// SPDX-License-Identifier: Apache-2.0
//
// Copyright 2008-2016 Conrad Sanderson (http://conradsanderson.id.au)
// Copyright 2008-2016 National ICT Australia (NICTA)
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
// ------------------------------------------------------------------------

//! \addtogroup glue_polyval
//! @{

template <typename eT>
inline void glue_polyval::apply_noalias(Mat<eT>& out, const Mat<eT>& P,
                                        const Mat<eT>& X) {
  arma_debug_sigprint();

  out.set_size(X.n_rows, X.n_cols);

  const eT* P_mem = P.memptr();
  const uword P_n_elem = P.n_elem;

  out.fill(P_mem[0]);

  for (uword i = 1; i < P_n_elem; ++i) {
    out = out % X + P_mem[i];
  }
}

template <typename T1, typename T2>
inline void glue_polyval::apply(Mat<typename T1::elem_type>& out,
                                const Glue<T1, T2, glue_polyval>& expr) {
  arma_debug_sigprint();

  typedef typename T1::elem_type eT;

  const quasi_unwrap<T1> UP(expr.A);
  const quasi_unwrap<T2> UX(expr.B);

  const Mat<eT>& P = UP.M;
  const Mat<eT>& X = UX.M;

  arma_conform_check(((P.is_vec() == false) && (P.is_empty() == false)),
                     "polyval(): argument P must be a vector");

  if (P.is_empty() || X.is_empty()) {
    out.zeros(X.n_rows, X.n_cols);
    return;
  }

  if (UP.is_alias(out) || UX.is_alias(out)) {
    Mat<eT> tmp;
    glue_polyval::apply_noalias(tmp, P, X);
    out.steal_mem(tmp);
  } else {
    glue_polyval::apply_noalias(out, P, X);
  }
}

//! @}
