Transform2D.fromJsonMap constructor

Transform2D.fromJsonMap(
  1. Map<String, Object?> map
)

Decodes a transform from a JSON-friendly map.

This format is shared between JSON serialization and action event payloads: {a,b,c,d,tx,ty}.

Throws ArgumentError when required fields are missing or not numeric.

Implementation

factory Transform2D.fromJsonMap(Map<String, Object?> map) {
  double requireNum(String key) {
    final value = map[key];
    if (value is num) return value.toDouble();
    throw ArgumentError.value(value, key, 'Must be a number.');
  }

  return Transform2D(
    a: requireNum('a'),
    b: requireNum('b'),
    c: requireNum('c'),
    d: requireNum('d'),
    tx: requireNum('tx'),
    ty: requireNum('ty'),
  );
}