long double minimum_enclosing_circle(polygon_t &convex_hull)
{
if (convex_hull.size() <= 1) return 0;
if (convex_hull.size() == 2) return distance_square(convex_hull[0], convex_hull[1]) / 4.0;
point_t s_a = convex_hull[0];
point_t s_b = convex_hull[1];
while (1) {
long double alpha = 100;
point_t v;
for (polygon_t::iterator p = convex_hull.begin(); p != convex_hull.end(); p++) {
if (*p == s_a || *p == s_b) continue;
long double a = angle(*p, s_a, s_b);
if (a < alpha) {
alpha = a;
v = *p;
}
}
if (alpha >= M_PI / 2) return distance_square(s_a, s_b) / 4.0;
// printf("s_a:(%ld, %ld) s_b:(%ld, %ld) v:(%ld, %ld)\n", s_a.first, s_a.second, s_b.first, s_b.second, v.first, v.second);
// printf("angle v-s_a-s_b: %Lf\n", angle(s_a, v, s_b));
if (angle(s_a, v, s_b) >= M_PI / 2) {
s_a = v;
continue;
}
// printf("angle v-s_b-s_a: %Lf\n", angle(s_b, v, s_a));
if (angle(s_b, v, s_a) >= M_PI / 2) {
s_b = v;
continue;
}
/* v, s_a, s_b */
fpoint_t center = find_center(v, s_a, s_b);
// printf("center: %Lf, %Lf\n", center.first, center.second);
// printf("%Lf = %Lf, %Lf\n", distance_square(center, v), distance_square(center, s_a), distance_square(center, s_b));
return distance_square(center, v);
}
}
bool inside_polygon(polygon_t &polygon, point_t point)
{
if (polygon.size() == 0) return false;
for (polygon_t::iterator p = polygon.begin(); p < polygon.end(); p++)
if (*p == point) return true;
if (polygon.size() == 1) return false;
long double total_area = area(polygon);
long double sub_area = 0;
for (unsigned i = 0; i < polygon.size(); i++) {
point_t a = point;
point_t b = polygon[i];
point_t c = polygon[(i + 1) % polygon.size()];
sub_area += fabsl((a.first * b.second + b.first * c.second + c.first * a.second) - (a.second * b.first + b.second * c.first + c.second * a.first)) / 2.0;
}
return (fabsl(total_area - sub_area) < 1e-10L);
}
circle_camera(int playerid, const polygon_t& hexagon) : playerid(playerid), hexagon(hexagon)
{
iter = hexagon.begin();
}