Re: Thanks for the tutorial!

[Alan Mackenzie]

Hello, Werner.

On Sat, Jul 20, 2024 at 04:12:19 +0000, Werner LEMBERG wrote:

> Hello Alan,


> > I was looking to convert some TTF fonts to bitmaps for use in the
> > Linux console, and I was wondering whether freetype might be the
> > right software for this.

> What exactly are you doing?

I am trying to enhance the Linux framebuffer console to handle an
unbounded number of glyphs, not just the 256 (or 512) it's restricted to
at the moment.  Also, I want to enable 24-bit colour in place of the
current 4-bit (or 3-bit) colour, but that's less important at the
moment.

I can't help thinking that somebody else MUST have done this already,
but why have I not heard of it, and what has happened to her/his code?

So, I need bitmap fonts for Unicode to be able to make this work.  GNU
Unifont is restricted to 8x16 pixel characters, which makes it
unsuitable for what I want to do - I know people who use a larger font
because their eyes can no longer see well enough for 8x16.  Seeing as
how there are a lot of existing .ttf fonts with open enough licences, it
seems converting some of these to .psfu bitmap fonts is a good way to
go.

> You have glyphs indices, and you want to convert them to bitmaps?  If
> this is correct, then FreeType is indeed the right application.
> However, if you have character codes, FreeType is too low-level, and
> you first need a shaping engine like HarfBuzz to get glyph indices –
> even for a console.  Without a shaping engine, only the simplest
> left-to-right text with old-style kerning pairs is supported
> correctly.

Yes.  It is clear that the Linux console can't handle everything.  I'm
not at all familiar with non-European writing methods, but the console
can surely be improved for European alphabets and this may spill over
into other scripts.

> > This tutorial is absolutely brilliant!  It goes into exactly the
> > right level of detail (at least, for me), and covered most (?all) of
> > the little points I thought I'd need to spend hours scanning a
> > manual for.

> > Many thanks to the person who took the trouble to write it so well.

> Thanks!  The praise goes mainly to David Turner, who has started the
> FreeType project many years ago.  Since then, the tutorial has been
> improved and updated here and there.

>     Werner

-- 
Alan Mackenzie (Nuremberg, Germany).