// Two boundary points known
Circle *makeCircleTwoPoints(vector<Point> &points, int fromIdx, int toIdx, Point p, Point q) {
Circle *temp = makeDiameter(p, q);
bool ContainsAll=1;
for(int i = fromIdx; i < toIdx; ++i) if(!temp->contains(points[i])){
ContainsAll = 0;
break;
}
if (ContainsAll) return temp;
Circle *left = NULL;
Circle *right = NULL;
for (int i = fromIdx; i < toIdx; ++i) {
Point r = points[i];
Point pq = q.subtract(p);
double cross = pq.cross(r.subtract(p));
Circle *c = makeCircumcircle(p, q, r);
if (c == NULL)
continue;
else if (cross > 0 && (left == NULL || pq.cross(c->c.subtract(p)) > pq.cross(left->c.subtract(p))))
left = c;
else if (cross < 0 && (right == NULL || pq.cross(c->c.subtract(p)) < pq.cross(right->c.subtract(p))))
right = c;
}
return right == NULL || (left != NULL && left->r) <= right->r ? left : right;
}
/*
* Returns the smallest circle that encloses all the given points. Runs in expected O(n) time, randomized.
* Note: If 0 points are given, null is returned. If 1 point is given, a circle of radius 0 is returned.
*/
Circle *makeCircle(vector<Point> points) {
random_shuffle(points.begin(),points.end());
Circle *c = NULL;
for (int i = 0; i < points.size(); i++) {
Point p = points[i];
if (c == NULL || !c->contains(p))
c = makeCircleOnePoint(points,0,i, p);
}
return c;
}
Circle *makeCircleOnePoint(vector<Point> &points, int fromIdx, int toIdx, Point p) {
Circle *c = new Circle(p, 0);
for (int i = fromIdx; i < toIdx; i++) {
Point q = points[i];
if (!c->contains(q)) {
if (c->r == 0)
c = makeDiameter(p, q);
else
c = makeCircleTwoPoints(points,0,i, p, q);
}
}
return c;
}
bool H2Geodesic::contains(const H2Point & p) const
{
if (isCircleInDiskModel())
{
Circle C;
getCircleInDiskModel(C);
return C.contains(p.getDiskCoordinate());
}
else
{
PlanarLine L;
getLineInDiskModel(L);
return L.contains(p.getDiskCoordinate());
}
}
