Linear scaling for key controlled axis

Change-Id: I429fc512a836d569a55f0ac6490d020f1e8c2808
Reviewed-by: Sean Harmer <sean.harmer@kdab.com>

7 files changed, 102 insertions, 1 deletions

diff --git a/src/input/backend/buttonaxisinput.cpp b/src/input/backend/buttonaxisinput.cpp
index 6f9040eae..6042b2eff 100644
--- a/src/input/backend/buttonaxisinput.cpp
+++ b/src/input/backend/buttonaxisinput.cpp
@@ -52,6 +52,10 @@ namespace Input {
 ButtonAxisInput::ButtonAxisInput()
     : AbstractAxisInput()
     , m_scale(0.0f)
+    , m_acceleration(-1.0f)
+    , m_deceleration(-1.0f)
+    , m_speedRatio(0.0f)
+    , m_lastUpdateTime(0)
 {
 }
 
@@ -61,6 +65,8 @@ void ButtonAxisInput::initializeFromPeer(const Qt3DCore::QNodeCreatedChangeBaseP
     const auto &data = typedChange->data;
     m_buttons = data.buttons;
     m_scale = data.scale;
+    m_acceleration = data.acceleration;
+    m_deceleration = data.deceleration;
     AbstractAxisInput::initializeFromPeer(change);
 }
 
@@ -68,9 +74,29 @@ void ButtonAxisInput::cleanup()
 {
     m_scale = 0.0f;
     m_buttons.clear();
+    m_acceleration = -1.0f;
+    m_deceleration = -1.0f;
     AbstractAxisInput::cleanup();
 }
 
+void ButtonAxisInput::updateSpeedRatio(qint64 currentTime, ButtonAxisInput::UpdateType type)
+{
+    const float accel = (type == Accelerate) ? acceleration() : -deceleration();
+
+    // Was in nanoseconds, while acceleration will be in units per square seconds
+    const float delta = m_lastUpdateTime ? (currentTime - m_lastUpdateTime) / 1000000000.0f : 0.0f;
+    const float speedRatio = m_speedRatio + delta * accel;
+
+    // Clamp it
+    m_speedRatio = qMax(0.0f, qMin(speedRatio, 1.0f));
+
+    // If we stopped, time to start over
+    if (type == Decelerate && m_speedRatio == 0.0f)
+        m_lastUpdateTime = 0;
+    else
+        m_lastUpdateTime = currentTime;
+}
+
 void ButtonAxisInput::sceneChangeEvent(const Qt3DCore::QSceneChangePtr &e)
 {
     if (e->type() == Qt3DCore::PropertyUpdated) {
@@ -79,6 +105,10 @@ void ButtonAxisInput::sceneChangeEvent(const Qt3DCore::QSceneChangePtr &e)
             m_scale = propertyChange->value().toFloat();
         } else if (propertyChange->propertyName() == QByteArrayLiteral("buttons")) {
             m_buttons = propertyChange->value().value<QVector<int>>();
+        } else if (propertyChange->propertyName() == QByteArrayLiteral("acceleration")) {
+            m_acceleration = propertyChange->value().toFloat();
+        } else if (propertyChange->propertyName() == QByteArrayLiteral("deceleration")) {
+            m_deceleration = propertyChange->value().toFloat();
         }
     }
     AbstractAxisInput::sceneChangeEvent(e);
diff --git a/src/input/backend/buttonaxisinput_p.h b/src/input/backend/buttonaxisinput_p.h
index 72f043bf4..9e82a6ebc 100644
--- a/src/input/backend/buttonaxisinput_p.h
+++ b/src/input/backend/buttonaxisinput_p.h
@@ -62,11 +62,24 @@ namespace Input {
 class Q_AUTOTEST_EXPORT ButtonAxisInput : public AbstractAxisInput
 {
 public:
+    enum UpdateType {
+        Accelerate,
+        Decelerate
+    };
+
     ButtonAxisInput();
     void cleanup() Q_DECL_FINAL;
 
     inline float scale() const { return m_scale; }
     inline QVector<int> buttons() const { return m_buttons; }
+
+    inline float acceleration() const { return m_acceleration < 0.0f ? qInf() : m_acceleration; }
+    inline float deceleration() const { return m_deceleration < 0.0f ? qInf() : m_deceleration; }
+    inline float speedRatio() const { return m_speedRatio; }
+    inline qint64 lastUpdateTime() const { return m_lastUpdateTime; }
+
+    void updateSpeedRatio(qint64 currentTime, UpdateType type);
+
     void sceneChangeEvent(const Qt3DCore::QSceneChangePtr &e) Q_DECL_FINAL;
 
 private:
@@ -74,6 +87,10 @@ private:
 
     QVector<int> m_buttons;
     float m_scale;
+    float m_acceleration;
+    float m_deceleration;
+    float m_speedRatio;
+    qint64 m_lastUpdateTime;
 };
 
 } // namespace Input
diff --git a/src/input/backend/updateaxisactionjob.cpp b/src/input/backend/updateaxisactionjob.cpp
index 63e7ff658..f811c9ac0 100644
--- a/src/input/backend/updateaxisactionjob.cpp
+++ b/src/input/backend/updateaxisactionjob.cpp
@@ -188,7 +188,11 @@ void UpdateAxisActionJob::updateAxis(LogicalDevice *device)
                     if (!buttons.isEmpty()) {
                         // TO DO: Linear Curver for the progression of the scale value
                         if (anyOfRequiredButtonsPressed(buttons, physicalDeviceBackend))
-                            axisValue += buttonInput->scale();
+                            buttonInput->updateSpeedRatio(m_currentTime, ButtonAxisInput::Accelerate);
+                        else if (buttonInput->speedRatio() != 0.0f)
+                            buttonInput->updateSpeedRatio(m_currentTime, ButtonAxisInput::Decelerate);
+
+                        axisValue += buttonInput->speedRatio() * buttonInput->scale();
                     }
                 }
 
diff --git a/src/input/backend/updateaxisactionjob_p.h b/src/input/backend/updateaxisactionjob_p.h
index 5a412c46c..3b71e7a88 100644
--- a/src/input/backend/updateaxisactionjob_p.h
+++ b/src/input/backend/updateaxisactionjob_p.h
@@ -64,6 +64,7 @@ class QAbstractPhysicalDeviceBackendNode;
 namespace Input {
 
 class AbstractAxisInput;
+class ButtonAxisInput;
 class InputHandler;
 
 class UpdateAxisActionJob : public Qt3DCore::QAspectJob
diff --git a/src/input/frontend/qbuttonaxisinput.cpp b/src/input/frontend/qbuttonaxisinput.cpp
index 0a5ac2156..f392605aa 100644
--- a/src/input/frontend/qbuttonaxisinput.cpp
+++ b/src/input/frontend/qbuttonaxisinput.cpp
@@ -96,6 +96,36 @@ QVector<int> QButtonAxisInput::buttons() const
     return d->m_buttons;
 }
 
+float QButtonAxisInput::acceleration() const
+{
+    Q_D(const QButtonAxisInput);
+    return d->m_acceleration;
+}
+
+void QButtonAxisInput::setAcceleration(float acceleration)
+{
+    Q_D(QButtonAxisInput);
+    if (d->m_acceleration != acceleration) {
+        d->m_acceleration = acceleration;
+        emit accelerationChanged(acceleration);
+    }
+}
+
+float QButtonAxisInput::deceleration() const
+{
+    Q_D(const QButtonAxisInput);
+    return d->m_deceleration;
+}
+
+void QButtonAxisInput::setDeceleration(float deceleration)
+{
+    Q_D(QButtonAxisInput);
+    if (d->m_deceleration != deceleration) {
+        d->m_deceleration = deceleration;
+        emit decelerationChanged(deceleration);
+    }
+}
+
 Qt3DCore::QNodeCreatedChangeBasePtr QButtonAxisInput::createNodeCreationChange() const
 {
     auto creationChange = Qt3DCore::QNodeCreatedChangePtr<QButtonAxisInputData>::create(this);
@@ -105,6 +135,8 @@ Qt3DCore::QNodeCreatedChangeBasePtr QButtonAxisInput::createNodeCreationChange()
     data.sourceDeviceId = qIdForNode(d->m_sourceDevice);
     data.buttons = d->m_buttons;
     data.scale = d->m_scale;
+    data.acceleration = d->m_acceleration;
+    data.deceleration = d->m_deceleration;
 
     return creationChange;
 }
diff --git a/src/input/frontend/qbuttonaxisinput.h b/src/input/frontend/qbuttonaxisinput.h
index 2b551b8fb..cb2cb891e 100644
--- a/src/input/frontend/qbuttonaxisinput.h
+++ b/src/input/frontend/qbuttonaxisinput.h
@@ -54,6 +54,8 @@ class QT3DINPUTSHARED_EXPORT QButtonAxisInput : public QAbstractAxisInput
     Q_OBJECT
     Q_PROPERTY(float scale READ scale WRITE setScale NOTIFY scaleChanged)
     Q_PROPERTY(QVector<int> buttons READ buttons WRITE setButtons NOTIFY buttonsChanged)
+    Q_PROPERTY(float acceleration READ acceleration WRITE setAcceleration NOTIFY accelerationChanged)
+    Q_PROPERTY(float deceleration READ deceleration WRITE setDeceleration NOTIFY decelerationChanged)
 
 public:
     explicit QButtonAxisInput(Qt3DCore::QNode *parent = nullptr);
@@ -61,14 +63,23 @@ public:
     float scale() const;
     QVector<int> buttons() const;
 
+    float acceleration() const;
+    float deceleration() const;
+
 public Q_SLOTS:
     void setScale(float scale);
     void setButtons(const QVector<int> &buttons);
 
+    void setAcceleration(float acceleration);
+    void setDeceleration(float deceleration);
+
 Q_SIGNALS:
     void scaleChanged(float scale);
     void buttonsChanged(const QVector<int> &buttons);
 
+    void accelerationChanged(float acceleration);
+    void decelerationChanged(float deceleration);
+
 private:
     Q_DECLARE_PRIVATE(QButtonAxisInput)
     Qt3DCore::QNodeCreatedChangeBasePtr createNodeCreationChange() const Q_DECL_OVERRIDE;
diff --git a/src/input/frontend/qbuttonaxisinput_p.h b/src/input/frontend/qbuttonaxisinput_p.h
index 5cd672bd9..e56e58575 100644
--- a/src/input/frontend/qbuttonaxisinput_p.h
+++ b/src/input/frontend/qbuttonaxisinput_p.h
@@ -63,16 +63,22 @@ public:
     QButtonAxisInputPrivate()
         : QAbstractAxisInputPrivate()
         , m_scale(0.0f)
+        , m_acceleration(-1.0f)
+        , m_deceleration(-1.0f)
     {}
 
     QVector<int> m_buttons;
     float m_scale;
+    float m_acceleration;
+    float m_deceleration;
 };
 
 struct QButtonAxisInputData : public QAbstractAxisInputData
 {
     QVector<int> buttons;
     float scale;
+    float acceleration;
+    float deceleration;
 };
 
 } // Qt3DInput