/**
* Simple polygon intersection test.
*
* <p>FIXME: while this is found on some web pages as "solution" and satisfies or needs, it
* clearly is not correct; not even for convex polygons: Consider a cross where the two bars are
* made out of four vertices each. No vertex is inside the other polygon, yet they intersect.
*
* <p>I knew this before writing this code, but this O(n) code was the simplest thing to come up
* with, and it would work for our current data sets. A way to fix this is to augment it with the
* obvious O(n*n) segment intersection test. (Note that you will still need to test for point
* containment, since the whole polygon could be contained in the other!)
*
* @param other Other polygon
* @return True when the polygons intersect
*/
public boolean intersects2DIncomplete(Polygon other) {
assert (this.getDimensionality() == 2);
assert (other.getDimensionality() == 2);
for (Vector v : this.points) {
if (other.containsPoint2D(v)) {
return true;
}
}
for (Vector v : other.points) {
if (this.containsPoint2D(v)) {
return true;
}
}
return false;
}
@Override
public void fullRedraw() {
setupCanvas();
final StyleLibrary style = context.getStyleLibrary();
CSSClass css = new CSSClass(svgp, POLYS);
// TODO: separate fill and line colors?
css.setStatement(
SVGConstants.CSS_STROKE_WIDTH_PROPERTY, style.getLineWidth(StyleLibrary.POLYGONS));
css.setStatement(SVGConstants.CSS_STROKE_PROPERTY, style.getColor(StyleLibrary.POLYGONS));
css.setStatement(SVGConstants.CSS_FILL_PROPERTY, SVGConstants.CSS_NONE_VALUE);
svgp.addCSSClassOrLogError(css);
svgp.updateStyleElement();
// draw data
for (DBIDIter iditer = rep.iterDBIDs(); iditer.valid(); iditer.advance()) {
try {
PolygonsObject poly = rep.get(iditer);
if (poly == null) {
continue;
}
SVGPath path = new SVGPath();
for (Polygon ppoly : poly.getPolygons()) {
Vector first = ppoly.get(0);
double[] f = proj.fastProjectDataToRenderSpace(first.getArrayRef());
path.moveTo(f[0], f[1]);
for (ArrayListIter<Vector> it = ppoly.iter(); it.valid(); it.advance()) {
if (it.getOffset() == 0) {
continue;
}
double[] p = proj.fastProjectDataToRenderSpace(it.get().getArrayRef());
path.drawTo(p[0], p[1]);
}
// close path.
path.drawTo(f[0], f[1]);
}
Element e = path.makeElement(svgp);
SVGUtil.addCSSClass(e, POLYS);
layer.appendChild(e);
} catch (ObjectNotFoundException e) {
// ignore.
}
}
}
