Bitmap tracer

Yesterday Oldes released nice program, bitmap tracer. ( http://box.lebeda.ws/~hmm/rebol/projects/vectorize/latest/vectorize.r ). It's written in rebcode and the algorythm is his own, not a implementation. He's using it for converting bitmap fonts to vector ones for usage in his REBOL/Flash dialect. And because it's Oldes, the usage is somehow tricky :)

do http://box.lebeda.ws/~hmm/rebol/projects/vectorize/latest/vectorize.r

probe vectorize http://box.lebeda.ws/~hmm/rebol/projects/vectorize/latest/img41.gif

If you try that code you can see result is not very REBOLish, a block of numbers. It's the coordinates in [x y x y ...] format, because rebcode cannot handle pair!. Erhm, pardon, rebcode cannot handle pair! ??

>> a: rebcode [x][pick y x 1 print y]
>> a 1x1
1

Seems it can :) Oldes has separate function for conversion of his row of numbers to pair! so usage seems like that:

probe ctx-vectorize/to-pairs vectorize http://box.lebeda.ws/~hmm/rebol/projects/vectorize/latest/img41.gif

Yes, great. Unfortunately, the result is somehow scaled and shifted, so somebody should correct 'vectorize function to support pairs or correct 'to-pairs function not to shift and scale result.

But these are just minor problems, they're result of Oldes' coding style. The main thing is that it's now possible to natively convert bitmap images to vectors. And that's great!