There is a lab on cdcb (shared library callback) that might answer your
questions.
In JHS: labrun_jijx_ 'Shared Library (b) (dll/so/dylib) - callback'
In Jqt: Help>Studio>Lab Category:System
You could run the lab in jconsole, but probably more convenient in JHS or
Jqt.
On Sun, Nov 29, 2020 at 3:46 AM emacstheviking <obji...@gmail.com> wrote:
> My application does not want Qt or wd in the mix at all. I want a pure J
> atop SDL2 implementation. I am striving for a pure J application that
> starts from J. I know I could write a C start and then use JDo from the
> library etc but this feels like defeat on some level as I am still learning
> J and want to see where it can go in the nooks and crannies.
>
> I have already experimented with initialise wd and then setting 'wd timer
> 10` and a callback. This works but. Not what I want. I don't want all that
> baggage at runtime.
>
> SDL has a thread creation routine but I have failed to find any
> documentation on 'cdcb'; the callback. I am not sure how to that but this
> morning I plan to try! The callback for SDL_Thread is int(void*) so,
> assuming the calling convention setup is accurate, if I...
>
> testcallback =: monad define
> NB. do something thread safe!
> 0
> )
>
> then
>
> sdl_createthread cdcb testcallback
>
> It can either do what I expect or go bang.
>
>
> the worst that can happen is a reboot, giving me a coffee making
> opportunity.
> :)
>
>
>
> On Sun, 29 Nov 2020 at 01:52, Thomas McGuire <tmcguir...@gmail.com> wrote:
>
> > Have you come up with a way to handle SDL events?
> >
> > I was able to read events but if I set up a polling loop I ran into
> > problems with J not getting time for handling
> > Its own user events. I made some attempts to use wd ‘msgs’ from the
> window
> > driver but was unsuccessful.
> >
> > Tom McGuire
> >
> > > On Nov 27, 2020, at 1:36 PM, emacstheviking <obji...@gmail.com> wrote:
> > >
> > > that took a few seconds to sink in but..yes, I see now.
> > >
> > > On Fri, 27 Nov 2020 at 16:46, bill lam <bbill....@gmail.com> wrote:
> > >
> > >> Well done!
> > >>
> > >> Sometimes I found it easier to read if negative index are used,
> > >>
> > >> 'rw rh' =. _2 _1 dmva sdl_getrenderoutputsize appr;(_1);(_1)
> > >>
> > >> On Sat, Nov 28, 2020, 12:19 AM emacstheviking <obji...@gmail.com>
> > wrote:
> > >>
> > >>> Final more J-like solution to my problem, thanks bill Iam for the
> > >> nudge...
> > >>>
> > >>> dmva =: 4 : '''''&$ each (x{y)'
> > >>>
> > >>> This allows me to specify the actual array positions I want
> de-arrayed
> > /
> > >>> scalerised and feels much more natural in use as I can now specify
> any
> > >>> number of positions and of course re-order things too. Probably the
> > only
> > >>> improvement now is the name!
> > >>>
> > >>> 'rw rh' =. 2 3 dmva sdl_getrenderoutputsize appr;(_1);(_1)
> > >>>
> > >>> I appreciate that ''$ is only producing scales because the first atom
> > of
> > >> my
> > >>> array contains a scalar. I think. !
> > >>> Thanks all once again,
> > >>> Sean.
> > >>>
> > >>>
> > >>> On Fri, 27 Nov 2020 at 13:05, bill lam <bbill....@gmail.com> wrote:
> > >>>
> > >>>> probably your width and height are not scalar but singleton array.
> you
> > >>> can
> > >>>> check them with monad $ .
> > >>>>
> > >>>> On Fri, Nov 27, 2020, 8:00 PM emacstheviking <obji...@gmail.com>
> > >> wrote:
> > >>>>
> > >>>>> Given these working external function declarations:
> > >>>>>
> > >>>>> SDL_GetWindowSize n x *i *i
> > >>>>> SDL_GetRendererOutputSize n x *i *i
> > >>>>> SDL_CreateRGBSurface > x i i i i i i i i
> > >>>>>
> > >>>>> then these two calls:
> > >>>>>
> > >>>>> 'ww wh'=:2}.sdl_getwindowsize appw;(,_1);(,_1)
> > >>>>> 'rw rh'=:2}.sdl_getrendereroutputsize appr;(,_1);(,_1)
> > >>>>>
> > >>>>> work and produce values of 1024 for ww and rw, and 768 for wh and
> rh
> > >>>>> respectively, as expected.
> > >>>>> However, when creating the rgb surface it raises a domain error
> and I
> > >>>> have
> > >>>>> been tearing my hair out to understand why.
> > >>>>> I have posted the full code at the end of this plea for help and
> > >>>>> enlightenment.
> > >>>>>
> > >>>>> args=.0;width;height;32;16bff0000;16bff00;16bff;16bff000000
> > >>>>> smoutput args
> > >>>>> sfc=: sdl_creatergbsurface args
> > >>>>>
> > >>>>> cder''
> > >>>>> 6 1
> > >>>>>
> > >>>>> yet calling it with literals or even the extracted 'y' value (a
> boxed
> > >>>>> dimension):
> > >>>>> args=.0;1024;768;32;16bff0000;16bff00;16bff;16bff000000. NB. works
> > >>>>> args=.0;width;height;32;16bff0000;16bff00;16bff;16bff000000. NB.
> > >> works
> > >>>>>
> > >>>>> I have used 3!:0 to examine the type, it is 4 (integer) in all
> cases
> > >>>>> (ww,wh,rw,rh,width,height), ruling out those errors.
> > >>>>> Thanks,
> > >>>>> Sean. :|
> > >>>>>
> > >>>>> -- full code ---
> > >>>>>
> > >>>>> ugo =: 3 : 0
> > >>>>> NB. testing out domain errors around sdl_creatergbsurface...
> > >>>>> args =. SCREEN_X_MAX;SCREEN_Y_MAX
> > >>>>> scrw =. SCREEN_X_MAX
> > >>>>> scrh =. SCREEN_Y_MAX
> > >>>>> sdlprep scrw;scrh
> > >>>>> cairoprep''
> > >>>>> urun''
> > >>>>> uend^:y ''
> > >>>>> )
> > >>>>>
> > >>>>> sdlprep =: 3 : 0
> > >>>>> 'width height'=. y
> > >>>>> sdl_init SDL_INIT_EVERYTHING
> > >>>>> appw=:sdl_createwindow 'test window';0;0
> > >>>>> ;width;height;SDL_WINDOW_SHOWN+SDL_WINDOW_ALLOW_HIGHDPI
> > >>>>> appr=:sdl_createrenderer appw;_1
> > >>>>> ;SDL_RENDERER_ACCELERATED+SDL_RENDERER_PRESENTVSYNC
> > >>>>> 'ww wh'=:2}.sdl_getwindowsize appw;(,_1);(,_1)
> > >>>>> 'rw rh'=:2}.sdl_getrendereroutputsize appr;(,_1);(,_1)
> > >>>>> cxm=: rw % ww
> > >>>>> cym=: rh % wh
> > >>>>> smoutput 'window: ', (":appw), 'renderer:', (":appr)
> > >>>>> smoutput 'requested width:',(":width),' height:',(":height)
> > >>>>> smoutput 'render width: ',(":rw),' height:',(":rh)
> > >>>>> smoutput 'window width: ',(":ww),' height:',(":wh)
> > >>>>> smoutput 'x/y multipliers:',(":cxm),'/',(":cym)
> > >>>>> NB. This needs to be endian-aware at some point
> > >>>>> smoutput (": (width = rw))
> > >>>>> args=.0;width;height;32;16bff0000;16bff00;16bff;16bff000000
> > >>>>> smoutput args
> > >>>>> sfc=: sdl_creatergbsurface args
> > >>>>> NB. Practice structures. PACKING!!! Show printable format name
> > >>>>> pFormat=._3 ic memr (sfc+8),0,8 NB. sdl_surface->format
> > >>>>> format=._2 ic memr pFormat,0,4 NB. sdl_surface->format->format
> > >>>>> smoutput 'pixel format:',(psz sdl_getpixelformatname format)
> > >>>>> EMPTY
> > >>>>> )
> > >>>>>
> > >> ----------------------------------------------------------------------
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> > >>>>>
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