CODEWITHSUNDEEP
c++c
Grapes
Grapes

Reputation: 2563

Passing C variable to C++ function

I have an android project with OpenSL ES and need to do some cleaning up.

One of the things I want to do is separate some logic from one file.

The file has the following variable defined: 

static SLObjectItf engineObject = NULL;

This is a C variable as we access it like so:

(*engineObject)->Realize(engineObject, SL_BOOLEAN_FALSE);

I am trying to pass it off to another C++ class like so:

audioBuffer->Create(&engineObject);

This is how you would normally pass a pointer to SLObjectItf but it's a C variable so there is some different behaviour here.

This seems like a fairly straightforward task, here is the recieving function:

AudioBuffer::Create(SLObjectItf* engineEngine) 
{
    // ....
    (*engineEngine)->CreateAudioPlayer(engineEngine, &bqPlayerObject, &audioSrc, &audioSnk,
            3, ids, req);
}

And the error is:

request for member 'CreateAudioPlayer' in '* * engineEngine', which is of pointer type 'const SLEngineItf_* const' (maybe you meant to use '->' ?)

How do I pass a C variable into a C++ function and use it there?

Upvotes: 1

Views: 142

Answers (2)

man
man

Reputation: 197

'engineEngine' is passed as a pointer, try

engineEngine->CreateAudioPlayer(......

or

(*engineEngine).CreateAudioPlayer(.....

Upvotes: 0

Some programmer dude
Some programmer dude

Reputation: 409176

When looking at the header file, I see that SLObjectItf is defined as

typedef const struct SLObjectItf_ * const * SLObjectItf;

That means it's a pointer to pointer to a structure. When you pass a pointer to the SLObjectItf variable you pass a pointer to pointer to pointer to the structure, so *engineEngine is the pointer to pointer to structure. You need another dereference operator, or simply not pass it as a pointer.

Upvotes: 2

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