+//=======================================================================
+//function : BestSplit
+//purpose : Find better diagonal for cutting.
+//=======================================================================
+int SMESH_MeshEditor::BestSplit (const SMDS_MeshElement* theQuad,
+ SMESH::Controls::NumericalFunctorPtr theCrit)
+{
+ if (!theCrit.get())
+ return -1;
+
+ if (!theQuad || theQuad->GetType() != SMDSAbs_Face || theQuad->NbNodes() != 4)
+ return -1;
+
+ // retrieve element nodes
+ const SMDS_MeshNode* aNodes [4];
+ SMDS_ElemIteratorPtr itN = theQuad->nodesIterator();
+ int i = 0;
+ while (itN->more())
+ aNodes[ i++ ] = static_cast<const SMDS_MeshNode*>( itN->next() );
+
+ // compare two sets of possible triangles
+ double aBadRate1, aBadRate2; // to what extent a set is bad
+ SMDS_FaceOfNodes tr1 ( aNodes[0], aNodes[1], aNodes[2] );
+ SMDS_FaceOfNodes tr2 ( aNodes[2], aNodes[3], aNodes[0] );
+ aBadRate1 = getBadRate( &tr1, theCrit ) + getBadRate( &tr2, theCrit );
+
+ SMDS_FaceOfNodes tr3 ( aNodes[1], aNodes[2], aNodes[3] );
+ SMDS_FaceOfNodes tr4 ( aNodes[3], aNodes[0], aNodes[1] );
+ aBadRate2 = getBadRate( &tr3, theCrit ) + getBadRate( &tr4, theCrit );
+
+ if (aBadRate1 <= aBadRate2) // tr1 + tr2 is better
+ return 1; // diagonal 1-3
+
+ return 2; // diagonal 2-4
+}
+
