btDynamicsWorld::setInternalTickCallback() has no effect

[laurie71]

I'm trying to get called back on internal ticks, without success. I tried the naive approach:

    dynamicsWorld  = new ammo.btDiscreteDynamicsWorld(...)
    dynamicsWorld.setInternalTickCallback(pretick, this, true)
    dynamicsWorld.setInternalTickCallback(posttick, this, false)
    dynamicsWorld.stepSimulation(1/30, 5)

    function pretick(dw, timeStep)  { /* XXX never called */ }
    function posttick(dw, timeStep) { /* XXX never called */ }

I looked at Callbacks from C++ to JS in tests/wrapping.js, but that doesn't seem to apply in this case, as I'm not replacing a function on an object, just trying to pass JS objects/functions.

I think I can work around not being able to use the worldUserInfo parameter to setInternalTickCallback(), but I do need the callback function to get invoked.

Am I doing something wrong, or is this just not possible right now?

[ghost]

I'm having the same issue. It says setInternalTickCallback is supposed to take a 'btInternalTickCallback':
http://bulletphysics.org/Bullet/BulletFull/btDynamicsWorld_8h.html#ab9ff268d3f8e17f20d6bcd7a7ef354c5

Ammo.btInternalTickCallback is undefined...

[cschinko]

Any news regarding this issue?

[kripken]

I hope in the next few weeks to have a new version of ammo that uses a new
bindings generator, which should help with things like this.

On Thu, Apr 17, 2014 at 4:15 AM, cschinko notifications@github.com wrote:

Any news regarding this issue?

—
Reply to this email directly or view it on GitHubhttps://github.com//issues/30#issuecomment-40703726
.

[Usnul]

this seems to be axed entirely in the new build, can we bring it back please?
by the way, for those still searching, you need to first create a function pointer to pass in:

function callback(dw,timeDelta){
...
}
var fp = Ammo.Runtime.addFunction(callback);
dynamicWorld.setInternalTickCallback(fp);

also, you might need to go into your ammo.js and search for "functionPointers" then change value from "[]" to "new Array(x)" where x is number of pointers you wish to be able to hold, if this isn't done you will likely see an error in console when trying to invoke "addFunction".

[kripken]

Adding this to the new IDL files seems to require support for passing in function pointers, which I don't think we support yet. But shouldn't be too hard to add.

[ghost]

Any word on how to do this with the new IDL? I'd like to create a btInternalTickCallback to handle kinematic rigidbodies, since nothing I do will prevent dynamic rigidbodies from passing through fast moving kinematic rigidbodies (A and D to move the kinematic flippers, hold space to shoot the ball https://goote.ch/169f43e6e96e434d879039deede2bb7e.scene). Even if we were to create an interface for setInternalTickCallback() in the btDiscreteDynamicsWorld class, how would we be able to pass in a JavaScript function?

[Usnul]

Just a note, you can still do this, but you need to bypass IDL however, you will need to edit generated C files by hand. If you really need this then a gap-stop solution might work for you.

[cybafelo]

Hey all - I'm also struggling with this - is there some way to set a substep callback in ammo js? I really need this to speed up my game, and I don't want to write any gap-stop code..

[cybafelo]

Hey guys - any feedback on this - is it a simple thing? I don't know the details of emscripten but will try to build a new version of ammo soon - so that I could at least set an internal substep callback - or can someone tell me know if I should not even try this?

[Usnul]

@cybafelo
I did this in the past, might try to find it later. But it boils down to generation of C files from IDL that comes with ammo, IDL generator does not allow expression of interface such as one you describe, so you will have to edit generated C file by hand to add it, the rest is simple - just follow build process as usual.

[cybafelo]

ok - I tried the following - i modified the ammo.idl to have the following lines:

callback btInternalTickCallback = void (btDynamicsWorld world, float timeStep);

the float above should actually be btScalar but i didnt want to modify the idl too much (also btScalar is just a typedef for float or double)

then, in interface btDynamicsWorld i added the following line

void setInternalTickCallback(btInternalTickCallback cb, optional VoidPtr worldUserInfo, optional boolean isPreTick);

Now I rebuild ammo.js with python make.py, which builds a temp.js which I copy over to my ammo.js - it loads fine, everything still works - i have the function 'setInternalTickCallback' - but my callback doesn't execute (its a closure, ex.
myDiscreteDynamicsWorld.setInternalTickCallback( function(){ console.log('hello'); } );
I tried the example above with Ammo.Runtime but Ammo.Runtime is not defined. Help anyone?

So - it appears to be the same problem, setInternalTickCallback has no effect

my last attempt is

this.world.setInternalTickCallback( function(__a, __b) { console.log('internal tick callback'); } , null, true);

this.world is an instance of btDiscreteDynamicsWorld

[Usnul]

@cybafelo
it was a long time ago since i did this. However, reading my posts here - it appears that editing IDL will not work. I have been suggesting editing C files that are generated from the IDL. I'm sorry, but I can not help you further.

[MackeyK24]

Hey guys... I tried every thing listed above...

tried both 10 and 20 (make.py)

  emcc_args += '-s RESERVED_FUNCTION_POINTERS=10'.split(' ')

But i have NO Ammo.addFunction and/or NO Ammo.Runtime.addFunction

Anybody know what gives ???

[modstorm]

Do you have this arg included, it fixed it for me?

-s EXPORTED_RUNTIME_METHODS=[\'addFunction\']

[MackeyK24]

Thats weird... I could not get EXPORTED_RUNTIME_METHODS to work with Pointers_stringify

But luckily there is a EXTRA_EXPORTED_RUNTIME_METHODS that worked for me:

Update make.py

EMCC_ARGS:
emcc_args += '-s RESERVED_FUNCTION_POINTERS=20'.split(' ')
emcc_args += '-s EXTRA_EXPORTED_RUNTIME_METHODS=["addFunction"]'.split(' ')