Sorry, I sent it with the wrong subject. Here I go again:

On Wed, May 13, 2009 at 3:41 PM, Ricardo Moran <richi.moran at gmail.com>wrote:

> Thanks for the reply, Mariano! I tried your advice but I ended up with some
> "Could not coerce arguments" errors and crashing the VM several times :P.
> However, I tried something like this:
>
> IplImage>>free
> SqueakCV apiReleaseImage: handle asByteArrayPointer.
>
> SqueakCV>>apiReleaseImage: doublePointer
> <apicall: void 'cvReleaseImage' (byte*) module: 'cxcore110.dll'>
>  ^ self externalCallFailed
>
>
> It appears to be working. I don't know if this is the right way to do it,
> though. I don't know either if overriding #free is ok and it would not bring
> problems later...
>
>
>> >* 2)      To finalize objects the OpenCV library defines some functions such*>* as cvReleaseImage, cvReleaseMat, etc. As far as I can tell, these functions*>* receive a pointer-to-pointer as argument. How can I declare such a method in*>* Squeak? Having one object, how can I get the pointer to that object? Should*>* I use the #getHandle method?*>**
>> In OpenDBX we have a functions like this for example:
>>
>>     long odbx_init(odbx_t**, char*, char*, char*)
>>
>> This is how I declare it:
>>
>> apiInitialize: handle backend: backend host: host port: port
>>     <cdecl: long 'odbx_init' (ulong* char* char* char*) module: 'opendbx'>
>>     ^self externalCallFailed
>>
>> Remember a pinter to a pointer is a long :)
>>
>> And then in the code I do something like this:
>>
>> handleArray := WordArray with: 0.
>>     err := OpenDBX current
>>                 apiInitialize: handleArray
>>                 backend: self backend
>>                 host: aConnection settings host
>>                 port: aConnection settings port.
>>
>> Notice the WordArray.
>>
>> I have no idea of 1) and 3) sorry.
>>
>> I hope this helps. If this do help, perhaps we can put it in FFI wiki page.
>>
>> Cheers,
>>
>> Mariano
>>
>>
>
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