Add a comment to LatLngFromDegrees.
s2: Implement CellIDFromToken and CellID.ToToken.
r1: Add Interval.ClampPoint, Interval.Union, Interval.ApproxEqual.

Signed-off-by: David Symonds <dsymonds@golang.org>
r3: Add Vector.Norm2.

Signed-off-by: David Symonds <dsymonds@golang.org>
s2: Add Point.ApproxEqual.

Signed-off-by: David Symonds <dsymonds@golang.org>
r2: New package with Point and Rect types.

Signed-off-by: David Symonds <dsymonds@golang.org>
r3: Add Vector.IsUnit

Signed-off-by: David Symonds <dsymonds@golang.org>
Add uNorm, vNorm and tests to the stuv util file.
Add siTiToST conversion method.

Signed-off-by: David Symonds <dsymonds@golang.org>
s2: Add Cap type.

Signed-off-by: David Symonds <dsymonds@golang.org>
s2: Add ChildBegin/ChildEnd family of methods.

Signed-off-by: David Symonds <dsymonds@golang.org>
s2: Add Cell type.

Add a couple of methods to s2.CellID that are needed for that.

Signed-off-by: David Symonds <dsymonds@golang.org>
s2: Add PointArea function for computing the area of a triangle.

	BenchmarkPointArea              10000000        240 ns/op
	BenchmarkPointAreaGirardCase    10000000        275 ns/op

Signed-off-by: David Symonds <dsymonds@golang.org>
s2: Add RobustSign and OrderedCCW functions.

Signed-off-by: David Symonds <dsymonds@golang.org>
s2: Define the Region interface.

This is currently satisfied by Cap, Cell, CellUnion and Rect.

Signed-off-by: David Symonds <dsymonds@golang.org>
Fix polar point test.
s2: Port some testing helper methods.

This includes the string parsing of textual lat/lng sets,
helper methods to make s2.Point and s2.Rect from those strings, and
some of the random methods from the C++ implementations to
maintain some similar level of performance and functionality when
comparing C++ and Go test results.

Signed-off-by: David Symonds <dsymonds@golang.org>
s2: Add EmptyRect and some more test cases.

Signed-off-by: David Symonds <dsymonds@golang.org>
s2: Add Cap.RectBound.

Signed-off-by: David Symonds <dsymonds@golang.org>
Add gitignore
Add LICENSE