/* (non-Javadoc)
* @see math.geom2d.circulinear.CirculinearCurve2D#transform(math.geom2d.transform.CircleInversion2D)
*/
public CircleLine2D transform(CircleInversion2D inv) {
// Extract inversion parameters
Point2D center = inv.center();
Point2D c1 = this.center();
// If circles are concentric, creates directly the new circle
if (center.distance(c1) < Shape2D.ACCURACY) {
double r0 = inv.radius();
double r2 = r0 * r0 / this.r;
return new Circle2D(center, r2, this.direct);
}
// line joining centers of the two circles
StraightLine2D centersLine = new StraightLine2D(center, c1);
// get the two intersection points with the line joining the circle centers
Collection<Point2D> points = this.intersections(centersLine);
if (points.size() < 2) {
throw new RuntimeException(
"Intersection of circle with line through center has less than 2 points");
}
Iterator<Point2D> iter = points.iterator();
Point2D p1 = iter.next();
Point2D p2 = iter.next();
// If the circle contains the inversion center, it transforms into a
// straight line
if (this.distance(center) < Shape2D.ACCURACY) {
// choose the intersection point that is not the center
double dist1 = center.distance(p1);
double dist2 = center.distance(p2);
Point2D p0 = dist1 < dist2 ? p2 : p1;
// transform the point, and return the perpendicular
p0 = p0.transform(inv);
return StraightLine2D.createPerpendicular(centersLine, p0);
}
// For regular cases, the circle transforms into an other circle
// transform the two extreme points of the circle,
// resulting in a diameter of the new circle
p1 = p1.transform(inv);
p2 = p2.transform(inv);
// compute center and diameter of transformed circle
double diam = p1.distance(p2);
c1 = Point2D.midPoint(p1, p2);
// create the transformed circle
boolean direct = !this.isDirect() ^ this.isInside(inv.center());
return new Circle2D(c1, diam / 2, direct);
}
/*
* (non-Javadoc)
*
* @see math.geom2d.Shape2D#transform(math.geom2d.AffineTransform2D)
*/
public PointArray2D transform(AffineTransform2D trans) {
PointArray2D res = new PointArray2D(points.size());
for (Point2D point : points) res.add(point.transform(trans));
return res;
}
public PointArray2D transform(CircleInversion2D inv) {
PointArray2D array = new PointArray2D(points.size());
for (Point2D point : points) array.add(point.transform(inv));
return array;
}
