/** Determines whether two line segments intersect. **/ public static final boolean linesIntersect(final double aX0, final double aY0, final double aX1, final double aY1, final double bX0, final double bY0, final double bX1, final double bY1) { return (area(aX0, aY0, aX1, aY1, bX0, bY0) > 0) != (area(aX0, aY0, aX1, aY1, bX1, bY1) > 0) && (area(bX0, bY0, bX1, bY1, aX0, aY0) > 0) != (area(bX0, bY0, bX1, bY1, aX1, aY1) > 0); }
private static final boolean isLocallyInside(final Node a, final Node b) { // if a is cw if (area(a.previous.getX(), a.previous.getY(), a.getX(), a.getY(), a.next.getX(), a.next.getY()) < 0) { return area(a.getX(), a.getY(), b.getX(), b.getY(), a.next.getX(), a.next.getY()) >= 0 && area(a.getX(), a.getY(), a.previous.getX(), a.previous.getY(), b.getX(), b.getY()) >= 0; } // ccw return area(a.getX(), a.getY(), b.getX(), b.getY(), a.previous.getX(), a.previous.getY()) < 0 || area(a.getX(), a.getY(), a.next.getX(), a.next.getY(), b.getX(), b.getY()) < 0; }
nextNode = currEar.next; final boolean isReflex = area(prevNode.getX(), prevNode.getY(), currEar.getX(), currEar.getY(), nextNode.getX(), nextNode.getY()) >= 0; if (isReflex == false && isEar(currEar, mortonOptimized) == true) {
prevNode = node.previous; if (node.isSteiner == false && isVertexEquals(node, nextNode) || area(prevNode.getX(), prevNode.getY(), node.getX(), node.getY(), nextNode.getX(), nextNode.getY()) == 0) {
/** Determines whether a polygon node forms a valid ear with adjacent nodes. **/ private static final boolean isEar(final Node ear, final boolean mortonOptimized) { if (mortonOptimized == true) { return mortonIsEar(ear); } // make sure there aren't other points inside the potential ear Node node = ear.next.next; while (node != ear.previous) { if (pointInEar(node.getX(), node.getY(), ear.previous.getX(), ear.previous.getY(), ear.getX(), ear.getY(), ear.next.getX(), ear.next.getY()) && area(node.previous.getX(), node.previous.getY(), node.getX(), node.getY(), node.next.getX(), node.next.getY()) >= 0) { return false; } node = node.next; } return true; }
if (p.idx != ear.previous.idx && p.idx != ear.next.idx && pointInEar(p.getX(), p.getY(), ear.previous.getX(), ear.previous.getY(), ear.getX(), ear.getY(), ear.next.getX(), ear.next.getY()) && area(p.previous.getX(), p.previous.getY(), p.getX(), p.getY(), p.next.getX(), p.next.getY()) >= 0) return false; p = p.previousZ; area(n.previous.getX(), n.previous.getY(), n.getX(), n.getY(), n.next.getX(), n.next.getY()) >= 0) return false; n = n.nextZ; if (p.idx != ear.previous.idx && p.idx != ear.next.idx && pointInEar(p.getX(), p.getY(), ear.previous.getX(), ear.previous.getY(), ear.getX(), ear.getY(), ear.next.getX(), ear.next.getY()) && area(p.previous.getX(), p.previous.getY(), p.getX(), p.getY(), p.next.getX(), p.next.getY()) >= 0) { return false; if (n.idx != ear.previous.idx && n.idx != ear.next.idx && pointInEar(n.getX(), n.getY(), ear.previous.getX(), ear.previous.getY(), ear.getX(), ear.getY(), ear.next.getX(), ear.next.getY()) && area(n.previous.getX(), n.previous.getY(), n.getX(), n.getY(), n.next.getX(), n.next.getY()) >= 0) { return false;