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Diffstat (limited to 'vendor/github.com/golang/geo/s2/query_options.go')
| -rw-r--r-- | vendor/github.com/golang/geo/s2/query_options.go | 196 |
1 files changed, 0 insertions, 196 deletions
diff --git a/vendor/github.com/golang/geo/s2/query_options.go b/vendor/github.com/golang/geo/s2/query_options.go deleted file mode 100644 index 9b7e38d62..000000000 --- a/vendor/github.com/golang/geo/s2/query_options.go +++ /dev/null @@ -1,196 +0,0 @@ -// Copyright 2019 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 ( - "math" - - "github.com/golang/geo/s1" -) - -const maxQueryResults = math.MaxInt32 - -// queryOptions represents the set of all configurable parameters used by all of -// the Query types. Most of these fields have non-zero defaults, so initialization -// is handled within each Query type. All of the exported methods accept user -// supplied sets of options to set or adjust as necessary. -// -// Several of the defaults depend on the distance interface type being used -// (e.g. minDistance, maxDistance, etc.) -// -// If a user sets an option value that a given query type doesn't use, it is ignored. -type queryOptions struct { - // maxResults specifies that at most MaxResults edges should be returned. - // This must be at least 1. - // - // The default value is to return all results. - maxResults int - - // distanceLimit specifies that only edges whose distance to the target is - // within this distance should be returned. - // - // Note that edges whose distance is exactly equal to this are - // not returned. In most cases this doesn't matter (since distances are - // not computed exactly in the first place), but if such edges are needed - // then you can retrieve them by specifying the distance as the next - // largest representable distance. i.e. distanceLimit.Successor(). - // - // The default value is the infinity value, such that all results will be - // returned. - distanceLimit s1.ChordAngle - - // maxError specifies that edges up to MaxError further away than the true - // closest edges may be substituted in the result set, as long as such - // edges satisfy all the remaining search criteria (such as DistanceLimit). - // This option only has an effect if MaxResults is also specified; - // otherwise all edges closer than MaxDistance will always be returned. - // - // Note that this does not affect how the distance between edges is - // computed; it simply gives the algorithm permission to stop the search - // early as soon as the best possible improvement drops below MaxError. - // - // This can be used to implement distance predicates efficiently. For - // example, to determine whether the minimum distance is less than D, set - // MaxResults == 1 and MaxDistance == MaxError == D. This causes - // the algorithm to terminate as soon as it finds any edge whose distance - // is less than D, rather than continuing to search for an edge that is - // even closer. - // - // The default value is zero. - maxError s1.ChordAngle - - // includeInteriors specifies that polygon interiors should be included - // when measuring distances. In other words, polygons that contain the target - // should have a distance of zero. (For targets consisting of multiple connected - // components, the distance is zero if any component is contained.) This - // is indicated in the results by returning a (ShapeID, EdgeID) pair - // with EdgeID == -1, i.e. this value denotes the polygons's interior. - // - // Note that for efficiency, any polygon that intersects the target may or - // may not have an EdgeID == -1 result. Such results are optional - // because in that case the distance to the polygon is already zero. - // - // The default value is true. - includeInteriors bool - - // specifies that distances should be computed by examining every edge - // rather than using the ShapeIndex. - // - // TODO(roberts): When optimized is implemented, update the default to false. - // The default value is true. - useBruteForce bool - - // region specifies that results must intersect the given Region. - // - // Note that if you want to set the region to a disc around a target - // point, it is faster to use a PointTarget with distanceLimit set - // instead. You can also set a distance limit and also require that results - // lie within a given rectangle. - // - // The default is nil (no region limits). - region Region -} - -// UseBruteForce sets or disables the use of brute force in a query. -func (q *queryOptions) UseBruteForce(x bool) *queryOptions { - q.useBruteForce = x - return q -} - -// IncludeInteriors specifies whether polygon interiors should be -// included when measuring distances. -func (q *queryOptions) IncludeInteriors(x bool) *queryOptions { - q.includeInteriors = x - return q -} - -// MaxError specifies that edges up to dist away than the true -// matching edges may be substituted in the result set, as long as such -// edges satisfy all the remaining search criteria (such as DistanceLimit). -// This option only has an effect if MaxResults is also specified; -// otherwise all edges closer than MaxDistance will always be returned. -func (q *queryOptions) MaxError(x s1.ChordAngle) *queryOptions { - q.maxError = x - return q -} - -// MaxResults specifies that at most MaxResults edges should be returned. -// This must be at least 1. -func (q *queryOptions) MaxResults(x int) *queryOptions { - // TODO(roberts): What should be done if the value is <= 0? - q.maxResults = int(x) - return q -} - -// DistanceLimit specifies that only edges whose distance to the target is -// within, this distance should be returned. Edges whose distance is equal -// are not returned. -// -// To include values that are equal, specify the limit with the next largest -// representable distance such as limit.Successor(), or set the option with -// Furthest/ClosestInclusiveDistanceLimit. -func (q *queryOptions) DistanceLimit(x s1.ChordAngle) *queryOptions { - q.distanceLimit = x - return q -} - -// ClosestInclusiveDistanceLimit sets the distance limit such that results whose -// distance is exactly equal to the limit are also returned. -func (q *queryOptions) ClosestInclusiveDistanceLimit(limit s1.ChordAngle) *queryOptions { - q.distanceLimit = limit.Successor() - return q -} - -// FurthestInclusiveDistanceLimit sets the distance limit such that results whose -// distance is exactly equal to the limit are also returned. -func (q *queryOptions) FurthestInclusiveDistanceLimit(limit s1.ChordAngle) *queryOptions { - q.distanceLimit = limit.Predecessor() - return q -} - -// ClosestConservativeDistanceLimit sets the distance limit such that results -// also incorporates the error in distance calculations. This ensures that all -// edges whose true distance is less than or equal to limit will be returned -// (along with some edges whose true distance is slightly greater). -// -// Algorithms that need to do exact distance comparisons can use this -// option to find a set of candidate edges that can then be filtered -// further (e.g., using CompareDistance). -func (q *queryOptions) ClosestConservativeDistanceLimit(limit s1.ChordAngle) *queryOptions { - q.distanceLimit = limit.Expanded(minUpdateDistanceMaxError(limit)) - return q -} - -// FurthestConservativeDistanceLimit sets the distance limit such that results -// also incorporates the error in distance calculations. This ensures that all -// edges whose true distance is greater than or equal to limit will be returned -// (along with some edges whose true distance is slightly less). -func (q *queryOptions) FurthestConservativeDistanceLimit(limit s1.ChordAngle) *queryOptions { - q.distanceLimit = limit.Expanded(-minUpdateDistanceMaxError(limit)) - return q -} - -// newQueryOptions returns a set of options using the given distance type -// with the proper default values. -func newQueryOptions(d distance) *queryOptions { - return &queryOptions{ - maxResults: maxQueryResults, - distanceLimit: d.infinity().chordAngle(), - maxError: 0, - includeInteriors: true, - useBruteForce: false, - region: nil, - } -} |