Пример #1
0
bool polygonCollision( polygon & poly1, polygon & poly2 )
{
	polyIterator itr1 = poly1.begin();
	int intersectionCount = 0;
	
	while( itr1 != poly1.end() )
	{
		polyIterator itr2 = poly2.begin();
		while( itr2 != poly2.end() )
		{
			point intersection = itr1->checkIntersection( *itr2 );
			if ( itr1->isPointOnLine( intersection ) )
			{
				intersectionCount++;
				if( intersectionCount >= 8 )
				{
					return true;
				}
			}
			++itr2;
		}
		++itr1;
	}	
	return false;
}
Пример #2
0
void convex_hull(polygon in, polygon& hull){
	hull.clear();
	
	if(in.size() < 3){ hull = in; return; }
	
	int pos = 0;
	for(int i = 1; i < in.size(); i++) if(in[i] < in[pos]) pos = i;
	swap(in[0], in[pos]);
	refer = in[0];
	
	sort(in.begin() + 1, in.end(), cmp_angle);
	in.resize(unique(in.begin(), in.end()) - in.begin());
	
	hull.push_back(in[0]); hull.push_back(in[1]);
	
	in.push_back(in[0]); //isto evita pontos colineares no final do poligono
	for(int i = 2; i < in.size(); ){
		if(hull.size() > 2 && side_sign(hull[hull.size() - 2], hull[hull.size() - 1], in[i]) <= 0){
			hull.pop_back();
		}
		else hull.push_back(in[i++]);
	}
	//tira a duplicata
	hull.pop_back();
}
Пример #3
0
// Returns a list of points on the convex hull in counter-clockwise order.
// NOTE: the last point in the returned list is the same as the first one.
void convex_hull_2(polygon P, polygon& hull) {
	hull.clear();
	
	// Sort points lexicographically
	sort(P.begin(), P.end());
	P.resize(unique(P.begin(), P.end()) - P.begin());
	
	// Build lower hull
	for (int i = 0; i < P.size(); i ++) {
		while (hull.size() >= 2 && side_sign(hull[hull.size() - 2], hull[hull.size() - 1], P[i]) <= 0)
			hull.pop_back();
		hull.push_back(P[i]);
	};
 
	// Build upper hull
	for (int i = P.size()-2, t = hull.size() + 1; i >= 0; i --) {
		while (hull.size() >= t && side_sign(hull[hull.size()-2], hull[hull.size()-1], P[i]) <= 0)
			hull.pop_back();
		hull.push_back(P[i]);
	};
}
Пример #4
0
bool linePolyCollision( line & testLine, polygon & testPoly)
{
	// 2 intersections should be a collision
	polyIterator itr = testPoly.begin();
	int collCounter = 0;
	int pointCount = 1;
	while( itr != testPoly.end() )
	{
		point collPoint = testLine.checkIntersection( *itr );
		if ( testLine.isPointOnLine( collPoint ) )
		{
			collCounter++;
		}
		++itr;
		pointCount++;
	}

	if( collCounter > 1 )
	{
		return true;
	}
	return false;
}
Пример #5
0
pair<polygon, polygon> split(polygon & P, int k) {
    polygon p1(P.begin(), P.begin() + k);
    polygon p2(P.begin() + k, P.end());
    return {p1, p2};
}