Salome HOME
Issue #1834: Fix length of lines
[modules/shaper.git] / src / SketchPlugin / SketchPlugin_ConstraintSplit.cpp
index e53185f413b11ceb49bbbf5e3a36e75866733a02..156dc33fa77c26aecca9e8bbc00b0263727cdcb3 100755 (executable)
@@ -1,13 +1,17 @@
 // Copyright (C) 2014-20xx CEA/DEN, EDF R&D -->
 
 // File:    SketchPlugin_ConstraintSplit.cpp
-// Created: 17 Jul 2016
+// Created: 25 Aug 2016
 // Author:  Natalia ERMOLAEVA
 
 #include "SketchPlugin_ConstraintSplit.h"
 
+#include <GeomAPI_Dir2d.h>
 #include <GeomAPI_Pnt2d.h>
+#include <GeomAPI_XY.h>
 #include <GeomDataAPI_Point2D.h>
+#include <GeomAlgoAPI_ShapeTools.h>
+
 #include <ModelAPI_AttributeReference.h>
 #include <ModelAPI_AttributeString.h>
 #include <ModelAPI_AttributeRefAttr.h>
@@ -15,6 +19,7 @@
 
 #include <ModelAPI_Validator.h>
 #include <ModelAPI_Session.h>
+#include <ModelAPI_AttributeDouble.h>
 
 #include <SketchPlugin_Line.h>
 #include <SketchPlugin_Arc.h>
 #include <SketchPlugin_ConstraintEqual.h>
 #include <SketchPlugin_ConstraintParallel.h>
 #include <SketchPlugin_ConstraintTangent.h>
+#include <SketchPlugin_ConstraintLength.h>
 #include <SketchPlugin_ConstraintMirror.h>
 #include <SketchPlugin_MultiRotation.h>
 #include <SketchPlugin_MultiTranslation.h>
 
-//#include <ModelAPI_Data.h>
 #include <ModelAPI_Events.h>
-//#include <ModelAPI_Session.h>
-//#include <ModelAPI_Validator.h>
-//
 #include <SketchPlugin_Line.h>
 #include <SketchPlugin_Arc.h>
 #include <SketchPlugin_Circle.h>
-//#include <SketchPlugin_Point.h>
-//#include <SketchPlugin_Sketch.h>
-//#include <SketchPlugin_Tools.h>
-//
 
 #include <ModelGeomAlgo_Point2D.h>
 #include <Events_Loop.h>
-//
-//#include <math.h>
-//
-//const double tolerance = 1.e-7;
-//const double paramTolerance = 1.e-4;
-
-///// \brief Attract specified point on theNewArc to the attribute of theFeature
-//static void recalculateAttributes(FeaturePtr theNewArc, const std::string& theNewArcAttribute,
-//  FeaturePtr theFeature, const std::string& theFeatureAttribute);
-//
-///// \brief Calculates center of fillet arc and coordinates of tangency points
-//static void calculateFilletCenter(FeaturePtr theFeatureA, FeaturePtr theFeatureB,
-//                                  double theRadius, bool theNotInversed[2],
-//                                  std::shared_ptr<GeomAPI_XY>& theCenter,
-//                                  std::shared_ptr<GeomAPI_XY>& theTangentA,
-//                                  std::shared_ptr<GeomAPI_XY>& theTangentB);
-//
-///// Get point on 1/3 length of edge from fillet point
-//static void getPointOnEdge(const FeaturePtr theFeature,
-//                           const std::shared_ptr<GeomAPI_Pnt2d> theFilletPoint,
-//                           std::shared_ptr<GeomAPI_Pnt2d>& thePoint);
-//
-///// Get distance from point to feature
-//static double getProjectionDistance(const FeaturePtr theFeature,
-//                             const std::shared_ptr<GeomAPI_Pnt2d> thePoint);
-//
-///// Get coincide edges for fillet
-//static std::set<FeaturePtr> getCoincides(const FeaturePtr& theConstraintCoincidence);
+
+#include <cmath>
+
+//#define DEBUG_SPLIT
+#ifdef DEBUG_SPLIT
+#include <iostream>
+#endif
+
+static const double PI = 3.141592653589793238463;
 
 SketchPlugin_ConstraintSplit::SketchPlugin_ConstraintSplit()
-//: myListOfPointsChangedInCode(false),
-//  myRadiusChangedByUser(false),
-//  myRadiusChangedInCode(false),
-//  myRadiusInitialized(false)
 {
 }
 
@@ -84,9 +59,6 @@ void SketchPlugin_ConstraintSplit::initAttributes()
   data()->addAttribute(SketchPlugin_Constraint::VALUE(), ModelAPI_AttributeReference::typeId());
   data()->addAttribute(SketchPlugin_Constraint::ENTITY_A(), ModelAPI_AttributeRefAttr::typeId());
   data()->addAttribute(SketchPlugin_Constraint::ENTITY_B(), ModelAPI_AttributeRefAttr::typeId());
-
-  //data()->addAttribute(SketchPlugin_Constraint::VALUE(), ModelAPI_AttributeDouble::typeId());
-  //data()->addAttribute(SketchPlugin_Constraint::ENTITY_A(), ModelAPI_AttributeRefAttrList::typeId());
 }
 
 void SketchPlugin_ConstraintSplit::execute()
@@ -100,10 +72,12 @@ void SketchPlugin_ConstraintSplit::execute()
     setError("Error: Base object is not initialized.");
     return;
   }
-  AttributePoint2DPtr aFirstPointAttr = getPointOfRefAttr(aData->attribute(SketchPlugin_Constraint::ENTITY_A()));
-  AttributePoint2DPtr aSecondPointAttr = getPointOfRefAttr(aData->attribute(SketchPlugin_Constraint::ENTITY_B()));
-  if (!aFirstPointAttr.get() || !aFirstPointAttr->isInitialized() ||
-      !aSecondPointAttr.get() || !aSecondPointAttr->isInitialized()) {
+  AttributePoint2DPtr aFirstPointAttrOfSplit = 
+    getPointOfRefAttr(aData->attribute(SketchPlugin_Constraint::ENTITY_A()));
+  AttributePoint2DPtr aSecondPointAttrOfSplit = 
+    getPointOfRefAttr(aData->attribute(SketchPlugin_Constraint::ENTITY_B()));
+  if (!aFirstPointAttrOfSplit.get() || !aFirstPointAttrOfSplit->isInitialized() ||
+      !aSecondPointAttrOfSplit.get() || !aSecondPointAttrOfSplit->isInitialized()) {
     setError("Error: Sub-shape is not initialized.");
     return;
   }
@@ -118,83 +92,232 @@ void SketchPlugin_ConstraintSplit::execute()
   // Find feature constraints
   FeaturePtr aBaseFeature = ModelAPI_Feature::feature(aBaseObjectAttr->value());
   ResultPtr aBaseFeatureResult = getFeatureResult(aBaseFeature);
-
-  std::set<FeaturePtr> aFeaturesToDelete;
+  std::set<FeaturePtr> aFeaturesToDelete, aFeaturesToUpdate;
   std::map<FeaturePtr, IdToPointPair> aTangentFeatures;
   std::map<FeaturePtr, IdToPointPair> aCoincidenceToFeature;
-  std::map<FeaturePtr, IdToPointPair> aCoincidenceToPoint;
-  getConstraints(aFeaturesToDelete, aTangentFeatures, aCoincidenceToFeature, aCoincidenceToPoint);
+  getConstraints(aFeaturesToDelete, aFeaturesToUpdate, aTangentFeatures, aCoincidenceToFeature);
+
+  std::map<AttributePtr, std::list<AttributePtr> > aBaseRefAttributes;
+  std::list<AttributePtr> aRefsToFeature;
+  getRefAttributes(aBaseFeature, aBaseRefAttributes, aRefsToFeature);
+
+  std::map<AttributePtr, AttributePtr> aBasePointModifiedAttributes;
+
+#ifdef DEBUG_SPLIT
+  std::cout << std::endl;
+  std::cout << "SketchPlugin_ConstraintSplit::execute()" << std::endl;
+  std::cout << std::endl;
+
+  SketchPlugin_Sketch* aSketch = sketch();
+  std::cout << "SKETCH FEATURES (before split) [" << aSketch->numberOfSubs() << "]:" << std::endl;
+  for (int i = 0, aNbSubs = aSketch->numberOfSubs(); i < aNbSubs; i++) {
+    std::cout << getFeatureInfo(aSketch->subFeature(i), false) << std::endl;
+  }
+
+  std::cout << std::endl;
+  std::cout << "---- IN PARAMETERS ----" << std::endl;
+  std::cout << "Base feature:" << getFeatureInfo(aBaseFeature) << std::endl;
+  std::cout << std::endl;
+
+  if (!aCoincidenceToFeature.empty()) {
+    std::cout << "Coincidences to base feature[" << 
+      aCoincidenceToFeature.size() << "]: " << std::endl;
+    std::map<FeaturePtr, IdToPointPair>::const_iterator anIt = aCoincidenceToFeature.begin(),
+                                                        aLast = aCoincidenceToFeature.end();
+    for (int i = 1; anIt != aLast; anIt++, i++) {
+      FeaturePtr aFeature = (*anIt).first;
+      std::string anAttributeId = (*anIt).second.first;
+      std::shared_ptr<GeomDataAPI_Point2D> aPointAttr = (*anIt).second.second;
+
+      std::cout << i << "-" << getFeatureInfo(aFeature) << std::endl;
+      std::cout <<     " -Attribute to correct:" << anAttributeId << std::endl;
+      std::cout <<     " -Point attribute:" << 
+        ModelGeomAlgo_Point2D::getPointAttributeInfo(aPointAttr) << std::endl;
+    }
+  }
+
+  if (!aTangentFeatures.empty()) {
+    std::cout << std::endl;
+    std::cout << "Tangencies to base feature[" << aTangentFeatures.size() << "]: " << std::endl;
+    std::map<FeaturePtr, IdToPointPair>::const_iterator anIt = aTangentFeatures.begin(),
+                                                        aLast = aTangentFeatures.end();
+    for (int i = 1; anIt != aLast; anIt++, i++) {
+      FeaturePtr aFeature = (*anIt).first;
+      std::string anAttributeId = (*anIt).second.first;
+      std::shared_ptr<GeomDataAPI_Point2D> aPointAttr = (*anIt).second.second;
+
+      std::cout << i << "-" << getFeatureInfo(aFeature) << std::endl;
+      std::cout <<     " -Attribute to correct:" << anAttributeId << std::endl;
+      std::cout <<     " -Point attribute:" << 
+        ModelGeomAlgo_Point2D::getPointAttributeInfo(aPointAttr) << std::endl;
+    }
+  }
+
+  std::map<AttributePtr, std::list<AttributePtr> >::const_iterator 
+    aRefIt = aBaseRefAttributes.begin(), aRefLast = aBaseRefAttributes.end();
+  std::cout << std::endl << "References to attributes of base feature [" << 
+    aBaseRefAttributes.size() << "]" << std::endl;
+  for (; aRefIt != aRefLast; aRefIt++) {
+    AttributePtr aBaseAttr = aRefIt->first;
+    std::list<AttributePtr> aRefAttributes = aRefIt->second;
+    std::string aRefsInfo;
+    std::list<AttributePtr>::const_iterator aRefAttrIt = aRefAttributes.begin(),
+                                            aRefAttrLast = aRefAttributes.end();
+    for (; aRefAttrIt != aRefAttrLast; aRefAttrIt++) {
+      if (!aRefsInfo.empty())
+        aRefsInfo.append(",");
+      AttributePtr aRAttr = *aRefAttrIt;
+      aRefsInfo.append(aRAttr->id());
+      FeaturePtr aRFeature = ModelAPI_Feature::feature(aRAttr->owner());
+      aRefsInfo.append("(" + aRFeature->name() + ") ");
+    }
+    std::shared_ptr<GeomDataAPI_Point2D> aPointAttr = 
+      std::dynamic_pointer_cast<GeomDataAPI_Point2D>(aBaseAttr);
+    std::cout << aPointAttr->id().c_str() << 
+      ": " << "[" << aRefAttributes.size() << "] " << aRefsInfo << std::endl;
+  }
+  std::cout << std::endl;
+  std::cout << std::endl << "References to base feature [" << 
+    aRefsToFeature.size() << "]" << std::endl;
+  std::list<AttributePtr>::const_iterator aRefAttrIt = aRefsToFeature.begin(),
+                                          aRefAttrLast = aRefsToFeature.end();
+  std::string aRefsInfo;
+  for (; aRefAttrIt != aRefAttrLast; aRefAttrIt++) {
+    if (!aRefsInfo.empty())
+      aRefsInfo.append(",");
+    AttributePtr aRAttr = *aRefAttrIt;
+    aRefsInfo.append(aRAttr->id());
+    FeaturePtr aRFeature = ModelAPI_Feature::feature(aRAttr->owner());
+    aRefsInfo.append("(" + aRFeature->name() + ") ");
+  }
+  std::cout << "[" << aRefsToFeature.size() << "] " << aRefsInfo << std::endl;
 
 
+  std::cout << std::endl;
+  std::cout << "---- SPLIT ----" << std::endl;
+  std::cout << std::endl;
+#endif
+
   std::string aFeatureKind = aBaseFeature->getKind();
   FeaturePtr aSplitFeature, anAfterFeature;
   std::set<AttributePoint2DPtr> aFurtherCoincidences;
-  /*if (aFeatureKind == SketchPlugin_Line::ID())
-    splitLine(aSplitFeature, anOtherFeatures);
-  else*/ if (aFeatureKind == SketchPlugin_Arc::ID())
-    splitArc(aSplitFeature, aBaseFeature, anAfterFeature, aFurtherCoincidences);
-  /*if (aFeatureKind == SketchPlugin_Circle::ID())
-    splitCircle(aSplitFeature, anOtherFeatures);
-  FeaturePtr aSplitFeature;
-  std::set<FeaturePtr> anOtherFeatures;*/
-
-  //setConstraints(aSplitFeature, aBaseFeature, anAfterFeature, aFeaturesToDelete, aTangentFeatures,
-  //               aCoincidenceToFeature, aCoincidenceToPoint);
-  if (true) {
+  std::set<FeaturePtr> aCreatedFeatures;
+  std::set<std::pair<AttributePtr, AttributePtr>> aModifiedAttributes;
+  if (aFeatureKind == SketchPlugin_Line::ID())
+    splitLine(aSplitFeature, aBaseFeature, anAfterFeature, aFurtherCoincidences, aCreatedFeatures,
+              aModifiedAttributes);
+  else if (aFeatureKind == SketchPlugin_Arc::ID())
+    splitArc(aSplitFeature, aBaseFeature, anAfterFeature, aFurtherCoincidences, aCreatedFeatures,
+             aModifiedAttributes);
+  if (aFeatureKind == SketchPlugin_Circle::ID()) {
+    FeaturePtr aCircleFeature = aBaseFeature;
+    splitCircle(aSplitFeature, aBaseFeature, anAfterFeature, aFurtherCoincidences, 
+      aCreatedFeatures, aModifiedAttributes);
+
+    updateRefFeatureConstraints(getFeatureResult(aBaseFeature), aRefsToFeature);
+
+    aFeaturesToDelete.insert(aCircleFeature);
+    // as circle is removed, temporary fill this attribute*/
+    aBaseObjectAttr->setObject(ResultPtr());
+  }
+
+#ifdef DEBUG_SPLIT
+  std::cout << "---- OUT PARAMETERS ----" << std::endl;
+  std::cout << "Base modified feature:" << getFeatureInfo(aBaseFeature) << std::endl;
+  std::cout << "Split feature:" << getFeatureInfo(aSplitFeature) << std::endl;
+  std::cout << "After feature:" << getFeatureInfo(anAfterFeature) << std::endl;
+  std::cout << std::endl;
+
+  std::cout << "Created features by split:[" << aCreatedFeatures.size() << "]" << std::endl;
+  std::set<FeaturePtr>::const_iterator aFIt = aCreatedFeatures.begin(),
+                                       aFLast = aCreatedFeatures.end();
+  for (; aFIt != aFLast; aFIt++) {
+    std::cout << getFeatureInfo(*aFIt) << std::endl;
+  }
+  std::cout << std::endl;
+
+  std::cout << "Attributes for further Coincidences:" << std::endl;
+  std::set<AttributePoint2DPtr>::const_iterator anIt = aFurtherCoincidences.begin(),
+                                                aLast = aFurtherCoincidences.end();
+  for (; anIt != aLast; anIt++) {
+    AttributePtr anAttribute = *anIt;
+    FeaturePtr aFeature = ModelAPI_Feature::feature(anAttribute->owner());
+    std::cout << ModelGeomAlgo_Point2D::getPointAttributeInfo(anAttribute)
+              << " [" << getFeatureInfo(aFeature, false) << "]" << std::endl;
+  }
+
+  std::cout << "Modifed attributes (constraints to attributes are moved here):" << std::endl;
+  std::set<std::pair<AttributePtr, AttributePtr> >::const_iterator 
+    aPIt = aModifiedAttributes.begin(), aPLast = aModifiedAttributes.end();
+  std::string aResInfo;
+  for (; aPIt != aPLast; aPIt++) {
+    if (!aResInfo.empty())
+      aResInfo += "\n";
+
+    std::pair<AttributePtr, AttributePtr> aPair = *aPIt;
+
+    AttributePtr anAttr = aPair.first;
+    aResInfo.append(anAttr->id());
+    FeaturePtr aFeature = ModelAPI_Feature::feature(anAttr->owner());
+    aResInfo.append("(" + aFeature->name() + ") ");
+
+    aResInfo.append("  - is modified to -  ");
+
+    anAttr = aPair.second;
+    aResInfo.append(anAttr->id());
+    aFeature = ModelAPI_Feature::feature(anAttr->owner());
+    aResInfo.append("(" + aFeature->name() + ") ");
+  }
+  std::cout << aResInfo << std::endl;
+#endif
+
   std::set<ResultPtr> aFeatureResults;
   aFeatureResults.insert(getFeatureResult(aBaseFeature));
   if (anAfterFeature.get() && anAfterFeature != aBaseFeature)
     aFeatureResults.insert(getFeatureResult(anAfterFeature));
 
   // coincidence to feature
-  std::map<FeaturePtr, IdToPointPair>::const_iterator aCIt = aCoincidenceToFeature.begin(),
-                                                            aCLast = aCoincidenceToFeature.end();
-  for (; aCIt != aCLast; aCIt++) {
-    FeaturePtr aCoincFeature = aCIt->first;
-    std::string anAttributeId = aCIt->second.first;
-    AttributePoint2DPtr aCoincPoint = aCIt->second.second;
-    std::set<AttributePoint2DPtr>::const_iterator aFCIt = aFurtherCoincidences.begin(),
-                                                  aFCLast = aFurtherCoincidences.end();
-    std::shared_ptr<GeomAPI_Pnt2d> aCoincPnt = aCoincPoint->pnt();
-    AttributePoint2DPtr aFeaturePointAttribute;
-    for (; aFCIt != aFCLast && !aFeaturePointAttribute.get(); aFCIt++) {
-      AttributePoint2DPtr aFCAttribute = *aFCIt;
-      if (aCoincPnt->isEqual(aFCAttribute->pnt()))
-        aFeaturePointAttribute = aFCAttribute;
-    }
-    if (aFeaturePointAttribute.get()) {
-      aCoincFeature->refattr(anAttributeId)->setAttr(aFeaturePointAttribute);
-    }
-    else {
-      /// find feature by shape intersected the point
-      ResultPtr aResultForCoincidence = *(aFeatureResults.begin());
-
-      if (aFeatureResults.size() > 1) { // try to find point on additional feature
-        ResultPtr anAddtionalResult = *(aFeatureResults.begin()++);
-        GeomShapePtr aShape = anAddtionalResult->shape();
+  updateCoincidenceConstraintsToFeature(aCoincidenceToFeature, aFurtherCoincidences,
+                                        aFeatureResults);
+  // tangency
+  updateTangentConstraintsToFeature(aTangentFeatures, aFurtherCoincidences);
 
-        std::shared_ptr<GeomAPI_Pnt2d> aPnt2d = aCoincPoint->pnt();
-        std::shared_ptr<GeomAPI_Pnt> aPoint = sketch()->to3D(aPnt2d->x(), aPnt2d->y());
+  updateRefAttConstraints(aBaseRefAttributes, aModifiedAttributes);
 
-        std::shared_ptr<GeomAPI_Pnt> aProjectedPoint;
-        if (ModelGeomAlgo_Point2D::isPointOnEdge(aShape, aPoint, aProjectedPoint))
-          aResultForCoincidence = anAddtionalResult;
-      }
-      aCoincFeature->refattr(anAttributeId)->setObject(aResultForCoincidence);
-    }
-  }
-  // coincidence to points
-  // TODO
-  // tangency
-  // TODO
-  }
   // delete constraints
+#ifdef DEBUG_SPLIT
+  std::cout << "remove features and references:" << std::endl;
+  std::set<FeaturePtr>::const_iterator aDIt = aFeaturesToDelete.begin(),
+                                       aDLast = aFeaturesToDelete.end();
+  for (; aDIt != aDLast; aDIt++) {
+    std::cout << getFeatureInfo(*aDIt, false) << std::endl;
+    std::cout << std::endl;
+  }
+#endif
   ModelAPI_Tools::removeFeaturesAndReferences(aFeaturesToDelete);
 
+#ifdef DEBUG_SPLIT
+  std::cout << "update features after split:" << std::endl;
+  std::set<FeaturePtr>::const_iterator anUIt = aFeaturesToUpdate.begin(),
+                                       anULast = aFeaturesToUpdate.end();
+  for (; anUIt != anULast; anUIt++) {
+    std::cout << getFeatureInfo(*anUIt, false) << std::endl;
+    std::cout << std::endl;
+  }
+#endif
+  updateFeaturesAfterSplit(aFeaturesToUpdate);
+
   // Send events to update the sub-features by the solver.
   if(isUpdateFlushed) {
     Events_Loop::loop()->setFlushed(anUpdateEvent, true);
   }
+
+#ifdef DEBUG_SPLIT
+  std::cout << "SKETCH FEATURES (after split) [" << aSketch->numberOfSubs() << "]:" << std::endl;
+  for (int i = 0, aNbSubs = aSketch->numberOfSubs(); i < aNbSubs; i++) {
+    std::cout << getFeatureInfo(aSketch->subFeature(i), false) << std::endl;
+  }
+#endif
 }
 
 bool SketchPlugin_ConstraintSplit::isMacro() const
@@ -202,13 +325,64 @@ bool SketchPlugin_ConstraintSplit::isMacro() const
   return true;
 }
 
+AISObjectPtr SketchPlugin_ConstraintSplit::getAISObject(AISObjectPtr thePrevious)
+{
+  AttributeReferencePtr aBaseObjectAttr = std::dynamic_pointer_cast<ModelAPI_AttributeReference>(
+                                           data()->attribute(SketchPlugin_Constraint::VALUE()));
+  FeaturePtr aBaseFeature = ModelAPI_Feature::feature(aBaseObjectAttr->value());
+
+  AttributePoint2DPtr aFirstPointAttrOfSplit = getPointOfRefAttr(
+                                        data()->attribute(SketchPlugin_Constraint::ENTITY_A()));
+  AttributePoint2DPtr aSecondPointAttrOfSplit = getPointOfRefAttr(
+                                        data()->attribute(SketchPlugin_Constraint::ENTITY_B()));
+
+  if (aBaseObjectAttr->isInitialized() && aBaseFeature.get() &&
+      aFirstPointAttrOfSplit->isInitialized() &&
+      aSecondPointAttrOfSplit->isInitialized()) {
+
+    ResultPtr aResult = getFeatureResult(aBaseFeature);
+    GeomShapePtr aBaseShape = aResult->shape();
+    std::list<std::shared_ptr<GeomAPI_Pnt> > aPoints;
+
+    std::shared_ptr<GeomAPI_Pnt2d> aStartPnt2d = aFirstPointAttrOfSplit->pnt();
+    std::shared_ptr<GeomAPI_Pnt> aStartPoint = sketch()->to3D(aStartPnt2d->x(), aStartPnt2d->y());
+    aPoints.push_back(aStartPoint);
+
+    std::shared_ptr<GeomAPI_Pnt2d> aSecondPnt2d = aSecondPointAttrOfSplit->pnt();
+    std::shared_ptr<GeomAPI_Pnt> aSecondPoint = 
+      sketch()->to3D(aSecondPnt2d->x(), aSecondPnt2d->y());
+    aPoints.push_back(aSecondPoint);
+
+    std::set<std::shared_ptr<GeomAPI_Shape> > aSplitShapes;
+
+    GeomAlgoAPI_ShapeTools::splitShape(aBaseShape, aPoints, aSplitShapes);
+    std::shared_ptr<GeomAPI_Shape> aShape = 
+      GeomAlgoAPI_ShapeTools::findShape(aPoints, aSplitShapes);
+
+    AISObjectPtr anAIS = thePrevious;
+    if (aShape) {
+      if (!anAIS)
+        anAIS = AISObjectPtr(new GeomAPI_AISObject);
+      anAIS->createShape(aShape);
+      anAIS->setWidth(5);
+      std::vector<int> aColor;
+      aColor = Config_PropManager::color("Visualization", "sketch_entity_color",
+                                          SKETCH_ENTITY_COLOR);
+     anAIS->setColor(aColor[0], aColor[1], aColor[2]);
+    }
+    return anAIS;
+  }
+  return AISObjectPtr();
+}
+
 std::shared_ptr<GeomDataAPI_Point2D> SketchPlugin_ConstraintSplit::getPointOfRefAttr(
-                                                                  const AttributePtr& theAttribute)
+                                                      const AttributePtr& theAttribute)
 {
   AttributePoint2DPtr aPointAttribute;
 
   if (theAttribute->attributeType() == ModelAPI_AttributeRefAttr::typeId()) {
-    AttributeRefAttrPtr aRefAttr = std::dynamic_pointer_cast<ModelAPI_AttributeRefAttr>(theAttribute);
+    AttributeRefAttrPtr aRefAttr = 
+      std::dynamic_pointer_cast<ModelAPI_AttributeRefAttr>(theAttribute);
     if (aRefAttr.get() && aRefAttr->isInitialized()) {
       AttributePtr anAttribute = aRefAttr->attr();
       if (anAttribute.get() && anAttribute->attributeType() == GeomDataAPI_Point2D::typeId())
@@ -239,16 +413,16 @@ void SketchPlugin_ConstraintSplit::getFeaturePoints(AttributePoint2DPtr& theStar
   }
   if (!aStartAttributeName.empty() && !anEndAttributeName.empty()) {
     theStartPointAttr = std::dynamic_pointer_cast<GeomDataAPI_Point2D>(
-                                                         aBaseFeature->attribute(aStartAttributeName));
+                                         aBaseFeature->attribute(aStartAttributeName));
     theEndPointAttr = std::dynamic_pointer_cast<GeomDataAPI_Point2D>(
-                                                         aBaseFeature->attribute(anEndAttributeName));
+                                         aBaseFeature->attribute(anEndAttributeName));
   }
 }
 
 void SketchPlugin_ConstraintSplit::getConstraints(std::set<FeaturePtr>& theFeaturesToDelete,
+                                      std::set<FeaturePtr>& theFeaturesToUpdate,
                                       std::map<FeaturePtr, IdToPointPair>& theTangentFeatures,
-                                      std::map<FeaturePtr, IdToPointPair>& theCoincidenceToFeature,
-                                      std::map<FeaturePtr, IdToPointPair>& theCoincidenceToPoint)
+                                      std::map<FeaturePtr, IdToPointPair>& theCoincidenceToFeature)
 {
   std::shared_ptr<ModelAPI_Data> aData = data();
 
@@ -258,7 +432,10 @@ void SketchPlugin_ConstraintSplit::getConstraints(std::set<FeaturePtr>& theFeatu
   FeaturePtr aBaseFeature = ModelAPI_Feature::feature(aBaseObjectAttr->value());
   ResultPtr aBaseFeatureResult = getFeatureResult(aBaseFeature);
 
-  const std::set<AttributePtr>& aRefsList = aBaseFeatureResult->data()->refsToMe();
+  std::set<AttributePtr> aRefsList = aBaseFeatureResult->data()->refsToMe();
+  std::set<AttributePtr> aFRefsList = aBaseFeature->data()->refsToMe();
+  aRefsList.insert(aFRefsList.begin(), aFRefsList.end());
+
   std::set<AttributePtr>::const_iterator aIt;
   for (aIt = aRefsList.cbegin(); aIt != aRefsList.cend(); ++aIt) {
     std::shared_ptr<ModelAPI_Attribute> aAttr = (*aIt);
@@ -268,28 +445,45 @@ void SketchPlugin_ConstraintSplit::getConstraints(std::set<FeaturePtr>& theFeatu
         aRefFeatureKind == SketchPlugin_MultiRotation::ID() ||
         aRefFeatureKind == SketchPlugin_MultiTranslation::ID())
       theFeaturesToDelete.insert(aRefFeature);
+    else if (aRefFeatureKind == SketchPlugin_ConstraintLength::ID())
+      theFeaturesToUpdate.insert(aRefFeature);
     else if (aRefFeatureKind == SketchPlugin_ConstraintTangent::ID()) {
       if (aBaseFeature->getKind() == SketchPlugin_Circle::ID()) /// TEMPORARY limitaion
-        theFeaturesToDelete.insert(aRefFeature); /// until tangency between arc and line is implemented
+        /// until tangency between arc and line is implemented
+        theFeaturesToDelete.insert(aRefFeature); 
       else {
         std::string anAttributeToBeModified;
         AttributePoint2DPtr aTangentPoint;
         ObjectPtr aResult1 = aRefFeature->refattr(SketchPlugin_Constraint::ENTITY_A())->object();
         ObjectPtr aResult2 = aRefFeature->refattr(SketchPlugin_Constraint::ENTITY_B())->object();
         if (aResult1.get() && aResult2.get()) {
-          FeaturePtr aCoincidenceFeature = SketchPlugin_ConstraintCoincidence::findCoincidenceFeature
-                                                                    (ModelAPI_Feature::feature(aResult1),
-                                                                     ModelAPI_Feature::feature(aResult2));
-          aTangentPoint = SketchPlugin_ConstraintCoincidence::getPoint(aCoincidenceFeature);
+          FeaturePtr aCoincidenceFeature = 
+            SketchPlugin_ConstraintCoincidence::findCoincidenceFeature
+                                                       (ModelAPI_Feature::feature(aResult1),
+                                                        ModelAPI_Feature::feature(aResult2));
+          // get the point not lying on the splitting feature
+          for (int i = 0; i < CONSTRAINT_ATTR_SIZE; ++i) {
+            AttributeRefAttrPtr aRefAttr = aCoincidenceFeature->refattr(ATTRIBUTE(i));
+            if (!aRefAttr || aRefAttr->isObject())
+              continue;
+            AttributePoint2DPtr aPoint =
+                std::dynamic_pointer_cast<GeomDataAPI_Point2D>(aRefAttr->attr());
+            if (!aPoint)
+              continue;
+            if (aPoint->owner() != aBaseFeature) {
+              aTangentPoint = aPoint;
+              break;
+            }
+          }
         }
         if (aTangentPoint.get()) {
           FeaturePtr aFeature1 = ModelAPI_Feature::feature(aResult1);
           std::string anAttributeToBeModified = aFeature1 == aBaseFeature
-                       ? SketchPlugin_Constraint::ENTITY_B() : SketchPlugin_Constraint::ENTITY_A();
+                       ? SketchPlugin_Constraint::ENTITY_A() : SketchPlugin_Constraint::ENTITY_B();
           theTangentFeatures[aRefFeature] = std::make_pair(anAttributeToBeModified, aTangentPoint);
         }
-        else
-          theFeaturesToDelete.insert(aRefFeature); /// there is not coincident point between tangent constraint
+        else /// there is not coincident point between tangent constraint
+          theFeaturesToDelete.insert(aRefFeature); 
       }
     }
     else if (aRefFeatureKind == SketchPlugin_ConstraintCoincidence::ID()) {
@@ -302,25 +496,26 @@ void SketchPlugin_ConstraintSplit::getConstraints(std::set<FeaturePtr>& theFeatu
         FeaturePtr aFeature = anAttrA->isObject() ? ModelAPI_Feature::feature(anAttrA->object())
                                                   : FeaturePtr();
         isToFeature = aFeature.get() && aFeature == aBaseFeature;
-        anAttributeToBeModified = SketchPlugin_Constraint::ENTITY_B();
+        anAttributeToBeModified = anAttrA->id();
         if (!isToFeature) {
           aFeature = anAttrB->isObject() ? ModelAPI_Feature::feature(anAttrB->object())
                                          : FeaturePtr();
           isToFeature = aFeature.get() && aFeature == aBaseFeature;
-          anAttributeToBeModified = SketchPlugin_Constraint::ENTITY_A();
+          anAttributeToBeModified = anAttrB->id();
         }
         if (isToFeature)
           aCoincidentPoint = SketchPlugin_ConstraintCoincidence::getPoint(aRefFeature);
       }
       if (!isToFeature) { /// coincidence to point on base feature
         AttributePtr anAttribute;
+
         if (!anAttrA->isObject()) {
           AttributePtr aCurAttribute = anAttrA->attr();
           if (aCurAttribute.get()) {
             FeaturePtr aCurFeature = ModelAPI_Feature::feature(aCurAttribute->owner());
             if (aCurFeature.get() && aCurFeature == aBaseFeature) {
-              anAttribute = anAttrA->attr();
-              anAttributeToBeModified = SketchPlugin_Constraint::ENTITY_A();
+              anAttribute = anAttrB->attr();
+              anAttributeToBeModified = anAttrA->id();
             }
           }
         }
@@ -329,8 +524,8 @@ void SketchPlugin_ConstraintSplit::getConstraints(std::set<FeaturePtr>& theFeatu
           if (aCurAttribute.get()) {
             FeaturePtr aCurFeature = ModelAPI_Feature::feature(aCurAttribute->owner());
             if (aCurFeature.get() && aCurFeature == aBaseFeature) {
-              anAttribute = anAttrB->attr();
-              anAttributeToBeModified = SketchPlugin_Constraint::ENTITY_B();
+              anAttribute = anAttrA->attr();
+              anAttributeToBeModified = anAttrB->id();
             }
           }
         }
@@ -341,9 +536,6 @@ void SketchPlugin_ConstraintSplit::getConstraints(std::set<FeaturePtr>& theFeatu
         if (isToFeature)
           theCoincidenceToFeature[aRefFeature] = std::make_pair(anAttributeToBeModified,
                                                                 aCoincidentPoint);
-        else
-          theCoincidenceToPoint[aRefFeature] = std::make_pair(anAttributeToBeModified,
-                                                              aCoincidentPoint);
       }
       else
         theFeaturesToDelete.insert(aRefFeature); /// this case should not happen
@@ -351,30 +543,335 @@ void SketchPlugin_ConstraintSplit::getConstraints(std::set<FeaturePtr>& theFeatu
   }
 }
 
-/*void SketchPlugin_ConstraintSplit::setConstraints(const FeaturePtr& theSplitFeature,
-                                                  const FeaturePtr& theBaseFeature,
-                                                  const FeaturePtr& theAfterFeature,
-    const std::set<std::shared_ptr<ModelAPI_Feature>>& theFeaturesToDelete,
-    const std::map<std::shared_ptr<ModelAPI_Feature>, std::shared_ptr<GeomDataAPI_Point2D> >& theTangentFeatures,
-    const std::map<std::shared_ptr<ModelAPI_Feature>, std::shared_ptr<GeomDataAPI_Point2D> >& theCoincidenceToFeature,
-    const std::map<std::shared_ptr<ModelAPI_Feature>, std::shared_ptr<GeomDataAPI_Point2D> >& theCoincidenceToPoint)
+void SketchPlugin_ConstraintSplit::getRefAttributes(const FeaturePtr& theFeature,
+                                    std::map<AttributePtr, std::list<AttributePtr> >& theRefs,
+                                    std::list<AttributePtr>& theRefsToFeature)
 {
-  // coincidence to feature
+  theRefs.clear();
 
+  std::list<AttributePtr> aPointAttributes = 
+    theFeature->data()->attributes(GeomDataAPI_Point2D::typeId());
+  std::set<AttributePtr> aPointAttributesSet;
 
-  // coincidence to points
+  std::list<AttributePtr>::const_iterator aPIt = 
+    aPointAttributes.begin(), aPLast = aPointAttributes.end();
+  for (; aPIt != aPLast; aPIt++)
+    aPointAttributesSet.insert(*aPIt);
 
-  // tangency
+  std::set<AttributePtr> aRefsAttributes = getFeatureResult(theFeature)->data()->refsToMe();
+  std::set<AttributePtr> aFRefsList = theFeature->data()->refsToMe();
+  aRefsAttributes.insert(aFRefsList.begin(), aFRefsList.end());
 
-  // delete constraints
+  std::set<AttributePtr>::const_iterator aIt;
+  for (aIt = aRefsAttributes.cbegin(); aIt != aRefsAttributes.cend(); ++aIt) {
+    AttributePtr anAttr = (*aIt);
+    FeaturePtr anAttrFeature = ModelAPI_Feature::feature(anAttr->owner());
+    if (anAttrFeature.get() != this &&
+        anAttr.get() && anAttr->attributeType() == ModelAPI_AttributeRefAttr::typeId()) {
+      AttributeRefAttrPtr aRefAttr = std::dynamic_pointer_cast<ModelAPI_AttributeRefAttr>(anAttr);
+      if (!aRefAttr->isObject()) { /// find attributes referenced to feature point attributes
+        AttributePtr anAttrInRef = aRefAttr->attr();
+        if (anAttrInRef.get() && 
+            aPointAttributesSet.find(anAttrInRef) != aPointAttributesSet.end()) {
+          if (theRefs.find(anAttrInRef) != theRefs.end())
+            theRefs[anAttrInRef].push_back(aRefAttr);
+          else {
+            std::list<AttributePtr> anAttrList;
+            anAttrList.push_back(aRefAttr);
+            theRefs[anAttrInRef] = anAttrList;
+          }
+        }
+      }
+      else { /// find attributes referenced to feature itself
+        theRefsToFeature.push_back(anAttr);
+      }
+    }
+  }
+}
+
+void SketchPlugin_ConstraintSplit::updateCoincidenceConstraintsToFeature(
+      const std::map<std::shared_ptr<ModelAPI_Feature>, IdToPointPair>& theCoincidenceToFeature,
+      const std::set<std::shared_ptr<GeomDataAPI_Point2D> >& theFurtherCoincidences,
+      const std::set<ResultPtr>& theFeatureResults)
+{
+  if (theCoincidenceToFeature.empty())
+    return;
+
+  std::map<FeaturePtr, IdToPointPair>::const_iterator aCIt = theCoincidenceToFeature.begin(),
+                                                            aCLast = theCoincidenceToFeature.end();
+#ifdef DEBUG_SPLIT
+  std::cout << std::endl;
+  std::cout << "Coincidences to feature(modified):"<< std::endl;
+#endif
+  for (; aCIt != aCLast; aCIt++) {
+    FeaturePtr aCoincFeature = aCIt->first;
+    std::string anAttributeId = aCIt->second.first;
+    AttributePoint2DPtr aCoincPoint = aCIt->second.second;
+    std::set<AttributePoint2DPtr>::const_iterator aFCIt = theFurtherCoincidences.begin(),
+                                                  aFCLast = theFurtherCoincidences.end();
+    std::shared_ptr<GeomAPI_Pnt2d> aCoincPnt = aCoincPoint->pnt();
+    AttributePoint2DPtr aFeaturePointAttribute;
+    for (; aFCIt != aFCLast && !aFeaturePointAttribute.get(); aFCIt++) {
+      AttributePoint2DPtr aFCAttribute = *aFCIt;
+      if (aCoincPnt->isEqual(aFCAttribute->pnt()))
+        aFeaturePointAttribute = aFCAttribute;
+    }
+    if (aFeaturePointAttribute.get()) {
+      aCoincFeature->refattr(anAttributeId)->setObject(ResultPtr());
+      aCoincFeature->refattr(anAttributeId)->setAttr(aFeaturePointAttribute);
+    }
+    else {
+      /// find feature by shape intersected the point
+      ResultPtr aResultForCoincidence = *(theFeatureResults.begin());
+
+      if (theFeatureResults.size() > 1) { // try to find point on additional feature
+        ResultPtr anAddtionalResult = *(theFeatureResults.begin()++);
+        GeomShapePtr aShape = anAddtionalResult->shape();
+
+        std::shared_ptr<GeomAPI_Pnt2d> aPnt2d = aCoincPoint->pnt();
+        std::shared_ptr<GeomAPI_Pnt> aPoint = sketch()->to3D(aPnt2d->x(), aPnt2d->y());
+
+        std::shared_ptr<GeomAPI_Pnt> aProjectedPoint;
+        if (ModelGeomAlgo_Point2D::isPointOnEdge(aShape, aPoint, aProjectedPoint))
+          aResultForCoincidence = anAddtionalResult;
+      }
+      aCoincFeature->refattr(anAttributeId)->setObject(aResultForCoincidence);
+    }
+#ifdef DEBUG_SPLIT
+  std::cout << " -" << getFeatureInfo(aCoincFeature) << std::endl;
+#endif
+  }
+}
+
+void SketchPlugin_ConstraintSplit::updateTangentConstraintsToFeature(
+      const std::map<std::shared_ptr<ModelAPI_Feature>, IdToPointPair>& theTangentFeatures,
+      const std::set<std::shared_ptr<GeomDataAPI_Point2D> >& theFurtherCoincidences)
+{
+  if (theTangentFeatures.empty())
+    return;
+
+  std::map<FeaturePtr, IdToPointPair>::const_iterator aTIt = theTangentFeatures.begin(),
+                                                      aTLast = theTangentFeatures.end();
+#ifdef DEBUG_SPLIT
+  std::cout << std::endl;
+  std::cout << "Tangencies to feature(modified):"<< std::endl;
+#endif
+  for (; aTIt != aTLast; aTIt++) {
+    FeaturePtr aTangentFeature = aTIt->first;
+    std::string anAttributeId = aTIt->second.first;
+    AttributePoint2DPtr aTangentPoint = aTIt->second.second;
+    std::set<AttributePoint2DPtr>::const_iterator aFCIt = theFurtherCoincidences.begin(),
+                                                  aFCLast = theFurtherCoincidences.end();
+    std::shared_ptr<GeomAPI_Pnt2d> aCoincPnt = aTangentPoint->pnt();
+    AttributePoint2DPtr aFeaturePointAttribute;
+    /// here we rely on created coincidence between further coincidence point and tangent result
+    for (; aFCIt != aFCLast && !aFeaturePointAttribute.get(); aFCIt++) {
+      AttributePoint2DPtr aFCAttribute = *aFCIt;
+      if (aCoincPnt->isEqual(aFCAttribute->pnt()))
+        aFeaturePointAttribute = aFCAttribute;
+    }
+    if (aFeaturePointAttribute.get()) {
+      FeaturePtr aFeature = 
+        std::dynamic_pointer_cast<ModelAPI_Feature>(aFeaturePointAttribute->owner());
+      aTangentFeature->refattr(anAttributeId)->setObject(getFeatureResult(aFeature));
+    }
+#ifdef DEBUG_SPLIT
+  std::cout << " -" << getFeatureInfo(aTangentFeature) << std::endl;
+#endif
+  }
+}
+
+void SketchPlugin_ConstraintSplit::updateRefFeatureConstraints(
+                                                  const ResultPtr& theFeatureBaseResult,
+                                                  const std::list<AttributePtr>& theRefsToFeature)
+{
+  std::list<AttributePtr>::const_iterator anIt = theRefsToFeature.begin(),
+                                          aLast = theRefsToFeature.end();
+  for (; anIt != aLast; anIt++) {
+    AttributeRefAttrPtr aRefAttr = std::dynamic_pointer_cast<ModelAPI_AttributeRefAttr>(*anIt);
+    if (aRefAttr.get())
+      aRefAttr->setObject(theFeatureBaseResult);
+  }
+}
+
+void SketchPlugin_ConstraintSplit::updateRefAttConstraints(
+                    const std::map<AttributePtr, std::list<AttributePtr> >& theBaseRefAttributes,
+                    const std::set<std::pair<AttributePtr, AttributePtr> >& theModifiedAttributes)
+{
+#ifdef DEBUG_SPLIT
+  std::cout << "SketchPlugin_ConstraintSplit::updateRefAttConstraints" << std::endl;
+#endif
+
+  std::set<std::pair<AttributePtr, AttributePtr> >::const_iterator 
+    anIt = theModifiedAttributes.begin(),  aLast = theModifiedAttributes.end();
+  for (; anIt != aLast; anIt++) {
+    AttributePtr anAttribute = anIt->first;
+
+    /// not found in references
+    if (theBaseRefAttributes.find(anAttribute) == theBaseRefAttributes.end()) 
+      continue;
+    std::list<AttributePtr> aRefAttributes = theBaseRefAttributes.at(anAttribute);
+    std::list<AttributePtr>::const_iterator aRefIt = aRefAttributes.begin(),
+                                            aRLast = aRefAttributes.end();
+
+    AttributePtr aNewAttribute = anIt->second;
+    for (; aRefIt != aRLast; aRefIt++) {
+      AttributeRefAttrPtr aRefAttr = std::dynamic_pointer_cast<ModelAPI_AttributeRefAttr>(*aRefIt);
+      if (aRefAttr.get()) {
+        aRefAttr->setAttr(aNewAttribute);
+#ifdef DEBUG_SPLIT
+        FeaturePtr aFeature = ModelAPI_Feature::feature(aRefAttr->owner());
+        std::cout << " -" << getFeatureInfo(aFeature) << std::endl;
+#endif
+      }
+    }
+  }
+}
+
+void SketchPlugin_ConstraintSplit::splitLine(FeaturePtr& theSplitFeature,
+                                             FeaturePtr& theBaseFeatureModified,
+                                             FeaturePtr& theAfterFeature,
+                                             std::set<AttributePoint2DPtr>& thePoints,
+                                             std::set<FeaturePtr>& theCreatedFeatures,
+                 std::set<std::pair<AttributePtr, AttributePtr>>& theModifiedAttributes)
+{
+  std::set<FeaturePtr> aCreatedFeatures;
+  FeaturePtr aConstraintFeature;
+  theBaseFeatureModified = FeaturePtr(); // it will contain modified base feature
+
+  SketchPlugin_Sketch* aSketch = sketch();
+  if (!aSketch)
+    return;
+
+  AttributeReferencePtr aBaseObjectAttr = std::dynamic_pointer_cast<ModelAPI_AttributeReference>(
+                                           data()->attribute(SketchPlugin_Constraint::VALUE()));
+  FeaturePtr aBaseFeature = ModelAPI_Feature::feature(aBaseObjectAttr->value());
+  std::string aFeatureKind = aBaseFeature->getKind();
+  if (aFeatureKind != SketchPlugin_Line::ID())
+    return;
+
+  AttributePoint2DPtr aFirstPointAttrOfSplit = 
+    getPointOfRefAttr(data()->attribute(SketchPlugin_Constraint::ENTITY_A()));
+  AttributePoint2DPtr aSecondPointAttrOfSplit = 
+    getPointOfRefAttr(data()->attribute(SketchPlugin_Constraint::ENTITY_B()));
+  AttributePoint2DPtr aStartPointAttrOfBase, anEndPointAttrOfBase;
+  getFeaturePoints(aStartPointAttrOfBase, anEndPointAttrOfBase);
+  if (!aStartPointAttrOfBase.get() && !anEndPointAttrOfBase.get()) {
+    setError("Error: Feature has no start and end points.");
+    return;
+  }
+
+  arrangePointsOnLine(aStartPointAttrOfBase, anEndPointAttrOfBase, 
+                      aFirstPointAttrOfSplit, aSecondPointAttrOfSplit);
+
+#ifdef DEBUG_SPLIT
+  std::cout << "Arranged points (to build split between 1st and 2nd points:" << std::endl;
+  std::cout << "Start point: " << 
+    ModelGeomAlgo_Point2D::getPointAttributeInfo(aStartPointAttrOfBase) << std::endl;
+  std::cout << "1st point:   " << 
+    ModelGeomAlgo_Point2D::getPointAttributeInfo(aFirstPointAttrOfSplit) << std::endl;
+  std::cout << "2nd point:   " << 
+    ModelGeomAlgo_Point2D::getPointAttributeInfo(aSecondPointAttrOfSplit) << std::endl;
+  std::cout << "End point:   " << 
+    ModelGeomAlgo_Point2D::getPointAttributeInfo(anEndPointAttrOfBase) << std::endl;
+#endif
+
+  /// create a split feature
+  theSplitFeature = 
+    createLineFeature(aBaseFeature, aFirstPointAttrOfSplit, aSecondPointAttrOfSplit);
+  theCreatedFeatures.insert(theSplitFeature);
+
+  // before split feature
+  if (aStartPointAttrOfBase->pnt()->isEqual(aFirstPointAttrOfSplit->pnt())) {
+    theModifiedAttributes.insert(std::make_pair(aStartPointAttrOfBase,
+                                        theSplitFeature->attribute(SketchPlugin_Line::START_ID())));
+  }
+  else {
+    theBaseFeatureModified = aBaseFeature; ///< use base feature to store all constraints here
+    /// move end arc point to start of split
+  }
+
+  // after split feature
+  if (!aSecondPointAttrOfSplit->pnt()->isEqual(anEndPointAttrOfBase->pnt())) {
+    FeaturePtr aFeature;
+    if (!theBaseFeatureModified.get()) {
+      aFeature = aBaseFeature; ///< use base feature to store all constraints here
+      fillAttribute(aFeature->attribute(SketchPlugin_Line::START_ID()), aSecondPointAttrOfSplit);
+      aFeature->execute(); // to update result
+    }
+    else {
+      aFeature = createLineFeature(aBaseFeature, aSecondPointAttrOfSplit, anEndPointAttrOfBase);
+      theCreatedFeatures.insert(aFeature);
+      theModifiedAttributes.insert(std::make_pair(anEndPointAttrOfBase,
+                                             aFeature->attribute(SketchPlugin_Line::END_ID())));
+    }
+    aConstraintFeature = createConstraint(SketchPlugin_ConstraintCoincidence::ID(),
+                     theSplitFeature->attribute(SketchPlugin_Line::END_ID()),
+                     aFeature->attribute(SketchPlugin_Line::START_ID()));
+    theCreatedFeatures.insert(aConstraintFeature);
+
+    thePoints.insert(std::dynamic_pointer_cast<GeomDataAPI_Point2D>
+                                (aFeature->attribute(SketchPlugin_Line::START_ID())));
+    thePoints.insert(std::dynamic_pointer_cast<GeomDataAPI_Point2D>
+                                (aFeature->attribute(SketchPlugin_Line::END_ID())));
 
-}*/
+    if (!theBaseFeatureModified.get())
+      theBaseFeatureModified = aFeature;
+    else
+      theAfterFeature = aFeature;
+  }
+  else {
+    thePoints.insert(std::dynamic_pointer_cast<GeomDataAPI_Point2D>
+                                  (theSplitFeature->attribute(SketchPlugin_Line::END_ID())));
+    theModifiedAttributes.insert(std::make_pair(anEndPointAttrOfBase,
+                                   theSplitFeature->attribute(SketchPlugin_Line::END_ID())));
+  }
+  // base split, that is defined before split feature should be changed at end
+  // (after the after feature creation). Otherwise modified value will be used in after feature
+  // before split feature
+  if (!aStartPointAttrOfBase->pnt()->isEqual(aFirstPointAttrOfSplit->pnt())) {
+    /// move end arc point to start of split
+    fillAttribute(theBaseFeatureModified->attribute(SketchPlugin_Line::END_ID()), 
+                                                    aFirstPointAttrOfSplit);
+    theBaseFeatureModified->execute(); // to update result
+    aConstraintFeature = createConstraint(SketchPlugin_ConstraintCoincidence::ID(),
+                     theBaseFeatureModified->attribute(SketchPlugin_Line::END_ID()),
+                     theSplitFeature->attribute(SketchPlugin_Line::START_ID()));
+    theCreatedFeatures.insert(aConstraintFeature);
+
+    thePoints.insert(std::dynamic_pointer_cast<GeomDataAPI_Point2D>
+                             (theBaseFeatureModified->attribute(SketchPlugin_Line::START_ID())));
+    thePoints.insert(std::dynamic_pointer_cast<GeomDataAPI_Point2D>
+                               (theBaseFeatureModified->attribute(SketchPlugin_Line::END_ID())));
+  }
+  else
+    thePoints.insert(std::dynamic_pointer_cast<GeomDataAPI_Point2D>
+                                       (theSplitFeature->attribute(SketchPlugin_Line::START_ID())));
+
+  // additional constraints between split and base features
+  aConstraintFeature = createConstraintForObjects(SketchPlugin_ConstraintParallel::ID(),
+                                                       getFeatureResult(aBaseFeature),
+                                                       getFeatureResult(theSplitFeature));
+  theCreatedFeatures.insert(aConstraintFeature);
+  if (theAfterFeature.get()) {
+    aConstraintFeature = createConstraintForObjects(SketchPlugin_ConstraintParallel::ID(),
+                                                    getFeatureResult(aBaseFeature),
+                                                    getFeatureResult(theAfterFeature));
+    theCreatedFeatures.insert(aConstraintFeature);
+  }
+}
 
 void SketchPlugin_ConstraintSplit::splitArc(FeaturePtr& theSplitFeature,
-                                            FeaturePtr& theBaseFeature,
+                                            FeaturePtr& theBaseFeatureModified,
                                             FeaturePtr& theAfterFeature,
-                                            std::set<AttributePoint2DPtr>& thePoints)
+                                            std::set<AttributePoint2DPtr>& thePoints,
+                                            std::set<FeaturePtr>& theCreatedFeatures,
+                 std::set<std::pair<AttributePtr, AttributePtr>>& theModifiedAttributes)
 {
+  std::set<FeaturePtr> aCreatedFeatures;
+  FeaturePtr aConstraintFeature;
+  theBaseFeatureModified = FeaturePtr(); // it will contain modified base feature
+
   SketchPlugin_Sketch* aSketch = sketch();
   if (!aSketch)
     return;
@@ -386,92 +883,201 @@ void SketchPlugin_ConstraintSplit::splitArc(FeaturePtr& theSplitFeature,
   if (aFeatureKind != SketchPlugin_Arc::ID())
     return;
 
-  AttributePoint2DPtr aFirstPointAttr = getPointOfRefAttr(data()->attribute(SketchPlugin_Constraint::ENTITY_A()));
-  AttributePoint2DPtr aSecondPointAttr = getPointOfRefAttr(data()->attribute(SketchPlugin_Constraint::ENTITY_B()));
-  AttributePoint2DPtr aStartPointAttr, anEndPointAttr;
-  getFeaturePoints(aStartPointAttr, anEndPointAttr);
-  if (!aStartPointAttr.get() && !anEndPointAttr.get()) {
+  AttributePoint2DPtr aFirstPointAttrOfSplit = 
+    getPointOfRefAttr(data()->attribute(SketchPlugin_Constraint::ENTITY_A()));
+  AttributePoint2DPtr aSecondPointAttrOfSplit = 
+    getPointOfRefAttr(data()->attribute(SketchPlugin_Constraint::ENTITY_B()));
+  AttributePoint2DPtr aStartPointAttrOfBase, anEndPointAttrOfBase;
+  getFeaturePoints(aStartPointAttrOfBase, anEndPointAttrOfBase);
+  if (!aStartPointAttrOfBase.get() && !anEndPointAttrOfBase.get()) {
     setError("Error: Feature has no start and end points.");
     return;
   }
 
-  arrangePoints(aStartPointAttr, anEndPointAttr, aFirstPointAttr, aSecondPointAttr);
+  // manually change type of arc to avoid incorrect self-constrainting of the tangent arc
+  aBaseFeature->string(SketchPlugin_Arc::ARC_TYPE())->setValue(
+      SketchPlugin_Arc::ARC_TYPE_CENTER_START_END());
+
+  arrangePointsOnArc(aBaseFeature, aStartPointAttrOfBase, anEndPointAttrOfBase,
+                     aFirstPointAttrOfSplit, aSecondPointAttrOfSplit);
+#ifdef DEBUG_SPLIT
+  std::cout << "Arranged points (to build split between 1st and 2nd points:" << std::endl;
+  std::cout << "Start point: " << 
+    ModelGeomAlgo_Point2D::getPointAttributeInfo(aStartPointAttrOfBase) << std::endl;
+  std::cout << "1st point:   " << 
+    ModelGeomAlgo_Point2D::getPointAttributeInfo(aFirstPointAttrOfSplit) << std::endl;
+  std::cout << "2nd point:   " << 
+    ModelGeomAlgo_Point2D::getPointAttributeInfo(aSecondPointAttrOfSplit) << std::endl;
+  std::cout << "End point:   " << 
+    ModelGeomAlgo_Point2D::getPointAttributeInfo(anEndPointAttrOfBase) << std::endl;
+#endif
 
   /// split feature
-  theSplitFeature = createArcFeature(aBaseFeature, aFirstPointAttr, aSecondPointAttr);
+  theSplitFeature = createArcFeature(aBaseFeature, aFirstPointAttrOfSplit, aSecondPointAttrOfSplit);
+  theCreatedFeatures.insert(theSplitFeature);
 
   // before split feature
-  if (!aStartPointAttr->pnt()->isEqual(aFirstPointAttr->pnt())) {
-    theBaseFeature = aBaseFeature; ///< use base feature to store all constraints here
+  if (aStartPointAttrOfBase->pnt()->isEqual(aFirstPointAttrOfSplit->pnt())) {
+    theModifiedAttributes.insert(std::make_pair(aStartPointAttrOfBase,
+                                  theSplitFeature->attribute(SketchPlugin_Arc::START_ID())));
+  }
+  else {
+    theBaseFeatureModified = aBaseFeature; ///< use base feature to store all constraints here
     /// move end arc point to start of split
   }
 
   // after split feature
-  if (!aSecondPointAttr->pnt()->isEqual(anEndPointAttr->pnt())) {
+  if (!aSecondPointAttrOfSplit->pnt()->isEqual(anEndPointAttrOfBase->pnt())) {
     FeaturePtr aFeature;
-    if (!theBaseFeature.get()) {
+    if (!theBaseFeatureModified.get()) {
       aFeature = aBaseFeature; ///< use base feature to store all constraints here
-      fillAttribute(aFeature->attribute(SketchPlugin_Arc::START_ID()), aSecondPointAttr);
+      fillAttribute(aFeature->attribute(SketchPlugin_Arc::START_ID()), aSecondPointAttrOfSplit);
       aFeature->execute(); // to update result
     }
-    else
-      aFeature = createArcFeature(aBaseFeature, aSecondPointAttr, anEndPointAttr);
-
-    createConstraint(SketchPlugin_ConstraintCoincidence::ID(),
+    else {
+      aFeature = createArcFeature(aBaseFeature, aSecondPointAttrOfSplit, anEndPointAttrOfBase);
+      theCreatedFeatures.insert(aFeature);
+      theModifiedAttributes.insert(std::make_pair(anEndPointAttrOfBase,
+                                                  aFeature->attribute(SketchPlugin_Arc::END_ID())));
+    }
+    aConstraintFeature = createConstraint(SketchPlugin_ConstraintCoincidence::ID(),
                      theSplitFeature->attribute(SketchPlugin_Arc::END_ID()),
                      aFeature->attribute(SketchPlugin_Arc::START_ID()));
+    theCreatedFeatures.insert(aConstraintFeature);
+
     thePoints.insert(std::dynamic_pointer_cast<GeomDataAPI_Point2D>
-                                (theBaseFeature->attribute(SketchPlugin_Arc::START_ID())));
+                                (aFeature->attribute(SketchPlugin_Arc::START_ID())));
     thePoints.insert(std::dynamic_pointer_cast<GeomDataAPI_Point2D>
-                                (theBaseFeature->attribute(SketchPlugin_Arc::END_ID())));
+                                (aFeature->attribute(SketchPlugin_Arc::END_ID())));
 
-    if (!theBaseFeature.get())
-      theBaseFeature = aFeature;
+    if (!theBaseFeatureModified.get())
+      theBaseFeatureModified = aFeature;
     else
       theAfterFeature = aFeature;
   }
-  else
+  else {
     thePoints.insert(std::dynamic_pointer_cast<GeomDataAPI_Point2D>
                                   (theSplitFeature->attribute(SketchPlugin_Arc::END_ID())));
-
+    theModifiedAttributes.insert(std::make_pair(anEndPointAttrOfBase,
+                                   theSplitFeature->attribute(SketchPlugin_Arc::END_ID())));
+  }
   // base split, that is defined before split feature should be changed at end
   // (after the after feature creation). Otherwise modified value will be used in after feature
   // before split feature
-  if (!aStartPointAttr->pnt()->isEqual(aFirstPointAttr->pnt())) {
+  if (!aStartPointAttrOfBase->pnt()->isEqual(aFirstPointAttrOfSplit->pnt())) {
     /// move end arc point to start of split
-    fillAttribute(theBaseFeature->attribute(SketchPlugin_Arc::END_ID()), aFirstPointAttr);
-    theBaseFeature->execute(); // to update result
-    createConstraint(SketchPlugin_ConstraintCoincidence::ID(),
-                     theBaseFeature->attribute(SketchPlugin_Arc::END_ID()),
+    fillAttribute(theBaseFeatureModified->attribute(SketchPlugin_Arc::END_ID()),
+                                                    aFirstPointAttrOfSplit);
+    theBaseFeatureModified->execute(); // to update result
+    aConstraintFeature = createConstraint(SketchPlugin_ConstraintCoincidence::ID(),
+                     theBaseFeatureModified->attribute(SketchPlugin_Arc::END_ID()),
                      theSplitFeature->attribute(SketchPlugin_Arc::START_ID()));
+    theCreatedFeatures.insert(aConstraintFeature);
+
     thePoints.insert(std::dynamic_pointer_cast<GeomDataAPI_Point2D>
-                                        (theBaseFeature->attribute(SketchPlugin_Arc::START_ID())));
+                             (theBaseFeatureModified->attribute(SketchPlugin_Arc::START_ID())));
     thePoints.insert(std::dynamic_pointer_cast<GeomDataAPI_Point2D>
-                                        (theBaseFeature->attribute(SketchPlugin_Arc::END_ID())));
+                               (theBaseFeatureModified->attribute(SketchPlugin_Arc::END_ID())));
   }
   else
     thePoints.insert(std::dynamic_pointer_cast<GeomDataAPI_Point2D>
                                        (theSplitFeature->attribute(SketchPlugin_Arc::START_ID())));
 
   // additional constraints between split and base features
-  createConstraintForObjects(SketchPlugin_ConstraintEqual::ID(), getFeatureResult(aBaseFeature),
+  aConstraintFeature = createConstraintForObjects(SketchPlugin_ConstraintEqual::ID(),
+                                                       getFeatureResult(aBaseFeature),
                                                        getFeatureResult(theSplitFeature));
-  createConstraintForObjects(SketchPlugin_ConstraintTangent::ID(), getFeatureResult(theSplitFeature),
-                                                         getFeatureResult(aBaseFeature));
+  theCreatedFeatures.insert(aConstraintFeature);
+  aConstraintFeature = createConstraintForObjects(SketchPlugin_ConstraintTangent::ID(),
+                                                       getFeatureResult(theSplitFeature),
+                                                       getFeatureResult(aBaseFeature));
+  theCreatedFeatures.insert(aConstraintFeature);
   if (theAfterFeature.get()) {
-    createConstraintForObjects(SketchPlugin_ConstraintEqual::ID(), getFeatureResult(aBaseFeature),
-                                                         getFeatureResult(theAfterFeature));
-    createConstraintForObjects(SketchPlugin_ConstraintTangent::ID(), getFeatureResult(theSplitFeature),
-                                                         getFeatureResult(theAfterFeature));
+    aConstraintFeature = createConstraintForObjects(SketchPlugin_ConstraintEqual::ID(),
+                                                    getFeatureResult(aBaseFeature),
+                                                    getFeatureResult(theAfterFeature));
+    theCreatedFeatures.insert(aConstraintFeature);
+    aConstraintFeature = createConstraintForObjects(SketchPlugin_ConstraintTangent::ID(),
+                                                    getFeatureResult(theSplitFeature),
+                                                    getFeatureResult(theAfterFeature));
+    theCreatedFeatures.insert(aConstraintFeature);
   }
 }
 
-void SketchPlugin_ConstraintSplit::arrangePoints(const AttributePoint2DPtr& theStartPointAttr,
-                                                 const AttributePoint2DPtr& theEndPointAttr,
-                                                 AttributePoint2DPtr& theFirstPointAttr,
-                                                 AttributePoint2DPtr& theLastPointAttr)
+void SketchPlugin_ConstraintSplit::splitCircle(FeaturePtr& theSplitFeature,
+                                               FeaturePtr& theBaseFeatureModified,
+                                               FeaturePtr& theAfterFeature,
+                                               std::set<AttributePoint2DPtr>& thePoints,
+                                               std::set<FeaturePtr>& theCreatedFeatures,
+                 std::set<std::pair<AttributePtr, AttributePtr>>& theModifiedAttributes)
+{
+  std::set<FeaturePtr> aCreatedFeatures;
+  FeaturePtr aConstraintFeature;
+  theBaseFeatureModified = FeaturePtr(); // it will contain modified base feature
+
+  SketchPlugin_Sketch* aSketch = sketch();
+  if (!aSketch)
+    return;
+
+  AttributeReferencePtr aBaseObjectAttr = std::dynamic_pointer_cast<ModelAPI_AttributeReference>(
+                                           data()->attribute(SketchPlugin_Constraint::VALUE()));
+  FeaturePtr aBaseFeature = ModelAPI_Feature::feature(aBaseObjectAttr->value());
+  std::string aFeatureKind = aBaseFeature->getKind();
+  if (aFeatureKind != SketchPlugin_Circle::ID())
+    return;
+
+  AttributePoint2DPtr aFirstPointAttrOfSplit = 
+    getPointOfRefAttr(data()->attribute(SketchPlugin_Constraint::ENTITY_A()));
+  AttributePoint2DPtr aSecondPointAttrOfSplit = 
+    getPointOfRefAttr(data()->attribute(SketchPlugin_Constraint::ENTITY_B()));
+
+  /// split feature
+  theSplitFeature = 
+    createArcFeature(aBaseFeature, aFirstPointAttrOfSplit, aSecondPointAttrOfSplit);
+  bool aSplitReversed = std::dynamic_pointer_cast<SketchPlugin_Arc>(theSplitFeature)->isReversed();
+  theCreatedFeatures.insert(theSplitFeature);
+
+  /// base feature is a left part of the circle
+  theBaseFeatureModified = createArcFeature(aBaseFeature, 
+    aFirstPointAttrOfSplit, aSecondPointAttrOfSplit);
+  std::dynamic_pointer_cast<SketchPlugin_Arc>(
+    theBaseFeatureModified)->setReversed(!aSplitReversed);
+  theBaseFeatureModified->execute();
+
+  theModifiedAttributes.insert(
+    std::make_pair(aBaseFeature->attribute(SketchPlugin_Circle::CENTER_ID()),
+                  theBaseFeatureModified->attribute(SketchPlugin_Arc::CENTER_ID())));
+
+  theCreatedFeatures.insert(theBaseFeatureModified);
+
+  thePoints.insert(std::dynamic_pointer_cast<GeomDataAPI_Point2D>
+                             (theBaseFeatureModified->attribute(SketchPlugin_Arc::START_ID())));
+  thePoints.insert(std::dynamic_pointer_cast<GeomDataAPI_Point2D>
+                             (theBaseFeatureModified->attribute(SketchPlugin_Arc::END_ID())));
+
+  // additional constraints between split and base features
+  aConstraintFeature = createConstraint(SketchPlugin_ConstraintCoincidence::ID(),
+                     theBaseFeatureModified->attribute(SketchPlugin_Arc::END_ID()),
+                     theSplitFeature->attribute(SketchPlugin_Arc::END_ID()));
+  theCreatedFeatures.insert(aConstraintFeature);
+  aConstraintFeature = createConstraint(SketchPlugin_ConstraintCoincidence::ID(),
+                     theBaseFeatureModified->attribute(SketchPlugin_Arc::START_ID()),
+                     theSplitFeature->attribute(SketchPlugin_Arc::START_ID()));
+  theCreatedFeatures.insert(aConstraintFeature);
+
+  aConstraintFeature = createConstraintForObjects(SketchPlugin_ConstraintTangent::ID(),
+                                                       getFeatureResult(theSplitFeature),
+                                                       getFeatureResult(theBaseFeatureModified));
+  theCreatedFeatures.insert(aConstraintFeature);
+}
+
+void SketchPlugin_ConstraintSplit::arrangePointsOnLine(
+    const AttributePoint2DPtr& theStartPointAttr,
+    const AttributePoint2DPtr& theEndPointAttr,
+    AttributePoint2DPtr& theFirstPointAttr,
+    AttributePoint2DPtr& theLastPointAttr) const
 {
-  /// if first point is closer to last point, wrap first and last values
+  // if first point is closer to last point, swap first and last values
   if (theStartPointAttr->pnt()->distance(theFirstPointAttr->pnt()) >
       theStartPointAttr->pnt()->distance(theLastPointAttr->pnt())) {
     AttributePoint2DPtr aTmpPoint = theFirstPointAttr;
@@ -480,6 +1086,43 @@ void SketchPlugin_ConstraintSplit::arrangePoints(const AttributePoint2DPtr& theS
   }
 }
 
+void SketchPlugin_ConstraintSplit::arrangePointsOnArc(
+    const FeaturePtr& theArc,
+    const std::shared_ptr<GeomDataAPI_Point2D>& theStartPointAttr,
+    const std::shared_ptr<GeomDataAPI_Point2D>& theEndPointAttr,
+    std::shared_ptr<GeomDataAPI_Point2D>& theFirstPointAttr,
+    std::shared_ptr<GeomDataAPI_Point2D>& theSecondPointAttr) const
+{
+  static const double anAngleTol = 1.e-12;
+
+  std::shared_ptr<GeomAPI_Pnt2d> aCenter = std::dynamic_pointer_cast<GeomDataAPI_Point2D>(
+      theArc->attribute(SketchPlugin_Arc::CENTER_ID()))->pnt();
+  bool isReversed = theArc->boolean(SketchPlugin_Arc::INVERSED_ID())->value();
+
+  // collect directions to each point
+  std::shared_ptr<GeomAPI_Dir2d> aStartDir(
+      new GeomAPI_Dir2d(theStartPointAttr->pnt()->xy()->decreased(aCenter->xy())));
+  std::shared_ptr<GeomAPI_Dir2d> aFirstPtDir(
+      new GeomAPI_Dir2d(theFirstPointAttr->pnt()->xy()->decreased(aCenter->xy())));
+  std::shared_ptr<GeomAPI_Dir2d> aSecondPtDir(
+      new GeomAPI_Dir2d(theSecondPointAttr->pnt()->xy()->decreased(aCenter->xy())));
+
+  // sort points by their angular values
+  double aFirstPtAngle = aStartDir->angle(aFirstPtDir);
+  double aSecondPtAngle = aStartDir->angle(aSecondPtDir);
+  double aPeriod = isReversed ? -2.0 * PI : 2.0 * PI;
+  if (fabs(aFirstPtAngle) > anAngleTol && isReversed == (aFirstPtAngle > 0.))
+    aFirstPtAngle += aPeriod;
+  if (fabs(aSecondPtAngle) > anAngleTol && isReversed == (aSecondPtAngle > 0.))
+    aSecondPtAngle += aPeriod;
+
+  if (fabs(aFirstPtAngle) > fabs(aSecondPtAngle)) {
+    AttributePoint2DPtr aTmpPoint = theFirstPointAttr;
+    theFirstPointAttr = theSecondPointAttr;
+    theSecondPointAttr = aTmpPoint;
+  }
+}
+
 void SketchPlugin_ConstraintSplit::fillAttribute(const AttributePtr& theModifiedAttribute,
                                                  const AttributePtr& theSourceAttribute)
 {
@@ -492,6 +1135,24 @@ void SketchPlugin_ConstraintSplit::fillAttribute(const AttributePtr& theModified
     aModifiedAttribute->setValue(aSourceAttribute->pnt());
 }
 
+FeaturePtr SketchPlugin_ConstraintSplit::createLineFeature(const FeaturePtr& theBaseFeature,
+                                                           const AttributePtr& theFirstPointAttr,
+                                                           const AttributePtr& theSecondPointAttr)
+{
+  FeaturePtr aFeature;
+  SketchPlugin_Sketch* aSketch = sketch();
+  if (!aSketch || !theBaseFeature.get())
+    return aFeature;
+
+  aFeature = aSketch->addFeature(SketchPlugin_Line::ID());
+
+  fillAttribute(aFeature->attribute(SketchPlugin_Line::START_ID()), theFirstPointAttr);
+  fillAttribute(aFeature->attribute(SketchPlugin_Line::END_ID()), theSecondPointAttr);
+  aFeature->execute(); // to obtain result
+
+  return aFeature;
+}
+
 FeaturePtr SketchPlugin_ConstraintSplit::createArcFeature(const FeaturePtr& theBaseFeature,
                                                           const AttributePtr& theFirstPointAttr,
                                                           const AttributePtr& theSecondPointAttr)
@@ -501,24 +1162,41 @@ FeaturePtr SketchPlugin_ConstraintSplit::createArcFeature(const FeaturePtr& theB
   if (!aSketch || !theBaseFeature.get())
     return aFeature;
 
-  aFeature = aSketch->addFeature(theBaseFeature->getKind());
-  // update fillet arc: make the arc correct for sure, so, it is not needed to process the "attribute updated"
+  std::string aCenterAttributeId;
+  if (theBaseFeature->getKind() == SketchPlugin_Arc::ID())
+    aCenterAttributeId = SketchPlugin_Arc::CENTER_ID();
+  else if (theBaseFeature->getKind() == SketchPlugin_Circle::ID())
+    aCenterAttributeId = SketchPlugin_Circle::CENTER_ID();
+
+  if (aCenterAttributeId.empty())
+    return aFeature;
+
+  aFeature = aSketch->addFeature(SketchPlugin_Arc::ID());
+  // update fillet arc: make the arc correct for sure, so, it is not needed to process 
+  // the "attribute updated"
   // by arc; moreover, it may cause cyclicity in hte mechanism of updater
   aFeature->data()->blockSendAttributeUpdated(true);
 
   aFeature->string(SketchPlugin_Arc::ARC_TYPE())->setValue(
                 SketchPlugin_Arc::ARC_TYPE_CENTER_START_END());
+
   fillAttribute(aFeature->attribute(SketchPlugin_Arc::CENTER_ID()),
-                theBaseFeature->attribute(SketchPlugin_Arc::CENTER_ID()));
+                theBaseFeature->attribute(aCenterAttributeId));
   fillAttribute(aFeature->attribute(SketchPlugin_Arc::START_ID()), theFirstPointAttr);
   fillAttribute(aFeature->attribute(SketchPlugin_Arc::END_ID()), theSecondPointAttr);
+
+  /// fill referersed state of created arc as it is on the base arc
+  if (theBaseFeature->getKind() == SketchPlugin_Arc::ID()) {
+    bool aReversed = theBaseFeature->boolean(SketchPlugin_Arc::INVERSED_ID())->value();
+    aFeature->boolean(SketchPlugin_Arc::INVERSED_ID())->setValue(aReversed);
+  }
   aFeature->data()->blockSendAttributeUpdated(false);
   aFeature->execute(); // to obtain result
 
   return aFeature;
 }
 
-void SketchPlugin_ConstraintSplit::createConstraint(const std::string& theConstraintId,
+FeaturePtr SketchPlugin_ConstraintSplit::createConstraint(const std::string& theConstraintId,
                                                     const AttributePtr& theFirstAttribute,
                                                     const AttributePtr& theSecondAttribute)
 {
@@ -530,9 +1208,12 @@ void SketchPlugin_ConstraintSplit::createConstraint(const std::string& theConstr
   aRefAttr = std::dynamic_pointer_cast<ModelAPI_AttributeRefAttr>(
                                  aConstraint->attribute(SketchPlugin_Constraint::ENTITY_B()));
   aRefAttr->setAttr(theSecondAttribute);
+
+  return aConstraint;
 }
 
-void SketchPlugin_ConstraintSplit::createConstraintForObjects(const std::string& theConstraintId,
+FeaturePtr SketchPlugin_ConstraintSplit::createConstraintForObjects(
+                                                    const std::string& theConstraintId,
                                                     const ObjectPtr& theFirstObject,
                                                     const ObjectPtr& theSecondObject)
 {
@@ -544,6 +1225,30 @@ void SketchPlugin_ConstraintSplit::createConstraintForObjects(const std::string&
   aRefAttr = std::dynamic_pointer_cast<ModelAPI_AttributeRefAttr>(
                                  aConstraint->attribute(SketchPlugin_Constraint::ENTITY_B()));
   aRefAttr->setObject(theSecondObject);
+
+  return aConstraint;
+}
+
+void SketchPlugin_ConstraintSplit::updateFeaturesAfterSplit(
+                                                   const std::set<FeaturePtr>& theFeaturesToUpdate)
+{
+  std::set<FeaturePtr>::const_iterator anIt = theFeaturesToUpdate.begin(),
+                                       aLast = theFeaturesToUpdate.end();
+  for (; anIt != aLast; anIt++) {
+    FeaturePtr aRefFeature = std::dynamic_pointer_cast<ModelAPI_Feature>(*anIt);
+    std::string aRefFeatureKind = aRefFeature->getKind();
+    if (aRefFeatureKind == SketchPlugin_ConstraintLength::ID()) {
+      std::shared_ptr<SketchPlugin_ConstraintLength> aLenghtFeature =
+                              std::dynamic_pointer_cast<SketchPlugin_ConstraintLength>(*anIt);
+      if (aLenghtFeature.get()) {
+        std::shared_ptr<ModelAPI_AttributeDouble> aValueAttr = std::dynamic_pointer_cast<
+            ModelAPI_AttributeDouble>(aLenghtFeature->attribute(SketchPlugin_Constraint::VALUE()));
+        double aValue;
+        if (aLenghtFeature->computeLenghtValue(aValue) && aValueAttr.get())
+          aValueAttr->setValue(aValue);
+      }
+    }
+  }
 }
 
 std::shared_ptr<ModelAPI_Result> SketchPlugin_ConstraintSplit::getFeatureResult(
@@ -562,3 +1267,85 @@ std::shared_ptr<ModelAPI_Result> SketchPlugin_ConstraintSplit::getFeatureResult(
   return aResult;
 }
 
+std::set<std::shared_ptr<ModelAPI_Attribute> > SketchPlugin_ConstraintSplit::getEdgeAttributes(
+                                           const std::shared_ptr<ModelAPI_Feature>& theFeature)
+{
+  std::set<std::shared_ptr<ModelAPI_Attribute> > anAttributes;
+
+  std::string aFeatureKind = theFeature->getKind();
+  if (aFeatureKind == SketchPlugin_Line::ID()) {
+    anAttributes.insert(theFeature->attribute(SketchPlugin_Line::START_ID()));
+    anAttributes.insert(theFeature->attribute(SketchPlugin_Line::END_ID()));
+  }
+  else if (aFeatureKind == SketchPlugin_Arc::ID()) {
+    anAttributes.insert(theFeature->attribute(SketchPlugin_Arc::START_ID()));
+    anAttributes.insert(theFeature->attribute(SketchPlugin_Arc::END_ID()));
+  }
+  else if (aFeatureKind == SketchPlugin_Circle::ID()) {
+  }
+
+  return anAttributes;
+}
+
+
+std::string SketchPlugin_ConstraintSplit::getFeatureInfo(
+                                               const std::shared_ptr<ModelAPI_Feature>& theFeature,
+                                               const bool isUseAttributesInfo)
+{
+  std::string anInfo;
+  if (!theFeature.get()) {
+    return "none";
+  }
+
+  if (theFeature->data()->isValid())
+    anInfo.append(theFeature->data()->name().c_str());
+
+  if (isUseAttributesInfo) {
+    std::string aPointsInfo = ModelGeomAlgo_Point2D::getPontAttributesInfo(theFeature,
+                                                             getEdgeAttributes(theFeature));
+    /// processing of feature with point 2d attributes, like line, arc, circle
+    if (!aPointsInfo.empty()) { 
+      anInfo += ": ";
+      anInfo += "\n";
+      anInfo += aPointsInfo;
+    }
+    else { /// process constraint coincidence, find points in ref attr attributes
+      std::list<AttributePtr> anAttrs = theFeature->data()->attributes(
+                                                       ModelAPI_AttributeRefAttr::typeId());
+      std::list<AttributePtr>::const_iterator anIt = anAttrs.begin(), aLast = anAttrs.end();
+      std::string anAttributesInfo;
+      for(; anIt != aLast; anIt++) {
+        if (!anAttributesInfo.empty()) {
+          anAttributesInfo.append(", ");
+          anAttributesInfo += "\n";
+        }
+        AttributePtr anAttr = *anIt;
+        std::string aValue = "not defined";
+        std::string aType = anAttr->attributeType();
+        if (aType == ModelAPI_AttributeRefAttr::typeId()) {
+          std::shared_ptr<ModelAPI_AttributeRefAttr> aRefAttr =
+                             std::dynamic_pointer_cast<ModelAPI_AttributeRefAttr>(anAttr);
+          if (aRefAttr.get()) {
+            if (aRefAttr->isObject()) {
+              FeaturePtr aFeature = ModelAPI_Feature::feature(aRefAttr->object());
+              aValue = "<object:>" + getFeatureInfo(aFeature, false);
+            }
+            else {
+              AttributePtr anAttribute = aRefAttr->attr();
+              if (anAttribute.get()) {
+                FeaturePtr aFeature = ModelAPI_Feature::feature(anAttribute->owner());
+                aValue = "<attr:>" + ModelGeomAlgo_Point2D::getPointAttributeInfo(anAttribute) +
+                         " [" + getFeatureInfo(aFeature, false) + "]";
+              }
+            }
+          }
+        }
+        anAttributesInfo.append("    " + anAttr->id() + ": " + aValue);
+      }
+      if (!anAttributesInfo.empty())
+        anInfo = anInfo + "\n" + anAttributesInfo;
+    }
+  }
+  return anInfo;
+}
+