init static method

Contact init(Fixture fixtureA, int indexA, Fixture fixtureB, int indexB,)

Implementation

static Contact init(
  Fixture fixtureA,
  int indexA,
  Fixture fixtureB,
  int indexB,
) {
  // Remember that we use the order in the enum here to determine in which
  // order the arguments should come in the different contact classes.
  // { CIRCLE, EDGE, POLYGON, CHAIN }
  // TODO(spydon): Clean this mess up.
  final typeA = fixtureA.type.index < fixtureB.type.index
      ? fixtureA.type
      : fixtureB.type;
  final typeB = fixtureA.type == typeA ? fixtureB.type : fixtureA.type;
  final indexTemp = indexA;
  final firstIndex = fixtureA.type == typeA ? indexA : indexB;
  final secondIndex = fixtureB.type == typeB ? indexB : indexTemp;
  final temp = fixtureA;
  final firstFixture = fixtureA.type == typeA ? fixtureA : fixtureB;
  final secondFixture = fixtureB.type == typeB ? fixtureB : temp;

  if (typeA == ShapeType.circle && typeB == ShapeType.circle) {
    return CircleContact(firstFixture, secondFixture);
  } else if (typeA == ShapeType.polygon && typeB == ShapeType.polygon) {
    return PolygonContact(firstFixture, secondFixture);
  } else if (typeA == ShapeType.circle && typeB == ShapeType.polygon) {
    return PolygonAndCircleContact(secondFixture, firstFixture);
  } else if (typeA == ShapeType.circle && typeB == ShapeType.edge) {
    return EdgeAndCircleContact(
      secondFixture,
      secondIndex,
      firstFixture,
      firstIndex,
    );
  } else if (typeA == ShapeType.edge && typeB == ShapeType.polygon) {
    return EdgeAndPolygonContact(
      firstFixture,
      firstIndex,
      secondFixture,
      secondIndex,
    );
  } else if (typeA == ShapeType.circle && typeB == ShapeType.chain) {
    return ChainAndCircleContact(
      secondFixture,
      secondIndex,
      firstFixture,
      firstIndex,
    );
  } else if (typeA == ShapeType.polygon && typeB == ShapeType.chain) {
    return ChainAndPolygonContact(
      secondFixture,
      secondIndex,
      firstFixture,
      firstIndex,
    );
  } else {
    assert(false, 'Not compatible contact type');
    return CircleContact(firstFixture, secondFixture);
  }
}