82 lines
2.1 KiB
Go
82 lines
2.1 KiB
Go
/*
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Package pluscode provides an abstraction for Google's Open Location Code package.
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Copyright (c) 2018 - 2022 Michael Mayer <hello@photoprism.app>
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This program is free software: you can redistribute it and/or modify
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it under Version 3 of the GNU Affero General Public License (the "AGPL"):
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<https://docs.photoprism.app/license/agpl>
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU Affero General Public License for more details.
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The AGPL is supplemented by our Trademark and Brand Guidelines,
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which describe how our Brand Assets may be used:
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<https://photoprism.app/trademark>
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Feel free to send an e-mail to hello@photoprism.app if you have questions,
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want to support our work, or just want to say hello.
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Additional information can be found in our Developer Guide:
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<https://docs.photoprism.app/developer-guide/>
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*/
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package pluscode
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import (
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"fmt"
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olc "github.com/google/open-location-code/go"
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"github.com/photoprism/photoprism/pkg/s2"
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)
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var defaultLen = 8
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// Encode returns the plus code for the given coordinates using the default length.
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func Encode(lat, lng float64) string {
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result, _ := EncodeLength(lat, lng, defaultLen)
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return result
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}
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// EncodeLength returns the plus code for the given coordinates.
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func EncodeLength(lat, lng float64, length int) (plusCode string, err error) {
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if lat < -90 || lat > 90 {
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return "", fmt.Errorf("latitude out of range (%f)", lat)
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}
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if lng < -180 || lng > 180 {
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return "", fmt.Errorf("longitude out of range (%f)", lng)
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}
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return olc.Encode(lat, lng, length), nil
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}
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// LatLng returns the coordinates for a plus code token.
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func LatLng(token string) (lat, lng float64) {
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if token == "" || token == "-" {
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return lat, lng
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}
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c, err := olc.Decode(token)
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if err != nil {
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return lat, lng
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}
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lat, lng = c.Center()
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return lat, lng
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}
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// S2 returns the S2 cell token for the plus code using the default cell level.
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func S2(plusCode string) string {
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lat, lng := LatLng(plusCode)
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s2Token := s2.Token(lat, lng)
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return s2Token
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}
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