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Merged
pfeiferj merged 1 commit into from
Aug 9, 2026
Merged

Avoid allocating global offline area grid #97

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93 changes: 51 additions & 42 deletions maps/generate_offline.go
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Original file line number Diff line number Diff line change
Expand Up @@ -4,6 +4,7 @@ import (
"context"
"fmt"
"log/slog"
"math"
"os"
"runtime"
"strconv"
Expand Down Expand Up @@ -89,18 +90,26 @@ func CreateBoundsDir(a Area, s OfflineSettings) error {
return errors.Wrap(err, "could not create bounds directory")
}

const (
latitudeAreas = int(180 / ms.AREA_BOX_DEGREES)
longitudeAreas = int(360 / ms.AREA_BOX_DEGREES)
)

func areaBox(latitudeIndex int, longitudeIndex int) m.Box {
minLatitude := -90 + float64(latitudeIndex)*ms.AREA_BOX_DEGREES
minLongitude := -180 + float64(longitudeIndex)*ms.AREA_BOX_DEGREES
return m.Box{
MinPos: m.NewPosition(minLatitude, minLongitude),
MaxPos: m.NewPosition(minLatitude+ms.AREA_BOX_DEGREES, minLongitude+ms.AREA_BOX_DEGREES),
}
}

// Generates bounding boxes for storing ways
func generateAreas() []Area {
areas := make([]Area, int((361/ms.AREA_BOX_DEGREES)*(181/ms.AREA_BOX_DEGREES)))
index := 0
for i := float64(-90); i < 90; i += ms.AREA_BOX_DEGREES {
for j := float64(-180); j < 180; j += ms.AREA_BOX_DEGREES {
a := &areas[index]
a.Box = m.Box{
MinPos: m.NewPosition(i, j),
MaxPos: m.NewPosition(i+ms.AREA_BOX_DEGREES, j+ms.AREA_BOX_DEGREES),
}
index += 1
areas := make([]Area, latitudeAreas*longitudeAreas)
for i := range latitudeAreas {
for j := range longitudeAreas {
areas[i*longitudeAreas+j].Box = areaBox(i, j)
}
}
return areas
Expand Down Expand Up @@ -333,42 +342,42 @@ func GenerateOffline(s OfflineSettings) {
slog.Info("Done Generating Offline Map")
}

var AREAS = generateAreas()
func areaForPosition(pos m.Position) (Area, bool) {
latitude := pos.Lat()
longitude := pos.Lon()
if math.IsNaN(latitude) || math.IsNaN(longitude) ||
latitude < -90 || latitude > 90 || longitude < -180 || longitude > 180 {
return Area{}, false
}

latitudeIndex := int(math.Ceil(latitude/ms.AREA_BOX_DEGREES)) + latitudeAreas/2 - 1
longitudeIndex := int(math.Ceil(longitude/ms.AREA_BOX_DEGREES)) + longitudeAreas/2 - 1
if latitudeIndex < 0 {
latitudeIndex = 0
}
if longitudeIndex < 0 {
longitudeIndex = 0
}

return Area{Box: areaBox(latitudeIndex, longitudeIndex)}, true
}

func FindWaysAroundPosition(pos m.Position) (Offline, error) {
for _, area := range AREAS {
inBox := area.Box.PosInside(pos)
if inBox {
boundsName := GenerateBoundsFileName(area, DEFAULT_SETTINGS)
slog.Info("Loading bounds file", "filename", boundsName)
data, err := os.ReadFile(boundsName)
o := ReadOffline(data)
if !o.Loaded {
area := Area{}
areas := generateAreas()
for _, a := range areas {
if a.Box.PosInside(pos) {
area = a
}
}
o.box.Set(area.Box)
}
return o, errors.Wrap(err, "could not read current offline data file")
}
area, found := areaForPosition(pos)
if !found {
cBox := utils.Curry[m.Box]{}
cBox.Set(area.Box)
return Offline{Loaded: false, box: cBox}, nil
}
area := Area{}
areas := generateAreas()
for _, a := range areas {
if a.Box.PosInside(pos) {
area = a
}

boundsName := GenerateBoundsFileName(area, DEFAULT_SETTINGS)
slog.Info("Loading bounds file", "filename", boundsName)
data, err := os.ReadFile(boundsName)
o := ReadOffline(data)
if !o.Loaded {
o.box.Set(area.Box)
}
cBox := utils.Curry[m.Box]{}
cBox.Set(area.Box)
return Offline{
Loaded: false,
box: cBox,
}, nil
return o, errors.Wrap(err, "could not read current offline data file")
}

func ParseMaxSpeed(maxspeed string) float64 {
Expand Down