Function EXRLayers

third-party/tinyexr/tinyexr.h:6139–6182

}  // namespace tinyexr

int EXRLayers(const char *filename, const char **layer_names[], int *num_layers,
              const char **err) {
  EXRVersion exr_version;
  EXRHeader exr_header;
  InitEXRHeader(&exr_header);

  {
    int ret = ParseEXRVersionFromFile(&exr_version, filename);
    if (ret != TINYEXR_SUCCESS) {
      tinyexr::SetErrorMessage("Invalid EXR header.", err);
      return ret;
    }

    if (exr_version.multipart || exr_version.non_image) {
      tinyexr::SetErrorMessage(
          "Loading multipart or DeepImage is not supported  in LoadEXR() API",
          err);
      return TINYEXR_ERROR_INVALID_DATA;  // @fixme.
    }
  }

  int ret = ParseEXRHeaderFromFile(&exr_header, &exr_version, filename, err);
  if (ret != TINYEXR_SUCCESS) {
    FreeEXRHeader(&exr_header);
    return ret;
  }

  std::vector<std::string> layer_vec;
  tinyexr::GetLayers(exr_header, layer_vec);

  (*num_layers) = int(layer_vec.size());
  (*layer_names) = static_cast<const char **>(
      malloc(sizeof(const char *) * static_cast<size_t>(layer_vec.size())));
  for (size_t c = 0; c < static_cast<size_t>(layer_vec.size()); c++) {
#ifdef _MSC_VER
    (*layer_names)[c] = _strdup(layer_vec[c].c_str());
#else
    (*layer_names)[c] = strdup(layer_vec[c].c_str());
#endif
  }

  FreeEXRHeader(&exr_header);
  return TINYEXR_SUCCESS;
}

int LoadEXR(float **out_rgba, int *width, int *height, const char *filename,
            const char **err) {