[HarfBuzz] Fwd: Harfbuzz with linebreaking

[Kelvin Ma]

Also this might be jumping the gun a bit since we still don’t even have the
“safe-to-break” thing yet but how do we know when it’s okay to reshape a
broken segment or if it should just be moved to the next line? A ligature
like “ffi” can and should be broken into “f” and “fi” if needed (like
“ef-ficiency”) but a ligature like “👨‍👩‍👧‍👦” should never be shaped in
2 pieces

On Mon, Jun 13, 2016 at 10:33 PM, Kelvin Ma <kelvinsthirteen at gmail.com>
wrote:

> If you mean how does the linebreaking work in Knockout, it places
> characters/glyphs (it works 1-to-1 character-to-glyph, no ligatures,
> substitutions) until the glyphs overrun the line length. Then it goes
> backwards to the last space character and forward to the next space
> character to get the word that the line was broken on. Then it iterates
> through hyphenation points until one of them is short enough to accommodate
> both itself and a hyphen glyph. Because it works with a 1-to-1 relationship
> between glyphs and characters it just counts the number of glyphs printed
> and uses that as the index offset for laying out the next line.
>
> It’s a slightly more complicated process than that in reality because it
> also checks for other breaking characters like em dashes and slashes not
> just spaces, and it skips hyphenations that contain more than the original
> amount of characters. It can also do pairwise kerning (checks current and
> previous glyph to get kerning offset) but it doesn’t work often in practice
> because most modern fonts encode the kerning data in a different table than
> where freetype knows to look for it, and I’m currently using freetype to do
> what harfbuzz should be doing.
>
> It works in normal time which is nice but not ideal because there is no
> ligatures, little kerning, no substitutions, etc. So no opentype features
> basically. Which is why I need harfbuzz.
>
> On Mon, Jun 13, 2016 at 10:01 PM, Khaled Hosny <khaledhosny at eglug.org>
> wrote:
>
>> On Mon, Jun 13, 2016 at 11:00:16AM -0400, Kelvin Ma wrote:
>> > So I’ve not received an answer to this anywhere, so, how do I typeset
>> > paragraphs with Harfbuzz? How do I use the ‘safe-to-break’ iterator?
>>
>> How are you doing line breaking right now?
>>
>> Regards,
>> Khaled
>>
>
>
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