Use gomobile to build native libraries

.github/workflows/android.yml

@@ -58,9 +58,9 @@ jobs:
  local-cache: true
 
  - name: Build Golang library
- run: python3 app/src/main/golang/build.py -m 26 -a all -d
+ run: go generate app/src/main/golang/Geomag.go
  env:
- ANDROID_NDK_ROOT: ${{ steps.setup-ndk.outputs.ndk-path }}
+ ANDROID_NDK_HOME: ${{ steps.setup-ndk.outputs.ndk-path }}
 
  - name: Set up Gradle
  uses: gradle/gradle-build-action@v2

app/src/main/golang/Geomag.go

@@ -0,0 +1,67 @@
+package geomag
+
+//go:generate bash -c "if [ ! -d libs ]; then mkdir libs; fi"
+//go:generate gomobile bind -target android -androidapi 26 -javapkg go -trimpath -v -o libs/geomag.aar
+
+import (
+ "github.com/proway2/go-igrf/igrf"
+ "github.com/westphae/geomag/pkg/egm96"
+ "github.com/westphae/geomag/pkg/wmm"
+ "time"
+)
+
+//export igrf
+func IGRF(lat, lon, alt, date float64) *MagneticField {
+ data := igrf.New()
+ mag, _ := data.IGRF(lat, lon, alt, date)
+
+ return newMagneticField(
+ mag.Declination,
+ mag.DeclinationSV,
+ mag.Inclination,
+ mag.InclinationSV,
+ mag.HorizontalIntensity,
+ mag.HorizontalSV,
+ mag.NorthComponent,
+ mag.NorthSV,
+ mag.EastComponent,
+ mag.EastSV,
+ mag.VerticalComponent,
+ mag.VerticalSV,
+ mag.TotalIntensity,
+ mag.TotalSV,
+ )
+}
+
+//export wmm
+func WMM(lat, lon, alt, date float64) *MagneticField {
+ tt := wmm.DecimalYear(date)
+ loc := egm96.NewLocationGeodetic(lat, lon, alt)
+ mag, _ := wmm.CalculateWMMMagneticField(loc, tt.ToTime())
+ x, y, z, dx, dy, dz := mag.Ellipsoidal()
+
+ return newMagneticField(
+ mag.D(),
+ mag.DD(),
+ mag.I(),
+ mag.DI(),
+ mag.H(),
+ mag.DH(),
+ x,
+ dx,
+ y,
+ dy,
+ z,
+ dz,
+ mag.F(),
+ mag.DF(),
+ )
+}
+
+//export toDecimalYears
+func ToDecimalYears(year, month, day, hour, min, sec, nsec int) float64 {
+ dateTime := time.Date(year, time.Month(month), day,
+ hour, min, sec, nsec, time.UTC)
+
+ return float64(wmm.TimeToDecimalYears(dateTime))
+}

app/src/main/golang/MagneticField.go

@@ -0,0 +1,45 @@
+package geomag
+
+type MagneticField struct {
+ Declination float64
+ DeclinationSV float64
+ Inclination float64
+ InclinationSV float64
+ HorizontalIntensity float64
+ HorizontalSV float64
+ NorthComponent float64
+ NorthSV float64
+ EastComponent float64
+ EastSV float64
+ VerticalComponent float64
+ VerticalSV float64
+ TotalIntensity float64
+ TotalSV float64
+}
+
+func newMagneticField(
+ declination, declinationSV,
+ inclination, inclinationSV,
+ horizontalIntensity, horizontalSV,
+ northComponent, northSV,
+ eastComponent, eastSV,
+ verticalComponent, verticalSV,
+ totalIntensity, totalSV float64,
+) *MagneticField {
+ return &MagneticField{
+ Declination: declination,
+ DeclinationSV: declinationSV,
+ Inclination: inclination,
+ InclinationSV: inclinationSV,
+ HorizontalIntensity: horizontalIntensity,
+ HorizontalSV: horizontalSV,
+ NorthComponent: northComponent,
+ NorthSV: northSV,
+ EastComponent: eastComponent,
+ EastSV: eastSV,
+ VerticalComponent: verticalComponent,
+ VerticalSV: verticalSV,
+ TotalIntensity: totalIntensity,
+ TotalSV: totalSV,
+ }
+}