bug#69602: 29.1; Image :map should adjust with :scale and :rotation

[Joseph Turner]

Eli Zaretskii <eliz@gnu.org> writes:

>> From: Joseph Turner <joseph@breatheoutbreathe.in>
>> Date: Thu, 07 Mar 2024 23:02:24 -0800
>>
>> Joseph Turner <joseph@breatheoutbreathe.in> writes:
>>
>> > The attached patch adds two hooks in `image.el' which allow packages to
>> > recompute an image's map after it's rescaled or rotated.
>>
>> In this new attached patch, rescaling image maps is handled within
>> image.el.  No new hooks are added.  This change should be backwards
>> compatible, except that :unscaled-map is now a reserved image property.
>
> Are we sure no Lisp program out there would want the coordinates in
> :map to remain unchanged under these transformation?  Maybe we should
> add a variable to control this, so that the change could be truly
> backward-compatible?

Good point.  Thanks!

What if explicitly passing :unscaled-map 'no-recalculate in
`create-image' prevented :map from being recalculated later?

If not, what kind of variable did you have in mind?  A special variable
let-bound the call?  Or another argument to `create-image'?

See patches.

0002-Allow-map-to-not-be-recalculated-after-image-rescali.patch
Description: Text Data

0001-Recalculate-map-when-image-scale-changes.patch
Description: Text Data