Grand test fixup (#138)

* start fixing up tests

* fix up tests + automate with drone

* fiddle with linting

* messing about with drone.yml

* some more fiddling

* hmmm

* add cache

* add vendor directory

* verbose

* ci updates

* update some little things

* update sig

vendor/github.com/golang/geo/s2/shape.go

@@ -0,0 +1,263 @@
+// Copyright 2017 Google Inc. All rights reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package s2
+
+import (
+	"sort"
+)
+
+// Edge represents a geodesic edge consisting of two vertices. Zero-length edges are
+// allowed, and can be used to represent points.
+type Edge struct {
+	V0, V1 Point
+}
+
+// Cmp compares the two edges using the underlying Points Cmp method and returns
+//
+//   -1 if e <  other
+//    0 if e == other
+//   +1 if e >  other
+//
+// The two edges are compared by first vertex, and then by the second vertex.
+func (e Edge) Cmp(other Edge) int {
+	if v0cmp := e.V0.Cmp(other.V0.Vector); v0cmp != 0 {
+		return v0cmp
+	}
+	return e.V1.Cmp(other.V1.Vector)
+}
+
+// sortEdges sorts the slice of Edges in place.
+func sortEdges(e []Edge) {
+	sort.Sort(edges(e))
+}
+
+// edges implements the Sort interface for slices of Edge.
+type edges []Edge
+
+func (e edges) Len() int           { return len(e) }
+func (e edges) Swap(i, j int)      { e[i], e[j] = e[j], e[i] }
+func (e edges) Less(i, j int) bool { return e[i].Cmp(e[j]) == -1 }
+
+// ShapeEdgeID is a unique identifier for an Edge within an ShapeIndex,
+// consisting of a (shapeID, edgeID) pair.
+type ShapeEdgeID struct {
+	ShapeID int32
+	EdgeID  int32
+}
+
+// Cmp compares the two ShapeEdgeIDs and returns
+//
+//   -1 if s <  other
+//    0 if s == other
+//   +1 if s >  other
+//
+// The two are compared first by shape id and then by edge id.
+func (s ShapeEdgeID) Cmp(other ShapeEdgeID) int {
+	switch {
+	case s.ShapeID < other.ShapeID:
+		return -1
+	case s.ShapeID > other.ShapeID:
+		return 1
+	}
+	switch {
+	case s.EdgeID < other.EdgeID:
+		return -1
+	case s.EdgeID > other.EdgeID:
+		return 1
+	}
+	return 0
+}
+
+// ShapeEdge represents a ShapeEdgeID with the two endpoints of that Edge.
+type ShapeEdge struct {
+	ID   ShapeEdgeID
+	Edge Edge
+}
+
+// Chain represents a range of edge IDs corresponding to a chain of connected
+// edges, specified as a (start, length) pair. The chain is defined to consist of
+// edge IDs {start, start + 1, ..., start + length - 1}.
+type Chain struct {
+	Start, Length int
+}
+
+// ChainPosition represents the position of an edge within a given edge chain,
+// specified as a (chainID, offset) pair. Chains are numbered sequentially
+// starting from zero, and offsets are measured from the start of each chain.
+type ChainPosition struct {
+	ChainID, Offset int
+}
+
+// A ReferencePoint consists of a point and a boolean indicating whether the point
+// is contained by a particular shape.
+type ReferencePoint struct {
+	Point     Point
+	Contained bool
+}
+
+// OriginReferencePoint returns a ReferencePoint with the given value for
+// contained and the origin point. It should be used when all points or no
+// points are contained.
+func OriginReferencePoint(contained bool) ReferencePoint {
+	return ReferencePoint{Point: OriginPoint(), Contained: contained}
+}
+
+// typeTag is a 32-bit tag that can be used to identify the type of an encoded
+// Shape. All encodable types have a non-zero type tag. The tag associated with
+type typeTag uint32
+
+const (
+	// Indicates that a given Shape type cannot be encoded.
+	typeTagNone        typeTag = 0
+	typeTagPolygon     typeTag = 1
+	typeTagPolyline    typeTag = 2
+	typeTagPointVector typeTag = 3
+	typeTagLaxPolyline typeTag = 4
+	typeTagLaxPolygon  typeTag = 5
+
+	// The minimum allowable tag for future user-defined Shape types.
+	typeTagMinUser typeTag = 8192
+)
+
+// Shape represents polygonal geometry in a flexible way. It is organized as a
+// collection of edges that optionally defines an interior. All geometry
+// represented by a given Shape must have the same dimension, which means that
+// an Shape can represent either a set of points, a set of polylines, or a set
+// of polygons.
+//
+// Shape is defined as an interface in order to give clients control over the
+// underlying data representation. Sometimes an Shape does not have any data of
+// its own, but instead wraps some other type.
+//
+// Shape operations are typically defined on a ShapeIndex rather than
+// individual shapes. An ShapeIndex is simply a collection of Shapes,
+// possibly of different dimensions (e.g. 10 points and 3 polygons), organized
+// into a data structure for efficient edge access.
+//
+// The edges of a Shape are indexed by a contiguous range of edge IDs
+// starting at 0. The edges are further subdivided into chains, where each
+// chain consists of a sequence of edges connected end-to-end (a polyline).
+// For example, a Shape representing two polylines AB and CDE would have
+// three edges (AB, CD, DE) grouped into two chains: (AB) and (CD, DE).
+// Similarly, an Shape representing 5 points would have 5 chains consisting
+// of one edge each.
+//
+// Shape has methods that allow edges to be accessed either using the global
+// numbering (edge ID) or within a particular chain. The global numbering is
+// sufficient for most purposes, but the chain representation is useful for
+// certain algorithms such as intersection (see BooleanOperation).
+type Shape interface {
+	// NumEdges returns the number of edges in this shape.
+	NumEdges() int
+
+	// Edge returns the edge for the given edge index.
+	Edge(i int) Edge
+
+	// ReferencePoint returns an arbitrary reference point for the shape. (The
+	// containment boolean value must be false for shapes that do not have an interior.)
+	//
+	// This reference point may then be used to compute the containment of other
+	// points by counting edge crossings.
+	ReferencePoint() ReferencePoint
+
+	// NumChains reports the number of contiguous edge chains in the shape.
+	// For example, a shape whose edges are [AB, BC, CD, AE, EF] would consist
+	// of two chains (AB,BC,CD and AE,EF). Every chain is assigned a chain Id
+	// numbered sequentially starting from zero.
+	//
+	// Note that it is always acceptable to implement this method by returning
+	// NumEdges, i.e. every chain consists of a single edge, but this may
+	// reduce the efficiency of some algorithms.
+	NumChains() int
+
+	// Chain returns the range of edge IDs corresponding to the given edge chain.
+	// Edge chains must form contiguous, non-overlapping ranges that cover
+	// the entire range of edge IDs. This is spelled out more formally below:
+	//
+	//  0 <= i < NumChains()
+	//  Chain(i).length > 0, for all i
+	//  Chain(0).start == 0
+	//  Chain(i).start + Chain(i).length == Chain(i+1).start, for i < NumChains()-1
+	//  Chain(i).start + Chain(i).length == NumEdges(), for i == NumChains()-1
+	Chain(chainID int) Chain
+
+	// ChainEdgeReturns the edge at offset "offset" within edge chain "chainID".
+	// Equivalent to "shape.Edge(shape.Chain(chainID).start + offset)"
+	// but more efficient.
+	ChainEdge(chainID, offset int) Edge
+
+	// ChainPosition finds the chain containing the given edge, and returns the
+	// position of that edge as a ChainPosition(chainID, offset) pair.
+	//
+	//  shape.Chain(pos.chainID).start + pos.offset == edgeID
+	//  shape.Chain(pos.chainID+1).start > edgeID
+	//
+	// where pos == shape.ChainPosition(edgeID).
+	ChainPosition(edgeID int) ChainPosition
+
+	// Dimension returns the dimension of the geometry represented by this shape,
+	// either 0, 1 or 2 for point, polyline and polygon geometry respectively.
+	//
+	//  0 - Point geometry. Each point is represented as a degenerate edge.
+	//
+	//  1 - Polyline geometry. Polyline edges may be degenerate. A shape may
+	//      represent any number of polylines. Polylines edges may intersect.
+	//
+	//  2 - Polygon geometry. Edges should be oriented such that the polygon
+	//      interior is always on the left. In theory the edges may be returned
+	//      in any order, but typically the edges are organized as a collection
+	//      of edge chains where each chain represents one polygon loop.
+	//      Polygons may have degeneracies (e.g., degenerate edges or sibling
+	//      pairs consisting of an edge and its corresponding reversed edge).
+	//      A polygon loop may also be full (containing all points on the
+	//      sphere); by convention this is represented as a chain with no edges.
+	//      (See laxPolygon for details.)
+	//
+	// This method allows degenerate geometry of different dimensions
+	// to be distinguished, e.g. it allows a point to be distinguished from a
+	// polyline or polygon that has been simplified to a single point.
+	Dimension() int
+
+	// IsEmpty reports whether the Shape contains no points. (Note that the full
+	// polygon is represented as a chain with zero edges.)
+	IsEmpty() bool
+
+	// IsFull reports whether the Shape contains all points on the sphere.
+	IsFull() bool
+
+	// typeTag returns a value that can be used to identify the type of an
+	// encoded Shape.
+	typeTag() typeTag
+
+	// We do not support implementations of this interface outside this package.
+	privateInterface()
+}
+
+// defaultShapeIsEmpty reports whether this shape contains no points.
+func defaultShapeIsEmpty(s Shape) bool {
+	return s.NumEdges() == 0 && (s.Dimension() != 2 || s.NumChains() == 0)
+}
+
+// defaultShapeIsFull reports whether this shape contains all points on the sphere.
+func defaultShapeIsFull(s Shape) bool {
+	return s.NumEdges() == 0 && s.Dimension() == 2 && s.NumChains() > 0
+}
+
+// A minimal check for types that should satisfy the Shape interface.
+var (
+	_ Shape = &Loop{}
+	_ Shape = &Polygon{}
+	_ Shape = &Polyline{}
+)