Fixed code smells

protocol/adsb/fields/bds09.go

@@ -0,0 +1,208 @@
+package fields
+
+// NumericValueStatus is the status of the numeric values, such as air speed, velocity, etc.
+type NumericValueStatus byte
+
+const (
+	NVSNoInformation NumericValueStatus = iota // No velocity information
+	NVSRegular                                 // Velocity is computed on the linear scale value of field * factor
+	NVSMaximum                                 // Velocity field value indicates velocity greater the maximum of the scale
+)
+
+// ParseHeightDifference reads the Height difference from a 56 bits data field
+func ParseHeightDifference(data []byte) (int16, NumericValueStatus) {
+	negative := data[6]&0x80 != 0
+	difference := int16(data[6] & 0x7F)
+
+	if difference == 0 {
+		return 0, NVSNoInformation
+	} else if difference >= 127 {
+		if negative {
+			return -3150, NVSMaximum
+		} else {
+			return 3150, NVSMaximum
+		}
+	}
+
+	difference = (difference - 1) * 25
+	if negative {
+		difference = -difference
+	}
+
+	return difference, NVSRegular
+}
+
+// VerticalRateSource is the Source Bit for Vertical Rate definition
+//
+// Specified in Doc 9871 / Table A-2-9
+type VerticalRateSource byte
+
+const (
+	VerticalRateSourceGNSS       VerticalRateSource = iota // GNSS source
+	VerticalRateSourceBarometric                           // Barometric source
+)
+
+// DirectionNorthSouth is the Direction Bit NS Velocity definition
+//
+// Specified in Doc 9871 / Table A-2-9
+type DirectionNorthSouth byte
+
+func ParseDirectionNorthSouth(data []byte) DirectionNorthSouth {
+	return DirectionNorthSouth((data[3] & 0x80) >> 7)
+}
+
+func ParseVelocityNorthSouthNormal(data []byte) (velocity uint16, status NumericValueStatus) {
+	velocity = (uint16(data[3]&0x7F)<<8 | uint16(data[4]&0xE0)) >> 5
+	if velocity == 0 {
+		return 0, NVSNoInformation
+	} else if velocity >= 1023 {
+		return 1023, NVSMaximum
+	}
+	return velocity - 1, NVSRegular
+}
+
+func ParseVelocityNorthSouthSupersonic(data []byte) (velocity uint16, status NumericValueStatus) {
+	velocity = (uint16(data[3]&0x7F)<<8 | uint16(data[4]&0xE0)) >> 5
+	if velocity == 0 {
+		return 0, NVSNoInformation
+	} else if velocity >= 1023 {
+		return 4088, NVSMaximum
+	}
+	return (velocity - 1) * 4, NVSRegular
+}
+
+const (
+	DNSNorth DirectionNorthSouth = iota // North
+	DNSSouth                            // South
+)
+
+// DirectionEastWest is the Direction Bit EW Velocity definition
+//
+// Specified in Doc 9871 / Table A-2-9
+type DirectionEastWest byte
+
+func ParseDirectionEastWest(data []byte) DirectionEastWest {
+	return DirectionEastWest((data[1] & 0x04) >> 2)
+}
+
+func ParseVelocityEastWestNormal(data []byte) (velocity uint16, status NumericValueStatus) {
+	velocity = (uint16(data[1]&0x03) | uint16(data[2]))
+	if velocity == 0 {
+		return 0, NVSNoInformation
+	} else if velocity >= 1023 {
+		return 1023, NVSMaximum
+	}
+	return velocity - 1, NVSRegular
+}
+
+func ParseVelocityEastWestSupersonic(data []byte) (velocity uint16, status NumericValueStatus) {
+	velocity = (uint16(data[1]&0x03) | uint16(data[2]))
+	if velocity == 0 {
+		return 0, NVSNoInformation
+	} else if velocity >= 1023 {
+		return 4088, NVSMaximum
+	}
+	return (velocity - 1) * 4, NVSRegular
+}
+
+const (
+	DEWEast DirectionEastWest = iota // East
+	DEWWest                          // West
+)
+
+func ParseIntentChange(data []byte) bool {
+	return (data[1]&0x80)>>7 != 0
+}
+
+func ParseIFRCapability(data []byte) bool {
+	return (data[1]&0x40)>>6 != 0
+}
+
+// NavigationUncertaintyCategory is the Navigation Uncertainty Category definition
+//
+// Specified in Doc 9871 / Table A-2-9
+type NavigationUncertaintyCategory byte
+
+const (
+	NUCPUnknown                                             NavigationUncertaintyCategory = iota // Unknown
+	NUCPHorizontalLowerThan10VerticalLowerThan15Point2                                           // Horizontal <  10m/s and Vertical < 15.2m/s
+	NUCPHorizontalLowerThan3VerticalLowerThan4Point6                                             // Horizontal <   3m/s and Vertical <  4.6m/s
+	NUCPHorizontalLowerThan1VerticalLowerThan1Point5                                             // Horizontal <   1m/s and Vertical <  1.5m/s
+	NUCPHorizontalLowerThan0Point3VerticalLowerThan0Point46                                      // Horizontal < 0.3m/s and Vertical < 0.46m/s
+)
+
+func ParseeNavigationUncertaintyCategory(data []byte) NavigationUncertaintyCategory {
+	return NavigationUncertaintyCategory((data[1] & 0x38) >> 3)
+}
+
+func ParseMagneticHeading(data []byte) (heading float64, status bool) {
+	status = (data[1]&0x04)>>2 != 0
+	value := uint16(data[1]&0x03)<<8 | uint16(data[2])
+	heading = float64(value) * 360 / 1024.0
+	return
+}
+
+func ParseAirspeedNormal(data []byte) (speed uint16, status NumericValueStatus) {
+	velocity := (uint16(data[3]&0x7F)<<8 | uint16(data[4]&0xE0)) >> 5
+	if velocity == 0 {
+		return 0, NVSNoInformation
+	} else if velocity >= 1023 {
+		return 1023, NVSMaximum
+	}
+	return velocity - 1, NVSRegular
+}
+
+func ParseAirspeedSupersonic(data []byte) (speed uint16, status NumericValueStatus) {
+	velocity := (uint16(data[3]&0x7F)<<8 | uint16(data[4]&0xE0)) >> 5
+	if velocity == 0 {
+		return 0, NVSNoInformation
+	} else if velocity >= 1023 {
+		return 4088, NVSMaximum
+	}
+	return (velocity - 1) * 4, NVSRegular
+}
+
+func ParseVerticalRateSource(data []byte) VerticalRateSource {
+	return VerticalRateSource((data[4] & 0x10) >> 4)
+}
+
+func ParseVerticalRate(data []byte) (rate int16, status NumericValueStatus) {
+	negative := data[4]&0x08 != 0
+	rate = int16(uint16(data[4]&0x07)<<8 | uint16(data[5]&0xFC))
+	if rate == 0 {
+		return 0, NVSNoInformation
+	} else if rate >= 511 {
+		if negative {
+			return -32640, NVSMaximum
+		}
+		return 32640, NVSMaximum
+	}
+
+	rate = (rate - 1) * 64
+	if negative {
+		rate = -rate
+	}
+	return rate, NVSRegular
+}
+
+func ParseHeightDifferenceFromBaro(data []byte) (difference int16, status NumericValueStatus) {
+	negative := data[6]&0x80 != 0
+	difference = int16(data[6] & 0x7F)
+
+	if difference == 0 {
+		return 0, NVSNoInformation
+	} else if difference >= 127 {
+		if negative {
+			return -3150, NVSMaximum
+		} else {
+			return 3150, NVSMaximum
+		}
+	}
+
+	difference = (difference - 1) * 25
+	if negative {
+		difference = -difference
+	}
+
+	return difference, NVSRegular
+}