/**
* Transforms this circle by an affine transform. If the transformed shape is a circle (ellipse
* with equal axis lengths), returns an instance of Circle2D. The resulting ellipse is direct if
* this ellipse and the transform are either both direct or both indirect.
*/
public EllipseShape2D transform(AffineTransform2D trans) {
// When the transform is not a similarity, should switch to EllipseArc
// computation
if (!AffineTransform2D.isSimilarity(trans)) {
return this.asEllipse().transform(trans);
}
// If transform is a similarity, the result is a circle
Point2D center = this.center().transform(trans);
Point2D p1 = this.firstPoint().transform(trans);
boolean direct = !this.direct ^ trans.isDirect();
Circle2D result = new Circle2D(center, center.distance(p1), direct);
return result;
}
@Override
public Ray2D transform(AffineTransform2D trans) {
double[] tab = trans.coefficients();
double x1 = x0 * tab[0] + y0 * tab[1] + tab[2];
double y1 = x0 * tab[3] + y0 * tab[4] + tab[5];
return new Ray2D(x1, y1, dx * tab[0] + dy * tab[1], dx * tab[3] + dy * tab[4]);
}
@Override
public void update() {
this.defined = false;
// check parents are defined
if (!parent1.isDefined()) return;
if (!parent2.isDefined()) return;
Shape2D shape;
// extract first point
shape = parent1.getShape();
if (!(shape instanceof Point2D)) return;
Point2D point1 = (Point2D) shape;
// extract second point
shape = parent2.getShape();
if (!(shape instanceof Point2D)) return;
Point2D point2 = (Point2D) shape;
// update distance measure
this.trans =
AffineTransform2D.createTranslation(
point2.getX() - point1.getX(), point2.getY() - point1.getY());
this.defined = true;
}
/*
* (non-Javadoc)
*
* @see math.geom2d.Shape2D#transform(math.geom2d.AffineTransform2D)
*/
public EllipseArc2D transform(AffineTransform2D trans) {
// transform supporting ellipse
Ellipse2D ell = ellipse.transform(trans);
// ensure ellipse is direct
if (!ell.isDirect()) ell = ell.reverse();
// Compute position of end points on the transformed ellipse
double startPos = ell.project(this.firstPoint().transform(trans));
double endPos = ell.project(this.lastPoint().transform(trans));
// Compute the new arc
boolean direct = !(angleExtent > 0 ^ trans.isDirect());
return new EllipseArc2D(ell, startPos, endPos, direct);
}