/** Turns a List<CubicCurve2D.Float> into a SVG Element representing a sketch of that spline. */
Element splineToSketch(SVGDocument document, List<CubicCurve2D.Float> spline) {
String svgNS = SVGDOMImplementation.SVG_NAMESPACE_URI;
// <g> is an SVG group
// TODO: add a random(ish) rotation to the group
Element group = document.createElementNS(svgNS, "g");
// For each curve in the path, draw along it using a "brush". In
// our case the brush is a simple circle, but this could be changed
// to something more advanced.
for (CubicCurve2D.Float curve : spline) {
// TODO: magic number & step in loop guard
for (double i = 0.0; i <= 1.0; i += 0.01) {
Point2D result = evalParametric(curve, i);
// Add random jitter at some random positive or negative
// distance along the unit normal to the tangent of the
// curve
Point2D n = vectorUnitNormal(evalParametricTangent(curve, i));
float dx = (float) ((Math.random() - 0.5) * n.getX());
float dy = (float) ((Math.random() - 0.5) * n.getY());
Element brush = document.createElementNS(svgNS, "circle");
brush.setAttribute("cx", Double.toString(result.getX() + dx));
brush.setAttribute("cy", Double.toString(result.getY() + dy));
// TODO: magic number for circle radius
brush.setAttribute("r", Double.toString(1.0));
brush.setAttribute("fill", "green");
brush.setAttributeNS(null, "z-index", Integer.toString(zOrder.CONTOUR.ordinal()));
group.appendChild(brush);
}
}
return group;
}
