Re: [csswg-drafts] [css-fonts-4] Style Matching & grammar for font-style property and font-style property descriptor

> There are many questions here. I will try to separate my answers for each piece.

Myles, thanks for taking a look and your explanations.

>> mapped value of italic

> font-style: italic always maps to an italic value of 1.

Okay.

> Preinstalled fonts may define that they support the ital axis from 1.2 - 1.5, or from 0.3 - 0.54, which means the search for 1 still needs to occur. This is not describable with @font-face, and so will only occur with preinstalled fonts.

It may be a bit of a theoretical exploration, since we haven't yet seen fonts which scale on the 'ital' axis, but the OpenType fvar section at least describes the ital axis to scale between 0 and 1.

According to the [registered 'ital' axis definition](https://www.microsoft.com/typography/otspec/fvar.htm)  their axis values must be in the range of 0 to 1, so I believe only the 0.3 - 0.54 example may appear, the 1.2-1.5 should/must not according to OpenType and font with axis range starting from below zero or extending above 1 would violate the ital axis range definition. So I suggest we drop the part of searching the ital axis above 1 in ascending order, or simplify how this is phrased. But I may have missed an earlier discussion on why the search outside the valid range is added here.

So

> 2. Otherwise, italic values above the desired italic value are checked in ascending order followed by italic values below the desired italic value, until 0 is hit. Only positive values of italic values are checked in this stage.

would become

> 2. Otherwise, italic values below the desired italic value are checked in descending until 0 is hit. 

and

> 3. If no match is found, oblique values greater than or equal to 20deg are checked in ascending order followed by oblique values below 20deg in descending order, until 0 is hit. Only positive values of oblique values are checked in this stage.

would become

> 3. If no match is found, oblique values greater than or equal to 20deg are checked in ascending order followed by oblique values below 20deg in descending order.

plus dropping steps 4. and 5. What do you and others think?

Perhaps it would help to add a note explaining what you explained here: That the search along the `ital` axis only is only performed among the preinstalled fonts, and is currently not applicable to @font-face defined fonts.

Again, thanks for your explanations.

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Received on Friday, 16 June 2017 07:42:28 UTC