Add shortcut to change focus interpolation time (#707)

Closes #707 

include/openspace/interaction/navigationhandler.h

@@ -58,6 +58,7 @@ public:
     void setFocusNode(SceneGraphNode* node);
     void setCamera(Camera* camera);
     void resetCameraDirection();
+    void setInterpolationTime(float durationInSeconds);
 
     void setCameraStateFromDictionary(const ghoul::Dictionary& cameraDict);
 
@@ -72,6 +73,7 @@ public:
     const InputState& inputState() const;
     const OrbitalNavigator& orbitalNavigator() const;
     KeyframeNavigator& keyframeNavigator() const;
+    float interpolationTime() const;
 
     // Callback functions
     void keyboardCallback(Key key, KeyModifier modifier, KeyAction action);

include/openspace/interaction/orbitalnavigator.h

@@ -55,6 +55,8 @@ public:
 
     void setFocusNode(SceneGraphNode* focusNode);
     void startInterpolateCameraDirection(const Camera& camera);
+    float rotateToFocusInterpolationTime() const;
+    void setRotateToFocusInterpolationTime(float durationInSeconds);
 
     JoystickCameraStates& joystickStates();
 

modules/imgui/src/guispacetimecomponent.cpp

@@ -153,6 +153,19 @@ void GuiSpaceTimeComponent::render() {
         );
     }
 
+    float interpolationTime = global::navigationHandler.interpolationTime();
+    const bool interpolationTimeChanged = ImGui::SliderFloat(
+        "Interpolation Time",
+        &interpolationTime,
+        0.f,
+        10.f,
+        "%.1f seconds"
+    );
+
+    if (interpolationTimeChanged) {
+        global::navigationHandler.setInterpolationTime(interpolationTime);
+    }
+
     ImGui::SetCursorPosY(ImGui::GetCursorPosY() + 20.f);
 
     ImGui::Separator();

src/interaction/navigationhandler.cpp

@@ -135,6 +135,14 @@ KeyframeNavigator& NavigationHandler::keyframeNavigator() const {
     return *_keyframeNavigator;
 }
 
+float NavigationHandler::interpolationTime() const {
+    return _orbitalNavigator->rotateToFocusInterpolationTime();
+}
+
+void NavigationHandler::setInterpolationTime(float durationInSeconds) {
+    _orbitalNavigator->setRotateToFocusInterpolationTime(durationInSeconds);
+}
+
 void NavigationHandler::updateCamera(double deltaTime) {
     ghoul_assert(_inputState != nullptr, "InputState must not be nullptr");
     ghoul_assert(_camera != nullptr, "Camera must not be nullptr");

src/interaction/orbitalnavigator.cpp

@@ -404,6 +404,14 @@ void OrbitalNavigator::startInterpolateCameraDirection(const Camera& camera) {
     _cameraToSurfaceDistanceInterpolator.start();
 }
 
+float OrbitalNavigator::rotateToFocusInterpolationTime() const {
+    return _rotateToFocusInterpolationTime;
+}
+
+void OrbitalNavigator::setRotateToFocusInterpolationTime(float durationInSeconds) {
+    _rotateToFocusInterpolationTime = durationInSeconds;
+}
+
 bool OrbitalNavigator::followingNodeRotation() const {
     return _followRotationInterpolator.value() >= 1.0;
 }