Function tryPcSogs

src/SplatLoader.ts:540–602

(
  input: ArrayBuffer | Uint8Array | string,
)

}

export function tryPcSogs(
  input: ArrayBuffer | Uint8Array | string,
): PcSogsJson | PcSogsV2Json | undefined {
  // Try to parse input as SOGS JSON and see if it's valid
  try {
    let text: string;
    if (typeof input === "string") {
      text = input;
    } else {
      const fileBytes =
        input instanceof ArrayBuffer ? new Uint8Array(input) : input;
      if (fileBytes.length > 65536) {
        // Should be only a few KB, definitely not a SOGS JSON file
        return undefined;
      }
      text = new TextDecoder().decode(fileBytes);
    }

    const json = JSON.parse(text);
    if (!json || typeof json !== "object" || Array.isArray(json)) {
      return undefined;
    }
    const isVersion2 = json.version === 2;

    for (const key of ["means", "scales", "quats", "sh0"]) {
      if (
        !json[key] ||
        typeof json[key] !== "object" ||
        Array.isArray(json[key])
      ) {
        return undefined;
      }
      if (isVersion2) {
        // Expect files
        if (!json[key].files) {
          return undefined;
        }

        // Scales and sh0 should have codebooks
        if ((key === "scales" || key === "sh0") && !json[key].codebook) {
          return undefined;
        }
        // Means should have mins and maxs defined
        if (key === "means" && (!json[key].mins || !json[key].maxs)) {
          return undefined;
        }
      } else {
        // Expect shape and files
        if (!json[key].shape || !json[key].files) {
          return undefined;
        }
        // Besides 'quats' all other properties have mins and maxs
        if (key !== "quats" && (!json[key].mins || !json[key].maxs)) {
          return undefined;
        }
      }
    }
    // This is probably a PC SOGS file