Re: Slur with left and/or right arrow head

[Aaron Hill]

On 2019-04-17 12:16 pm, Thomas Morley wrote:
> One question I really couldn't answer is:
> What kind of value is `t´ in (define (bezier-angle control-points t) 
> ...)
> Seems not to be a x- or y-value, not an arc-length-value .., but what 
> else?

"t" is the standard name for the control value of parametric equations.  
(I believe it comes from "time".)  It ranges from zero to one, although 
technically it can extend beyond, since the math does not really care.

> Now all those nice bezier-tools are done I made some performance tests.
> Running my arrow-slur-03.ly gives
> real 0m4,318s
> user 0m4,000s
> sys 0m0,272s
>
> Your arrow-slur-03-patch.ly is a little slower
> real 0m4,661s
> user 0m4,075s
> sys 0m0,562s
>
> I posted the best values of multiple runs for both.
>
> I then implemented a counter in your (bezier-curve control-points t).
> It's called scaring 78368 times, which may explain it.

This is certainly expected due to the recursive approach.  It may be 
possible to reduce the calls by adjusting the approximations a bit.  For 
instance, I am computing the arc-length by simple subdivision into 
eleven pieces.  It might be possible to get acceptable results with 
fewer segments, which would ease some of the computational overhead.

But actually I am pleasantly surprised my code is only slightly worse.

> [ . . . ] why does Tie has a font-size property at all?

That I cannot speak to.  I'd have to dig through the code to see where 
it is used.


-- Aaron Hill