>I hope you are creating an abstract API at some level.  At the plugin
> level would be great, but at some level would be very good.  This would
> allow a subclass or alternate plugin to be developed for Quartz for
> example.  So if there could be a focus class like Canvas is now, we
> would have a general API that could evolve to other graphics
> environments and engines.  If you have no interest in this, then making
> your contribution stand-alone so someone else can package it as a
> canvas or other abstract API would be great.

My first version is just going to mirror the Cairo API itself in Squeak.

This is actually a general purpose drawing API; the Cairo design is such 
that individual backends (for instance a Quartz or PDF backend) can be 
used for actual image production.

My focus has been on the Cairo API itself; actual integration with Squeak 
has so far consisted of rendering to bitmaps in (separately allocated) 
memory. There is a plugin method for copying these back and forth to Forms.

Other backends that are written or are being written now (not by me) 
include:

* Quartz
* XWindows (XDrawable)
* SVG
* Windows GDI
* PDF
* Postscript
* PNG
* Glitz (using OpenGL; can render to GL textures, I believe)

Give the Cairo API a look (note that it is still somewhat in flux; for 
instance, there is discussion going on right now on the cairo developer's 
list about memory allocation/reference counting semantics, as well as 
which of the Porter/Duff operations really make sense to expose to 
programmers).

There may also be some people working on retained-mode graphics based on 
this API; this would improve the speed of (re) rendering widgets, etc.

The Mono project and others are basing their graphics work on Cairo.

http://cairographics.org/introduction

The API is described by the Cairo header file. Unfortunately, there's no 
real documentation much past this except for some slides, a small 
tutorial, and some example snippets. Note that it was changed last on 
1/5/05.

http://cvs.cairographics.org/cairo/src/cairo.h?view=markup

-- Ned Konz