On 23/07/11 07:12, Thorsten Froehlich wrote:
[...]
> There are no higher-level optimisations, as there is no detection (nor a
> complete list) of side effects some pattern functions do have (weel, had
> before 3.7). Further, the syntax tree is only kept as long as needed,
> which means as soon as the parser is done with a function.

Hmm. Thanks. What's actually used to evaluate the function, then? Is it
byte-compiled?

> Without knowing the specifics, most likely for your use the best way to
> eliminate common subexpressions is to use multiple functions and pass
> the subexpressions as arguments.

Yes, that's what I'm doing --- it's brittle and rather verbose. (A lot
of my functions take (x, y, z) coordinates, clip them to a sphere, and
actually do a texture calculation based the clipped value. It's a bit
painful.)

I don't suppose you know what happened to the old POVMan patch to allow
Renderman shader functions from Povray, do you? All the references I've
found appear to be dead...

-- 
┌─── ｄｇ＠ｃｏｗｌａｒｋ．ｃｏｍ ─────
http://www.cowlark.com ─────
│
│ "I have a mind like a steel trap. It's rusty and full of dead mice."
│ --- Anonymous, on rasfc

Post a reply to this message