S2LaxLoopShape

S2LaxLoopShape represents a closed loop of edges surrounding an interior region. It is similar to S2Loop::Shape except that this class allows duplicate vertices and edges. Loops may have any number of vertices, including 0, 1, or 2. (A one-vertex loop defines a degenerate edge consisting of a single point.)

Note that S2LaxLoopShape is faster to initialize and more compact than S2Loop::Shape, but does not support the same operations as S2Loop.

class S2LaxLoopShape : S2Shape {

this();

this(S2Point[] vertices);

this(S2Loop loop);

void initialize(S2Point[] vertices);

void initialize(S2Loop loop);

int numVertices();

const(S2Point) vertex(int i);

int numEdges();

Edge edge(int e0);

int dimension();

ReferencePoint getReferencePoint();

int numChains();

Chain chain(int i);

Edge chainEdge(int i, int j);

ChainPosition chainPosition(int e);

}

Constructors

this this(): Constructs an empty loop.
this this(S2Point[] vertices): Constructs an S2LaxLoopShape with the given vertices.
this this(S2Loop loop): Constructs an S2LaxLoopShape from the given S2Loop, by copying its data.

Members

Functions

chain Chain chain(int i): Undocumented in source. Be warned that the author may not have intended to support it.
chainEdge Edge chainEdge(int i, int j): Undocumented in source.
chainPosition ChainPosition chainPosition(int e): Undocumented in source. Be warned that the author may not have intended to support it.
dimension int dimension(): Not final; overridden by S2LaxClosedPolylineShape.
edge Edge edge(int e0): Undocumented in source.
getReferencePoint ReferencePoint getReferencePoint(): Not final; overridden by S2LaxClosedPolylineShape.
initialize void initialize(S2Point[] vertices): Initializes an S2LaxLoopShape with the given vertices.
initialize void initialize(S2Loop loop): Initializes an S2LaxLoopShape from the given S2Loop, by copying its data.
numChains int numChains(): Undocumented in source. Be warned that the author may not have intended to support it.
numEdges int numEdges(): S2Shape interface:
numVertices int numVertices(): Undocumented in source. Be warned that the author may not have intended to support it.
vertex const(S2Point) vertex(int i): Undocumented in source. Be warned that the author may not have intended to support it.

Inherited Members

From S2Shape

Edge struct Edge: An edge, consisting of two vertices "v0" and "v1". Zero-length edges are allowed, and can be used to represent points.
Chain struct Chain: A range of edge ids corresponding to a chain of zero or more connected edges, specified as a (start, length) pair. The chain is defined to consist of edge ids {start, start + 1, ..., start + length - 1}.
ChainPosition struct ChainPosition: The position of an edge within a given edge chain, specified as a (chain_id, offset) pair. Chains are numbered sequentially starting from zero, and offsets are measured from the start of each chain.
ReferencePoint struct ReferencePoint: A ReferencePoint consists of a point P and a boolean indicating whether P is contained by a particular shape.
numEdges int numEdges(): Returns the number of edges in this shape. Edges have ids ranging from 0 to num_edges() - 1.
edge Edge edge(int edge_id): Returns the endpoints of the given edge id.
dimension int dimension(): Returns the dimension of the geometry represented by this shape.
hasInterior bool hasInterior(): Convenience function that returns true if this shape has an interior.
getReferencePoint ReferencePoint getReferencePoint(): Returns an arbitrary point P along with a boolean indicating whether P is contained by the shape. (The boolean value must be 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] would consist of two chains (AB,BC,CD and AE,EF). Every chain is assigned a "chain id" numbered sequentially starting from zero.
chain Chain chain(int chain_id): Returns the range of edge ids corresponding to the given edge chain. The edge chains must form contiguous, non-overlapping ranges that cover the entire range of edge ids. This is spelled out more formally below:
chainEdge Edge chainEdge(int chain_id, int offset): Returns the edge at offset "offset" within edge chain "chain_id". Equivalent to "shape.edge(shape.chain(chain_id).start + offset)" but may be more efficient.
chainPosition ChainPosition chainPosition(int edge_id): Finds the chain containing the given edge, and returns the position of that edge as a (chain_id, offset) pair.
id int id(): A unique id assigned to this shape by S2ShapeIndex. Shape ids are assigned sequentially starting from 0 in the order shapes are added.
userData const(void*) userData(): Virtual methods that return pointers of your choice.
mutableUserData void* mutableUserData(): Undocumented in source. Be warned that the author may not have intended to support it.
_id int _id;: Assigned by MutableS2ShapeIndex when the shape is added.