From f98e5aacdf19dda99496de64f27414a579065447 Mon Sep 17 00:00:00 2001
From: azv <azv@opencascade.com>
Date: Thu, 9 Apr 2015 11:02:58 +0300
Subject: [PATCH] Mirror constraint behavior stabilization

---
 src/SketchSolver/SketchSolver_Constraint.cpp  | 32 ++++++++++++-------
 .../SketchSolver_ConstraintMirror.cpp         | 24 +++++++++++++-
 2 files changed, 43 insertions(+), 13 deletions(-)

diff --git a/src/SketchSolver/SketchSolver_Constraint.cpp b/src/SketchSolver/SketchSolver_Constraint.cpp
index b86ce1a28..1d2abb354 100644
--- a/src/SketchSolver/SketchSolver_Constraint.cpp
+++ b/src/SketchSolver/SketchSolver_Constraint.cpp
@@ -618,18 +618,24 @@ void SketchSolver_Constraint::calculateMiddlePoint(
 
     double xStart = anArcPoint[1][0] / aRad, xEnd = anArcPoint[2][0] / aRad;
     double yStart = anArcPoint[1][1] / aRad, yEnd = anArcPoint[2][1] / aRad;
+    double aTanStart = abs(xStart) < tolerance ? yStart : yStart / xStart;
+    double aTanEnd   = abs(xEnd) < tolerance   ? yEnd   : yEnd / xEnd;
+    double aCotStart = abs(yStart) < tolerance ? xStart : xStart / yStart;
+    double aCotEnd   = abs(yEnd) < tolerance   ? xEnd   : xEnd / yEnd;
     if (anArcPoint[1][0] * anArcPoint[2][0] < 0.0) {
       if (anArcPoint[1][0] > 0.0)
         yEnd = 2.0 - yEnd;
       else
         yStart = -2.0 - yStart;
     } else {
-      if (yStart > yEnd) {
-        yStart = 2.0 - yStart;
-        yEnd = -2.0 - yEnd;
-      } else {
-        yStart = -2.0 - yStart;
-        yEnd = 2.0 - yEnd;
+      if (aTanStart > aTanEnd) {
+        if (yStart > yEnd) {
+          yStart = 2.0 - yStart;
+          yEnd = -2.0 - yEnd;
+        } else {
+          yStart = -2.0 - yStart;
+          yEnd = 2.0 - yEnd;
+        }
       }
     }
     if (anArcPoint[1][1] * anArcPoint[2][1] < 0.0) {
@@ -638,12 +644,14 @@ void SketchSolver_Constraint::calculateMiddlePoint(
       else
         xStart = -2.0 - xStart;
     } else {
-      if (xStart > xEnd) {
-        xStart = 2.0 - xStart;
-        xEnd = -2.0 - xEnd;
-      } else {
-        xStart = -2.0 - xStart;
-        xEnd = 2.0 - xEnd;
+      if (aCotStart < aCotEnd) {
+        if (xStart > xEnd) {
+          xStart = 2.0 - xStart;
+          xEnd = -2.0 - xEnd;
+        } else {
+          xStart = -2.0 - xStart;
+          xEnd = 2.0 - xEnd;
+        }
       }
     }
     x = (1.0 - theCoeff) * xStart + theCoeff * xEnd;
diff --git a/src/SketchSolver/SketchSolver_ConstraintMirror.cpp b/src/SketchSolver/SketchSolver_ConstraintMirror.cpp
index f3ded1d30..fde4b811e 100644
--- a/src/SketchSolver/SketchSolver_ConstraintMirror.cpp
+++ b/src/SketchSolver/SketchSolver_ConstraintMirror.cpp
@@ -159,6 +159,20 @@ void SketchSolver_ConstraintMirror::process()
             0.0, aBothMiddlePoints[i], SLVS_E_UNKNOWN, aBothArcs[i].h, SLVS_E_UNKNOWN);
         aPonCircConstr.h = myStorage->addConstraint(aPonCircConstr);
         mySlvsConstraints.push_back(aPonCircConstr.h);
+        if (i == 0) {
+          // additional constraint for the point to be in the middle of a base arc
+          Slvs_Entity aLine1 = Slvs_MakeLineSegment(SLVS_E_UNKNOWN, myGroup->getId(),
+              myGroup->getWorkplaneId(), aBothArcs[i].point[1], aBothMiddlePoints[i]);
+          aLine1.h = myStorage->addEntity(aLine1);
+          Slvs_Entity aLine2 = Slvs_MakeLineSegment(SLVS_E_UNKNOWN, myGroup->getId(),
+              myGroup->getWorkplaneId(), aBothArcs[i].point[2], aBothMiddlePoints[i]);
+          aLine2.h = myStorage->addEntity(aLine2);
+          Slvs_Constraint aMiddleConstr = Slvs_MakeConstraint(SLVS_E_UNKNOWN, myGroup->getId(),
+              SLVS_C_EQUAL_LENGTH_LINES, myGroup->getWorkplaneId(),
+              0.0, SLVS_E_UNKNOWN, SLVS_E_UNKNOWN, aLine1.h, aLine2.h);
+          aMiddleConstr.h = myStorage->addConstraint(aMiddleConstr);
+          mySlvsConstraints.push_back(aMiddleConstr.h);
+        }
       }
 
       aBaseArcPoints[2] = aBothMiddlePoints[0];
@@ -319,6 +333,7 @@ void SketchSolver_ConstraintMirror::adjustConstraint()
     if (aPonCircA.h == SLVS_E_UNKNOWN || aPonCircB.h == SLVS_E_UNKNOWN)
       continue;
 
+    bool aNeedToResolve = myStorage->isNeedToResolve();
     // Calculate middle point for base arc and mirrored point on mirror arc
     Slvs_Entity aBaseArc = myStorage->getEntity(aPonCircA.entityA);
     Slvs_Entity aBasePoint = myStorage->getEntity(aPonCircA.ptA);
@@ -327,7 +342,14 @@ void SketchSolver_ConstraintMirror::adjustConstraint()
     calculateMiddlePoint(aBaseArc, 0.5, aParamX.val, aParamY.val);
     myStorage->updateParameter(aParamX);
     myStorage->updateParameter(aParamY);
+    Slvs_Entity aMirrorArc = myStorage->getEntity(aPonCircB.entityA);
     Slvs_Entity aMirrorPoint = myStorage->getEntity(aPonCircB.ptA);
-    makeMirrorEntity(aBasePoint, aMirrorPoint, aStartEnd);
+    aParamX = myStorage->getParameter(aMirrorPoint.param[0]);
+    aParamY = myStorage->getParameter(aMirrorPoint.param[1]);
+    calculateMiddlePoint(aMirrorArc, 0.5, aParamX.val, aParamY.val);
+    myStorage->updateParameter(aParamX);
+    myStorage->updateParameter(aParamY);
+    // To avoid looped recalculations of sketch
+    myStorage->setNeedToResolve(aNeedToResolve);
   }
 }
-- 
2.39.2