Пример #1
0
bool earQ(int i, int j, int k, const polygon& p)
{
	triangle t(p.vec_points[i], p.vec_points[k], p.vec_points[k]);
	if (cw(p.vec_points[i], p.vec_points[j], p.vec_points[k]))
		return false;
	
	for (int m = 0; m < p.get_n(); m++) {
		if ((m != i) && (m != j) && (m != k))
			if (t.contains(p.vec_points[m]))
				return false;
	}
	return true;
}
Пример #2
0
///////////////////////////////////////////////////////////////////////////
// triangulation implementation
///////////////////////////////////////////////////////////////////////////
triangulation::triangulation(const polygon& p) {
	int n = p.get_n();
	vector<int> vleft(n),	// left neighbor indices
					vright(n);	// rigth neighbor indices
	for (int j = 0; j < n; j++) {
		vleft[j] = ((j-1) + n) % n;
		vright[j] = ((j+1) + n) % n;
	}
	int i = n - 1;
	while ((int)vec_triangles.size() < (n-2)) {
		i = vright[i];
		if (earQ(vleft[i], i, vright[i], p)) {
			triangle t(p.vec_points[vleft[i]], p.vec_points[i], p.vec_points[vright[i]]);
			vec_triangles.push_back(t);
			vleft[vright[i]] = vleft[i];
			vright[vleft[i]] = vright[i];
		}
	}
}