@Override
protected boolean operateInternal(Set<Triangle> triangles) {
Triangle winner = random.choice(triangles);
float perfectness =
new BigDecimal("2").divide(winner.perfectness(), MathContext.DECIMAL128).floatValue();
float myRate = Math.max(perfectness, rate);
if (!random.rate(myRate)) {
return false;
}
for (Triangle t : triangles) {
if (t == winner) {
continue;
}
Segment common = TriangleUtils.segmentInCommon(winner, t);
if (common != null) {
boolean swapped = swap(triangles, winner, t, common);
return swapped;
}
}
return false;
}
public static boolean swap(Set<Triangle> triangles, Triangle a, Triangle b, Segment common) {
Point otherOfA = otherOf(a, common);
Point otherOfB = otherOf(b, common);
Line ab = Line.defineByPoints(otherOfA, otherOfB);
if (ab.distance(common.getP1()).doubleValue() < 0.001
|| ab.distance(common.getP2()).doubleValue() < 0.001) {
return false;
}
Triangle t1;
Triangle t2;
if (TriangleUtils.counterClockwise(otherOfA, otherOfB, common.getP1()) < 0) {
t1 = new Triangle(otherOfA, otherOfB, common.getP1());
t2 = new Triangle(otherOfA, common.getP2(), otherOfB);
} else {
t1 = new Triangle(otherOfB, otherOfA, common.getP1());
t2 = new Triangle(otherOfB, common.getP2(), otherOfA);
}
BigDecimal oldArea = a.area().add(b.area(), DECIMAL128).setScale(MY_SCALE, MY_RND);
BigDecimal newArea = t1.area().add(t2.area(), DECIMAL128).setScale(MY_SCALE, MY_RND);
if (oldArea.compareTo(newArea) == 0) {
triangles.remove(a);
triangles.remove(b);
triangles.add(t1);
triangles.add(t2);
return true;
}
return false;
}