Function LodePNGBitReader_init

depends/lodepng/lodepng.cpp:465–477

data size argument is in bytes. Returns error if size too large causing overflow */

/* data size argument is in bytes. Returns error if size too large causing overflow */
static unsigned LodePNGBitReader_init(LodePNGBitReader* reader, const unsigned char* data, size_t size) {
  size_t temp;
  reader->data = data;
  reader->size = size;
  /* size in bits, return error if overflow (if size_t is 32 bit this supports up to 500MB)  */
  if(lodepng_mulofl(size, 8u, &reader->bitsize)) return 105;
  /*ensure incremented bp can be compared to bitsize without overflow even when it would be incremented 32 too much and
  trying to ensure 32 more bits*/
  if(lodepng_addofl(reader->bitsize, 64u, &temp)) return 105;
  reader->bp = 0;
  reader->buffer = 0;
  return 0; /*ok*/
}

/*
ensureBits functions: