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From: "Erich Heinzle (a1039181 AT gmail DOT com) [via geda-user AT delorie DOT com]" <geda-user AT delorie DOT com>
Date: Wed, 14 Dec 2016 07:57:32 +1030
Message-ID: <CAHUm0tN+0S704XydhQAMH8Ut9VTXkYkuzzjQ1G+A7xT2Ub9zKQ@mail.gmail.com>
Subject: Re: [geda-user] A workflow for gEDA PCB font symbol/glyph creation
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Precedence: bulk

potrace is certainly useful for vectorising outlines, but cannot do
the offset paths that centerline/stroked/engraving fonts require.

I have already written code that can indirectly (via the Batik ttf2svg
utility) convert a TTF glyph into a set of silk lines, but this does
not achieve the needed offset paths for centerline/stroked/engraving
fonts.

I have made a bit of progress in automatically converting an outline
into a set of offset paths, but the end caps of the ascending and
descending limbs still need a bit of work, particularly for serif
fonts....






On Wed, Dec 14, 2016 at 12:29 AM,  <karl AT aspodata DOT se> wrote:
> Erich Heinzle:
>> I have had some success in converting graphical depictions of
>> lettering, i.e. from a simple picture, into gEDA PCB compatible font
>> glyphs with the following technique.
> ...
>> A .ppm format image with the glyphs/characters to be converted into a
>> stroked font compatible with gEDA PCB needs to be found, and its
>> dimensions in pixels, X, Y, noted
>>
>> PCB is then loaded, with the .ppm image selected for background display
>>
>> ./pcb-rnd --bg-image my_desired_symbols.ppm &
>>
>> the board width and height must then be made a multiple of X and Y, to
>> provide the correct aspect ratio for the exported symbols.
>>
>> For simple sans serif fonts, the centreline of the glyph can be
>> traced, to create a stroked, or centreline defined version of the
>> font. Once a set of silk lines has been generated for a glyph, they
>> can be selected, and copied into the paste buffer, being careful to
>> have the cursor suitably positioned at the lower left hand corner of
>> the glyph consistently for all glyphs processed, to ensure the
>> vertical alignment of glyphs is properly preserved in the resulting
>> font.
> ...
>
> Instead of traceing by hand, have you tried:
>
>  http://potrace.sourceforge.net/
>
> Regards,
> /Karl Hammar
>
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