// Overwrites "vertices" with the vertices of the given edge chain of "shape".
// If dimension == 1, the chain will have (chain.length + 1) vertices, and
// otherwise it will have (chain.length) vertices.
//
// This is a low-level helper method used in the implementations of some of
// the methods above.
public static void GetChainVertices(S2Shape shape, int chain_id, out S2Point[] vertices)
{
S2Shape.Chain chain = shape.GetChain(chain_id);
int num_vertices = chain.Length + (shape.Dimension() == 1 ? 1 : 0);
int e = 0;
var verts = new List <S2Point>();
if ((num_vertices & 1) != 0)
{
verts.Add(shape.ChainEdge(chain_id, e++).V0);
}
for (; e < num_vertices; e += 2)
{
var edge = shape.ChainEdge(chain_id, e);
verts.Add(edge.V0);
verts.Add(edge.V1);
}
vertices = verts.ToArray();
}
/// <summary>
/// Verifies that all methods of the two S2Shapes return identical results,
/// except for id() and type_tag().
/// </summary>
public static void ExpectEqual(S2Shape a, S2Shape b)
{
Assert.True(a.NumEdges() == b.NumEdges());
for (int i = 0; i < a.NumEdges(); ++i)
{
Assert.Equal(a.GetEdge(i), b.GetEdge(i));
Assert.True(a.GetChainPosition(i) == b.GetChainPosition(i));
}
Assert.True(a.Dimension() == b.Dimension());
Assert.True(a.GetReferencePoint() == b.GetReferencePoint());
Assert.True(a.NumChains() == b.NumChains());
for (int i = 0; i < a.NumChains(); ++i)
{
Assert.True(a.GetChain(i) == b.GetChain(i));
int chain_length = a.GetChain(i).Length;
for (int j = 0; j < chain_length; ++j)
{
Assert.True(a.ChainEdge(i, j) == b.ChainEdge(i, j));
}
}
}