the canvas quest

[Tim Janik <timj gtk org>]

hi all.

apologies for the mass mailing, i'm just trying to catch everyone
(remotely ;) involved.

i'm still in the need of a capable canvas implementation for beast
(http://beast.gtk.org) that basically supports:
- libart based anti-aliased rendering
- bpath, rect-ellipse, polygon functionality
- pixbufs
- zoomable text items (doing pango-based UTF8 rendering)

an evaluation of available canvas implementations revealed:
* dia-newcanvas (v0.6.10):
  - aa renderer not implemented
  - text not zoomable
  - doesn't use pango to render text
* foocanvas (recent CVS):
  - no aa rendering (probably not planned even)
  - text aparently doesn't zoom with other objects
* libgnomecanvas
  - exposure problems with pixbufs (years old but still remain)
  - text not zoomable
  - gets little maintenance if at all
* a wild variety of cut-n-paste versions of the above
  implementations in third-party projects (eel, gnumeric, etc...)

there may well be other significant differences, these are the
ones i focussed on for a start, because they are of interest to beast.
but beyond my requirements for beast...

i see a fundamental problem here in terms of effort duplication,
maintenance, and development platform consistency (i doubt i'm the
only person unsure about what to pick). so i'd like to see the
following issues being adressed:
- is there consensus about what the feature set of a future
  GNOME canvas platform will provide?
- (assuming "no" to the above) what are peoples opinions on:
  a) replacing lbgnomecanvas with say foocanvas
  b) merging foocanvas code/fixes back into libgnomecanvas
     (kinda defeats the idea of foocanvas being "leaner"
     than gnomecanvas in the first place, though that may
     be a questionable design goal in itself)
  c) implementing an aa renderer for dia-newcanvas, adding
     pango support to it so it becomes a suitable replacement
     for libgnomecanvas
- are there any other efforts currently being persued to reduce
  the rediculous cut-n-paste orgies of canvas code across
  various projects?

comments, corrections etc. are aprechiated. after all there seems
to be the need for a much larger problem to be solved than just
finding a canvas implementation for beast.

---
ciaoTJ