1 files changed, 117 insertions, 0 deletions
diff --git a/vendor/github.com/dsoprea/go-exif/v3/gps.go b/vendor/github.com/dsoprea/go-exif/v3/gps.go
new file mode 100644
index 000000000..7a61cd94d
--- /dev/null
+++ b/vendor/github.com/dsoprea/go-exif/v3/gps.go
@@ -0,0 +1,117 @@
+package exif
+
+import (
+	"errors"
+	"fmt"
+	"time"
+
+	"github.com/dsoprea/go-logging"
+	"github.com/golang/geo/s2"
+
+	"github.com/dsoprea/go-exif/v3/common"
+)
+
+var (
+	// ErrGpsCoordinatesNotValid means that some part of the geographic data was
+	// unparseable.
+	ErrGpsCoordinatesNotValid = errors.New("GPS coordinates not valid")
+)
+
+// GpsDegrees is a high-level struct representing geographic data.
+type GpsDegrees struct {
+	// Orientation describes the N/E/S/W direction that this position is
+	// relative to.
+	Orientation byte
+
+	// Degrees is a simple float representing the underlying rational degrees
+	// amount.
+	Degrees float64
+
+	// Minutes is a simple float representing the underlying rational minutes
+	// amount.
+	Minutes float64
+
+	// Seconds is a simple float representing the underlying ration seconds
+	// amount.
+	Seconds float64
+}
+
+// NewGpsDegreesFromRationals returns a GpsDegrees struct given the EXIF-encoded
+// information. The refValue is the N/E/S/W direction that this position is
+// relative to.
+func NewGpsDegreesFromRationals(refValue string, rawCoordinate []exifcommon.Rational) (gd GpsDegrees, err error) {
+	defer func() {
+		if state := recover(); state != nil {
+			err = log.Wrap(state.(error))
+		}
+	}()
+
+	if len(rawCoordinate) != 3 {
+		log.Panicf("new GpsDegrees struct requires a raw-coordinate with exactly three rationals")
+	}
+
+	gd = GpsDegrees{
+		Orientation: refValue[0],
+		Degrees:     float64(rawCoordinate[0].Numerator) / float64(rawCoordinate[0].Denominator),
+		Minutes:     float64(rawCoordinate[1].Numerator) / float64(rawCoordinate[1].Denominator),
+		Seconds:     float64(rawCoordinate[2].Numerator) / float64(rawCoordinate[2].Denominator),
+	}
+
+	return gd, nil
+}
+
+// String provides returns a descriptive string.
+func (d GpsDegrees) String() string {
+	return fmt.Sprintf("Degrees<O=[%s] D=(%g) M=(%g) S=(%g)>", string([]byte{d.Orientation}), d.Degrees, d.Minutes, d.Seconds)
+}
+
+// Decimal calculates and returns the simplified float representation of the
+// component degrees.
+func (d GpsDegrees) Decimal() float64 {
+	decimal := float64(d.Degrees) + float64(d.Minutes)/60.0 + float64(d.Seconds)/3600.0
+
+	if d.Orientation == 'S' || d.Orientation == 'W' {
+		return -decimal
+	}
+
+	return decimal
+}
+
+// Raw returns a Rational struct that can be used to *write* coordinates. In
+// practice, the denominator are typically (1) in the original EXIF data, and,
+// that being the case, this will best preserve precision.
+func (d GpsDegrees) Raw() []exifcommon.Rational {
+	return []exifcommon.Rational{
+		{Numerator: uint32(d.Degrees), Denominator: 1},
+		{Numerator: uint32(d.Minutes), Denominator: 1},
+		{Numerator: uint32(d.Seconds), Denominator: 1},
+	}
+}
+
+// GpsInfo encapsulates all of the geographic information in one place.
+type GpsInfo struct {
+	Latitude, Longitude GpsDegrees
+	Altitude            int
+	Timestamp           time.Time
+}
+
+// String returns a descriptive string.
+func (gi *GpsInfo) String() string {
+	return fmt.Sprintf("GpsInfo<LAT=(%.05f) LON=(%.05f) ALT=(%d) TIME=[%s]>",
+		gi.Latitude.Decimal(), gi.Longitude.Decimal(), gi.Altitude, gi.Timestamp)
+}
+
+// S2CellId returns the cell-ID of the geographic location on the earth.
+func (gi *GpsInfo) S2CellId() s2.CellID {
+	latitude := gi.Latitude.Decimal()
+	longitude := gi.Longitude.Decimal()
+
+	ll := s2.LatLngFromDegrees(latitude, longitude)
+	cellId := s2.CellIDFromLatLng(ll)
+
+	if cellId.IsValid() == false {
+		panic(ErrGpsCoordinatesNotValid)
+	}
+
+	return cellId
+}