Re: [css-fonts] definition of synthetic oblique within the 'font-style' property definition

On 05/12/2013 05:54 PM, John Daggett wrote:
> fantasai wrote:
>
>> As for how the synthesis for font-style should work, here is my
>> proposal:
>>
>>   a. For characters that are missing a vertical alternate glyph,
>>      one is assumed to exist with the same shape as the regular one.
>>   b. Italic/oblique regular glyphs (non-vertical alternates) are
>>      synthesized with a clockwise skew in the horizontal dimension.
>>   c. Italic/oblique vertical alternates (both real and assumed) are
>>      synthesized with a clockwise skew in the vertical dimension.
>>
>> There are no codepoint-specific rules, nor are any needed. We are,
>> exactly as you require, synthesizing a font face without regard to
>> how the individual glyphs will be typeset, and this synthesized font
>> face is then used as input into the font selection algorithm exactly
>> as if it were a real font.
>
> So just to confirm, the display of glyphs from actual faces labeled
> italic or oblique is not affected by this proposal, the glyphs are
> used "as is" without any additional shear operation?

Of course.

> How do different values of the text-orientation property affect the
> obliquing?  e.g. text-orientation: upright

They don't, except insofar as they trigger vertical alternate
substitution, since vertical alternates (real and assumed)
are given a different shear.

> What you're proposing sounds very close to what Microsoft Word /
> Internet Explorer implement currently.  Is what you're proposing
> different in some way?

Not that I know of, but I haven't explored the details of their
implementation.

~fantasai

Received on Monday, 13 May 2013 07:00:07 UTC