What I did is simple and sketchy. I inserted in FirstPage.qml
beginning from line 185 this:
SectionHeader {
anchors.left: parent.left
anchors.leftMargin: Theme.paddingMedium * 2
text: "Altitude Offset"
}
Slider {
minimumValue: -100
maximumValue: 100
stepSize: 1
value: settings.altitudeOffset
valueText: value + "m"
width: parent.width
onReleased: settings.altitudeOffset = value
}
and beginning from line 89, InfoField Altitude changed the formula this way:
InfoField {
label: qsTr("Altitude")
visible: settings.showAltitudeApp
value: {
if (providers.position.position.altitudeValid) {
if (settings.units === "MET") {
return locationFormatter.roundToDecimal(providers.position.position.coordinate.altitude - settings.altitudeOffset, 2) + " m"
} else {
return locationFormatter.roundToDecimal((providers.position.position.coordinate.altitude - settings.altitudeOffset) * 3.2808399, 2) + " ft"
}
}
return "-"
}
}
and I changed in CoverPage.qml
the InfoField beginning from line 56 this way:
InfoField {
label: qsTr("Altitude")
visible: settings.showAltitudeCover
fontpixelSize: Theme.fontSizeMedium
value: {
if (providers.position.position.altitudeValid) {
if (settings.units == "MET") {
// return locationFormatter.roundToDecimal(providers.position.position.coordinate.altitude, 2) + " m"
return locationFormatter.roundToDecimal(providers.position.position.coordinate.altitude - settings.altitudeOffset, 2) + " m"
} else {
// return locationFormatter.roundToDecimal(providers.position.position.coordinate.altitude * 3.2808399, 2) + " ft"
return locationFormatter.roundToDecimal((providers.position.position.coordinate.altitude - settings.altitudeOffset) * 3.2808399, 2) + " ft"
}
}
return "-"
}
}
This does only change the display on GPSInfo and has no effect to other apps.