Re: boost bind/lambda

I like to take this moment to thank everyone for their insights into
luabind, boost, and OpenGL issues. I've managed to luabind all the
constants/functions I need. Thanks again!

On Wed, Jan 5, 2011 at 4:25 PM, Nigel Atkinson <[email protected]> wrote:
> If you want to manage the life time of the data manually (or elsewhere in
> code), it's probably easiest to simply not use a shared pointer at all,
> and a raw one instead:
>
> GLfloat* givemefloat( .... etc
>
> class_<GLfloat>("GLfloat")
>
> If you really want to use a smart pointer for whatever reason, you can use
> a 'null deleter'. See
> http://www.boost.org/doc/libs/1_43_0/libs/smart_ptr/sp_techniques.html#static
> which explains it.
>
> As said previously by others it would be much better to use
> boost::shared_array rather than shared_ptr, which you can use a null
> deleter with.
>
> Nigel
>
>
> On Thu, January 6, 2011 6:27 am, beo wulf wrote:
>> This is _almost_ perfect, the only thing I can't figure out is:
>>
>> #typedef P boost::shared_ptr
>> #typedef V std::vector
>>
>> P<GLfloat> givemefloat(P<V<GLfloat> > p) {
>>   return P( & (*v) [0] );
>> }
>>
>> is bad in my case since I don't want the data to be tried to be freed
>> when the pointer returned by givemefloat expires. Is there a way to
>> have a boost pointer that doesn't reference count? (or if it must
>> reference count, reference count on the P<V<GLfloat>> object ?
>>
>> Thanks!
>>
>> On Wed, Jan 5, 2011 at 2:55 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.
>>>> >>
>>>> >>
>>>> >>
>>>> >> ----- Urspr�ngliche 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)
>>>> >> > ...
>>>> >> >
>>>> >> > ----- Urspr�ngliche 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)))
>>>> >> > � �]
>>>> >> > � �]
>>>> >> >
>>>> >> > � �;
>>>> >> > }
>>>> >> >
>>>> >> > ------------------------------------------------------------------------------
>>>> >> > 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
>>>> >
>>>> >
>>>> >
>>>> > ------------------------------------------------------------------------------
>>>> > 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
>>
>
>
>
> ------------------------------------------------------------------------------
> 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