Re: [Swig-user] JNI of primitive arrays: efficiency question

[William S F. <ws...@fu...>]

William S Fulton wrote:
> Stanford, Edward R. wrote:
>> I have tried to figure this out from the documentation, and retreated 
>> baffled.
>>
>> I have large arrays of floats (float[]) that I need to move back and 
>> forth from C++ to Java.  I am using arrays_java.i.
>>
>> For marshalling primitive types, does arrays_java.i se the more 
>> efficient GetFloatArrayRegion(...) and SetFloatArray(...) methods?  Or 
>> does it use the index-by-index assignment methods that have to be used 
>> with arrays of non-primitive types?
>>
>> If I can avoid defining my own typemaps and directors and still get an 
>> efficient transfer across the Java/C++ boundary, I'll be a happy man.
>>
> 
> It uses GetFloatArrayElements. Writing your own typemaps isn't that 
> hard. The Java docs show plenty of examples and you can see the ones in 
> arrays_java.i quite easily by looking at the preprocessed output by 
> running swig -E on a simple file that has a %include of arrays_java.i.
> 
But, I failed to mention that there are no director typemaps in 
arrays_java.i, you'd need to write these from scratch.

William