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[modules/shaper.git] / src / SketchPlugin / SketchPlugin_Arc.cpp
index 07e9b1a784176ae4117a6335d25f24a17537a07e..0eb84450c4e5dbbbf75634280721b4d011754fde 100644 (file)
-// Copyright (C) 2014-20xx CEA/DEN, EDF R&D -->
-
-// File:        SketchPlugin_Arc.cpp
-// Created:     26 Apr 2014
-// Author:      Artem ZHIDKOV
+// Copyright (C) 2014-2023  CEA, EDF
+//
+// This library is free software; you can redistribute it and/or
+// modify it under the terms of the GNU Lesser General Public
+// License as published by the Free Software Foundation; either
+// version 2.1 of the License, or (at your option) any later version.
+//
+// This library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+// Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public
+// License along with this library; if not, write to the Free Software
+// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
+//
+// See http://www.salome-platform.org/ or email : webmaster.salome@opencascade.com
+//
 
 #include "SketchPlugin_Arc.h"
 #include "SketchPlugin_Sketch.h"
+#include <SketchPlugin_ConstraintCoincidence.h>
+#include <SketchPlugin_ConstraintTangent.h>
+
+#include <Events_Loop.h>
 #include <ModelAPI_Data.h>
 #include <ModelAPI_ResultConstruction.h>
+#include <ModelAPI_AttributeDouble.h>
+#include <ModelAPI_AttributeRefAttr.h>
 #include <ModelAPI_AttributeSelection.h>
+#include <ModelAPI_AttributeString.h>
+#include <ModelAPI_Events.h>
 #include <ModelAPI_Validator.h>
 #include <ModelAPI_Session.h>
+#include <ModelAPI_Tools.h>
 
 #include <GeomAPI_Ax2.h>
 #include <GeomAPI_Circ2d.h>
 #include <GeomAPI_Circ.h>
+#include <GeomAPI_Dir2d.h>
+#include <GeomAPI_Dir.h>
+#include <GeomAPI_Lin2d.h>
+#include <GeomAPI_Lin.h>
 #include <GeomAPI_Pnt2d.h>
+#include <GeomAPI_Vertex.h>
+#include <GeomAPI_XY.h>
 #include <GeomDataAPI_Point2D.h>
 #include <GeomDataAPI_Dir.h>
 #include <GeomAlgoAPI_PointBuilder.h>
 #include <GeomAlgoAPI_EdgeBuilder.h>
 #include <GeomAlgoAPI_CompoundBuilder.h>
 // for sqrt on Linux
-#include <math.h>
-
-const double tolerance = 1e-7;
-const double paramTolerance = 1.e-4;
-const double PI =3.141592653589793238463;
+#include <cmath>
 
+static const double tolerance = 1e-7;
+static const double paramTolerance = 1.e-4;
+static const double PI = 3.141592653589793238463;
 
-static const std::string& INVERSED_ID()
-{
-  static const std::string MY_INVERSED_ID("InversedArc");
-  return MY_INVERSED_ID;
-}
 
 SketchPlugin_Arc::SketchPlugin_Arc()
-    : SketchPlugin_SketchEntity()
+: SketchPlugin_SketchEntity()
 {
-  myStartUpdate = false;
-  myEndUpdate = false;
-  // default values
-  myXEndBefore = 0;
-  myYEndBefore = 0;
-
-  myParamBefore = 0;
+  myParamBefore = 0.0;
 }
 
-void SketchPlugin_Arc::initAttributes()
+void SketchPlugin_Arc::initDerivedClassAttributes()
 {
-  SketchPlugin_SketchEntity::initAttributes();
-
   data()->addAttribute(CENTER_ID(), GeomDataAPI_Point2D::typeId());
   data()->addAttribute(START_ID(), GeomDataAPI_Point2D::typeId());
-  std::shared_ptr<GeomDataAPI_Point2D> anEndAttr = std::dynamic_pointer_cast<
-    GeomDataAPI_Point2D>(data()->addAttribute(END_ID(), GeomDataAPI_Point2D::typeId()));
+  data()->addAttribute(END_ID(), GeomDataAPI_Point2D::typeId());
+
   data()->addAttribute(EXTERNAL_ID(), ModelAPI_AttributeSelection::typeId());
   ModelAPI_Session::get()->validators()->registerNotObligatory(getKind(), EXTERNAL_ID());
 
-  data()->addAttribute(INVERSED_ID(), ModelAPI_AttributeBoolean::typeId());
-  AttributeBooleanPtr isInversed =
-      std::dynamic_pointer_cast<ModelAPI_AttributeBoolean>(attribute(INVERSED_ID()));
-  if (!isInversed->isInitialized())
-    isInversed->setValue(false);
+  AttributeBooleanPtr isReversed = std::dynamic_pointer_cast<ModelAPI_AttributeBoolean>(
+    data()->addAttribute(REVERSED_ID(), ModelAPI_AttributeBoolean::typeId()));
 
-  // get the initial values
-  if (anEndAttr->isInitialized()) {
-    myXEndBefore = anEndAttr->x();
-    myYEndBefore = anEndAttr->y();
+  data()->addAttribute(RADIUS_ID(), ModelAPI_AttributeDouble::typeId());
+  data()->addAttribute(ANGLE_ID(), ModelAPI_AttributeDouble::typeId());
+
+  // set after all to avoid in attributeChanged reference to not existing attributes
+  if (!isReversed->isInitialized()) {
+    isReversed->setValue(false);
   }
 }
 
 void SketchPlugin_Arc::execute()
 {
   SketchPlugin_Sketch* aSketch = sketch();
-  // result for the arc is set only when all obligatory attributes are initialized,
-  // otherwise AIS object is used to visualize the arc's preview
-  if (aSketch && isFeatureValid()) {
-    // compute a circle point in 3D view
-    std::shared_ptr<GeomDataAPI_Point2D> aCenterAttr = std::dynamic_pointer_cast<
-        GeomDataAPI_Point2D>(data()->attribute(CENTER_ID()));
-    // compute the arc start point
-    std::shared_ptr<GeomDataAPI_Point2D> aStartAttr = std::dynamic_pointer_cast<
-        GeomDataAPI_Point2D>(data()->attribute(START_ID()));
-
-    std::shared_ptr<GeomAPI_Pnt> aCenter(aSketch->to3D(aCenterAttr->x(), aCenterAttr->y()));
-    // make a visible point
-    std::shared_ptr<GeomAPI_Shape> aCenterPointShape = GeomAlgoAPI_PointBuilder::point(aCenter);
-    std::shared_ptr<ModelAPI_ResultConstruction> aConstr1 = document()->createConstruction(
-        data(), 0);
-    aConstr1->setShape(aCenterPointShape);
-    aConstr1->setIsInHistory(false);
-    setResult(aConstr1, 0);
-
-    // make a visible circle
-    std::shared_ptr<GeomDataAPI_Dir> aNDir = std::dynamic_pointer_cast<GeomDataAPI_Dir>(
-        aSketch->data()->attribute(SketchPlugin_Sketch::NORM_ID()));
-    std::shared_ptr<GeomAPI_Dir> aNormal = aNDir->dir();
-    std::shared_ptr<GeomAPI_Pnt> aStartPoint(aSketch->to3D(aStartAttr->x(), aStartAttr->y()));
-
-    // compute and change the arc end point
-    std::shared_ptr<GeomDataAPI_Point2D> anEndAttr = std::dynamic_pointer_cast<
-        GeomDataAPI_Point2D>(data()->attribute(END_ID()));
-    /* must be automatically done in attributeChanged
+  if(!aSketch) {
+    return;
+  }
+
+  std::shared_ptr<GeomDataAPI_Point2D> aCenterAttr =
+      std::dynamic_pointer_cast<GeomDataAPI_Point2D>(data()->attribute(CENTER_ID()));
+  std::shared_ptr<GeomDataAPI_Point2D> aStartAttr =
+      std::dynamic_pointer_cast<GeomDataAPI_Point2D>(data()->attribute(START_ID()));
+  std::shared_ptr<GeomDataAPI_Point2D> anEndAttr =
+      std::dynamic_pointer_cast<GeomDataAPI_Point2D>(data()->attribute(END_ID()));
+  if(!aCenterAttr->isInitialized() || !aStartAttr->isInitialized() || !anEndAttr->isInitialized()) {
+    return;
+  }
+
+  // Make a visible point.
+  SketchPlugin_Sketch::createPoint2DResult(this, sketch(), CENTER_ID(), 0);
+
+  // Make a visible arc.
+  std::shared_ptr<GeomAPI_Pnt> aCenter(aSketch->to3D(aCenterAttr->x(), aCenterAttr->y()));
+  std::shared_ptr<GeomAPI_Pnt> aStart(aSketch->to3D(aStartAttr->x(), aStartAttr->y()));
+  std::shared_ptr<GeomAPI_Pnt> anEnd(aSketch->to3D(anEndAttr->x(), anEndAttr->y()));
+  std::shared_ptr<GeomDataAPI_Dir> aNDir = std::dynamic_pointer_cast<GeomDataAPI_Dir>(
+      aSketch->data()->attribute(SketchPlugin_Sketch::NORM_ID()));
+  std::shared_ptr<GeomAPI_Dir> aNormal(new GeomAPI_Dir(aNDir->x(), aNDir->y(), aNDir->z()));
+
+  if (myParamBefore == 0) { // parameter has not been calculate yet
     std::shared_ptr<GeomAPI_Circ2d> aCircleForArc(
         new GeomAPI_Circ2d(aCenterAttr->pnt(), aStartAttr->pnt()));
-    std::shared_ptr<GeomAPI_Pnt2d> aProjection = aCircleForArc->project(anEndAttr->pnt());
-    if (aProjection && anEndAttr->pnt()->distance(aProjection) > tolerance)
-      anEndAttr->setValue(aProjection);
-    */
-    std::shared_ptr<GeomAPI_Pnt> aEndPoint(aSketch->to3D(anEndAttr->x(), anEndAttr->y()));
-    AttributeBooleanPtr isInversed =
-        std::dynamic_pointer_cast<ModelAPI_AttributeBoolean>(attribute(INVERSED_ID()));
-
-    std::shared_ptr<GeomAPI_Dir> anXDir(new GeomAPI_Dir(aStartPoint->xyz()->decreased(aCenter->xyz())));
-    std::shared_ptr<GeomAPI_Ax2> anAx2(new GeomAPI_Ax2(aCenter, aNormal, anXDir));
-    std::shared_ptr<GeomAPI_Circ> aCirc(new GeomAPI_Circ(anAx2, aCenter->distance(aStartPoint)));
-    double aParameterNew = 0.0;
-    if(aCirc->parameter(aEndPoint, paramTolerance, aParameterNew)) {
-      if(0 <= myParamBefore && myParamBefore <= PI / 2.0
-        && PI * 1.5 <= aParameterNew && aParameterNew <= PI * 2.0) {
-          isInversed->setValue(true);
-      } else if(PI * 1.5 <= myParamBefore && myParamBefore <= PI * 2.0
-        && 0 <= aParameterNew && aParameterNew <= PI / 2.0) {
-          isInversed->setValue(false);
-      }
-    }
-    myParamBefore = aParameterNew;
+    aCircleForArc->parameter(anEndAttr->pnt(), paramTolerance, myParamBefore);
+  }
 
-    std::shared_ptr<GeomAPI_Shape> aCircleShape;
-    if(!isInversed->value()) {
-      aCircleShape = GeomAlgoAPI_EdgeBuilder::lineCircleArc(aCenter, aStartPoint, aEndPoint, aNormal);
-    } else {
-      aCircleShape = GeomAlgoAPI_EdgeBuilder::lineCircleArc(aCenter, aEndPoint, aStartPoint, aNormal);
-    }
+  bool isReversed = boolean(REVERSED_ID())->value();
 
-    if (aCircleShape) {
-      std::shared_ptr<ModelAPI_ResultConstruction> aConstr2 = document()->createConstruction(
-          data(), 1);
-      aConstr2->setShape(aCircleShape);
-      aConstr2->setIsInHistory(false);
-      setResult(aConstr2, 1);
-    }
+  GeomEdgePtr anArcShape;
+  if (fabs(myParamBefore - 2.0 * PI) < paramTolerance) {
+    anArcShape = GeomAlgoAPI_EdgeBuilder::lineCircle(aCenter, aNormal, aStart->distance(aCenter));
+    myParamBefore = 0;
+  } else {
+    anArcShape = isReversed ?
+      GeomAlgoAPI_EdgeBuilder::lineCircleArc(aCenter, anEnd, aStart, aNormal)
+    : GeomAlgoAPI_EdgeBuilder::lineCircleArc(aCenter, aStart, anEnd, aNormal);
   }
-}
 
-AISObjectPtr SketchPlugin_Arc::getAISObject(AISObjectPtr thePrevious)
-{
-  SketchPlugin_Sketch* aSketch = sketch();
-  if (aSketch) {
-    // if the feature is valid, the execute() method should be performed, AIS object is empty
-    if (!isFeatureValid()) {
-      // compute a circle point in 3D view
-      std::shared_ptr<GeomDataAPI_Point2D> aCenterAttr = std::dynamic_pointer_cast<
-          GeomDataAPI_Point2D>(data()->attribute(CENTER_ID()));
-      if (aCenterAttr->isInitialized()) {
-        std::shared_ptr<GeomAPI_Pnt> aCenter(aSketch->to3D(aCenterAttr->x(), aCenterAttr->y()));
-
-        std::shared_ptr<GeomDataAPI_Point2D> aStartAttr = std::dynamic_pointer_cast<
-            GeomDataAPI_Point2D>(data()->attribute(SketchPlugin_Arc::START_ID()));
-        if (aStartAttr->isInitialized()) {
-          // make a visible circle
-          std::shared_ptr<GeomDataAPI_Dir> aNDir = std::dynamic_pointer_cast<GeomDataAPI_Dir>(
-              aSketch->data()->attribute(SketchPlugin_Sketch::NORM_ID()));
-          bool aHasPlane = aNDir && !(aNDir->x() == 0 && aNDir->y() == 0 && aNDir->z() == 0);
-          if (aHasPlane) {
-            std::shared_ptr<GeomAPI_Dir> aNormal = aNDir->dir();
-            std::shared_ptr<GeomAPI_Pnt> aStartPoint(aSketch->to3D(aStartAttr->x(), aStartAttr->y()));
-            std::shared_ptr<GeomAPI_Shape> aCircleShape = GeomAlgoAPI_EdgeBuilder::lineCircleArc(
-                                                            aCenter, aStartPoint, aStartPoint, aNormal);
-            if (aCircleShape) {
-              std::list<std::shared_ptr<GeomAPI_Shape> > aShapes;
-              // make a visible point
-              std::shared_ptr<GeomAPI_Shape> aCenterPointShape = GeomAlgoAPI_PointBuilder::point(aCenter);
-              aShapes.push_back(aCenterPointShape);
-
-              aShapes.push_back(aCircleShape);
-              if (!aShapes.empty())
-              {
-                std::shared_ptr<GeomAPI_Shape> aCompound = GeomAlgoAPI_CompoundBuilder::compound(aShapes);
-                AISObjectPtr anAIS = thePrevious;
-                if (!anAIS)
-                  anAIS = AISObjectPtr(new GeomAPI_AISObject);
-                anAIS->createShape(aCompound);
-                anAIS->setWidth(3);
-                return anAIS;
-              }
-            }
-          }
-        }
+  // calculate tolerances for start and end points of the arc and set them to the result shape
+  // (this is done to fix gaps which appear because of inaccurate computation of arcs in PlaneGCS,
+  // which leads to difference in SketchPlugin_Arc attributes and boundary points of result shape)
+  if (anArcShape) {
+    for (int ind = 0; ind < 2; ++ind) {
+      bool isFirst = ind == 0;
+      GeomPointPtr anArcBndPoint = isFirst == isReversed ? anEnd : aStart;
+      GeomPointPtr aShapePoint = isFirst ? anArcShape->firstPoint() : anArcShape->lastPoint();
+      double aDistance = anArcBndPoint->distance(aShapePoint);
+      // avoid setting too high tolerance because it may be caused by incomplete update of an arc
+      if (aDistance > tolerance && aDistance < 100. * tolerance) {
+        if (isFirst)
+          anArcShape->setFirstPointTolerance(aDistance);
+        else
+          anArcShape->setLastPointTolerance(aDistance);
       }
     }
   }
-  return AISObjectPtr();
-}
-
-void SketchPlugin_Arc::move(double theDeltaX, double theDeltaY)
-{
-  std::shared_ptr<ModelAPI_Data> aData = data();
-  if (!aData->isValid())
-    return;
-
-  myStartUpdate = true;
-  myEndUpdate = true;
-  std::shared_ptr<GeomDataAPI_Point2D> aPoint2 = std::dynamic_pointer_cast<GeomDataAPI_Point2D>(
-      aData->attribute(SketchPlugin_Arc::START_ID()));
-  aPoint2->move(theDeltaX, theDeltaY);
-
-  std::shared_ptr<GeomDataAPI_Point2D> aPoint3 = std::dynamic_pointer_cast<GeomDataAPI_Point2D>(
-      aData->attribute(SketchPlugin_Arc::END_ID()));
-  aPoint3->move(theDeltaX, theDeltaY);
-  myStartUpdate = false;
-  myEndUpdate = false;
-
-  std::shared_ptr<GeomDataAPI_Point2D> aPoint1 = std::dynamic_pointer_cast<GeomDataAPI_Point2D>(
-      aData->attribute(SketchPlugin_Arc::CENTER_ID()));
-  aPoint1->move(theDeltaX, theDeltaY);
-}
 
-bool SketchPlugin_Arc::isFixed() {
-  return data()->selection(EXTERNAL_ID())->context().get() != NULL;
+  std::shared_ptr<ModelAPI_ResultConstruction> aResult = document()->createConstruction(data(), 1);
+  aResult->setShape(anArcShape);
+  aResult->setIsInHistory(false);
+  setResult(aResult, 1);
 }
 
-bool SketchPlugin_Arc::isFeatureValid()
+bool SketchPlugin_Arc::isFixed()
 {
-  std::shared_ptr<GeomDataAPI_Point2D> aCenterAttr = std::dynamic_pointer_cast<
-      GeomDataAPI_Point2D>(data()->attribute(SketchPlugin_Arc::CENTER_ID()));
-  std::shared_ptr<GeomDataAPI_Point2D> aStartAttr = std::dynamic_pointer_cast<
-      GeomDataAPI_Point2D>(data()->attribute(SketchPlugin_Arc::START_ID()));
-  std::shared_ptr<GeomDataAPI_Point2D> anEndAttr = std::dynamic_pointer_cast<
-      GeomDataAPI_Point2D>(data()->attribute(SketchPlugin_Arc::END_ID()));
-
-  return aCenterAttr->isInitialized() && aStartAttr->isInitialized() && anEndAttr->isInitialized();
+  return data()->selection(EXTERNAL_ID())->context().get() != NULL;
 }
 
 void SketchPlugin_Arc::attributeChanged(const std::string& theID)
@@ -242,86 +168,130 @@ void SketchPlugin_Arc::attributeChanged(const std::string& theID)
       GeomDataAPI_Point2D>(data()->attribute(START_ID()));
   std::shared_ptr<GeomDataAPI_Point2D> anEndAttr = std::dynamic_pointer_cast<
       GeomDataAPI_Point2D>(data()->attribute(END_ID()));
-  // the second condition for unability to move external segments anywhere
-  if (theID == EXTERNAL_ID() || isFixed()) {
+
+  // The second condition for unability to move external segments anywhere.
+  if(theID == EXTERNAL_ID() || isFixed()) {
     std::shared_ptr<GeomAPI_Shape> aSelection = data()->selection(EXTERNAL_ID())->value();
+    if(!aSelection) {
+      // empty shape in selection shows that the shape is equal to context
+      ResultPtr anExtRes = selection(EXTERNAL_ID())->context();
+      if(anExtRes) {
+        aSelection = anExtRes->shape();
+      }
+    }
     // update arguments due to the selection value
-    if (aSelection && !aSelection->isNull() && aSelection->isEdge()) {
+    if(aSelection && !aSelection->isNull() && aSelection->isEdge()) {
       std::shared_ptr<GeomAPI_Edge> anEdge( new GeomAPI_Edge(aSelection));
       std::shared_ptr<GeomAPI_Circ> aCirc = anEdge->circle();
-      if (aCirc.get()) {
+      if(aCirc.get()) {
+        bool aWasBlocked = data()->blockSendAttributeUpdated(true);
+        aCenterAttr->setValue(sketch()->to2D(aCirc->center()));
         aStartAttr->setValue(sketch()->to2D(anEdge->firstPoint()));
         anEndAttr->setValue(sketch()->to2D(anEdge->lastPoint()));
-        aCenterAttr->setValue(sketch()->to2D(aCirc->center()));
+        data()->blockSendAttributeUpdated(aWasBlocked, false);
+
+        std::shared_ptr<GeomAPI_Circ2d> aCircle2d =
+          std::shared_ptr<GeomAPI_Circ2d>(new GeomAPI_Circ2d(aCenterAttr->pnt(),
+                                                             aStartAttr->pnt()));
+
+        double anEndParam = 0.0;
+        aCircle2d->parameter(anEndAttr->pnt(), paramTolerance, anEndParam);
+        myParamBefore = anEndParam;
+
+        double aMidParam  = anEndParam / 2.0;
+        std::shared_ptr<GeomAPI_Pnt2d> aMidPnt2d;
+        aCircle2d->D0(aMidParam, aMidPnt2d);
+        std::shared_ptr<GeomAPI_Pnt> aMinPnt = sketch()->to3D(aMidPnt2d->x(), aMidPnt2d->y());
+        double aStartParam = 0.0;
+        aCirc->parameter(anEdge->firstPoint(), paramTolerance, aStartParam);
+        aCirc->parameter(aMinPnt, paramTolerance, aMidParam);
+        aCirc->parameter(anEdge->lastPoint(), paramTolerance, anEndParam);
+
+        // adjust period
+        anEndParam -= aStartParam;
+        aMidParam -= aStartParam;
+        if (anEndParam < 0.0)
+          anEndParam += 2.0 * PI;
+        if (aMidParam < 0.0)
+          aMidParam += 2.0 * PI;
+
+        aWasBlocked = data()->blockSendAttributeUpdated(true);
+        if(aMidParam < anEndParam) {
+          setReversed(false);
+        } else {
+          setReversed(true);
+        }
+        data()->blockSendAttributeUpdated(aWasBlocked, false);
       }
     }
-    return;
-  }
-  if (!aCenterAttr->isInitialized())
-    return;
-  if (!aStartAttr->isInitialized())
-    return;
-  if (!anEndAttr->isInitialized())
-    return;
-
-  // update the points in accordance to the changed point changes
-  if (theID == END_ID() && !myEndUpdate) {
-    myEndUpdate = true;
-    // compute and change the arc end point
-    std::shared_ptr<GeomAPI_Circ2d> aCircleForArc(
-        new GeomAPI_Circ2d(aCenterAttr->pnt(), aStartAttr->pnt()));
-    std::shared_ptr<GeomAPI_Pnt2d> aProjection = aCircleForArc->project(anEndAttr->pnt());
-    if (aProjection && anEndAttr->pnt()->distance(aProjection) > tolerance) {
-      if (!isStable()) { // issue #855: trying to update only not-updated coordinate if it is possible
-        if (abs(myXEndBefore - anEndAttr->x()) < 1.e-10) { // keep Y unchanged
-          double aVy = aCenterAttr->y() - anEndAttr->y();
-          double aVy2 = aVy * aVy;
-          double aR2 = aCircleForArc->radius() * aCircleForArc->radius();
-          if (aVy2 <= aR2) {
-            double aDX = sqrt(aR2 - aVy * aVy);
-            if (anEndAttr->x() > aCenterAttr->x())
-              aProjection->setX(aCenterAttr->x() + aDX);
-            else 
-              aProjection->setX(aCenterAttr->x() - aDX);
-            aProjection->setY(anEndAttr->y());
+  } else if(theID == CENTER_ID() || theID == START_ID() || theID == END_ID()) {
+    if(!aCenterAttr->isInitialized()
+      || !aStartAttr->isInitialized()
+      || !anEndAttr->isInitialized()) {
+      return;
+    }
+    std::shared_ptr<GeomAPI_Pnt2d> aCenter = aCenterAttr->pnt();
+    std::shared_ptr<GeomAPI_Pnt2d> aStart = aStartAttr->pnt();
+    std::shared_ptr<GeomAPI_Pnt2d> anEnd = anEndAttr->pnt();
+    double aRadius = aCenter->distance(aStart);
+    if (aRadius < tolerance)
+      return;
+    std::shared_ptr<GeomAPI_Circ2d> aCircleForArc(new GeomAPI_Circ2d(aCenter, aStart));
+
+    // Do not recalculate REVERSED flag if the arc is not consistent
+    std::shared_ptr<GeomAPI_Pnt2d> aProjection = aCircleForArc->project(anEnd);
+    if (aProjection && anEnd->distance(aProjection) <= tolerance) {
+      double aParameterNew = 0.0;
+      if(aCircleForArc->parameter(anEnd, paramTolerance, aParameterNew)) {
+        bool aWasBlocked = data()->blockSendAttributeUpdated(true);
+        if(myParamBefore <= PI / 2.0 && aParameterNew >= PI * 1.5) {
+          if(!boolean(REVERSED_ID())->value()) {
+            boolean(REVERSED_ID())->setValue(true);
           }
-        } else if (abs(myYEndBefore - anEndAttr->y()) < 1.e-10) { // keep X unchanged
-          double aVx = aCenterAttr->x() - anEndAttr->x();
-          double aVx2 = aVx * aVx;
-          double aR2 = aCircleForArc->radius() * aCircleForArc->radius();
-          if (aVx2 <= aR2) {
-            double aDY = sqrt(aR2 - aVx * aVx);
-            if (anEndAttr->y() > aCenterAttr->y())
-              aProjection->setY(aCenterAttr->y() + aDY);
-            else 
-              aProjection->setY(aCenterAttr->y() - aDY);
-            aProjection->setX(anEndAttr->x());
+        } else if(myParamBefore >= PI * 1.5 && aParameterNew <= PI / 2.0) {
+          if(boolean(REVERSED_ID())->value()) {
+            boolean(REVERSED_ID())->setValue(false);
           }
         }
+        data()->blockSendAttributeUpdated(aWasBlocked, false);
       }
+      if (fabs(aParameterNew) < paramTolerance ||
+          fabs(aParameterNew - 2.0 * PI) < paramTolerance)
+        aParameterNew = 2.0 * PI;
+      myParamBefore = aParameterNew;
+    }
+  }
 
-      anEndAttr->setValue(aProjection);
+  double aRadius = 0;
+  double anAngle = 0;
+  if(aCenterAttr->isInitialized() && aStartAttr->isInitialized()) {
+    aRadius = aCenterAttr->pnt()->distance(aStartAttr->pnt());
+    if(anEndAttr->isInitialized()) {
+      if(aStartAttr->pnt()->isEqual(anEndAttr->pnt())) {
+        anAngle = 360;
+      } else {
+        GeomAPI_Circ2d aCircleForArc(aCenterAttr->pnt(), aStartAttr->pnt());
+        double aStartParam, anEndParam;
+        aCircleForArc.parameter(aStartAttr->pnt(), paramTolerance, aStartParam);
+        aCircleForArc.parameter(anEndAttr->pnt(), paramTolerance, anEndParam);
+        anAngle = (anEndParam - aStartParam) / PI * 180.0;
+        if(isReversed()) anAngle = 360.0 - anAngle;
+      }
     }
-    myXEndBefore = anEndAttr->x();
-    myYEndBefore = anEndAttr->y();
-    myEndUpdate = false;
-  } else if (theID == START_ID() && !myStartUpdate) {
-    myStartUpdate = true;
-    // compute and change the arc start point
-    std::shared_ptr<GeomAPI_Circ2d> aCircleForArc(
-        new GeomAPI_Circ2d(aCenterAttr->pnt(), anEndAttr->pnt()));
-    std::shared_ptr<GeomAPI_Pnt2d> aProjection = aCircleForArc->project(aStartAttr->pnt());
-    if (aProjection && aStartAttr->pnt()->distance(aProjection) > tolerance)
-      aStartAttr->setValue(aProjection);
-    myStartUpdate = false;
-  } else if (theID == CENTER_ID() && !myEndUpdate) {
-    myEndUpdate = true;
-    // compute and change the arc end point
-    std::shared_ptr<GeomAPI_Circ2d> aCircleForArc(
-        new GeomAPI_Circ2d(aCenterAttr->pnt(), aStartAttr->pnt()));
-    std::shared_ptr<GeomAPI_Pnt2d> aProjection = aCircleForArc->project(anEndAttr->pnt());
-    if (aProjection && anEndAttr->pnt()->distance(aProjection) > tolerance)
-      anEndAttr->setValue(aProjection);
-    myEndUpdate = false;
   }
+
+  bool aWasBlocked = data()->blockSendAttributeUpdated(true);
+  real(RADIUS_ID())->setValue(aRadius);
+  real(ANGLE_ID())->setValue(anAngle);
+  data()->blockSendAttributeUpdated(aWasBlocked, false);
+}
+
+void SketchPlugin_Arc::setReversed(bool isReversed)
+{
+  boolean(REVERSED_ID())->setValue(isReversed);
+}
+
+bool SketchPlugin_Arc::isReversed()
+{
+  return boolean(REVERSED_ID())->value();
 }