Finds all polygons in the given "query_index" that completely contain a connected component of the target geometry. (For example, if the target consists of 10 points, this method finds polygons that contain any of those 10 points.) For each such polygon, "visitor" is called with the S2Shape of the polygon along with a point of the target geometry that is contained by that polygon.
Returns an S2Cap that bounds the set of points whose distance to the target is DistanceT::Zero().
The following method is provided as a convenience for classes that compute distances to a collection of indexed geometry, such as S2ClosestEdgeQuery and S2ClosestPointQuery. It returns the maximum number of indexed objects for which it is faster to compute the distance by brute force (e.g., by testing every edge) rather than by using an index. (The appropriate value is different for each index type and can be estimated for a given (distance target, index type) pair by running benchmarks.)
Specifies that whenever one of the UpdateMinDistance() methods above returns "true", the returned distance is allowed to be up to "max_error" larger than the true minimum distance. In other words, it gives this target object permission to terminate its distance calculation as soon as it has determined that (1) the minimum distance is less than "min_dist" and (2) the best possible further improvement is less than "max_error".
If the distance to the point "p" "min_dist", then updates "min_dist" and returns true. Otherwise returns false.
If the distance to the edge (v0, v1) is less than "min_dist", then updates "min_dist" and returns true. Otherwise returns false.
If the distance to the given S2Cell (including its interior) is less than "min_dist", then updates "min_dist" and returns true. Otherwise returns false.
S2DistanceTarget represents a geometric object to which distances are measured. For example, there are subtypes for measuring distances to a point, an edge, or to an S2ShapeIndex (an arbitrary collection of geometry). S2DistanceTarget objects are provided for the benefit of classes that measure distances and/or find nearby geometry, such as S2ClosestEdgeQuery and S2ClosestPointQuery.
Implementations do *not* need to be thread-safe. They may cache data or allocate temporary data structures in order to improve performance. For this reason, S2DistanceTarget objects are typically passed as pointers rather than as const references.
The Distance template argument is used to represent distances. Usually this type is a thin wrapper around S1ChordAngle, but another distance type may be substituted as long as it implements the API below. This can be used to change the comparison function (e.g., to find the furthest edges from the target), or to get more accuracy if desired.
The Distance concept is as follows:
class Distance { public: // Default and copy constructors, assignment operator: Distance(); Distance(const Distance&); Distance& operator=(const Distance&);
// Factory methods: static Distance Zero(); // Returns a zero distance. static Distance Infinity(); // Larger than any valid distance. static Distance Negative(); // Smaller than any valid distance.
// Comparison operators: friend bool operator==(Distance x, Distance y); friend bool operator<(Distance x, Distance y);
// Delta represents the positive difference between two distances. // It is used together with operator-() to implement Options::max_error(). // Typically Distance::Delta is simply S1ChordAngle. class Delta { public: Delta(); Delta(const Delta&); Delta& operator=(const Delta&); friend bool operator==(Delta x, Delta y); static Delta Zero(); };
// Subtraction operator. Note that the second argument represents a // delta between two distances. This distinction is important for // classes that compute maximum distances (e.g., S2FurthestEdgeQuery). friend Distance operator-(Distance x, Delta delta);
// Method that returns an upper bound on the S1ChordAngle corresponding // to this Distance (needed to implement Options::max_distance // efficiently). For example, if Distance measures WGS84 ellipsoid // distance then the corresponding angle needs to be 0.56% larger. S1ChordAngle GetChordAngleBound() const; };