Eli Ribble
9dccd21cee
* Create a nwe AddressAndMapLocator which abstracts out the behavior of selecting a location * Fix the overlay causing render errors on the MapLocator by getting rid of the overlay and just using a lock indicator * Fix MapLocator zooming in to the wrong place by not framing the markers * Remove Latlng from platform and just use Location with optional accuracy * Use nested types with form-encoded POST * Fix styles on water report page
121 lines
3.1 KiB
Go
121 lines
3.1 KiB
Go
package h3utils
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import (
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"fmt"
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"strings"
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"github.com/Gleipnir-Technology/go-geojson2h3/v2"
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//"github.com/tidwall/geojson"
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"github.com/uber/h3-go/v4"
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)
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/*
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func h3ToBoundsGeoJSON(c h3.Cell) (string, error) {
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b, err := h3.CellToBoundary(c)
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if err != nil {
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respondError(w, "Failed to get cell boundary", err, http.StatusInternalServerError)
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return
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}
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features, err := geojson2h3.ToFeatureCollection(b)
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if err != nil {
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return "", fmt.Errorf("Failed to convert boundary to
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}
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*/
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func ToCell(s string) (h3.Cell, error) {
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c := h3.CellFromString(s)
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if !c.IsValid() {
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return c, fmt.Errorf("Invalid cell definition '%s'", s)
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}
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return c, nil
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}
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func H3ToGeoJSON(indexes []h3.Cell) (interface{}, error) {
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featureCollection, err := geojson2h3.ToFeatureCollection(indexes)
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if err != nil {
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return "", fmt.Errorf("Failed to get feature collection: %w", err)
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}
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return featureCollection.JSON(), nil
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}
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// Given a cell at a smaller resolution remap it to the larger resolution
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func scaleCell(cell h3.Cell, resolution int) (h3.Cell, error) {
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r := cell.Resolution()
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if r == resolution {
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return cell, nil
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}
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latLong, err := cell.LatLng()
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if err != nil {
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return 0, fmt.Errorf("Failed to get latlng: %w", err)
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}
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scaled, err := h3.LatLngToCell(latLong, resolution)
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if err != nil {
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return 0, fmt.Errorf("Failed to create latlng: %w", err)
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}
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return scaled, nil
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}
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func GetCell(x, y float64, resolution int) (h3.Cell, error) {
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latLng := h3.NewLatLng(y, x)
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return h3.LatLngToCell(latLng, resolution)
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}
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func CellToPostgisGeometry(c h3.Cell) (string, error) {
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boundary, err := h3.CellToBoundary(c)
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if err != nil {
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return "", fmt.Errorf("Failed to get cell boundary: %w", err)
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}
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var sb strings.Builder
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for i, p := range boundary {
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if i > 0 {
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sb.WriteString(",")
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}
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fmt.Fprintf(&sb, "%g %g", p.Lng, p.Lat)
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}
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// add the first point on to the end to close the polygon
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sb.WriteString(",")
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fmt.Fprintf(&sb, "%g %g", boundary[0].Lng, boundary[0].Lat)
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return fmt.Sprintf("POLYGON((%s))", sb.String()), nil
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}
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// Convert from an accuracy in meters of GPS coordinates to the H3 Resolution that has at least
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// the same area. In other words, for a GPS coordinate accuracy of 2m you have pi*(2m)^2 or ~12.5m^2
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// of area which corresponds to resolution 13 (average area of 43.87^2) vs resolution 14 (average area 6.26m^2)
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// See https://h3geo.org/docs/core-library/restable
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func MeterAccuracyToH3Resolution(accuracy_in_meters float64) int {
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area := accuracy_in_meters * accuracy_in_meters * 3.1415
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if area < 0.895 {
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return 15
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} else if area < 6.267 {
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return 14
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} else if area < 43.87 {
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return 13
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} else if area < 307.092 {
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return 12
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} else if area < 2149.643 {
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return 11
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} else if area < 15_047.502 {
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return 10
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} else if area < 105_332.513 {
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return 9
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} else if area < 737_327.598 {
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return 8
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} else if area < 5_161_293.360 {
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return 7
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} else if area < 36_129_062.164 {
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return 6
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} else if area < 252_903_858.182 {
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return 5
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} else if area < 1_770_347_654.491 {
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return 4
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} else if area < 12_393_434_655.088 {
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return 3
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} else if area < 86_801_780_398.997 {
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return 2
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} else if area < 609_788_441_794.134 {
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return 1
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} else {
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return 0
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}
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}
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