Function deflateFixed

depends/lodepng/lodepng.cpp:2029–2072

}

static unsigned deflateFixed(LodePNGBitWriter* writer, Hash* hash,
                             const unsigned char* data,
                             size_t datapos, size_t dataend,
                             const LodePNGCompressSettings* settings, unsigned final) {
  HuffmanTree tree_ll; /*tree for literal values and length codes*/
  HuffmanTree tree_d; /*tree for distance codes*/

  unsigned BFINAL = final;
  unsigned error = 0;
  size_t i;

  HuffmanTree_init(&tree_ll);
  HuffmanTree_init(&tree_d);

  error = generateFixedLitLenTree(&tree_ll);
  if(!error) error = generateFixedDistanceTree(&tree_d);

  if(!error) {
    writeBits(writer, BFINAL, 1);
    writeBits(writer, 1, 1); /*first bit of BTYPE*/
    writeBits(writer, 0, 1); /*second bit of BTYPE*/

    if(settings->use_lz77) /*LZ77 encoded*/ {
      uivector lz77_encoded;
      uivector_init(&lz77_encoded);
      error = encodeLZ77(&lz77_encoded, hash, data, datapos, dataend, settings->windowsize,
                         settings->minmatch, settings->nicematch, settings->lazymatching);
      if(!error) writeLZ77data(writer, &lz77_encoded, &tree_ll, &tree_d);
      uivector_cleanup(&lz77_encoded);
    } else /*no LZ77, but still will be Huffman compressed*/ {
      for(i = datapos; i < dataend; ++i) {
        writeBitsReversed(writer, tree_ll.codes[data[i]], tree_ll.lengths[data[i]]);
      }
    }
    /*add END code*/
    if(!error) writeBitsReversed(writer,tree_ll.codes[256], tree_ll.lengths[256]);
  }

  /*cleanup*/
  HuffmanTree_cleanup(&tree_ll);
  HuffmanTree_cleanup(&tree_d);

  return error;
}

static unsigned lodepng_deflatev(ucvector* out, const unsigned char* in, size_t insize,
                                 const LodePNGCompressSettings* settings) {