draw method

void draw(Canvas canvas, Paint paint, Size size)

Implementation

void draw(Canvas canvas, Paint paint, Size size) {
  final double cX = size.width;
  final double cY = size.height;

  paint.shader = Utils.createShader(cX, cY, _colors, angle: _angle[0]);

  _path.reset();

  if (_stub) _loadStubWaves();

  if (_animateToAmplitude != _amplitude) {
    _amplitude += _animateAmplitudeDiff * 16;
    if (_animateAmplitudeDiff > 0) {
      if (_amplitude > _animateToAmplitude) {
        _amplitude = _animateToAmplitude;
      }
    } else {
      if (_amplitude < _animateToAmplitude) {
        _amplitude = _animateToAmplitude;
      }
    }
  }

  _update(_amplitude, _stub ? 0.1 : 0.8);

  for (int i = 0; i < N; i++) {
    List<v.Vector4> pointStart = [];
    List<v.Vector4> pointEnd = [];

    double progress = _progress[i];
    int nextIndex = i + 1 < N ? i + 1 : 0;
    double progressNext = _progress[nextIndex];
    double r1 = _radius[i] * (1.0 - progress) + _radiusNext[i] * progress;
    double r2 = _radius[nextIndex] * (1.0 - progressNext) +
        _radiusNext[nextIndex] * progressNext;
    double angle1 = _angle[i] * (1.0 - progress) + _angleNext[i] * progress;
    double angle2 = _angle[nextIndex] * (1 - progressNext) +
        _angleNext[nextIndex] * progressNext;

    double l = L * (min(r1, r2) + (max(r1, r2) - min(r1, r2)) / 2.0);

    var sp1 = Utils.transformPoint(
        v.Vector4(cX, cY - r1, 0.0, 1.0), cX, cY, angle1);
    pointStart.add(sp1);

    var sp2 = Utils.transformPoint(
        v.Vector4(cX + l, cY - r1, 0.0, 1.0), cX, cY, angle1);
    pointStart.add(sp2);

    var ep1 = Utils.transformPoint(
        v.Vector4(cX, cY - r2, 0.0, 1.0), cX, cY, angle2);
    pointEnd.add(ep1);

    var ep2 = Utils.transformPoint(
        v.Vector4(cX - l, cY - r2, 0.0, 1.0), cX, cY, angle2);
    pointEnd.add(ep2);

    if (i == 0) {
      _path.moveTo(pointStart[0].x, pointStart[0].y);
    }

    _path.cubicTo(
      pointStart[1].x,
      pointStart[1].y,
      pointEnd[1].x,
      pointEnd[1].y,
      pointEnd[0].x,
      pointEnd[0].y,
    );
  }

  canvas.save();
  canvas.translate(cX, cY);
  canvas.scale(_autoScale ? _findWaveScale() : _scale);
  canvas.translate(-cX, -cY);
  canvas.drawPath(_path, paint);
  canvas.restore();
}