On Fri, 7 Dec 2018 09:06:03 +0100 "Mikael P. Sundqvist" <mic...@gmail.com> wrote:
> 2) Support for transforming images in a more general way. With the > zscaled, slanted, ... we are able to transform any object in an affine > way. It would be nice to be able to transform any object in a more > general way (i.e. by a mapping defined by the user). The example code > below shows what happens in the complex plane with a grid and a curve > when the mapping z to z^2 is applied. I have generalized my rewrite of the MP graph macros to handle any arbitrary mapping from data space to drawing (2D) space. At present, I have only considered the simple functions of log (and sqrt) scales as well as polar coordinates (x,y) = f(theta,r) with f(theta,r) = (r sin theta, r cos theta) as I have real use cases for these. I also consider a simple 3D->2D mapping. It would be very easy to transform z = a+ib to z^2 for example, as you show, The approach transforms a picture, applying to all stroked and filled paths, as well as to the *position* of text objects. I have not looked into somehow transforming a bitmap image. > Perhaps I am missing something, > but I'm not able to apply this to a piece of text for example, or to > apply it directly to a picture. Instead, I have to loop over all > separate paths. I think the ideal would be to have a "ftransformed" > (or with some other name), and then just define a function (as fun in > the example below), and then be able to do "draw X ftransformed fun;", > where X is some(any?) general object. Is that doable? for i within pic : ... endfor So, yes, easy to write a primary (but I don't like the name "ftransformed"). Using lua helpers can make this efficient. Alan ___________________________________________________________________________________ If your question is of interest to others as well, please add an entry to the Wiki! maillist : ntg-context@ntg.nl / http://www.ntg.nl/mailman/listinfo/ntg-context webpage : http://www.pragma-ade.nl / http://context.aanhet.net archive : https://bitbucket.org/phg/context-mirror/commits/ wiki : http://contextgarden.net ___________________________________________________________________________________
