Package com.google.common.geometry
Interface S2Shape
- All Known Subinterfaces:
S2LaxPolygonShape
,S2LaxPolylineShape
,S2ShapeAspect.EdgeAspect.Closed
,S2ShapeAspect.EdgeAspect.Open
,S2ShapeAspect.Mixed
- All Known Implementing Classes:
S2Edge
,S2LaxPolygonShape.MultiArray
,S2LaxPolygonShape.MultiList
,S2LaxPolygonShape.MultiPacked
,S2LaxPolygonShape.MultiSnapped
,S2LaxPolygonShape.SimpleArray
,S2LaxPolygonShape.SimpleList
,S2LaxPolygonShape.SimplePacked
,S2LaxPolygonShape.SimpleSnapped
,S2LaxPolylineShape.MultiArray
,S2LaxPolylineShape.MultiPacked
,S2LaxPolylineShape.MultiSnapped
,S2LaxPolylineShape.SimpleArray
,S2LaxPolylineShape.SimpleList
,S2LaxPolylineShape.SimplePacked
,S2LaxPolylineShape.SimpleSnapped
,S2Loop
,S2Point.Shape
,S2Polygon.Shape
,S2Polyline
,S2ShapeAspect.ChainAspect.Multi
,S2ShapeAspect.ChainAspect.Multi.Array
,S2ShapeAspect.ChainAspect.Multi.Packed
,S2ShapeAspect.ChainAspect.Multi.Snapped
,S2ShapeAspect.ChainAspect.Simple
,S2ShapeAspect.ChainAspect.Simple.Array
,S2ShapeAspect.ChainAspect.Simple.Packed
,S2ShapeAspect.ChainAspect.Simple.Snapped
,S2ShapeUtil.S2EdgeVectorShape
@GwtCompatible
public interface S2Shape
S2Shape is an abstract base class that defines a shape. Typically it wraps some other geometric
object in order to provide access to its edges without duplicating the edge data.
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Nested Class Summary
Nested ClassesModifier and TypeInterfaceDescriptionstatic final class
A simple receiver for the endpoints of an edge.static class
A point with a known containment relationship. -
Method Summary
Modifier and TypeMethodDescriptionchain
(int chain) Returns a view of the vertices in the given chain.chains()
Returns a view of thechains
in this shape.boolean
Returns true if this shape containsS2.origin()
.int
Returns the dimension of the geometry represented by this shape.void
getChainEdge
(int chainId, int offset, S2Shape.MutableEdge result) Returns the edge for the given chain id and offset inresult
.int
getChainLength
(int chainId) Returns the number of edge ids corresponding to the edge chain for the given chain id.int
getChainStart
(int chainId) Returns the first edge id corresponding to the edge chain for the given chain id.getChainVertex
(int chainId, int edgeOffset) Returns the start point of the edge that would be returned bygetChainEdge(int, int, com.google.common.geometry.S2Shape.MutableEdge)
, or the endpoint of the last edge ifedgeOffset==getChainLength(chainId)
.void
getEdge
(int index, S2Shape.MutableEdge result) Returns the edge for the given index inresult
.default S2Shape.ReferencePoint
Returns a point referenced to, i.e.boolean
Returns true if this shape has an interior, i.e.int
Returns the number of contiguous edge chains in the shape.int
numEdges()
Returns the number of edges in this shape.
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Method Details
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numEdges
int numEdges()Returns the number of edges in this shape. -
getEdge
Returns the edge for the given index inresult
. Must not return zero-length edges.- Parameters:
index
- which edge to set intoresult
, from 0 tonumEdges()
- 1
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hasInterior
boolean hasInterior()Returns true if this shape has an interior, i.e. the shape consists of one or more closed non-intersecting loops. -
containsOrigin
boolean containsOrigin()Returns true if this shape containsS2.origin()
. Should return false for shapes that do not have an interior. -
numChains
int numChains()Returns the number of contiguous edge chains in the shape. For example, a shape whose edges are [AB, BC, CD, AE, EF] may consist of two chains [A, B, C, D] and [A, E, F]. Every chain is assigned a chain id numbered sequentially starting from zero.An empty shape has no chains. A full shape (which contains the entire globe) has one chain with no edges. Other shapes should have at least one chain, and the sum of all valid
chain lengths
should equalnumEdges()
(that is, edges may only be used by a single chain).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. -
getChainStart
int getChainStart(int chainId) Returns the first edge id corresponding to the edge chain for the given chain id. The edge chains must form contiguous, non-overlapping ranges that cover the entire range of edge ids.- Parameters:
chainId
- which edge chain to return its start, from 0 tonumChains()
- 1
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getChainLength
int getChainLength(int chainId) Returns the number of edge ids corresponding to the edge chain for the given chain id. The edge chains must form contiguous, non-overlapping ranges that cover the entire range of edge ids.- Parameters:
chainId
- which edge chain to return its length, from 0 tonumChains()
- 1
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getChainEdge
Returns the edge for the given chain id and offset inresult
. Must not return zero-length edges.- Parameters:
chainId
- which chain contains the edge to return, from 0 tonumChains()
- 1offset
- position from chain start for the edge to return, from 0 togetChainLength(int)
- 1
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getChainVertex
Returns the start point of the edge that would be returned bygetChainEdge(int, int, com.google.common.geometry.S2Shape.MutableEdge)
, or the endpoint of the last edge ifedgeOffset==getChainLength(chainId)
. -
chain
Returns a view of the vertices in the given chain. Note2D
shapes omit the last vertex, as it's a duplicate of the first. -
chains
Returns a view of thechains
in this shape. -
dimension
int dimension()Returns the dimension of the geometry represented by this shape.- 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.
Note that 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.
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getReferencePoint
Returns a point referenced to, i.e. indicating containment by, this shape.
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