Function updateHashChain

src/lodepng.cpp:1415–1420

wpos = pos & (windowsize - 1)*/

/*wpos = pos & (windowsize - 1)*/
static void updateHashChain(Hash* hash, size_t wpos, int hashval)
{
  hash->val[wpos] = hashval;
  if(hash->head[hashval] != -1) hash->chain[wpos] = hash->head[hashval];
  hash->head[hashval] = wpos;
}

/*
LZ77-encode the data. Return value is error code. The input are raw bytes, the output