Re: etienne delacroix: Precisions on the forth SWIG architecture: return by value structs

[Jack Lucas]

Apologies if I'm not using the mailing list correctly.  I don't do it much.

I'm Arnaut Daniel on github.  Keeping track of this thread since it'd be 
interesting to find a better way to do the bindings.  Gforth and Raylib are a 
lot of fun.

Also I don't remember what the earliest version I used was that works with the 
bindings, but you can't use 0.7.3.

Thanks to Francois for taking interest.

Arnaut/Jack

------- Original Message -------
On Monday, June 12th, 2023 at 2:10 PM, Francois Gallois 
<francois.gallois.pro@gmail.com> wrote:


>
>
> On Mon, Jun 12, 2023 at 06:52:35PM +0200, etienne delacroix wrote:
>
> > thanks for presenting this problem. I have been very much wanting to use
> > gforth to do graphics, but since my intel Mac got stolen I have problems
> > installing the latest. gforth. only. the. 0.7.3 is working on the M1
> >
> > when I tried to include the raylib3.fs. file into. gforth 0.7.3. I got
> > the following error:
> >
> > raylib3.fs:567: Undefined word
> >
> > c-function InitWindow InitWindow n n >>>s<<< -- void ( width height title
> > -- )
> >
> > Backtrace:
> >
> > $15883DB80 throw
> >
> > $15883DC18 parse-libcc-type
> >
> > $158840E58 parse-function-types
> >
> > $158841108 c-function-ft
> >
> > ok
> >
> > line 567. is the very first. c-function. line...
> >
> > so I tried
> > see. c-function. which returns existing code
> >
> > see c-function
> >
> > : c-function
> >
> > Defer latestxt dup c-function-rt latestxt c-function-ft latestxt swap
> > defer!
> >
> > ; ok
> >
> > so I am not sure what the undefined word here
> >
> > my question. is first of all to know if the arnault Daniel. gforth ray lib.
> > is working with
> > gforth. 0.7.3. ????
> > and if you have been able to make this package work as it is....
> >
> > merci d'avance
> >
> > On Mon, Jun 12, 2023 at 3:06 PM Francois Gallois <
> > francois.gallois.pro@gmail.com> wrote:
> >
> > > Hello there,
> > > I've been taking a look at the gforth bindings for Raylib at
> > > https://github.com/ArnautDaniel/gforth-raylib in order to update them to
> > > the
> > > latest version. One of the biggest problems the original authors has been
> > > facing
> > > was converting the structures passed by value by raylib into pointers to
> > > allow
> > > their use, such as :
> > >
> > > `\\c Vector2 * iGetWindowScaleDPI(Vector2 * p){ \\c Vector2 v = 
> > > GetWindowScaleDPI(); \\c *p = v; return p; } c-function 
> > > iGetWindowScaleDPI iGetWindowScaleDPI a -- a ( emptyVector2 -- Vector2 )`
> > >
> > > It seems that the "default behavior" for SWIG is to convert structures
> > > returned
> > > by value into pointers (
> > > https://www.swig.org/Doc3.0/SWIGDocumentation.pdf#__WKANCHOR_58)
> > > (this is the link to the docs of the relevant version of SWIG for
> > > https://github.com/GeraldWodni/swig, which I've been using according to
> > > the
> > > manual).
> > >
> > > Has anyone played around enough with forth-SWIG to explain in more detail
> > > how
> > > the current implementation behaves? I'd like to make that kind of fixes
> > > automatic.
> > >
> > > Separately, would there be a way to "typedef" some structures as stack
> > > objects?
> > > In the specific case of raylib but also as a common example, I would like
> > > to
> > > convert a Vector of 2 objects:
> > >
> > > `struct Vector2 { int x; int y; };`
> > >
> > > into 2 stack objects, meaning that a function `foo` that takes a Vector2
> > > (`int foo(Vector2 vec);`) can be called with `x y foo` in Forth,
> > > and that calling a `Vector2 bar();` puts `x y` on the stack.
> > > Could someone light my lantern on the things that could make that kind of
> > > template possible?
> > >
> > > I'll be continuing to search on my side of things, but comments would be
> > > much
> > > appreciated.
> > >
> > > Thanks for your hard work, and have fun.
> > >
> > > ---
> > > François Gallois
> > > "All told, a category is just a monad in the bicategory of spans, what's
> > > the
> > > problem?"
>
>
> My apologies for not adding those precisions. The bindings only work with the
> latest version built from source (built on Fedora here), and when trying to do
> your own bindings, you must use the swig version packed with the latest 
> source.
> I don't know what is the first version with which it will work, but you'll 
> have
> a simpler time if you just build from source.
>
> I managed to make the binding work by building the Raylib 3.5.0 source on my
> machine, and by copying the .h files in the directory of gforth-raylib. With 
> all
> of this, I managed to successfully run the binding, and to run the provided
> example, though I didn't try any further experimentations. Stay aware that the
> version you need to use is Raylib 3.5.0 (you can find the documentation in the
> .h file). You can sure have fun with that, and I advise you to open an issue 
> on
> Github in case you have any further questions about the design of the binding;
> the author was very responsive!
>
> Bonne soirée
>
> --
> François Gallois
> "All told, a category is just a monad in the bicategory of
> spans, what's the problem?"