/*

 * Copyright (c) 2017 Thomas Pornin <pornin@bolet.org>

 *

 * Permission is hereby granted, free of charge, to any person obtaining 

 * a copy of this software and associated documentation files (the

 * "Software"), to deal in the Software without restriction, including

 * without limitation the rights to use, copy, modify, merge, publish,

 * distribute, sublicense, and/or sell copies of the Software, and to

 * permit persons to whom the Software is furnished to do so, subject to

 * the following conditions:

 *

 * The above copyright notice and this permission notice shall be 

 * included in all copies or substantial portions of the Software.

 *

 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, 

 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF

 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND 

 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS

 * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN

 * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN

 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE

 * SOFTWARE.

 */

#include "inner.h"

/* see inner.h */

void

br_i15_encode(void *dst, size_t len, const uint16_t *x)

{

  unsigned char *buf;

  size_t u, xlen;

  uint32_t acc;

  int acc_len;

  xlen = (x[0] + 15) >> 4;

  if (xlen == 0) {

    memset(dst, 0, len);

    return;

  }

  u = 1;

  acc = 0;

  acc_len = 0;

  buf = dst;

  while (len -- > 0) {

    if (acc_len < 8) {

      if (u <= xlen) {

        acc += (uint32_t)x[u ++] << acc_len;

      }

      acc_len += 15;

    }

    buf[len] = (unsigned char)acc;

    acc >>= 8;

    acc_len -= 8;

  }

}