#pragma OPENCL EXTENSION cl_khr_fp64 : enable

double2 sample(const double qy, const double qz,
        const double r, const double h, const int dwba) {
    return (double2)(qy,qz);
}

__kernel void dwba(const int ny, const int nz,
        const double r, const double h,
        const __global double* qy, const __global double *qz,
        __global double* res, const int dwba, const int vector) {

    if (vector == 0) {
        int iy = get_global_id(0);
        int iz = get_global_id(1);
        int ind = iz+nz*iy;

        if (qz[iz] < 0) {
            res[ind] = 0;
            return;
        }

        res[ind] = length(sample(qy[iy], qz[iz], r, h, dwba));
    } else {
        const double q0 = 2*M_PI/0.139;
        const double alpha_i = 0.2*M_PI/180.;
        double2 tmp;
        int i = get_global_id(0);
        res[2*i] = 0;
        res[2*i+1] = 1;
        if (i < ny) {
            if (dwba == 0) {
                tmp = sample(qy[i], 0, r, h, dwba);
            } else {
                tmp = sample(qy[i], -q0*sin(alpha_i), r, h, dwba);
            }
            res[2*i] = tmp.x;
            res[2*i+1] = tmp.y;
        }
        if (i < nz) {
            tmp = sample(0, qz[i], r, h, dwba);
            res[2*(i+ny)] = tmp.x;
            res[2*(i+ny)+1] = tmp.y;
        }
    }
}