Re: Image transformations

[Alan Third]

On Fri, Jun 28, 2019 at 10:50:52PM +0300, Eli Zaretskii wrote:
> > Date: Fri, 28 Jun 2019 19:36:04 +0100
> > From: Alan Third <address@hidden>
> > Cc: address@hidden
> > 
> > My only concern is that there is no simple way to tell whether you
> > should be using ‘:type imagemagick’ or not.  There’s no automatic
> > fallback between types. I know we want fallback in principal, but
> > I’d imagined it done at the lisp level, and this function doesn’t
> > help too much.
> 
> This function is about the capabilities of a frame.  AFAIK, in an
> Emacs built with ImageMagick support we will use ImageMagick for
> everything, unless the user somehow forces us not to, isn't that so?
> If so, the function is correct disregarding the image library in use,
> since if the caller wants a specific image library, that caller will
> have to figure out on their own what transformations are available.

If I were to do:

  (insert-image (create-image "image.png"))

Emacs will use libpng, whether or not ImageMagick is available. I
would have to force ImageMagick use. You may be thinking of
image-mode, which inserts ‘:type imagemagick’ if you rotate or scale
an image using the key bindings (+, -, r).

If you want to change to defaulting to ImageMagick where available I’m
sure we can.
-- 
Alan Third