Improve capturing of cursor in mouse lock mode

- Avoid jumpy first motion after activating lock - Fix capture of cursor to map center -- because the camera controller has no knowledge of the map canvas geometry (specifically the window position), we can't set the global mouse cursor position directly from the controller and instead need to push reponsibility for this up to the 3d map canvas widget instead
qgis · Jan 14, 2021 · a630ef4 · a630ef4
1 parent 0cb2f50
commit a630ef4
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Showing 4 changed files with 24 additions and 21 deletions.
diff --git a/src/3d/qgscameracontroller.cpp b/src/3d/qgscameracontroller.cpp
@@ -614,36 +614,41 @@ void QgsCameraController::onPositionChangedFlyNavigation( Qt3DInput::QMouseEvent
 
   if ( mCaptureFpsMouseMovements )
   {
+    const double dx = QCursor::pos().x() - mMousePos.x();
+    const double dy = QCursor::pos().y() - mMousePos.y();
+    mMousePos = QCursor::pos();
+
     if ( mIgnoreNextMouseMove )
     {
       mIgnoreNextMouseMove = false;
       return;
     }
 
-    double dx = QCursor::pos().x() - mMousePos.x();
-    double dy = QCursor::pos().y() - mMousePos.y();
     if ( mPressedButton != Qt3DInput::QMouseEvent::RightButton )
     {
       float diffPitch = -1 * 0.2f * dy;
       float diffYaw = - 0.2f * dx;
       rotateCamera( diffPitch, diffYaw );
       updateCameraFromPose( false );
     }
+
     mIgnoreNextMouseMove = true;
-    QCursor::setPos( mViewport.width(), mViewport.height() );
-    mMousePos = QCursor::pos();
+
+    // reset cursor back to center of map widget
+    emit setCursorPosition( QPoint( mViewport.width() / 2, mViewport.height() / 2 ) );
   }
   else
   {
+    const double dx = mouse->x() - mMousePos.x();
+    const double dy = mouse->y() - mMousePos.y();
+    mMousePos = QPoint( mouse->x(), mouse->y() );
+
     if ( mIgnoreNextMouseMove )
     {
-      mMousePos = QPoint( mouse->x(), mouse->y() );
       mIgnoreNextMouseMove = false;
       return;
     }
 
-    double dx = mouse->x() - mMousePos.x();
-    double dy = mouse->y() - mMousePos.y();
     if ( mPressedButton ==  Qt3DInput::QMouseEvent::LeftButton || mPressedButton ==  Qt3DInput::QMouseEvent::MiddleButton )
     {
       float diffPitch = 0.2f * dy;
@@ -659,8 +664,6 @@ void QgsCameraController::onPositionChangedFlyNavigation( Qt3DInput::QMouseEvent
       QVector3D cameraPosDiff = dx / mViewport.width() * cameraLeft + dy / mViewport.height() * cameraUp;
       moveCameraPositionBy( 5.0 * mCameraMovementSpeed * cameraPosDiff );
     }
-
-    mMousePos = QPoint( mouse->x(), mouse->y() );
   }
 }
 

diff --git a/src/3d/qgscameracontroller.h b/src/3d/qgscameracontroller.h
@@ -196,6 +196,12 @@ class _3D_EXPORT QgsCameraController : public Qt3DCore::QEntity
     //! Emitted when the navigation mode is changed using the hotkey ctrl + ~
     void navigationModeHotKeyPressed( QgsCameraController::NavigationMode mode );
 
+    /**
+     * Emitted when the mouse cursor position should be moved to the specified \a point
+     * on the map viewport.
+     */
+    void setCursorPosition( QPoint point );
+
   private slots:
     void onPositionChanged( Qt3DInput::QMouseEvent *mouse );
     void onWheel( Qt3DInput::QWheelEvent *wheel );

diff --git a/src/app/3d/qgs3dmapcanvas.cpp b/src/app/3d/qgs3dmapcanvas.cpp
@@ -113,15 +113,11 @@ void Qgs3DMapCanvas::setMap( Qgs3DMapSettings *map )
   resetView();
 
   // Connect the camera to the navigation widget.
-  QObject::connect(
-    this->cameraController(),
-    &QgsCameraController::cameraChanged,
-    mNavigationWidget,
-    [ = ]
+  connect( cameraController(), &QgsCameraController::cameraChanged, mNavigationWidget, &Qgs3DNavigationWidget::updateFromCamera );
+  connect( cameraController(), &QgsCameraController::setCursorPosition, this, [ = ]( QPoint point )
   {
-    mNavigationWidget->updateFromCamera();
-  }
-  );
+    QCursor::setPos( mapToGlobal( point ) );
+  } );
 
   emit mapSettingsChanged();
 }

diff --git a/src/app/3d/qgs3dnavigationwidget.h b/src/app/3d/qgs3dnavigationwidget.h
@@ -31,15 +31,13 @@ class Qgs3DNavigationWidget : public QWidget
   public:
     Qgs3DNavigationWidget( Qgs3DMapCanvas *parent = nullptr );
 
+  public slots:
+
     /**
      * Update the state of navigation widget from camera's state
      */
     void updateFromCamera();
 
-  signals:
-
-  public slots:
-
   private:
     Qgs3DMapCanvas *mParent3DMapCanvas = nullptr;
     QToolButton *mZoomInButton = nullptr;