Places: Add new package pkg/geo/latlng #465 #5080

Signed-off-by: Michael Mayer <michael@photoprism.app>

pkg/geo/latlng/latlng.go

@@ -0,0 +1,25 @@
+/*
+Package latlng provides latitude and longitude functions and constants.
+
+Copyright (c) 2018 - 2025 PhotoPrism UG. All rights reserved.
+
+	This program is free software: you can redistribute it and/or modify
+	it under Version 3 of the GNU Affero General Public License (the "AGPL"):
+	<https://docs.photoprism.app/license/agpl>
+
+	This program is distributed in the hope that it will be useful,
+	but WITHOUT ANY WARRANTY; without even the implied warranty of
+	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+	GNU Affero General Public License for more details.
+
+	The AGPL is supplemented by our Trademark and Brand Guidelines,
+	which describe how our Brand Assets may be used:
+	<https://www.photoprism.app/trademark>
+
+Feel free to send an email to hello@photoprism.app if you have questions,
+want to support our work, or just want to say hello.
+
+Additional information can be found in our Developer Guide:
+<https://docs.photoprism.app/developer-guide/>
+*/
+package latlng

pkg/geo/latlng/round.go

@@ -0,0 +1,15 @@
+package latlng
+
+import "math"
+
+var RoundDecimals = float64(10000000)
+
+// Round rounds the given coordinate to six decimal places.
+func Round(c float64) float64 {
+	return math.Round(c*RoundDecimals) / RoundDecimals
+}
+
+// RoundCoords rounds the given latitude and longitude to six decimal places.
+func RoundCoords(lat, lng float64) (float64, float64) {
+	return Round(lat), Round(lng)
+}

pkg/geo/latlng/round_test.go

@@ -0,0 +1,22 @@
+package latlng
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestRound(t *testing.T) {
+	t.Run("Germany", func(t *testing.T) {
+		assert.Equal(t, 48.5634483, Round(48.56344833333333))
+		assert.Equal(t, 8.9968783, Round(8.996878333333333))
+	})
+}
+
+func TestRoundCoords(t *testing.T) {
+	t.Run("Germany", func(t *testing.T) {
+		lat, lng := RoundCoords(48.56344833333333, 8.996878333333333)
+		assert.Equal(t, 48.5634483, lat)
+		assert.Equal(t, 8.9968783, lng)
+	})
+}