Re: [PATCH] no-outline-stencil backend property

[Knut Petersen]

Am 24.01.2017 um 14:49 schrieb David Kastrup:
> > > What a steaming heap of something. So your code would likely have
> > > worked in LilyPond 2.16. I think it would make sense to create a new
> > > type of stencil expression explicitly intended to bypass
> > > outlining. Probably by just containing _two_ stencils: one for
> > > typesetting, one for outlining. That would make for a much more
> > > transparent manner of programming things like that.
> > There's no need for two stencils.
> That's what you claim.  And then you use no-outline on your stencil,
yes, here only expr_ is extended, it's still one stencil
> and
> use \with-dimension in order to stack this with another stencil that has
> just a box outline (one that survives into both dimensions as well as
> outline).  I still count two.
Why should I use with-dimension? The original stencil and its dimensions
are unchanged and will be used in the stencil interpreter. no-outline() hides
the dimensions from the code in stencil-integral.cc, but they are still present
and the stencil interpreter uses them.

> > I propose to include the attached code.
> Which completely _drops_ any outline.  So if you want a different
> outline, you need to combine this with some stencil that has an outline
> but no ink.  How do you remove the ink from arbitrary stencils?  You
> can't.  So you are tied down to use this trick in connection with
> stencils that insist on having an outline but no ink.

David, this is NO-outline code. It' not a fake-some-arbitrary-outline-stencil.

The code is useful for e.g. whiteout, watermarks etc. Define a stencil as usual,
color it, scale it, whatever else. Just mark a stencil x with x.no_outline();

The result is:
        -> the outline is completely ignored in stencil_traverser(), so no 
collisions are detected.
        -> the stencil is drawn in interpret_stencil_expression() as it would 
be drawn without the no_outline layer.

That's the intended use. It's probably much faster than the current solution 
with a transparent
stencil, dimensions forced to zero and delayed evaluation. It is short, 
therefore easy to understand,
and it is elegant.

> Really, that makes little sense.
Think again.

Knut