Re: master f480484: * doc/lispref/display.texi (Low-Level Font): Describe max-width.

Re: master f480484: * doc/lispref/display.texi (Low-Level Font): Describe max-width.

[Robert Pluim]

>>>>> On Sun, 20 Oct 2019 08:55:21 -0400 (EDT), lekktu@gmail.com (Juanma Barranquero) said:

    Juanma> branch: master
    Juanma> commit f480484cae173e64a81a9698693fc89569471126
    Juanma> Author: Juanma Barranquero <lekktu@gmail.com>
    Juanma> Commit: Juanma Barranquero <lekktu@gmail.com>

    Juanma>     * doc/lispref/display.texi (Low-Level Font): Describe max-width.
    Juanma> ---
    Juanma>  doc/lispref/display.texi | 3 +++
    Juanma>  1 file changed, 3 insertions(+)

    Juanma> diff --git a/doc/lispref/display.texi b/doc/lispref/display.texi
    Juanma> index f35b11f..82d9f1d 100644
    Juanma> --- a/doc/lispref/display.texi
    Juanma> +++ b/doc/lispref/display.texi
    Juanma> @@ -3821,6 +3821,9 @@ upward.
    Juanma>  @itemx default-ascent
    Juanma>  Numbers controlling how to compose characters.
 
    Juanma> +@item max-width
    Juanma> +The maximum advance width of the font.
    Juanma> +

How is this distinct from the 'retreat' width of the font?

More seriously, Iʼm assuming this is the maximum width of a character
in the font, in which case we should say so.

Robert

Re: master f480484: * doc/lispref/display.texi (Low-Level Font): Describe max-width.

[Juanma Barranquero]

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On Mon, Oct 21, 2019 at 5:13 PM Robert Pluim <rpluim@gmail.com> wrote:

> How is this distinct from the 'retreat' width of the font?

I don't know that the "retreat" width of the font is.

> More seriously, Iʼm assuming this is the maximum width of a character
> in the font, in which case we should say so.

That's the same definition for max-with given a bit later when describing
query-font's result. I just copied it for font-info.

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Re: master f480484: * doc/lispref/display.texi (Low-Level Font): Describe max-width.

[Robert Pluim]

>>>>> On Mon, 21 Oct 2019 17:42:16 +0200, Juanma Barranquero <lekktu@gmail.com> said:

    Juanma> On Mon, Oct 21, 2019 at 5:13 PM Robert Pluim <rpluim@gmail.com> wrote:
    >> How is this distinct from the 'retreat' width of the font?

    Juanma> I don't know that the "retreat" width of the font is.

That was meant as a joke. Never mind.

    >> More seriously, Iʼm assuming this is the maximum width of a character
    >> in the font, in which case we should say so.

    Juanma> That's the same definition for max-with given a bit later when describing
    Juanma> query-font's result. I just copied it for font-info.

OK, I guess thatʼs all we have to go on then.

Robert

Re: master f480484: * doc/lispref/display.texi (Low-Level Font): Describe max-width.

[Juanma Barranquero]

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On Mon, Oct 21, 2019 at 6:24 PM Robert Pluim <rpluim@gmail.com> wrote:

> That was meant as a joke. Never mind.

Oh. Advance. Retreat. Got it (finally!). Sorry for being dense.

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Re: master f480484: * doc/lispref/display.texi (Low-Level Font): Describe max-width.

[Eli Zaretskii]

> From: Robert Pluim <rpluim@gmail.com>
> Date: Mon, 21 Oct 2019 17:13:20 +0200
> Cc: Juanma Barranquero <lekktu@gmail.com>
> 
>     Juanma> +@item max-width
>     Juanma> +The maximum advance width of the font.
>     Juanma> +
> 
> How is this distinct from the 'retreat' width of the font?

A font never retreats.

> More seriously, Iʼm assuming this is the maximum width of a character
> in the font, in which case we should say so.

No, it's the maximum, over all the characters of the font, of the
number if pixels to advance after drawing a character.  It could be
different from the character width when there are overlaps.

I'm not sure we should go into such details here, because describing
the fundamentals of digital typography is well out of scope of this
manual.  People should look elsewhere for the detailed information
about this.