/// <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));
}
}
}
// Returns true if the given shape contains the given point. Most clients
// should not use this method, since its running time is linear in the number
// of shape edges. Instead clients should create an S2ShapeIndex and use
// S2ContainsPointQuery, since this strategy is much more efficient when many
// points need to be tested.
//
// Polygon boundaries are treated as being semi-open (see S2ContainsPointQuery
// and S2VertexModel for other options).
//
// CAVEAT: Typically this method is only used internally. Its running time is
// linear in the number of shape edges.
public static bool ContainsBruteForce(this S2Shape shape, S2Point point)
{
if (shape.Dimension() < 2)
{
return(false);
}
var ref_point = shape.GetReferencePoint();
if (ref_point.Point == point)
{
return(ref_point.Contained);
}
S2CopyingEdgeCrosser crosser = new(ref_point.Point, point);
bool inside = ref_point.Contained;
for (int e = 0; e < shape.NumEdges(); ++e)
{
var edge = shape.GetEdge(e);
inside ^= crosser.EdgeOrVertexCrossing(edge.V0, edge.V1);
}
return(inside);
}