@phaserjs/phaser/textures/parsers/KTXParser.js

Phaser 4

export function KTXParser(data) {
  const idCheck = [171, 75, 84, 88, 32, 49, 49, 187, 13, 10, 26, 10];
  const id = new Uint8Array(data, 0, 12);
  for (let i = 0; i < id.length; i++) {
    if (id[i] !== idCheck[i]) {
      console.error("KTXParser - Invalid file format");
      return;
    }
  }
  const size = Uint32Array.BYTES_PER_ELEMENT;
  const head = new DataView(data, 12, 13 * size);
  const littleEndian = head.getUint32(0, true) === 67305985;
  const glType = head.getUint32(1 * size, littleEndian);
  if (glType !== 0) {
    console.warn("KTXParser - Only compressed formats supported");
    return;
  }
  const internalFormat = head.getUint32(4 * size, littleEndian);
  const width = head.getUint32(6 * size, littleEndian);
  const height = head.getUint32(7 * size, littleEndian);
  const mipmapLevels = Math.max(1, head.getUint32(11 * size, littleEndian));
  const bytesOfKeyValueData = head.getUint32(12 * size, littleEndian);
  const mipmaps = new Array(mipmapLevels);
  let offset = 12 + 13 * 4 + bytesOfKeyValueData;
  let levelWidth = width;
  let levelHeight = height;
  for (let i = 0; i < mipmapLevels; i++) {
    const levelSize = new Int32Array(data, offset, 1)[0];
    offset += 4;
    mipmaps[i] = {
      data: new Uint8Array(data, offset, levelSize),
      width: levelWidth,
      height: levelHeight
    };
    console.log("KTX", i, "size", levelWidth, levelHeight);
    levelWidth = Math.max(1, levelWidth >> 1);
    levelHeight = Math.max(1, levelHeight >> 1);
    offset += levelSize;
  }
  return {
    mipmaps,
    width,
    height,
    internalFormat,
    compressed: true,
    generateMipmap: false
  };
}