Function InitTileOffsets

tutorials/common/image/tinyexr.h:5723–5767

Return sum of tile blocks. 0 = error

// Return sum of tile blocks.
// 0 = error
static int InitTileOffsets(OffsetData& offset_data,
  const EXRHeader* exr_header,
  const std::vector<int>& num_x_tiles,
  const std::vector<int>& num_y_tiles) {
  int num_tile_blocks = 0;
  offset_data.num_x_levels = static_cast<int>(num_x_tiles.size());
  offset_data.num_y_levels = static_cast<int>(num_y_tiles.size());
  switch (exr_header->tile_level_mode) {
  case TINYEXR_TILE_ONE_LEVEL:
  case TINYEXR_TILE_MIPMAP_LEVELS:
    TINYEXR_CHECK_AND_RETURN_C(offset_data.num_x_levels == offset_data.num_y_levels, 0);
    offset_data.offsets.resize(size_t(offset_data.num_x_levels));

    for (unsigned int l = 0; l < offset_data.offsets.size(); ++l) {
      offset_data.offsets[l].resize(size_t(num_y_tiles[l]));

      for (unsigned int dy = 0; dy < offset_data.offsets[l].size(); ++dy) {
        offset_data.offsets[l][dy].resize(size_t(num_x_tiles[l]));
        num_tile_blocks += num_x_tiles[l];
      }
    }
    break;

  case TINYEXR_TILE_RIPMAP_LEVELS:

    offset_data.offsets.resize(static_cast<size_t>(offset_data.num_x_levels) * static_cast<size_t>(offset_data.num_y_levels));

    for (int ly = 0; ly < offset_data.num_y_levels; ++ly) {
      for (int lx = 0; lx < offset_data.num_x_levels; ++lx) {
        int l = ly * offset_data.num_x_levels + lx;
        offset_data.offsets[size_t(l)].resize(size_t(num_y_tiles[size_t(ly)]));

        for (size_t dy = 0; dy < offset_data.offsets[size_t(l)].size(); ++dy) {
          offset_data.offsets[size_t(l)][dy].resize(size_t(num_x_tiles[size_t(lx)]));
          num_tile_blocks += num_x_tiles[size_t(lx)];
        }
      }
    }
    break;

  default:
    return 0;
  }
  return num_tile_blocks;
}

static bool IsAnyOffsetsAreInvalid(const OffsetData& offset_data) {
  for (unsigned int l = 0; l < offset_data.offsets.size(); ++l)