and version details.

There is NO warranty. Redistribution of this software is covered by
the terms of the GNU General Public License, version 2 or (at your option)
any later version. For more information about these matters, see the file
named COPYING and the LuaTeX source.

LuaTeX is Copyright 2020 Taco Hoekwater and the LuaTeX Team.


Typing lua gives command not found and texlua is system one.

anyhow, so what you see (in the file) is (per line) transform matrices 
that are slightly different so what you then see is rounding to the 
device pixels



Should I see it on non-HiDPI as well? Because it seems it's there.


Regards,

Vedran

i wouldn't loose sleep over it .. nowadays fonts also evolve and that 
gives larger differences


Hans

-
  Hans Hagen | PRAGMA ADE
  Ridderstraat 27 | 8061 GH Hasselt | The Netherlands
   tel: 038 477 53 69 | www.pragma-ade.nl | www.pragma-pod.nl
-



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[NTG-context] LuaTeX and PDF.js

2021-01-07 Thread Vedran Miletić

Hello,

I compared latest ConTeXt standalone (LuaTeX 2.08) against TeX Live 2020 
(LuaTeX 1.12). The produced PDFs are:


https://miletic.net/lipsum-112.pdf
https://miletic.net/lipsum-208.pdf

Viewing them with Evince (and I assume Adobe Reader, I don't have it at 
hand to test) shows only minor differences in (horizontal) character 
spacing, which I would expect; the text looks reasonably good either 
way. However, viewing them with PDF.js shows a large difference:


https://miletic.net/lipsum-pdfjs-112.png
https://miletic.net/lipsum-pdfjs-208.png

As you can observe, b, m, n, p, and r (and possibly others) are moved 
slightly above other letters. Is this the expected behavior? If not, is 
this an issue with the way PDF.js is displaying the PDF or the way 
LuaTeX is producing it?


Thanks in advance.

Regards,
Vedran Miletić


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Re: [NTG-context] LuaTeX and PDF.js

2021-01-07 Thread Hans Hagen

On 1/8/2021 12:39 AM, Vedran Miletić wrote:


It's whatever ConTeXt standalone has. I don't have any extra Lua installed:


--credits should mention the lua version


Should I see it on non-HiDPI as well? Because it seems it's there.


depends on what you consider (non) hdpi ... the positioning of glyphs 
depends on font scale, rounding of stems and such (hints in fonts but 
these get less relevant with high res displays), caching, inter glyph 
corrections (that pdftex/luatex/...) put in the text stream to resync 
within certain tolerances, etc ... (often a print is a better reference 
as displays are seldom 600+ dpi) .. it's also why often expansion looks 
bad on screen because even a sub percentage difference can give such 
effects

 Hans

-
  Hans Hagen | PRAGMA ADE
  Ridderstraat 27 | 8061 GH Hasselt | The Netherlands
   tel: 038 477 53 69 | www.pragma-ade.nl | www.pragma-pod.nl
-
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Re: [NTG-context] LuaTeX and PDF.js

2021-01-07 Thread Hans Hagen

On 1/7/2021 10:10 PM, Vedran Miletić wrote:

Hello,

I compared latest ConTeXt standalone (LuaTeX 2.08) against TeX Live 2020 
(LuaTeX 1.12). The produced PDFs are:


https://miletic.net/lipsum-112.pdf
https://miletic.net/lipsum-208.pdf

Viewing them with Evince (and I assume Adobe Reader, I don't have it at 
hand to test) shows only minor differences in (horizontal) character 
spacing, which I would expect; the text looks reasonably good either 
way. However, viewing them with PDF.js shows a large difference:


https://miletic.net/lipsum-pdfjs-112.png
https://miletic.net/lipsum-pdfjs-208.png

As you can observe, b, m, n, p, and r (and possibly others) are moved 
slightly above other letters. Is this the expected behavior? If not, is 
this an issue with the way PDF.js is displaying the PDF or the way 
LuaTeX is producing it?
what lua does your 2.08 have? if it's 5.2. then such small differences 
can be a side effect of lua (different number models), serialization of 
numbers (default accuracy), or maybe rounding in the lua=>tex font 
interface (there were some fixes iir), the number of digist that the 
backend uses, etc


anyhow, so what you see (in the file) is (per line) transform matrices 
that are slightly different so what you then see is rounding to the 
device pixels


i wouldn't loose sleep over it .. nowadays fonts also evolve and that 
gives larger differences


Hans

-
  Hans Hagen | PRAGMA ADE
  Ridderstraat 27 | 8061 GH Hasselt | The Netherlands
   tel: 038 477 53 69 | www.pragma-ade.nl | www.pragma-pod.nl
-
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