Re: master a739cab6637 2/2: ; * doc/lispref/display.texi (Image Descriptors): Insert missing text.

[Eli Zaretskii <eliz@gnu.org>]

> From: Po Lu <luangruo@yahoo.com>
> Cc: rpluim@gmail.com,  emacs-devel@gnu.org
> Date: Thu, 06 Jun 2024 21:58:20 +0800
> 
> How's this?
> 
> Alternatively, the symbol @code{default} may be specified, indicating
> that the image should be scaled in one of two ways, selected by the
> value of the @code{image-scaling-factor} variable.  This value is either
> a number providing a constant scale factor, or the default, @code{auto},
> in which case the image will be scaled in proportion to the average
> widths (@pxref{Low-Level Font}) of the default faces of frames on which
> it is displayed and where this default width exceeds @code{10} pixels.
> If no other value is provided, @code{create-image} will specify
> @code{default} in image specifications it creates.

Better, but still "needs work".  Here's my suggestion:

  @var{scale} can also be the symbol @code{default}, which means to
  use the value of @code{image-scaling-factor}.  If that value is a
  number, it is the scale factor to use; if it is @code{auto} (the
  default), it means to compute the scaling factor based on pixel size
  of the font used by the frame's default face (@pxref{Low-Level
  Font}).

And I would like to explain more about "computing the scaling factor
based on pixel size of the font used by the frame's default face", and
what happens if the default font's width is 10 pixels or below, but
your text doesn't really tell that story.  I think it should.  (Btw,
the default width of the font in "emacs -Q" on Windows is 8, so it
will always hit the case which was left unexplained.)

Thanks.