overlaps360 method

bool overlaps360(AngleRange range2)

Returns true if this angle range overlaps range2's angle range (exclusive of the endpoints).

Both ranges are projected onto the 0–360 degree circle before comparison, so ranges that are numerically far apart (e.g. 350–20 and 720–740) are still recognised as overlapping if their arcs share common ground.

How the wrap-around split works

When a projected range crosses 0° (i.e. max360 < min360 after normalisation), the arc is split into two contiguous sub-ranges that together cover the same arc without crossing the 0°/360° boundary:

  sub-range 1:  [min360, 360°]   — the tail end of the circle
  sub-range 2:  [0°,     max360] — the head end of the circle

max360 is kept at its normalised value (< min360); adding 2π to it would produce a value > 360°, which is geometrically wrong for a range that is supposed to live within the 0–360° circle.

Implementation

bool overlaps360(AngleRange range2) {
  if (overlaps(range2)) return true;

  // No direct overlap — check whether the 0–360 projections overlap.
  // If a projected range crosses 0° (max360 < min360), split it into two
  // sub-ranges that together tile the same arc within [0°, 360°].
  final list1 = <AngleRange>[];
  final min360 = minValue.angle360;
  final max360 = maxValue.angle360;
  if (max360 < min360) {
    // Arc crosses 0°: split into [min360, 360°] ∪ [0°, max360].
    list1
      ..add(AngleRange(min360, Angle(rad: twoPi)))
      ..add(AngleRange(Angle(rad: 0), max360));
  } else {
    list1.add(AngleRange(min360, max360));
  }

  final list2 = <AngleRange>[];
  final min360two = range2.minValue.angle360;
  final max360two = range2.maxValue.angle360;
  if (max360two < min360two) {
    // Arc crosses 0°: split into [min360two, 360°] ∪ [0°, max360two].
    list2
      ..add(AngleRange(min360two, Angle(rad: twoPi)))
      ..add(AngleRange(Angle(rad: 0), max360two));
  } else {
    list2.add(AngleRange(min360two, max360two));
  }

  // Check every pair of sub-ranges for overlap.
  for (final range1 in list1) {
    for (final range2 in list2) {
      if (range1.overlaps(range2)) return true;
    }
  }

  return false;
}