Hi,
> On 26 Nov 2018, at 09:28, Yuriy Babah <babah.yuri...@gmail.com> wrote:
>
> Hi !
>
> I'm trying to call a very simple function from C ++ lib, writed for the test.
> function with prototype:
>
> extern "C" float interpolationFunc(float* xm, float* ym, int size, float x).
>
> In Pharo7 wrote:
> FFIExamples class >> interpolationFunc_xm: xM ym: yM size: size x: x
> ^ self ffiCall: #(float interpolationFunc #(float * xM , float * yM , int
> size , float x)) module: 'libinterpolationLib.so'
>
> in Playground i'm doing:
> xm := FFIExternalArray externalNewType: 'float' size: 2.
> ym := xm clone.
> #(2 3) doWithIndex: [:each :i | xm at: i put: each].
> #(3 4) doWithIndex: [:each :i | ym at: i put: each].
> FFIExamples interpolationFunc_xm: xm pointer ym: ym pointer size: 2 x: 2.5 .
This is incorrect. “xm” and “ym” are already pointers (references)
When you pass "xm pointer” you are actually passing a pointer to a pointer (a
float** in this case)
This looks better:
FFIExamples
interpolationFunc_xm: xm getHandle
ym: ym getHandle
size: 2
x: 2.5 .
Still, you need to do something with those arrays after using them, since you
are creating them with externalNewType:… (which mean it allocates the memory
space).
You will need to send #free to them.
Other solution would be to not use #externalNewType:size: but plain
#newType:size:
Cheers,
Esteban
>
> last expression returninп me 0.0, but right is 3.5.
>
> I'm dit the same in Python3 ctypes, and there work's fine.
>
> In UnifiedFFI booklet is absent chapter "Arrays", anybody may help with whot
> i'm doing wrong?
