Re: (kawa pictures) square-limit pictures

[Per Bothner <per at bothner dot com>]

On 10/30/2016 11:54 AM, Sudarshan S Chawathe wrote:

> An issue related (I think) to the choice of names is how closely the
> library follows the original SICP pictures language v. how closely it
> tries to match Kawa's composable pictures style.  Here I am thinking
> about, for instance, the implementation of "below" using SICP's explicit
> notion of painting into frames (and frame transformations) v. using
> Kawa's re-center and vbox.  When I first started writing the
> square-limit example, I went with the first option, but then decided
> that is probably not in the spirit of the Kawa pictures library.  There
> is probably value in having both methods.

I've considered adding a procedure to help bridge the SICP
model and the Kawa model.  Something like:

(transform-to RECT PICTURE)

This would be equivalent to some (with-transform TRANSFORM PICTURE)
such that the bounds of the result matches RECT.

More generally RECT could be a parallelogram.  (Note a rotated rectangle is
a parallelogram but is not considered a rectangle.) In that case the
bounds of the transform would not match RECT, but would have the
same bounds as RECT.

The RECT corresponds to the "frame" of SICP.
--
	--Per Bothner
per@bothner.com   http://per.bothner.com/