Hi Conal, Do you have any links to this interesting work of Jefferson Heard? Blogs or something? I failed to Google it, I mainly found his OpenGL TrueType bindings on Hackage and his beautiful http://bluheron.europa.renci.org/docs/BeautifulCode.pdf
Regarding semantics, modern GPUs are able to render 2D graphics (e.g. filled or stroked curves) as real functions / relations; you don't need fine tessellation anymore since these computational monsters have become so fast that per pixel inside / outside testing are feasible now. It's basically a simple form of real-time ray-tracing :) A quick search revealed another paper using these techniques http://alice.loria.fr/publications/papers/2005/VTM/vtm.pdf Cheers, Peter 2009/1/31 Conal Elliott <co...@conal.net> > Hi Antony, > > >> Hopefully some enterprising Haskell hacker will wrap Cairo in a nice >> purely functional API. > > > Jefferson Heard is working on such a thing, called Hieroglyph. Lately I've > been helping him simplify the design and shift it toward a clear, composable > semantic basis, i.e. "genuinely functional" (as in the Fruit paper), meaning > that it can be understood & reasoned about in precise terms via model that > is much simpler than IO. > > In the process, I realized more clearly that the *very goal* of making a > purely functional wrapper around an imperative library leads to muddled > thinking. It's easy to hide the IO without really eliminating it from the > semantics, especially if the goal is defined in terms of an IO-based > library. Much harder, and I think much more rewarding, is to design > semantically, from the ground up, and then figure out how to implement the > elegant semantics with the odds & ends at hand (like Cairo, OpenGL, GPU > architectures, ...). > > Regards, > > - Conal > > On Fri, Jan 30, 2009 at 1:56 PM, Antony Courtney < > antony.court...@gmail.com> wrote: > >> On Fri, Jan 30, 2009 at 4:25 PM, Bryan O'Sullivan <b...@serpentine.com> >> wrote: >> > On Fri, Jan 30, 2009 at 1:11 PM, Antony Courtney < >> antony.court...@gmail.com> >> > wrote: >> >> >> >> A 2-D vector graphics library such as Java2D ( or Quartz on OS/X or >> >> GDI+ on Windows ) supports things like computing tight bounding >> >> rectangles for arbitrary shapes, hit testing for determining whether a >> >> point is inside or outside a shape and constructive area geometry for >> >> shape compositing and clipping without dropping down to a raster >> >> representation. >> > >> > These are the kinds of capabilities provided by Cairo, which is very >> > pleasant to use (PDF-style imaging model) and quite portable. There are >> > already Cairo bindings provided by gtk2hs, too. >> > >> >> Hi Bryan, >> >> Nice to hear from you! Been a while... >> >> Just had a quick look and it does indeed appear that Cairo now >> supports some of the features I mention above (bounds calculations and >> hit testing). Cairo has clearly come a long way from when I was last >> working on Fruit and Haven in 2003/2004; back then it looked like it >> only provided a way to render or rasterize vector graphics on to >> bitmap surfaces and not much else. >> >> It's not clear to me if the Cairo API in its current form supports >> vector-level clipping or constructive area geometry, and it looks like >> the API is still pretty render-centric (e.g. is it possible to obtain >> the vector representation of rendering text in a particular font?). >> That might make it challenging to use Cairo for something like the >> Haven API, but maybe one can live without that level of generality. >> >> In any case: delighted to see progress on this front! Hopefully some >> enterprising Haskell hacker will wrap Cairo in a nice purely >> functional API. >> >> -Antony >> _______________________________________________ >> Haskell-Cafe mailing list >> Haskell-Cafe@haskell.org >> http://www.haskell.org/mailman/listinfo/haskell-cafe >> > > > _______________________________________________ > Haskell-Cafe mailing list > Haskell-Cafe@haskell.org > http://www.haskell.org/mailman/listinfo/haskell-cafe > >
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