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

How can I access the C++ source associated with the rgl function shade3d. More
specifically, I'm interested in the part of the code used by arrow3d to draw
arrow heads.

I'm not familiar with how GitHub is organized and I've put in a lot of
effort doing searches there and on the web in general. The result has been a few
fragments of rgl C++ code but not what I'm looking for.


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On 29/07/2020 5:35 p.m., Byron Dom via R-help wrote:
> How can I access the C++ source associated with the rgl function shade3d.
More specifically, I'm interested in the part of the code used by arrow3d to
draw arrow heads.
> 
> I'm not familiar with how GitHub is organized and I've put in a lot
of effort doing searches there and on the web in general. The result has been a
few fragments of rgl C++ code but not what I'm looking for.
shade3d() is purely written in R:  so just type "shade3d" and
you'll see
that it's a generic function.  Most commonly it is used on objects of 
type "mesh3d", so type "rgl:::shade3d.mesh3d" and you can
see the full
source.  It makes calls to other R functions; C++ doesn't come in until 
it has chosen to draw triangles or quadrilaterals.  I think you probably 
don't care about how those are drawn, but let me know if you are.

The arrow3d function is also a pure R function, but not a generic.  You 
can see the source by typing "arrow3d".

Duncan Murdoch

To begin with, don't assume it is in C++... R supports multiple compiled
languages, and rgl appears to have both C++ and C in it.

I googled "r rgl github" and found an online copy of the src (source)
files right away. 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 am afraid I don't have time to dig into the source to identify which file
you need. Keeping in mind that the rgl package is an interface to lower level
code, beware that you may need to leave the R code to find what you are looking
for... in which case you would be dealing with a different code base and
community of coders.

On July 29, 2020 2:35:33 PM PDT, Byron Dom via R-help <r-help at
r-project.org> wrote:
>How can I access the C++ source associated with the rgl function
>shade3d. More specifically, I'm interested in the part of the code used
>by arrow3d to draw arrow heads.
>
>I'm not familiar with how GitHub is organized and I've put in a lot
of
>effort doing searches there and on the web in general. The result has
>been a few fragments of rgl C++ code but not what I'm looking for.
>
>
>	[[alternative HTML version deleted]]
>
>______________________________________________
>R-help at r-project.org mailing list -- To UNSUBSCRIBE and more, see
>https://stat.ethz.ch/mailman/listinfo/r-help
>PLEASE do read the posting guide
>http://www.R-project.org/posting-guide.html
>and provide commented, minimal, self-contained, reproducible code.
-- 
Sent from my phone. Please excuse my brevity.

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 6:34 p.m., Jeff Newmiller wrote:
> To begin with, don't assume it is in C++... R supports multiple
compiled languages, and rgl appears to have both C++ and C in it.
Also a few thousand lines of Javascript, but in this case, the 
interesting code is all in R.
> 
> I googled "r rgl github" and found an online copy of the src
(source) files right away. 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.
If you're using RStudio, a really convenient way to view the source for 
a package whose source is on Github (maybe the majority of packages 
these days?) is to create a new project from it.  Then you can use the 
built-in search functions to jump to the source of any function.

For rgl, you can get a copy of the Github mirror of the source by 
specifying the "Repository URL" as
"https://github.com/rforge/rgl", and
the "Project directory name" as "pkg/rgl".  (The source is
hosted in
Subversion on R-forge.r-project.org, but Subversion is less familiar to 
most people these days and R-forge is pretty old-fashioned, so I'd go 
with Github instead.  There are some irritating things about Github.)

Once you've got it in RStudio, you can type "shade3d" in the
"Go to
file/function" box, and it will offer the generic as well as the two 
methods shade3d.mesh3d and shade3d.shapelist3d.

This kind of search is probably also possible in other front ends (ESS 
etc.), and some purists probably know how to set it all up in command 
line BSD Unix, but I don't.

Duncan Murdoch
> I am afraid I don't have time to dig into the source to identify which
file you need. Keeping in mind that the rgl package is an interface to lower
level code, beware that you may need to leave the R code to find what you are
looking for... in which case you would be dealing with a different code base and
community of coders.
> 
> On July 29, 2020 2:35:33 PM PDT, Byron Dom via R-help <r-help at
r-project.org> wrote:
>> How can I access the C++ source associated with the rgl function
>> shade3d. More specifically, I'm interested in the part of the code
used
>> by arrow3d to draw arrow heads.
>>
>> I'm not familiar with how GitHub is organized and I've put in a
lot of
>> effort doing searches there and on the web in general. The result has
>> been a few fragments of rgl C++ code but not what I'm looking for.
>>
>>
>> 	[[alternative HTML version deleted]]
>>
>> ______________________________________________
>> R-help at r-project.org mailing list -- To UNSUBSCRIBE and more, see
>> https://stat.ethz.ch/mailman/listinfo/r-help
>> PLEASE do read the posting guide
>> http://www.R-project.org/posting-guide.html
>> and provide commented, minimal, self-contained, reproducible code.
>