Re: Drawing in images?

[MON KEY <monkey@sandpframing.com>]

On Thu, Aug 27, 2009 at 2:31 AM, <joakim@verona.se> wrote:
> MON KEY <monkey@sandpframing.com> writes:
>> there are some really amazing applications for applying
>> annotations/text-properties/alist lookups on 'regions' of processed
>> text/images...
>
> This should be possible by drawing a SVG image on top of another
> image. The SVG image is XML which can be generated in a buffer within
> Emacs.
>
> One difficulty with this aproach is that there isnt really much support for
> alpha channels in Emacs. Also latency in interactive use might not be
> spectacular.
>
> One difficulty with this aproach is that there isnt really much support for
> alpha channels in Emacs.

Why worry about layering with alpha channels at all then? Obv. SVG is
lighter (from a data size perspective) than a .bmp or .jpg but its
still considerably heavier than an Emacs text/string.

Isn't it possible to use an image as an Emacs window's background (if
not can't GTK be leveraged towards that end)?

Why not just use a smallish glyph e.g. `.' (or something smaller
dedicated to the purpose) and the text based facilites from artist.el
(or bespoke equivalent).
AIUI the position of the glyphs isn't necessarily the same as the
_size_ of the glyph as rendered.

Would a layered placement of an SVG provide/allow more user accuracy
than an equivalently positioned glyph. If so, how much more? Does the
gain warrant a departure from a text oriented approach? Why reinvent
Emacs as an image editor? It seems more reasonable to reorient the
task to an arena where Emacs is best acclimated - as a _text_ editor
:)

> Also latency in interactive use might not be spectacular.

If a window could have the image as a background over which text could
be displayed then interactive latency needn't necessarily be an issue.
Scaling/rescaling the box could be made by 'setting' a new rectangle
(or other shape)... e.g. artist-select-op-rectangle.

This approach might allow for interesting `annotation' applications as
well e.g. `artist-select-op-text-see-thru'
`artist-select-op-text-overwrite'. The use of text-properties here
could be are a very valuable feature; they are native to emacs, ought
to be able to carry much of the same information as an svg->xml
string, and can already interact with other native elisp facilities
and data structures without the need for additional XML
parsing/serializing routines.

> Joakim Verona

s_P