face-api/src/factories/WithFaceLandmarks.ts

import { FaceDetection } from '../classes/FaceDetection';
import { FaceLandmarks } from '../classes/FaceLandmarks';
import { FaceLandmarks68 } from '../classes/FaceLandmarks68';
import { isWithFaceDetection, WithFaceDetection } from './WithFaceDetection';

export type WithFaceLandmarks<
  TSource extends WithFaceDetection<{}>,
  TFaceLandmarks extends FaceLandmarks = FaceLandmarks68 > = TSource & {
    landmarks: TFaceLandmarks
    unshiftedLandmarks: TFaceLandmarks
    alignedRect: FaceDetection
  }

export function isWithFaceLandmarks(obj: any): obj is WithFaceLandmarks<WithFaceDetection<{}>, FaceLandmarks> {
  return isWithFaceDetection(obj)
    // eslint-disable-next-line dot-notation
    && obj['landmarks'] instanceof FaceLandmarks
    // eslint-disable-next-line dot-notation
    && obj['unshiftedLandmarks'] instanceof FaceLandmarks
    // eslint-disable-next-line dot-notation
    && obj['alignedRect'] instanceof FaceDetection;
}

export function extendWithFaceLandmarks<
  TSource extends WithFaceDetection<{}>,
  TFaceLandmarks extends FaceLandmarks = FaceLandmarks68 >(sourceObj: TSource, unshiftedLandmarks: TFaceLandmarks): WithFaceLandmarks<TSource, TFaceLandmarks> {
  const { box: shift } = sourceObj.detection;
  const landmarks = unshiftedLandmarks.shiftBy<TFaceLandmarks>(shift.x, shift.y);

  const rect = landmarks.align();
  const { imageDims } = sourceObj.detection;
  const alignedRect = new FaceDetection(sourceObj.detection.score, rect.rescale(imageDims.reverse()), imageDims);

  const extension = {
    landmarks,
    unshiftedLandmarks,
    alignedRect,
  };

  return { ...sourceObj, ...extension };
}