public void Test_S2LatLng_NegativeZeros()
{
Assert.True(IsIdentical(
S2LatLng.Latitude(new S2Point(1.0, 0.0, -0.0)).Radians, +0.0));
Assert.True(IsIdentical(
S2LatLng.Longitude(new S2Point(1.0, -0.0, 0.0)).Radians, +0.0));
Assert.True(IsIdentical(
S2LatLng.Longitude(new S2Point(-1.0, -0.0, 0.0)).Radians, S2.M_PI));
Assert.True(IsIdentical(
S2LatLng.Longitude(new S2Point(-0.0, 0.0, 1.0)).Radians, +0.0));
Assert.True(IsIdentical(
S2LatLng.Longitude(new S2Point(-0.0, -0.0, 1.0)).Radians, +0.0));
}
public void Test_RectBounder_MaxLatitudeRandom()
{
// Check that the maximum latitude of edges is computed accurately to within
// 3 * S2Constants.DoubleEpsilon (the expected maximum error). We concentrate on maximum
// latitudes near the equator and north pole since these are the extremes.
const int kIters = 100;
for (int iter = 0; iter < kIters; ++iter)
{
// Construct a right-handed coordinate frame (U,V,W) such that U points
// slightly above the equator, V points at the equator, and W is slightly
// offset from the north pole.
S2Point u = S2Testing.RandomPoint();
u = new S2Point(u.X, u.Y, S2.DoubleEpsilon * 1e-6 * Math.Pow(1e12, S2Testing.Random.RandDouble())); // log is uniform
u = u.Normalize();
S2Point v = S2.RobustCrossProd(new S2Point(0, 0, 1), u).Normalize();
S2Point w = S2.RobustCrossProd(u, v).Normalize();
// Construct a line segment AB that passes through U, and check that the
// maximum latitude of this segment matches the latitude of U.
S2Point a = (u - S2Testing.Random.RandDouble() * v).Normalize();
S2Point b = (u + S2Testing.Random.RandDouble() * v).Normalize();
S2LatLngRect ab_bound = GetEdgeBound(a, b);
Assert2.Near(S2LatLng.Latitude(u).Radians,
ab_bound.Lat.Hi, kRectError.LatRadians);
// Construct a line segment CD that passes through W, and check that the
// maximum latitude of this segment matches the latitude of W.
S2Point c = (w - S2Testing.Random.RandDouble() * v).Normalize();
S2Point d = (w + S2Testing.Random.RandDouble() * v).Normalize();
S2LatLngRect cd_bound = GetEdgeBound(c, d);
Assert2.Near(S2LatLng.Latitude(w).Radians,
cd_bound.Lat.Hi, kRectError.LatRadians);
}
}
