Re: boost bind/lambda

Comment on the example code:

You can't use a boost::shared_ptr with a dynamically-allocated array:
boost::shared_array is there for that purpose.

Ryan

On Wed, Jan 5, 2011 at 4:55 AM, Nigel Atkinson <[email protected]>wrote:

> You're on the right track.  Perhaps an example will help (and let me
> make sure it works as advertised!) Attached is a little program which
> I've tested with gcc 4 and luabind 0.9.  I've added a couple of
> comments.
>
> It should work if GLfloat is a #define rather than a typedef, but I've
> just checked on my machine (Linux), and it is a typedef.
>
> On another note, if you are binding all of OpenGL, are you going to do
> extensions?  That could be curly! Bound function pointers? That *might*
> work perhaps. Hmmm.
>
> Nigel
>
> On Tue, 2011-01-04 at 23:44 -0800, beo wulf wrote:
> > I've tried
> >
> > class_<GLfloat, boost::shared_ptr<GLfloat> > ....
> >
> > but I'm not sure what to do with this. Can you explain? (Luabind's
> > template blackmagicery is a couple levels above my paygrade).
> > Thanks!
> >
> > On Tue, Jan 4, 2011 at 11:26 PM, Nigel Atkinson <[email protected]>
> wrote:
> > > You could bind GLfloat as a class.  I've done this in the past with
> > > Ogre3d's "Real" witch is a typedef for float or double.  Depending on
> > > how your using in your scripts, that's all you may need to do, i.e
> > > without any defined methods. This makes GLfloat in scripts similar to
> an
> > > opaque pointer, where it's allways come from C++ and only really used
> by
> > > C++. You can also add operators and a constructor as well, to get more
> > > scripting use out of it.
> > >
> > > Using it this way as with pointers (arrays) make take a little
> tweaking,
> > > I'll have to have a play around when I have time.
> > >
> > > Nigel
> > >
> > > On Wed, 2011-01-05 at 06:17 +0000, Tony Kostanjsek wrote:
> > >> I might've been mistaken on the function pointer issue, but I've only
> used it
> > >> that way.
> > >>
> > >>
> > >>
> > >> ----- Ursprüngliche Mail ----
> > >> Von: beo wulf <[email protected]>
> > >> An: [email protected]
> > >> Gesendet: Mittwoch, den 5. Januar 2011, 6:55:19 Uhr
> > >> Betreff: Re: [luabind] boost bind/lambda
> > >>
> > >> Why does wrapping it on a tag_function work then?
> > >>
> > >> Writing wrappers is out of the question -- there are too many
> functions.
> > >>
> > >> On Tue, Jan 4, 2011 at 9:51 PM, Tony Kostanjsek <[email protected]>
> wrote:
> > >> > "def" requires an address or function pointer, but bind returns a
> temporary
> > >> > functor instance. Try to use a static instance or write a wrapper
> function
> > >> > implementation and pass that.
> > >> >
> > >> > Something like <type> func = bind(...)
> > >> > .def("glLightfv", &func)
> > >> > I'm not sure what <type> would look like though.
> > >> >
> > >> > Alternatively, something like this might work:
> > >> > void wrappedGlLightfv(GLenum light, GLenum pname, const
> > >> > boost::shared_ptr<std::vector<GLfloat>> fv)
> > >> > {
> > >> >  glLightfv(light, pname, &fv->get()->front()); // not quite sure
> about
> > >> front(),
> > >> > but you get the idea
> > >> > }
> > >> >
> > >> > ...
> > >> > .def("glLightfv", wrappedGlLightfv)
> > >> > ...
> > >> >
> > >> > ----- Ursprüngliche Mail ----
> > >> > Von: beo wulf <[email protected]>
> > >> > An: [email protected]
> > >> > Gesendet: Mittwoch, den 5. Januar 2011, 6:35:09 Uhr
> > >> > Betreff: [luabind] boost bind/lambda
> > >> >
> > >> > Goal: I want to luabind all of OpenGL.
> > >> > Problem: glLightfv( int, int, GLfloat*)
> > >> >
> > >> > Almost solution:  boost::bind
> > >> >
> > >> > The following code almost works -- it can use boost::bind to convert
> > >> > functions that take arg GLfloat* to take an arg of
> > >> > boost::shared_ptr<std::vector<GLfloat>> instead. However,
> boost::bind
> > >> > and luabind seem to not work with each other (in particular, the
> line
> > >> >
> > >> > , def("glLightfv2", bind(glLightfv, _1, _2, _3)) // ths line does
> not compile
> > >> >
> > >> > Why?
> > >> >
> > >> > Full code below:
> > >> >
> > >> >
> > >> >
> > >> > #include <boost/shared_ptr.hpp>
> > >> > #include <boost/bind.hpp>
> > >> >
> > >> > #include <vector>
> > >> > #include <iostream>
> > >> >
> > >> > #include <luabind/luabind.hpp>
> > >> > #include <luabind/operator.hpp>
> > >> > #include <luabind/adopt_policy.hpp>
> > >> > #include <luabind/copy_policy.hpp>
> > >> > #include <luabind/class_info.hpp>
> > >> >
> > >> > #include <GL/gl.h>
> > >> >
> > >> >
> > >> >
> > >> > #define P boost::shared_ptr
> > >> > #define V std::vector
> > >> >
> > >> > float foo(int x, int y, float* f) {
> > >> >  float ans = 0;
> > >> >  ans = x + y + f[0] + f[1] + f[2];
> > >> >  return ans;
> > >> > }
> > >> >
> > >> > float* get_raw(P<V<float> > p) {
> > >> >  return &((*p)[0]);
> > >> > }
> > >> >
> > >> > void test() { // works fine
> > >> >  P<V<float> > p(new V<float>());
> > >> >  p->push_back(1);
> > >> >  p->push_back(2);
> > >> >  p->push_back(3);
> > >> >
> > >> >  // I want this to output 9
> > >> >  std::cout << bind(foo, _1, _2, bind(get_raw, _3))(1, 2, p) <<
> std::endl;
> > >> > }
> > >> >
> > >> >
> > >> > int main() {
> > >> >  using namespace luabind;
> > >> >
> > >> >  lua_State *L;
> > >> >
> > >> >  module( L )
> > >> >    [
> > >> >    namespace_("gl") [
> > >> >      def( "glLightfv", glLightfv)
> > >> >      // Why do these two lines not compile?
> > >> > //    , def( "glLightfv2", bind(glLightfv, _1, _2, _3))
> > >> > //    , def( "glLightfv3", bind(glLightfv, _1, _2, bind(get_raw,
> _3)))
> > >> >    ]
> > >> >    ]
> > >> >
> > >> >    ;
> > >> > }
> > >> >
> > >> >
> ------------------------------------------------------------------------------
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> > >> >
> > >> >
> > >> >
> > >> >
> ------------------------------------------------------------------------------
> > >> > Learn how Oracle Real Application Clusters (RAC) One Node allows
> customers
> > >> > to consolidate database storage, standardize their database
> environment, and,
> > >> > should the need arise, upgrade to a full multi-node Oracle RAC
> database
> > >> > without downtime or disruption
> > >> > http://p.sf.net/sfu/oracle-sfdevnl
> > >> > _______________________________________________
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> > >> >
> > >>
> > >>
> ------------------------------------------------------------------------------
> > >> Learn how Oracle Real Application Clusters (RAC) One Node allows
> customers
> > >> to consolidate database storage, standardize their database
> environment, and,
> > >> should the need arise, upgrade to a full multi-node Oracle RAC
> database
> > >> without downtime or disruption
> > >> http://p.sf.net/sfu/oracle-sfdevnl
> > >> _______________________________________________
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> > >>
> > >>
> > >>
> > >>
> > >>
> ------------------------------------------------------------------------------
> > >> Learn how Oracle Real Application Clusters (RAC) One Node allows
> customers
> > >> to consolidate database storage, standardize their database
> environment, and,
> > >> should the need arise, upgrade to a full multi-node Oracle RAC
> database
> > >> without downtime or disruption
> > >> http://p.sf.net/sfu/oracle-sfdevnl
> > >> _______________________________________________
> > >> luabind-user mailing list
> > >> [email protected]
> > >> https://lists.sourceforge.net/lists/listinfo/luabind-user
> > >
> > >
> > >
> > >
> ------------------------------------------------------------------------------
> > > Learn how Oracle Real Application Clusters (RAC) One Node allows
> customers
> > > to consolidate database storage, standardize their database
> environment, and,
> > > should the need arise, upgrade to a full multi-node Oracle RAC database
> > > without downtime or disruption
> > > http://p.sf.net/sfu/oracle-sfdevnl
> > > _______________________________________________
> > > luabind-user mailing list
> > > [email protected]
> > > https://lists.sourceforge.net/lists/listinfo/luabind-user
> > >
> >
> >
> ------------------------------------------------------------------------------
> > Learn how Oracle Real Application Clusters (RAC) One Node allows
> customers
> > to consolidate database storage, standardize their database environment,
> and,
> > should the need arise, upgrade to a full multi-node Oracle RAC database
> > without downtime or disruption
> > http://p.sf.net/sfu/oracle-sfdevnl
> > _______________________________________________
> > luabind-user mailing list
> > [email protected]
> > https://lists.sourceforge.net/lists/listinfo/luabind-user
>
>
>
> ------------------------------------------------------------------------------
> Learn how Oracle Real Application Clusters (RAC) One Node allows customers
> to consolidate database storage, standardize their database environment,
> and,
> should the need arise, upgrade to a full multi-node Oracle RAC database
> without downtime or disruption
> http://p.sf.net/sfu/oracle-sfdevnl
> _______________________________________________
> luabind-user mailing list
> [email protected]
> https://lists.sourceforge.net/lists/listinfo/luabind-user
>
>


-- 
Ryan Pavlik
HCI Graduate Student
Virtual Reality Applications Center
Iowa State University

[email protected]
http://academic.cleardefinition.com
Internal VRAC/HCI Site: http://tinyurl.com/rpavlik

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Learn how Oracle Real Application Clusters (RAC) One Node allows customers
to consolidate database storage, standardize their database environment, and, 
should the need arise, upgrade to a full multi-node Oracle RAC database 
without downtime or disruption
http://p.sf.net/sfu/oracle-sfdevnl

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