UTM FromLngLat working

cmp/cmp.go

@@ -24,6 +24,11 @@ var (
 	NilCollection      = (*geom.Collection)(nil)
 )
 
+// BitToleranceFor returns the BitToleranceFor the given tolerance
+func BitToleranceFor(tol float64) int64 {
+	return int64(math.Float64bits(1.0+tol) - math.Float64bits(1.0))
+}
+
 // FloatSlice compare two sets of float slices.
 func FloatSlice(f1, f2 []float64) bool { return Float64Slice(f1, f2, Tolerance, BitTolerance) }
 

planar/coord/coord.go

@@ -0,0 +1,108 @@
+package coord
+
+import (
+	"fmt"
+	"math"
+)
+
+// Interface is an interface that wraps a ToLngLat methods
+//
+// ToLngLat should returns the a LngLat value in degrees that
+// represents that given value as closely as possible. It is
+// understood that this value may not be excate
+type Interface interface {
+	ToLngLat() LngLat
+}
+
+// LngLat describes Latitude,Longitude values
+type LngLat struct {
+	// Longitude in decimal degrees
+	Lng float64
+	// Latitude in decimal degrees
+	Lat float64
+}
+
+// NormalizeLng will insure that the longitude value is between 0-360
+func (l LngLat) NormalizeLng() LngLat {
+	return LngLat{
+		Lat: l.Lat,
+		Lng: l.Lng - float64(int64((l.Lng+180.0)/360.0)*360.0),
+	}
+}
+
+// LatInRadians returns the Latitude value in radians
+func (l LngLat) LatInRadians() float64 { return ToRadian(l.Lat) }
+
+// LngInRadians returns the Longitude value in radians
+func (l LngLat) LngInRadians() float64 { return ToRadian(l.Lng) }
+
+// LatAsDMS returns the latitude value in Degree Minute Seconds values
+func (l LngLat) LatAsDMS() DMS {
+	latD, latM, latS := toDMS(l.Lat)
+	latH := 'N'
+	if l.Lat < 0 {
+		latH = 'S'
+	}
+	return DMS{
+		Degree:     latD,
+		Minute:     latM,
+		Second:     latS,
+		Hemisphere: latH,
+	}
+}
+
+// LngAsDMS returns the longitude value in Degree Minute Seconds values
+func (l LngLat) LngAsDMS() DMS {
+	lngD, lngM, lngS := toDMS(l.Lng)
+	lngH := 'E'
+	if l.Lng < 0 {
+		lngH = 'W'
+	}
+	return DMS{
+		Degree:     lngD,
+		Minute:     lngM,
+		Second:     lngS,
+		Hemisphere: lngH,
+	}
+}
+
+// ToRadian will convert a value in degree to radians
+func ToRadian(degree float64) float64 {
+	return degree * math.Pi / 180.000
+}
+
+// ToDegree will convert a value in radians to degrees
+func ToDegree(radian float64) float64 {
+	return radian * 180.000 / math.Pi
+}
+
+// Ellipsoid describes an Ellipsoid
+// this may change when we get a proper projection package
+type Ellipsoid struct {
+	Name           string
+	Radius         float64
+	Eccentricity   float64
+	NATOCompatible bool
+}
+
+// Convert the given lng or lat value to the degree minute seconds values
+func toDMS(v float64) (d int64, m int64, s float64) {
+	var frac float64
+	df, frac := math.Modf(v)
+	mf, frac := math.Modf(60.0 * frac)
+	s = 60.0 * frac
+	return int64(math.Abs(df)), int64(math.Abs(mf)), math.Abs(s)
+}
+
+// DMS is the degree minutes and seconds
+type DMS struct {
+	Degree     int64
+	Minute     int64
+	Second     float64
+	Hemisphere rune
+}
+
+// String returns the string representation.
+func (dms DMS) String() string {
+	return fmt.Sprintf(`%d°%d'%f"%c`, dms.Degree, dms.Minute, dms.Second, dms.Hemisphere)
+}