Function transform_coordinates

src/api/c/transform_coordinates.cpp:43–82

template<typename T>
static af_array transform_coordinates(const af_array &tf_, const float d0_,
                                      const float d1_) {
    af::dim4 h_dims(4, 3);
    T zero = 0;
    T one  = 1;
    T d0   = static_cast<T>(d0_);
    T d1   = static_cast<T>(d1_);
    // clang-format off
    T h_in[4 * 3] = {zero, zero,  d1,   d1,
                     zero,   d0,  d0, zero,
                      one,  one, one,  one};
    // clang-format on

    const Array<T> tf = getArray<T>(tf_);
    Array<T> in       = createHostDataArray<T>(h_dims, h_in);

    std::vector<af_seq> idx(2);
    idx[0] = af_make_seq(0, 2, 1);

    // w = 1.0 / matmul(tf, in(span, 2));
    // iw = matmul(tf, in(span, 2));
    idx[1]      = af_make_seq(2, 2, 1);
    Array<T> iw = multiplyIndexed(in, tf, idx);

    // xt = w * matmul(tf, in(span, 0));
    // xt = matmul(tf, in(span, 0)) / iw;
    idx[1] = af_make_seq(0, 0, 1);
    Array<T> xt =
        arithOp<T, af_div_t>(multiplyIndexed(in, tf, idx), iw, iw.dims());

    // yt = w * matmul(tf, in(span, 1));
    // yt = matmul(tf, in(span, 1)) / iw;
    idx[1] = af_make_seq(1, 1, 1);
    Array<T> yw =
        arithOp<T, af_div_t>(multiplyIndexed(in, tf, idx), iw, iw.dims());

    // return join(1, xt, yt)
    Array<T> r = join(1, xt, yw);
    return getHandle(r);
}

af_err af_transform_coordinates(af_array *out, const af_array tf,
                                const float d0_, const float d1_) {