On 21 November 2013 22:40, Sean P. DeNigris <sean@clipperadams.com> wrote:

I'm wrapping the FMOD cross-platform audio library. The code is MIT and lives
at http://smalltalkhub.com/#!/~SeanDeNigris/FMOD

========
Problem #1:
========

I'm calling into the FMOD library with:
primStoreIsPlaying: channelHandle in: isPlayingHandle
�� <primitive: #primitiveNativeCall module: #NativeBoostPlugin>

�� "FMOD_RESULT FMOD_Channel_IsPlaying(
�� FMOD_CHANNEL *channel,
�� bool *isplaying);"

�� ^ self nbCall: #(FMOD_RESULT FMOD_Channel_IsPlaying(NBExternalAddress
channel, NBExternalAddress isPlayingHandle)).

I call the above with:
�� isPlaying
�� | isPlaying |
�� isPlaying := NBExternalAddress new.
�� self primStoreIsPlaying: channel in: isPlaying.
�� ^ isPlaying value > 0.

isPlaying is always 0. The method works directly from C with:
int isPlaying = 1;
�� while (isPlaying) {
�� FMOD_Channel_IsPlaying(channel, &isPlaying);
�� }

I also tried changing the callout signature to "... bool* isPlayingHandle)"
and passing "isPlaying := true." instead of using the NBExternalAddress
stuff.

err.. again, you must pass an address where value will be stored,

^ self nbCall: #(FMOD_RESULT FMOD_Channel_IsPlaying(

NBExternalAddress channel, NBExternalAddress * isPlayingHandle)).

otherwise you passing NULL pointer, and i quite surprised it not segfaults when you call it like that (looks like they have a check in the library )

��

��you can also use NBExternalTypeValue for that:

boolValueClass := NBExternalTypeValue ofType: 'bool'. "sure thing, creating anonymous class for each call is overkill, this should be done once, somewhere else"

boolValue := boolValueClass new.

self callTheThingWith: boolValue.

boolValue value ifTrue: [... blah]

(and this will work, assuming you have bool* in signature for this argument).

I have a few more questions, but this is the most pressing as it's holding
up any further development.

Thanks!

-----
Cheers,
Sean
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--
Best regards,
Igor Stasenko.