keyPolygon function

RoundedPolygon keyPolygon(KeyGeometry geometry, double aspect)

The polygon for geometry at cell aspect (width / height), normalized into the unit square (the long side spans 0–1, the short side is centred).

Implementation

RoundedPolygon keyPolygon(KeyGeometry geometry, double aspect) {
  final a = aspect.isFinite && aspect > 0 ? aspect : 1.0;
  final shortSide = math.min(a, 1);
  RoundedPolygon rect(double radiusFraction, {double smoothing = 0}) =>
      RoundedPolygon.rectangle(
        width: a,
        height: 1,
        rounding: CornerRounding(
          radius: radiusFraction.clamp(0.0, 0.5) * shortSide,
          smoothing: smoothing,
        ),
        centerX: a / 2,
        centerY: 0.5,
      );
  RoundedPolygon stretched(RoundedPolygon unit) =>
      _normalize(unit).transformed((x, y) => (x * a, y));

  final f = geometry.cornerFraction;
  final polygon = switch (geometry.kind) {
    KeyShapeKind.circle || KeyShapeKind.pill => rect(0.5),
    KeyShapeKind.roundedRect ||
    KeyShapeKind.keycap ||
    KeyShapeKind.stepped => rect(f),
    KeyShapeKind.squircle => rect(f, smoothing: 0.6),
    KeyShapeKind.hexagon => stretched(
      RoundedPolygon.fromVerticesNum(
        6,
        radius: 0.5,
        centerX: 0.5,
        centerY: 0.5,
        rounding: CornerRounding(radius: f * 0.5),
      ),
    ),
    KeyShapeKind.cut => _cutRect(a, f * shortSide),
    KeyShapeKind.m3eMorph => switch (geometry.m3eShape) {
      null || M3eShape.circle || M3eShape.pill => rect(0.5),
      M3eShape.square => rect(0.3),
      final shape => stretched(materialShape(shape)),
    },
  };
  return _normalize(polygon);
}