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author | 2024-08-02 11:46:41 +0000 | |
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committer | 2024-08-02 12:46:41 +0100 | |
commit | 94e87610c4ce9bbb1c614a61bab29c1422fed11b (patch) | |
tree | 2e06b8ce64212140e796f6077ba841b6cc678501 /vendor/github.com/golang/geo/s2/latlng.go | |
parent | [feature] Allow import of following and blocks via CSV (#3150) (diff) | |
download | gotosocial-94e87610c4ce9bbb1c614a61bab29c1422fed11b.tar.xz |
[chore] add back exif-terminator and use only for jpeg,png,webp (#3161)
* add back exif-terminator and use only for jpeg,png,webp
* fix arguments passed to terminateExif()
* pull in latest exif-terminator
* fix test
* update processed img
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Co-authored-by: tobi <tobi.smethurst@protonmail.com>
Diffstat (limited to 'vendor/github.com/golang/geo/s2/latlng.go')
-rw-r--r-- | vendor/github.com/golang/geo/s2/latlng.go | 101 |
1 files changed, 101 insertions, 0 deletions
diff --git a/vendor/github.com/golang/geo/s2/latlng.go b/vendor/github.com/golang/geo/s2/latlng.go new file mode 100644 index 000000000..a750304ab --- /dev/null +++ b/vendor/github.com/golang/geo/s2/latlng.go @@ -0,0 +1,101 @@ +// Copyright 2014 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 ( + "fmt" + "math" + + "github.com/golang/geo/r3" + "github.com/golang/geo/s1" +) + +const ( + northPoleLat = s1.Angle(math.Pi/2) * s1.Radian + southPoleLat = -northPoleLat +) + +// LatLng represents a point on the unit sphere as a pair of angles. +type LatLng struct { + Lat, Lng s1.Angle +} + +// LatLngFromDegrees returns a LatLng for the coordinates given in degrees. +func LatLngFromDegrees(lat, lng float64) LatLng { + return LatLng{s1.Angle(lat) * s1.Degree, s1.Angle(lng) * s1.Degree} +} + +// IsValid returns true iff the LatLng is normalized, with Lat ∈ [-π/2,π/2] and Lng ∈ [-π,π]. +func (ll LatLng) IsValid() bool { + return math.Abs(ll.Lat.Radians()) <= math.Pi/2 && math.Abs(ll.Lng.Radians()) <= math.Pi +} + +// Normalized returns the normalized version of the LatLng, +// with Lat clamped to [-π/2,π/2] and Lng wrapped in [-π,π]. +func (ll LatLng) Normalized() LatLng { + lat := ll.Lat + if lat > northPoleLat { + lat = northPoleLat + } else if lat < southPoleLat { + lat = southPoleLat + } + lng := s1.Angle(math.Remainder(ll.Lng.Radians(), 2*math.Pi)) * s1.Radian + return LatLng{lat, lng} +} + +func (ll LatLng) String() string { return fmt.Sprintf("[%v, %v]", ll.Lat, ll.Lng) } + +// Distance returns the angle between two LatLngs. +func (ll LatLng) Distance(ll2 LatLng) s1.Angle { + // Haversine formula, as used in C++ S2LatLng::GetDistance. + lat1, lat2 := ll.Lat.Radians(), ll2.Lat.Radians() + lng1, lng2 := ll.Lng.Radians(), ll2.Lng.Radians() + dlat := math.Sin(0.5 * (lat2 - lat1)) + dlng := math.Sin(0.5 * (lng2 - lng1)) + x := dlat*dlat + dlng*dlng*math.Cos(lat1)*math.Cos(lat2) + return s1.Angle(2*math.Atan2(math.Sqrt(x), math.Sqrt(math.Max(0, 1-x)))) * s1.Radian +} + +// NOTE(mikeperrow): The C++ implementation publicly exposes latitude/longitude +// functions. Let's see if that's really necessary before exposing the same functionality. + +func latitude(p Point) s1.Angle { + return s1.Angle(math.Atan2(p.Z, math.Sqrt(p.X*p.X+p.Y*p.Y))) * s1.Radian +} + +func longitude(p Point) s1.Angle { + return s1.Angle(math.Atan2(p.Y, p.X)) * s1.Radian +} + +// PointFromLatLng returns an Point for the given LatLng. +// The maximum error in the result is 1.5 * dblEpsilon. (This does not +// include the error of converting degrees, E5, E6, or E7 into radians.) +func PointFromLatLng(ll LatLng) Point { + phi := ll.Lat.Radians() + theta := ll.Lng.Radians() + cosphi := math.Cos(phi) + return Point{r3.Vector{math.Cos(theta) * cosphi, math.Sin(theta) * cosphi, math.Sin(phi)}} +} + +// LatLngFromPoint returns an LatLng for a given Point. +func LatLngFromPoint(p Point) LatLng { + return LatLng{latitude(p), longitude(p)} +} + +// ApproxEqual reports whether the latitude and longitude of the two LatLngs +// are the same up to a small tolerance. +func (ll LatLng) ApproxEqual(other LatLng) bool { + return ll.Lat.ApproxEqual(other.Lat) && ll.Lng.ApproxEqual(other.Lng) +} |