Am 07.08.2016 um 02:17 schrieb Bald Eagle:
> Thanks - I do understand and appreciate that there are a lot of things that are
> intertwined and virtually inextricably embedded in POV-Ray, and would take a
> major rewrite to fix, or add.
> I'll keep plugging away at it. :)
> 
> Can you explain what the following excerpt from the docs _means_ ?
> 
> "Also, function splines take the vector size into account. That is, a function
> containing a spline with five components will also return a five component
> vector (aka a color), a function containing a spline with two components will
> only return a two component vector and so on. "

Ah -- that explains why I was surprised that splines didn't work in
functions.

Having read the relevant portions of the docs again, it turns out you
can do the following:

  // Declare a normal spline.
  #declare MySpline = spline {
    ...
  }

  // Declare a spline function.
  // (Note that this returns a vector, not a float.)
  #declare MySplineFn = function { spline { MySpline } }

  // Use the spline function in a regular function.
  // (Note the `.x` to access the spline function result's
  // first coordinate; don't confuse it with the `x` denoting
  // the function's first parameter.)
  #declare MyFn = function(x) { ... MySplineFn(x).x ... }

(You can also place the actual definition of the spline into the spline
function itself.)

Post a reply to this message