public void testTraversalOrder()
{
for (var r = 0; r < 4; ++r)
{
for (var i = 0; i < 4; ++i)
{
// Check consistency with respect to swapping axes.
assertEquals(S2.IjToPos(r, i),
S2.IjToPos(r ^ S2.SwapMask, swapAxes(i)));
assertEquals(S2.PosToIj(r, i),
swapAxes(S2.PosToIj(r ^ S2.SwapMask, i)));
// Check consistency with respect to reversing axis directions.
assertEquals(S2.IjToPos(r, i),
S2.IjToPos(r ^ S2.InvertMask, invertBits(i)));
assertEquals(S2.PosToIj(r, i),
invertBits(S2.PosToIj(r ^ S2.InvertMask, i)));
// Check that the two tables are inverses of each other.
assertEquals(S2.IjToPos(r, S2.PosToIj(r, i)), i);
assertEquals(S2.PosToIj(r, S2.IjToPos(r, i)), i);
}
}
}