computeJointData method

Implementation

JointData computeJointData() {
  final weights = this.weights?.get().typedData() ?? [];
  // this are the indexes (0, 1, 2, 3) that have any relevance at all
  final relevantIndexes = weights.expand((w) {
    return w.storage.indexed
        .where((e) => e.$2 > 0.0)
        .map((e) => e.$1)
        .toSet();
  }).toSet();

  final joints = this.joints?.get().typedData() ?? [];
  final globalToLocalJointMap = Map.fromEntries(
    joints
        .expand((e) {
          return e.storage.indexed
              .where((e) => relevantIndexes.contains(e.$1))
              .map((e) => e.$2);
        })
        .toSet()
        .indexed
        .map((e) => MapEntry(e.$2.toInt(), e.$1)),
  );

  final localizedJoints = joints.map((joint) {
    return Vector4.array(
      joint.storage.map((e) {
        if (e == 0.0 && globalToLocalJointMap[e] == null) {
          // this must be a 0 weight value that just happens to be id = 0
          return 0.0;
        }
        return globalToLocalJointMap[e]!.toDouble();
      }).toList(),
    );
  }).toList();

  return JointData(
    weights: weights,
    localizedJoints: localizedJoints,
    jointMap: globalToLocalJointMap,
  );
}