Function CalculateNumXLevels

tutorials/common/image/tinyexr.h:5581–5617

}

static int CalculateNumXLevels(const EXRHeader* exr_header) {
  int min_x = exr_header->data_window.min_x;
  int max_x = exr_header->data_window.max_x;
  int min_y = exr_header->data_window.min_y;
  int max_y = exr_header->data_window.max_y;

  int num = 0;
  switch (exr_header->tile_level_mode) {
  case TINYEXR_TILE_ONE_LEVEL:

    num = 1;
    break;

  case TINYEXR_TILE_MIPMAP_LEVELS:

  {
    int w = max_x - min_x + 1;
    int h = max_y - min_y + 1;
    num = RoundLog2(std::max(w, h), exr_header->tile_rounding_mode) + 1;
  }
  break;

  case TINYEXR_TILE_RIPMAP_LEVELS:

  {
    int w = max_x - min_x + 1;
    num = RoundLog2(w, exr_header->tile_rounding_mode) + 1;
  }
  break;

  default:

    return -1;
  }

  return num;
}

static int CalculateNumYLevels(const EXRHeader* exr_header) {
  int min_x = exr_header->data_window.min_x;