[plt-dev] update on reimplementing MrEd

From: Paulo J. Matos (pocmatos at gmail.com)
Date: Fri Oct 30 17:21:59 EDT 2009

I think this is one of the most important changes to PLT-Scheme in many,
many versions to come. Thank you very much for this!

On Fri, 2009-10-30 at 15:17 -0600, Matthew Flatt wrote:
> After many months of no work toward reimplementing MrEd, I've found a
> little time to work on it lately.
> The original plan:
>  - Phase 1: convert the editor classes to Scheme (done!)
>  - Phase 2: convert the drawing classes to Scheme using Cairo+Pango
>  - Phase 3: convert the GUI classes to Scheme using Gtk/Cocoa/Win32
> Although there's still lots to do for Phase 2, I've gotten far enough
> that I'm sure it will work. I've implemented text, bitmaps, PNG and
> JPEG handling, PostScript generation, clipping regions, and aligned
> drawing.
> I can imagine releasing Phase 2 sometime early next year. That is, we'd
> throw out all the C++ code for drawing that's in MrEd, and we'd instead
> use Scheme+FFI code that draws via Cairo+Pango. (A canvas window would
> still be implemented by the current GUI binding, at first, but the
> canvas's DC would point back to the Scheme world.)
> Phase 3 is the most visible change and the one that interests most
> people, but phase 2 will at least offer some tangible benefits (unlike
> phase 1). For example, you will be able to use the drawing classes or
> libraries like `slideshow/pict' to generate PNG or PostScript files
> using `mzscheme' instead of `mred'.
> If you'd like to see the current state, it's still at
>   http://svn.plt-scheme.org/plt/branches/mflatt/mred-experiment/
> And I'd still be especially happy if someone writes libraries for
> reading GIFs or reading and writing BMPs, XBMs, or XPMs.
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