How to modify the perturbation of offshore wave boundary conditions?

[EmilioEchevarria]

Hi Cyprien and all,

I started to play around with XB-GPU running a simple case with both XBeach (CPU) and XBGPU. I'm running both cases with a jonswap spectrum (wavemodel=surfbeat and wbctype=jonstable for CPU, wavebndtype=4 for GPU). In each case there is a sort of 'perturbation' of the wave heights and directions along the offshore boundary (nx=0 in CPU, xx=0 in GPU), but that perturbation is quite different in both cases... (see figure attached)

So my question is, what parts of the code would have to be modified to change this perturbation? It seems to be somewhere in GenWGnLBW in makjonswap.cpp? Unless I'm doing something obviously wrong in the GPU case, which is also possible...

Many thanks,
Emilio