From 566167ab86325458d096678bb4f611d37d3f0cf3 Mon Sep 17 00:00:00 2001
From: Don Gagne <Don@laptop-3.local>
Date: Sun, 14 May 2017 15:54:27 -0700
Subject: [PATCH] Cubic relative altitude slider

---
 src/FlightDisplay/GuidedAltitudeSlider.qml | 35 +++++++++++++++-------
 1 file changed, 24 insertions(+), 11 deletions(-)

diff --git a/src/FlightDisplay/GuidedAltitudeSlider.qml b/src/FlightDisplay/GuidedAltitudeSlider.qml
index feafee1a0..a55c13077 100644
--- a/src/FlightDisplay/GuidedAltitudeSlider.qml
+++ b/src/FlightDisplay/GuidedAltitudeSlider.qml
@@ -21,18 +21,27 @@ Rectangle {
     readonly property real _maxAlt: 121.92  // 400 feet
     readonly property real _minAlt: 3
 
-    property var _activeVehicle:    QGroundControl.multiVehicleManager.activeVehicle
-    property real _vehicleAltitude: _activeVehicle ? _activeVehicle.altitudeRelative.rawValue : 0
-    property bool _fixedWing:       _activeVehicle ? _activeVehicle.fixedWing : false
-    property real _sliderMaxAlt:    _fixedWing ? _maxAlt : Math.min(_vehicleAltitude + 10, _maxAlt)
-    property real _sliderMinAlt:    _fixedWing ? _minAlt : Math.max(_vehicleAltitude - 10, _minAlt)
+    property var _guidedSettings:       QGroundControl.settingsManager.guidedSettings
+    property var _activeVehicle:        QGroundControl.multiVehicleManager.activeVehicle
+    property real _vehicleAltitude:     _activeVehicle ? _activeVehicle.altitudeRelative.rawValue : 0
+    property bool _fixedWing:           _activeVehicle ? _activeVehicle.fixedWing : false
+    property real _sliderMaxAlt:        _fixedWing ? _guidedSettings.fixedWingMaximumAltitude.value : _guidedSettings.vehicleMaximumAltitude.value
+    property real _sliderMinAlt:        _fixedWing ? _guidedSettings.fixedWingMinimumAltitude.value : _guidedSettings.vehicleMinimumAltitude.value
 
     function reset() {
-        altSlider.value = Math.min(Math.max(altSlider.minimumValue, 0), altSlider.maximumValue)
+        altSlider.value = 0
     }
 
     function getValue() {
-        return altSlider.value
+        return altField.newAltitude - _vehicleAltitude
+    }
+
+    function log10(value) {
+        if (value === 0) {
+            return 0
+        } else {
+            return Math.log(value) / Math.LN10
+        }
     }
 
     Column {
@@ -55,7 +64,11 @@ Rectangle {
             anchors.horizontalCenter:   parent.horizontalCenter
             text:                       Math.abs(newAltitude.toFixed(1)) + " " + QGroundControl.appSettingsDistanceUnitsString
 
-            property real newAltitude: QGroundControl.metersToAppSettingsDistanceUnits(_root._vehicleAltitude + altSlider.value).toFixed(1)
+            property real altGainRange: Math.max(_sliderMaxAlt - _vehicleAltitude, 0)
+            property real altLossRange: Math.max(_vehicleAltitude - _sliderMinAlt, 0)
+            property real altExp:       Math.pow(altSlider.value, 3)
+            property real altLossGain:  altExp * (altSlider.value > 0 ? altGainRange : altLossRange)
+            property real newAltitude: _vehicleAltitude + altLossGain // QGroundControl.metersToAppSettingsDistanceUnits(_root._vehicleAltitude + altSlider.value).toFixed(1)
         }
     }
 
@@ -67,9 +80,9 @@ Rectangle {
         anchors.left:       parent.left
         anchors.right:      parent.right
         orientation:        Qt.Vertical
-        minimumValue:       _root._sliderMinAlt - _root._vehicleAltitude
-        maximumValue:       _root._sliderMaxAlt - _root._vehicleAltitude
-        zeroCentered:  true
+        minimumValue:       -1
+        maximumValue:       1
+        zeroCentered:       true
         rotation:           180
 
         // We want slide up to be positive values
-- 
2.22.0