R help - Jul 2020 - Accessing the C++ source associated with the rgl function shade3d

Dear Byron,

On 2020-07-29 18:04 -0400, Duncan Murdoch wrote:
> The arrow3d function is also a pure R 
> function, but not a generic.  You can 
> see the source by typing "arrow3d".
... but if I type rgl::shade3d, I get

	> rgl::shade3d
	function (x, ...)
	UseMethod("shade3d")
	<bytecode: 0x562692966fb8>
	<environment: namespace:rgl>
	> dput(rgl::shade3d)
	function (x, ...)
	UseMethod("shade3d")

I've observed this is possible in the 
past, but now I can't remember how ...

On 2020-07-29 15:34 -0700, Jeff Newmiller wrote:
> On July 29, 2020 2:35:33 PM PDT, Byron Dom wrote:
> > I'm not familiar with how GitHub is 
> > organized 
> 
> The official way is to find the CRAN 
> package page and download the tar.gz 
> file and extract the files. Either 
> way, you get the whole package source 
> code this way.
I have a hunch this is the file you're 
looking for 
https://github.com/cran/rgl/blob/master/R/ashape3d.R 

Remember, dealing with code on github is 
just a small uptick from how Linux was 
developed before, by shipping around 
diffs and tarballs on a mailing list 
much similar to this one, Thorvalds 
merging them into the kernel in the 
authoritarian way.

You can do it!  *cheers*

Best,
Rasmus

[1] http://gameoftrees.org/

On 29/07/2020 7:27 p.m., Rasmus Liland wrote:
> Dear Byron,
> 
> On 2020-07-29 18:04 -0400, Duncan Murdoch wrote:
>> The arrow3d function is also a pure R
>> function, but not a generic.  You can
>> see the source by typing "arrow3d".
> 
> ... but if I type rgl::shade3d, I get
> 
> 	> rgl::shade3d
> 	function (x, ...)
> 	UseMethod("shade3d")
> 	<bytecode: 0x562692966fb8>
> 	<environment: namespace:rgl>
That includes the full source code to shade3d.  Like most generic 
functions, it's a one-liner.

In the part of my post that you deleted, I told the OP where to look next.
> 	> dput(rgl::shade3d)
> 	function (x, ...)
> 	UseMethod("shade3d")
> 
> I've observed this is possible in the
> past, but now I can't remember how ...
> 
> On 2020-07-29 15:34 -0700, Jeff Newmiller wrote:
>> On July 29, 2020 2:35:33 PM PDT, Byron Dom wrote:
>>> I'm not familiar with how GitHub is
>>> organized
>>
>> The official way is to find the CRAN
>> package page and download the tar.gz
>> file and extract the files. Either
>> way, you get the whole package source
>> code this way.
> 
> I have a hunch this is the file you're
> looking for
> https://github.com/cran/rgl/blob/master/R/ashape3d.R
No, that's not it.  That file works with mesh3d objects, but it has 
nothing to do with arrows.

Duncan Murdoch
> 
> Remember, dealing with code on github is
> just a small uptick from how Linux was
> developed before, by shipping around
> diffs and tarballs on a mailing list
> much similar to this one, Thorvalds
> merging them into the kernel in the
> authoritarian way.
> 
> You can do it!  *cheers*
> 
> Best,
> Rasmus
> 
> [1] http://gameoftrees.org/
>

On 2020-07-30 05:23 -0400, Duncan Murdoch wrote:
> On 29/07/2020 7:27 p.m., Rasmus Liland wrote:
> > On 2020-07-29 18:04 -0400, Duncan Murdoch wrote:
> > > The arrow3d function is also a pure R
> > > function, but not a generic.  You can
> > > see the source by typing "arrow3d".
> > 
> > ... but if I type rgl::shade3d, I get
> > 
> > 	> rgl::shade3d
> > 	function (x, ...)
> > 	UseMethod("shade3d")
> > 	<bytecode: 0x562692966fb8>
> > 	<environment: namespace:rgl>
> 
> That includes the full source code to 
> shade3d.  Like most generic functions, 
> it's a one-liner.
> 
> In the part of my post that you 
> deleted, I told the OP where to look 
> next.
This part:
> > > type "rgl:::shade3d.mesh3d" and you 
> > > can see the full source.
Three colons.  I didn't see it at first; 
Hmm ... I might have dyslexia or 
something ... 

So, Byron, this is the code that R 
reinterprets from the source,

	Rscript -e 'rgl:::arrow3d' | less
	Rscript -e 'rgl:::shade3d.mesh3d' | less

so you cannot necessarily grab a line 
from there and expect it to look exactly 
the same in the source files.

	rasmus at beefylinuxbox ~ % grep -R 'paste(allowedMeshColor,' src/rgl
	src/rgl/R/mesh3d.R:    stop("'meshColor' must be one of: ",
paste(allowedMeshColor, collapse = ", "))
	rasmus at beefylinuxbox ~ % grep -R 'pi - pi/nbarbs,' src/rgl
	1 rasmus at beefylinuxbox ~ % grep -R 'pi/nbarbs,' src/rgl
	src/rgl/R/arrow3d.R: phi <- seq(pi/nbarbs, 2*pi-pi/nbarbs, len = nbarbs)
	rasmus at beefylinuxbox ~ %
> > https://github.com/cran/rgl/blob/master/R/ashape3d.R
> 
> No, that's not it.  That file works 
> with mesh3d objects, but it has 
> nothing to do with arrows.
... I'm sorry, now I believe 
rgl::shade3d.mesh3d and rgl::arrow3d 
lives in 
https://github.com/cran/rgl/blob/master/R/mesh3d.R 
and 
https://github.com/cran/rgl/blob/master/R/arrow3d.R 
respectively.

Byron, there's a bunch of .cpp and .h 
files in 
https://github.com/cran/rgl/blob/master/src
you can look at to find the triangle or 
quadrilateral code you're interested in, 
I'm not quite sure what to look for 
there.

Best,
Rasmus