Joystick axes can now be specified as being exclusively-positive in the range [0:1.0] for the throttle. This should really be a vehicle-specific setting.

src/input/JoystickInput.cc

@@ -198,7 +198,12 @@ void JoystickInput::run()
                 axisValue = (axisValue - calibrationPositive[i]) / (calibrationNegative[i] - calibrationPositive[i]);
             }
             axisValue = 1.0f - axisValue;
-            axisValue = axisValue * 2.0f - 1.0f;
+
+            // If the joystick isn't limited to [0:1.0], map it into [-1.0:1.0].
+            if (!joystickAxesRangeLimited[i])
+            {
+                axisValue = axisValue * 2.0f - 1.0f;
+            }
 
             // Bound rounding errors
             if (axisValue > 1.0f) axisValue = 1.0f;
@@ -276,6 +281,7 @@ void JoystickInput::setActiveJoystick(int id)
         // Update cached joystick values
         joystickAxes.clear();
         joystickAxesInverted.clear();
+        joystickAxesRangeLimited.clear();
         for (int i = 0; i < joystickNumAxes; i++)
         {
             int axisValue = SDL_JoystickGetAxis(joystick, i);
@@ -283,6 +289,7 @@ void JoystickInput::setActiveJoystick(int id)
             emit axisValueChanged(i, axisValue);
 
             joystickAxesInverted.append(false);
+            joystickAxesRangeLimited.append(false);
         }
         joystickButtons = 0;
         for (int i = 0; i < joystickNumButtons; i++)
@@ -348,6 +355,14 @@ void JoystickInput::setAxisInversion(int axis, bool inverted)
     }
 }
 
+void JoystickInput::setAxisRangeLimit(int axis, bool rangeLimited)
+{
+    if (axis < joystickAxesRangeLimited.size())
+    {
+        joystickAxesRangeLimited[axis] = rangeLimited;
+    }
+}
+
 float JoystickInput::getCurrentValueForAxis(int axis)
 {
     if (axis < joystickAxes.size())

src/input/JoystickInput.h

@@ -156,8 +156,9 @@ protected:
     int joystickNumAxes;
     int joystickNumButtons;
 
-    QList<float> joystickAxes; ///< The values of every axes during the last sample
-    QList<bool> joystickAxesInverted; ///< Whether each axis should be used inverted from what was reported
+    QList<float> joystickAxes; ///< The values of every axes during the last sample.
+    QList<bool> joystickAxesInverted; ///< Whether each axis should be used inverted from what was reported.
+    QList<bool> joystickAxesRangeLimited; ///< Whether each axis should be scaled into [0:1.0] instead of [-1.0:1.0].
     quint16 joystickButtons;   ///< The state of every button. Bitfield supporting 16 buttons with 1s indicating that the button is down.
     int xHat, yHat;            ///< The horizontal/vertical hat directions. Values are -1, 0, 1, with (-1,-1) indicating bottom-left.
 
@@ -232,6 +233,12 @@ public slots:
      * @param inverted True indicates inverted from normal. Varies by controller.
      */
     void setAxisInversion(int axis, bool inverted);
+    /**
+     * @brief Specifies whether an axis should have its range limited to only positive values.
+     * @param axis The index of the axis to limit
+     * @param rangeLimited True if the axis should be limited, false otherwise.
+     */
+    void setAxisRangeLimit(int axis, bool rangeLimited);
 };
 
 #endif // _JOYSTICKINPUT_H_

src/ui/JoystickAxis.cc

@@ -9,9 +9,11 @@ JoystickAxis::JoystickAxis(int id, QWidget *parent) :
     ui(new Ui::JoystickAxis)
 {
     ui->setupUi(this);
+    ui->limitRangeCheckBox->hide(); // Hide the range checkbox by default. It's only activated by switching to the Throttle axis option.
     ui->label->setText(QString::number(id));
     connect(ui->comboBox, SIGNAL(currentIndexChanged(int)), this, SLOT(mappingComboBoxChanged(int)));
-    connect(ui->checkBox, SIGNAL(clicked(bool)), this, SLOT(inversionCheckBoxChanged(bool)));
+    connect(ui->invertedCheckBox, SIGNAL(clicked(bool)), this, SLOT(inversionCheckBoxChanged(bool)));
+    connect(ui->limitRangeCheckBox, SIGNAL(clicked(bool)), this, SLOT(limitRangeCheckBoxChanged(bool)));
 }
 
 JoystickAxis::~JoystickAxis()
@@ -26,6 +28,14 @@ void JoystickAxis::setValue(float value)
 
 void JoystickAxis::mappingComboBoxChanged(int newMapping)
 {
+    if (newMapping == JoystickInput::JOYSTICK_INPUT_MAPPING_THROTTLE)
+    {
+        ui->limitRangeCheckBox->show();
+    }
+    else
+    {
+        ui->limitRangeCheckBox->hide();
+    }
     emit mappingChanged(id, (JoystickInput::JOYSTICK_INPUT_MAPPING)newMapping);
 }
 
@@ -33,3 +43,16 @@ void JoystickAxis::inversionCheckBoxChanged(bool inverted)
 {
     emit inversionChanged(id, inverted);
 }
+
+void JoystickAxis::limitRangeCheckBoxChanged(bool limited)
+{
+    if (limited)
+    {
+        ui->progressBar->setRange(0, 100);
+    }
+    else
+    {
+        ui->progressBar->setRange(-100, 100);
+    }
+    emit rangeLimitChanged(id, limited);
+}

src/ui/JoystickAxis.h

@@ -21,6 +21,8 @@ signals:
     void mappingChanged(int id, JoystickInput::JOYSTICK_INPUT_MAPPING newMapping);
     /** @brief Signal a change in this axis' inversion status */
     void inversionChanged(int id, bool);
+    /** @brief Signal a change in this axis' range limit */
+    void rangeLimitChanged(int id, bool);
 
 public slots:
     /** @brief Update the displayed value of the included progressbar.
@@ -35,8 +37,10 @@ private:
 private slots:
     /** @brief Handle changes to the mapping dropdown bar. */
     void mappingComboBoxChanged(int newMapping);
-    /** @brief Handle changes to the inversion checkbox. */
+    /** @brief Emit signal when the inversion checkbox is changed. */
     void inversionCheckBoxChanged(bool inverted);
+    /** @brief Emit signal when the limit range checkbox is changed. */
+    void limitRangeCheckBoxChanged(bool limited);
 };
 
 #endif // JOYSTICKAXIS_H

src/ui/JoystickAxis.ui

@@ -87,9 +87,16 @@
     </widget>
    </item>
    <item>
+    <widget class="QCheckBox" name="limitRangeCheckBox">
+     <property name="text">
+      <string>Limit range</string>
+     </property>
+    </widget>
+   </item>
+   <item>
     <widget class="QProgressBar" name="progressBar">
      <property name="enabled">
-      <bool>false</bool>
+      <bool>true</bool>
      </property>
      <property name="sizePolicy">
       <sizepolicy hsizetype="Preferred" vsizetype="MinimumExpanding">
@@ -113,21 +120,30 @@
       <set>Qt::AlignCenter</set>
      </property>
      <property name="textVisible">
-      <bool>false</bool>
+      <bool>true</bool>
      </property>
      <property name="orientation">
       <enum>Qt::Vertical</enum>
      </property>
+     <property name="textDirection">
+      <enum>QProgressBar::TopToBottom</enum>
+     </property>
     </widget>
    </item>
    <item>
-    <widget class="QCheckBox" name="checkBox">
+    <widget class="QCheckBox" name="invertedCheckBox">
      <property name="sizePolicy">
-      <sizepolicy hsizetype="Preferred" vsizetype="Fixed">
+      <sizepolicy hsizetype="Minimum" vsizetype="Fixed">
        <horstretch>0</horstretch>
        <verstretch>0</verstretch>
       </sizepolicy>
      </property>
+     <property name="minimumSize">
+      <size>
+       <width>0</width>
+       <height>25</height>
+      </size>
+     </property>
      <property name="text">
       <string>Inverted</string>
      </property>

src/ui/JoystickWidget.cc

@@ -126,7 +126,7 @@ void JoystickWidget::updateUIForJoystick(int id)
         {
             JoystickButton* button = new JoystickButton(i, m_ui->buttonBox);
             // And make sure we insert BEFORE the vertical spacer.
-            m_ui->buttonLayout->insertWidget(i, button);
+            m_ui->buttonLayout->addWidget(button);
             buttons.append(button);
         }
     }
@@ -145,8 +145,8 @@ void JoystickWidget::updateUIForJoystick(int id)
             axis->setValue(joystick->getCurrentValueForAxis(i));
             connect(axis, SIGNAL(mappingChanged(int,JoystickInput::JOYSTICK_INPUT_MAPPING)), this->joystick, SLOT(setAxisMapping(int,JoystickInput::JOYSTICK_INPUT_MAPPING)));
             connect(axis, SIGNAL(inversionChanged(int,bool)), this->joystick, SLOT(setAxisInversion(int,bool)));
-            // And make sure we insert BEFORE the vertical spacer.
-            m_ui->axesLayout->insertWidget(i, axis);
+            connect(axis, SIGNAL(rangeLimitChanged(int,bool)), this->joystick, SLOT(setAxisRangeLimit(int,bool)));
+            m_ui->axesLayout->addWidget(axis);
             axes.append(axis);
         }
     }