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Diffstat (limited to 'vendor/github.com/golang/geo/s2/polyline_measures.go')
-rw-r--r-- | vendor/github.com/golang/geo/s2/polyline_measures.go | 53 |
1 files changed, 0 insertions, 53 deletions
diff --git a/vendor/github.com/golang/geo/s2/polyline_measures.go b/vendor/github.com/golang/geo/s2/polyline_measures.go deleted file mode 100644 index 38ce991b5..000000000 --- a/vendor/github.com/golang/geo/s2/polyline_measures.go +++ /dev/null @@ -1,53 +0,0 @@ -// Copyright 2018 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 - -// This file defines various measures for polylines on the sphere. These are -// low-level methods that work directly with arrays of Points. They are used to -// implement the methods in various other measures files. - -import ( - "github.com/golang/geo/r3" - "github.com/golang/geo/s1" -) - -// polylineLength returns the length of the given Polyline. -// It returns 0 for polylines with fewer than two vertices. -func polylineLength(p []Point) s1.Angle { - var length s1.Angle - - for i := 1; i < len(p); i++ { - length += p[i-1].Distance(p[i]) - } - return length -} - -// polylineCentroid returns the true centroid of the polyline multiplied by the -// length of the polyline. The result is not unit length, so you may wish to -// normalize it. -// -// Scaling by the Polyline length makes it easy to compute the centroid -// of several Polylines (by simply adding up their centroids). -// -// Note that for degenerate Polylines (e.g., AA) this returns Point(0, 0, 0). -// (This answer is correct; the result of this function is a line integral over -// the polyline, whose value is always zero if the polyline is degenerate.) -func polylineCentroid(p []Point) Point { - var centroid r3.Vector - for i := 1; i < len(p); i++ { - centroid = centroid.Add(EdgeTrueCentroid(p[i-1], p[i]).Vector) - } - return Point{centroid} -} |