implemented bezier interpolation into parameters inputs

app/widget/curvewidget/beziercontrolpointitem.cpp

@@ -74,7 +74,9 @@ void BezierControlPointItem::UpdatePos()
 
   // Scale handle offset
   handle_offset.setX(handle_offset.x() * x_scale_);
-  handle_offset.setY(handle_offset.y() * y_scale_);
+
+  // Flip the Y coordinate because bezier curves are drawn bottom to top
+  handle_offset.setY(-handle_offset.y() * y_scale_);
 
   setPos(handle_offset - rect().center());
 }

app/widget/curvewidget/curveview.cpp

@@ -236,7 +236,8 @@ void CurveView::SetItemYFromKeyframeValue(NodeKeyframe *key, KeyframeViewItem *i
 
 QPointF CurveView::ScalePoint(const QPointF &point)
 {
-  return QPointF(point.x() * scale_, point.y() * y_scale_);
+  // Flips Y coordinate because curves are drawn bottom to top
+  return QPointF(point.x() * scale_, - point.y() * y_scale_);
 }
 
 void CurveView::KeyframeValueChanged()

app/widget/keyframeview/keyframeviewbase.cpp

@@ -54,8 +54,6 @@ void KeyframeViewBase::mousePressEvent(QMouseEvent *event)
 
   active_tool_ = Core::instance()->tool();
 
-  rubberBandSelectionMode();
-
   if (event->button() == Qt::LeftButton) {
     QGraphicsView::mousePressEvent(event);
 
@@ -203,8 +201,11 @@ QPointF KeyframeViewBase::GenerateBezierControlPosition(const NodeKeyframe::Bezi
   return new_bezier_pos;
 }
 
-void KeyframeViewBase::ProcessBezierDrag(const QPointF& mouse_diff_scaled, bool include_opposing, bool undoable)
+void KeyframeViewBase::ProcessBezierDrag(QPointF mouse_diff_scaled, bool include_opposing, bool undoable)
 {
+  // Flip the mouse Y because bezier control points are drawn bottom to top, not top to bottom
+  mouse_diff_scaled.setY(-mouse_diff_scaled.y());
+
   QPointF new_bezier_pos = GenerateBezierControlPosition(dragging_bezier_point_->mode(),
                                                          dragging_bezier_point_start_,
                                                          mouse_diff_scaled);

app/widget/keyframeview/keyframeviewbase.h

@@ -38,7 +38,7 @@ private:
                                                const QPointF& start_point,
                                                const QPointF& scaled_cursor_diff);
 
-  void ProcessBezierDrag(const QPointF& mouse_diff_scaled, bool include_opposing, bool undoable);
+  void ProcessBezierDrag(QPointF mouse_diff_scaled, bool include_opposing, bool undoable);
 
   QPointF GetScaledCursorPos(const QPoint& cursor_pos);