Generalize pointer scaling and color change during trigger event (#1076)

* Renames Controller::pinchFactor to Controller::selectFactor

Right now we are using the `pinchFactor` value to scale the pointer target
as a select (trigger) gesture is closing during hand-tracking.

But since we are going to extend this to controllers' trigger button, we
are renaming it to `selectFactor` to make it generic to a select event.

* Scale down and change color of pointer target during select event

This patch extends the feature we currently have for pinch gesture,
where the pointer target is scaled as the pinch gesture closes, until
it is fully closed and the color is changed to blue.

With this, we provide a nice visual cue of the trigger event to the
user, and also make Wolvic interactions more consistent.

* Reduce pointer target maximum size a bit

It was (arguably) a bit too big already, and now that we are using it
for controllers too, it makes sense to reduce it a bit.

app/src/main/cpp/BrowserWorld.cpp

@@ -88,7 +88,7 @@ const double kHoverRate = 1.0 / 10.0;
 // 'azure' color, for active pinch gesture while on hand mode
 const vrb::Color kPointerColorSelected = vrb::Color(0.32f, 0.56f, 0.88f);
 // How big is the pointer target while in hand-tracking mode
-const float kPointerPinchSize = 5.0;
+const float kPointerSize = 3.0;
 
 class SurfaceObserver;
 typedef std::shared_ptr<SurfaceObserver> SurfaceObserverPtr;
@@ -515,16 +515,11 @@ BrowserWorld::State::UpdateControllers(bool& aRelayoutWidgets) {
         controller.pointer->SetTransform(reorient.AfineInverse().PostMultiply(translation).PostMultiply(localRotation));
 
         const float scale = (hitPoint - device->GetHeadTransform().MultiplyPosition(vrb::Vector(0.0f, 0.0f, 0.0f))).Magnitude();
-        if (controller.mode == ControllerMode::Device) {
-          controller.pointer->SetScale(scale);
+        controller.pointer->SetScale(scale + kPointerSize - controller.selectFactor * kPointerSize);
+        if (controller.selectFactor >= 1.0f)
+          controller.pointer->SetPointerColor(kPointerColorSelected);
+        else
           controller.pointer->SetPointerColor(VRBrowser::GetPointerColor());
-        } else {
-          controller.pointer->SetScale(scale + kPointerPinchSize - controller.pinchFactor * kPointerPinchSize);
-          if (controller.pinchFactor >= 1.0f)
-            controller.pointer->SetPointerColor(kPointerColorSelected);
-          else
-            controller.pointer->SetPointerColor(VRBrowser::GetPointerColor());
-        }
       }
     }
 
@@ -552,7 +547,7 @@ BrowserWorld::State::UpdateControllers(bool& aRelayoutWidgets) {
       vrb::Matrix iconMatrix = vrb::Matrix::Identity();
 
       // Scale the button down as the pinch gesture is closing
-      float scale = 1.0 - controller.pinchFactor * 0.5f;
+      float scale = 1.0 - controller.selectFactor * 0.5f;
       // Make the button disappear if pinch is closed
       scale = scale <= 0.5f ? 0.0f : scale;
       iconMatrix.ScaleInPlace(vrb::Vector(scale, scale, scale));

app/src/main/cpp/Controller.cpp

@@ -81,6 +81,7 @@ Controller::operator=(const Controller& aController) {
   handActionEnabled = aController.handActionEnabled;
   handActionButtonToggle = aController.handActionButtonToggle;
   handActionButtonTransform = aController.handActionButtonTransform;
+  selectFactor = aController.selectFactor;
   return *this;
 }
 
@@ -133,6 +134,7 @@ Controller::Reset() {
   handActionEnabled = false;
   handActionButtonToggle = nullptr;
   handActionButtonTransform = nullptr;
+  selectFactor = 0.0;
 }
 
 vrb::Vector Controller::StartPoint() const {

app/src/main/cpp/Controller.h

@@ -49,7 +49,7 @@ struct Controller {
   bool handActionEnabled;
   vrb::TogglePtr handActionButtonToggle;
   vrb::TransformPtr handActionButtonTransform;
-  float pinchFactor;
+  float selectFactor;
   vrb::TransformPtr beamParent;
   PointerPtr pointer;
   vrb::Matrix transformMatrix;

app/src/main/cpp/ControllerContainer.cpp

@@ -249,11 +249,11 @@ void ControllerContainer::SetMode(const int32_t aControllerIndex, ControllerMode
   m.list[aControllerIndex].mode = aMode;
 }
 
-void ControllerContainer::SetPinchFactor(const int32_t aControllerIndex, float aFactor)
+void ControllerContainer::SetSelectFactor(const int32_t aControllerIndex, float aFactor)
 {
   if (!m.Contains(aControllerIndex))
     return;
-  m.list[aControllerIndex].pinchFactor = aFactor;
+  m.list[aControllerIndex].selectFactor = aFactor;
 }
 
 void ControllerContainer::SetAimEnabled(const int32_t aControllerIndex, bool aEnabled) {

app/src/main/cpp/ControllerContainer.h

@@ -71,7 +71,7 @@ class ControllerContainer : public crow::ControllerDelegate  {
   void SetAimEnabled(const int32_t aControllerIndex, bool aEnabled = true) override;
   void SetHandActionEnabled(const int32_t aControllerIndex, bool aEnabled = false) override;
   void SetMode(const int32_t aControllerIndex, ControllerMode aMode = ControllerMode::None) override;
-  void SetPinchFactor(const int32_t aControllerIndex, float aFactor = 1.0f) override;
+  void SetSelectFactor(const int32_t aControllerIndex, float aFactor = 1.0f) override;
   void SetFrameId(const uint64_t aFrameId);
 protected:
   struct State;

app/src/main/cpp/ControllerDelegate.h

@@ -84,7 +84,7 @@ class ControllerDelegate {
   virtual void SetAimEnabled(const int32_t aControllerIndex, bool aEnabled = true) = 0;
   virtual void SetHandActionEnabled(const int32_t aControllerIndex, bool aEnabled = false) = 0;
   virtual void SetMode(const int32_t aControllerIndex, ControllerMode aMode = ControllerMode::None) = 0;
-  virtual void SetPinchFactor(const int32_t aControllerIndex, float aFactor = 1.0f) = 0;
+  virtual void SetSelectFactor(const int32_t aControllerIndex, float aFactor = 1.0f) = 0;
 protected:
   ControllerDelegate() {}
 private:

app/src/openxr/cpp/OpenXRInputSource.cpp

@@ -645,7 +645,7 @@ void OpenXRInputSource::EmulateControllerFromHand(device::RenderMode renderMode,
     double pinchFactor = 0.0f;
     mGestureManager->getTriggerPinchStatusAndFactor(mHandJoints, indexPinching, pinchFactor);
 
-    delegate.SetPinchFactor(mIndex, pinchFactor);
+    delegate.SetSelectFactor(mIndex, pinchFactor);
     bool triggerButtonPressed = indexPinching && !systemGestureDetected && hasAim;
     delegate.SetButtonState(mIndex, ControllerDelegate::BUTTON_TRIGGER,
                             device::kImmersiveButtonTrigger, triggerButtonPressed,
@@ -829,6 +829,9 @@ void OpenXRInputSource::Update(const XrFrameState& frameState, XrSpace localSpac
         auto immersiveButton = GetImmersiveButton(button);
         delegate.SetButtonState(mIndex, browserButton, immersiveButton.has_value() ? immersiveButton.value() : -1, state->clicked, state->touched, state->value);
 
+        if (button.type == OpenXRButtonType::Trigger)
+            delegate.SetSelectFactor(mIndex, state->value);
+
         // Select action
         if (renderMode == device::RenderMode::Immersive && button.type == OpenXRButtonType::Trigger && state->clicked != selectActionStarted) {
           selectActionStarted = state->clicked;