private static BezierCurve[] ApproximateCircle(Point2D center, double radius) {
// The circle is split into 4 sectors. Arc of each sector
// is approximated with bezier curve separately.
BezierCurve[] approximation = new BezierCurve[4];
double x = center.GetX();
double y = center.GetY();
approximation[0] = new BezierCurve(new List<Point2D>(new Point2D[] {
new Point2D.Double(x, y + radius),
new Point2D.Double(x + radius * circleApproximationConst, y + radius),
new Point2D.Double(x + radius, y + radius * circleApproximationConst),
new Point2D.Double(x + radius, y)
}));
approximation[1] = new BezierCurve(new List<Point2D>(new Point2D[] {
new Point2D.Double(x + radius, y),
new Point2D.Double(x + radius, y - radius * circleApproximationConst),
new Point2D.Double(x + radius * circleApproximationConst, y - radius),
new Point2D.Double(x, y - radius)
}));
approximation[2] = new BezierCurve(new List<Point2D>(new Point2D[] {
new Point2D.Double(x, y - radius),
new Point2D.Double(x - radius * circleApproximationConst, y - radius),
new Point2D.Double(x - radius, y - radius * circleApproximationConst),
new Point2D.Double(x - radius, y)
}));
approximation[3] = new BezierCurve(new List<Point2D>(new Point2D[] {
new Point2D.Double(x - radius, y),
new Point2D.Double(x - radius, y + radius * circleApproximationConst),
new Point2D.Double(x - radius * circleApproximationConst, y + radius),
new Point2D.Double(x, y + radius)
}));
return approximation;
}
private void WriteBezierCurve(BezierCurve curve, PdfContentByte canvas) {
IList<Point2D> basePoints = curve.GetBasePoints();
Point2D p2 = basePoints[1];
Point2D p3 = basePoints[2];
Point2D p4 = basePoints[3];
new PdfNumber(p2.GetX()).ToPdf(canvas.PdfWriter, canvas.InternalBuffer);
canvas.InternalBuffer.Append(' ');
new PdfNumber(p2.GetY()).ToPdf(canvas.PdfWriter, canvas.InternalBuffer);
canvas.InternalBuffer.Append(' ');
new PdfNumber(p3.GetX()).ToPdf(canvas.PdfWriter, canvas.InternalBuffer);
canvas.InternalBuffer.Append(' ');
new PdfNumber(p3.GetY()).ToPdf(canvas.PdfWriter, canvas.InternalBuffer);
canvas.InternalBuffer.Append(' ');
new PdfNumber(p4.GetX()).ToPdf(canvas.PdfWriter, canvas.InternalBuffer);
canvas.InternalBuffer.Append(' ');
new PdfNumber(p4.GetY()).ToPdf(canvas.PdfWriter, canvas.InternalBuffer);
canvas.InternalBuffer.Append(c);
}
