+ if (uv_eb.size() != nb || uv_er.size() != nr || uv_et.size() != nt || uv_el.size() != nl)
+ return error(COMPERR_BAD_INPUT_MESH);
+
+ if ( myNeedSmooth )
+ UpdateDegenUV( quad );
+
+ // arrays for normalized params
+ TColStd_SequenceOfReal npb, npr, npt, npl;
+ for (j = 0; j < nb; j++) {
+ npb.Append(uv_eb[j].normParam);
+ }
+ for (i = 0; i < nr; i++) {
+ npr.Append(uv_er[i].normParam);
+ }
+ for (j = 0; j < nt; j++) {
+ npt.Append(uv_et[j].normParam);
+ }
+ for (i = 0; i < nl; i++) {
+ npl.Append(uv_el[i].normParam);
+ }
+
+ int dl,dr;
+ // orientation of face and 3 main domain for future faces
+ // 0 top 1
+ // 1------------1
+ // | | | |
+ // | | | |
+ // | L | | R |
+ // left | | | | rigth
+ // | / \ |
+ // | / C \ |
+ // |/ \|
+ // 0------------0
+ // 0 bottom 1
+
+ // add some params to right and left after the first param
+ // insert to right
+ dr = nbv - nr;
+ double dpr = (npr.Value(2) - npr.Value(1))/(dr+1);
+ for (i=1; i<=dr; i++) {
+ npr.InsertAfter(1,npr.Value(2)-dpr);
+ }
+ // insert to left
+ dl = nbv - nl;
+ dpr = (npl.Value(2) - npl.Value(1))/(dl+1);
+ for (i=1; i<=dl; i++) {
+ npl.InsertAfter(1,npl.Value(2)-dpr);
+ }
+
+ gp_XY a0 (uv_eb.front().u, uv_eb.front().v);
+ gp_XY a1 (uv_eb.back().u, uv_eb.back().v);
+ gp_XY a2 (uv_et.back().u, uv_et.back().v);
+ gp_XY a3 (uv_et.front().u, uv_et.front().v);
+
+ int nnn = Min(nr,nl);
+ // auxilary sequence of XY for creation of nodes
+ // in the bottom part of central domain
+ // it's length must be == nbv-nnn-1
+ TColgp_SequenceOfXY UVL;
+ TColgp_SequenceOfXY UVR;
+ //==================================================
+
+ // step1: create faces for left domain
+ StdMeshers_Array2OfNode NodesL(1,dl+1,1,nl);
+ // add left nodes
+ for (j=1; j<=nl; j++)
+ NodesL.SetValue(1,j,uv_el[j-1].node);
+ if (dl>0) {
+ // add top nodes
+ for (i=1; i<=dl; i++)
+ NodesL.SetValue(i+1,nl,uv_et[i].node);
+ // create and add needed nodes
+ TColgp_SequenceOfXY UVtmp;
+ for (i=1; i<=dl; i++) {
+ double x0 = npt.Value(i+1);
+ double x1 = x0;
+ // diagonal node
+ double y0 = npl.Value(i+1);
+ double y1 = npr.Value(i+1);
+ gp_UV UV = calcUV(x0, x1, y0, y1, quad, a0, a1, a2, a3);
+ gp_Pnt P = S->Value(UV.X(),UV.Y());
+ SMDS_MeshNode * N = meshDS->AddNode(P.X(), P.Y(), P.Z());
+ meshDS->SetNodeOnFace(N, geomFaceID, UV.X(), UV.Y());
+ NodesL.SetValue(i+1,1,N);
+ if (UVL.Length()<nbv-nnn-1) UVL.Append(UV);
+ // internal nodes
+ for (j=2; j<nl; j++) {
+ double y0 = npl.Value(dl+j);
+ double y1 = npr.Value(dl+j);
+ gp_UV UV = calcUV(x0, x1, y0, y1, quad, a0, a1, a2, a3);
+ gp_Pnt P = S->Value(UV.X(),UV.Y());
+ SMDS_MeshNode* N = meshDS->AddNode(P.X(), P.Y(), P.Z());
+ meshDS->SetNodeOnFace(N, geomFaceID, UV.X(), UV.Y());
+ NodesL.SetValue(i+1,j,N);
+ if (i==dl) UVtmp.Append(UV);
+ }
+ }
+ for (i=1; i<=UVtmp.Length() && UVL.Length()<nbv-nnn-1; i++) {
+ UVL.Append(UVtmp.Value(i));
+ }
+ // create faces
+ for (i=1; i<=dl; i++) {
+ for (j=1; j<nl; j++) {
+ SMDS_MeshFace* F =
+ myHelper->AddFace(NodesL.Value(i,j), NodesL.Value(i+1,j),
+ NodesL.Value(i+1,j+1), NodesL.Value(i,j+1));
+ if (F) meshDS->SetMeshElementOnShape(F, geomFaceID);
+ }
+ }
+ }
+ else {
+ // fill UVL using c2d
+ for (i=1; i<npl.Length() && UVL.Length()<nbv-nnn-1; i++) {
+ UVL.Append(gp_UV (uv_el[i].u, uv_el[i].v));
+ }
+ }
+
+ // step2: create faces for right domain
+ StdMeshers_Array2OfNode NodesR(1,dr+1,1,nr);
+ // add right nodes
+ for (j=1; j<=nr; j++)
+ NodesR.SetValue(1,j,uv_er[nr-j].node);
+ if (dr>0) {
+ // add top nodes
+ for (i=1; i<=dr; i++)
+ NodesR.SetValue(i+1,1,uv_et[nt-1-i].node);
+ // create and add needed nodes
+ TColgp_SequenceOfXY UVtmp;
+ for (i=1; i<=dr; i++) {
+ double x0 = npt.Value(nt-i);
+ double x1 = x0;
+ // diagonal node
+ double y0 = npl.Value(i+1);
+ double y1 = npr.Value(i+1);
+ gp_UV UV = calcUV(x0, x1, y0, y1, quad, a0, a1, a2, a3);
+ gp_Pnt P = S->Value(UV.X(),UV.Y());
+ SMDS_MeshNode * N = meshDS->AddNode(P.X(), P.Y(), P.Z());
+ meshDS->SetNodeOnFace(N, geomFaceID, UV.X(), UV.Y());
+ NodesR.SetValue(i+1,nr,N);
+ if (UVR.Length()<nbv-nnn-1) UVR.Append(UV);
+ // internal nodes
+ for (j=2; j<nr; j++) {
+ double y0 = npl.Value(nbv-j+1);
+ double y1 = npr.Value(nbv-j+1);
+ gp_UV UV = calcUV(x0, x1, y0, y1, quad, a0, a1, a2, a3);
+ gp_Pnt P = S->Value(UV.X(),UV.Y());
+ SMDS_MeshNode* N = meshDS->AddNode(P.X(), P.Y(), P.Z());
+ meshDS->SetNodeOnFace(N, geomFaceID, UV.X(), UV.Y());
+ NodesR.SetValue(i+1,j,N);
+ if (i==dr) UVtmp.Prepend(UV);
+ }
+ }
+ for (i=1; i<=UVtmp.Length() && UVR.Length()<nbv-nnn-1; i++) {
+ UVR.Append(UVtmp.Value(i));
+ }
+ // create faces
+ for (i=1; i<=dr; i++) {
+ for (j=1; j<nr; j++) {
+ SMDS_MeshFace* F =
+ myHelper->AddFace(NodesR.Value(i,j), NodesR.Value(i+1,j),
+ NodesR.Value(i+1,j+1), NodesR.Value(i,j+1));
+ if (F) meshDS->SetMeshElementOnShape(F, geomFaceID);
+ }
+ }
+ }
+ else {
+ // fill UVR using c2d
+ for (i=1; i<npr.Length() && UVR.Length()<nbv-nnn-1; i++) {
+ UVR.Append(gp_UV(uv_er[i].u, uv_er[i].v));
+ }
+ }
+
+ // step3: create faces for central domain
+ StdMeshers_Array2OfNode NodesC(1,nb,1,nbv);
+ // add first line using NodesL
+ for (i=1; i<=dl+1; i++)
+ NodesC.SetValue(1,i,NodesL(i,1));
+ for (i=2; i<=nl; i++)
+ NodesC.SetValue(1,dl+i,NodesL(dl+1,i));
+ // add last line using NodesR
+ for (i=1; i<=dr+1; i++)
+ NodesC.SetValue(nb,i,NodesR(i,nr));
+ for (i=1; i<nr; i++)
+ NodesC.SetValue(nb,dr+i+1,NodesR(dr+1,nr-i));
+ // add top nodes (last columns)
+ for (i=dl+2; i<nbh-dr; i++)
+ NodesC.SetValue(i-dl,nbv,uv_et[i-1].node);
+ // add bottom nodes (first columns)
+ for (i=2; i<nb; i++)
+ NodesC.SetValue(i,1,uv_eb[i-1].node);
+
+ // create and add needed nodes
+ // add linear layers
+ for (i=2; i<nb; i++) {
+ double x0 = npt.Value(dl+i);
+ double x1 = x0;
+ for (j=1; j<nnn; j++) {
+ double y0 = npl.Value(nbv-nnn+j);
+ double y1 = npr.Value(nbv-nnn+j);
+ gp_UV UV = calcUV(x0, x1, y0, y1, quad, a0, a1, a2, a3);
+ gp_Pnt P = S->Value(UV.X(),UV.Y());
+ SMDS_MeshNode* N = meshDS->AddNode(P.X(), P.Y(), P.Z());
+ meshDS->SetNodeOnFace(N, geomFaceID, UV.X(), UV.Y());
+ NodesC.SetValue(i,nbv-nnn+j,N);
+ }
+ }
+ // add diagonal layers
+ for (i=1; i<nbv-nnn; i++) {
+ double du = UVR.Value(i).X() - UVL.Value(i).X();
+ double dv = UVR.Value(i).Y() - UVL.Value(i).Y();
+ for (j=2; j<nb; j++) {
+ double u = UVL.Value(i).X() + du*npb.Value(j);
+ double v = UVL.Value(i).Y() + dv*npb.Value(j);
+ gp_Pnt P = S->Value(u,v);
+ SMDS_MeshNode* N = meshDS->AddNode(P.X(), P.Y(), P.Z());
+ meshDS->SetNodeOnFace(N, geomFaceID, u, v);
+ NodesC.SetValue(j,i+1,N);
+ }
+ }
+ // create faces
+ for (i=1; i<nb; i++) {
+ for (j=1; j<nbv; j++) {
+ SMDS_MeshFace* F =
+ myHelper->AddFace(NodesC.Value(i,j), NodesC.Value(i+1,j),
+ NodesC.Value(i+1,j+1), NodesC.Value(i,j+1));
+ if (F) meshDS->SetMeshElementOnShape(F, geomFaceID);
+ }
+ }
+ // TODO ???
+ } // end Multiple Reduce implementation
+ else { // Simple Reduce (!MultipleReduce)
+ //=========================================================
+ if (nr == nl) {
+ if (nt < nb) {
+ // it is a base case => not shift quad
+ //shiftQuad(quad,0,true);
+ }
+ else {
+ // we have to shift quad on 2
+ shiftQuad(quad,2,true);
+ }
+ }
+ else {
+ if (nl > nr) {
+ // we have to shift quad on 1
+ shiftQuad(quad,1,true);
+ }
+ else {
+ // we have to shift quad on 3
+ shiftQuad(quad,3,true);
+ }
+ }
+
+ nb = quad->side[0]->NbPoints();
+ nr = quad->side[1]->NbPoints();
+ nt = quad->side[2]->NbPoints();
+ nl = quad->side[3]->NbPoints();
+
+ // number of rows and columns
+ int nrows = nr - 1; // and also == nl - 1
+ int ncol_top = nt - 1;
+ int ncol_bot = nb - 1;
+ int npair_top = ncol_top / 2;
+ // maximum number of bottom elements for "linear" simple reduce 4->2
+ int max_lin42 = ncol_top + npair_top * 2 * nrows;
+ // maximum number of bottom elements for "linear" simple reduce 3->1
+ int max_lin31 = ncol_top + ncol_top * 2 * nrows;
+ // maximum number of bottom elements for "tree" simple reduce 4->2
+ int max_tree42 = 0;
+ // number of rows needed to reduce ncol_bot to ncol_top using simple 4->2 "tree"
+ int nrows_tree42 = int( log( (double)(ncol_bot / ncol_top) )/log((double)2) ); // needed to avoid overflow at pow(2) while computing max_tree42
+ if (nrows_tree42 < nrows) {
+ max_tree42 = npair_top * pow(2.0, nrows + 1);
+ if ( ncol_top > npair_top * 2 ) {
+ int delta = ncol_bot - max_tree42;
+ for (int irow = 1; irow < nrows; irow++) {
+ int nfour = delta / 4;
+ delta -= nfour * 2;
+ }
+ if (delta <= (ncol_top - npair_top * 2))
+ max_tree42 = ncol_bot;
+ }
+ }
+ // maximum number of bottom elements for "tree" simple reduce 3->1
+ //int max_tree31 = ncol_top * pow(3.0, nrows);
+ bool is_lin_31 = false;
+ bool is_lin_42 = false;
+ bool is_tree_31 = false;
+ bool is_tree_42 = false;
+ int max_lin = max_lin42;
+ if (ncol_bot > max_lin42) {
+ if (ncol_bot <= max_lin31) {
+ is_lin_31 = true;
+ max_lin = max_lin31;
+ }
+ }
+ else {
+ // if ncol_bot is a 3*n or not 2*n
+ if ((ncol_bot/3)*3 == ncol_bot || (ncol_bot/2)*2 != ncol_bot) {
+ is_lin_31 = true;
+ max_lin = max_lin31;
+ }
+ else {
+ is_lin_42 = true;
+ }
+ }
+ if (ncol_bot > max_lin) { // not "linear"
+ is_tree_31 = (ncol_bot > max_tree42);
+ if (ncol_bot <= max_tree42) {
+ if ((ncol_bot/3)*3 == ncol_bot || (ncol_bot/2)*2 != ncol_bot) {
+ is_tree_31 = true;
+ }
+ else {
+ is_tree_42 = true;
+ }
+ }
+ }
+
+ const vector<UVPtStruct>& uv_eb = quad->side[0]->GetUVPtStruct(true,0);
+ const vector<UVPtStruct>& uv_er = quad->side[1]->GetUVPtStruct(false,1);
+ const vector<UVPtStruct>& uv_et = quad->side[2]->GetUVPtStruct(true,1);
+ const vector<UVPtStruct>& uv_el = quad->side[3]->GetUVPtStruct(false,0);
+
+ if (uv_eb.size() != nb || uv_er.size() != nr || uv_et.size() != nt || uv_el.size() != nl)
+ return error(COMPERR_BAD_INPUT_MESH);
+
+ myHelper->SetElementsOnShape( true );
+
+ gp_UV uv[ UV_SIZE ];
+ uv[ UV_A0 ].SetCoord( uv_eb.front().u, uv_eb.front().v);
+ uv[ UV_A1 ].SetCoord( uv_eb.back().u, uv_eb.back().v );
+ uv[ UV_A2 ].SetCoord( uv_et.back().u, uv_et.back().v );
+ uv[ UV_A3 ].SetCoord( uv_et.front().u, uv_et.front().v);
+
+ vector<UVPtStruct> curr_base = uv_eb, next_base;
+
+ UVPtStruct nullUVPtStruct; nullUVPtStruct.node = 0;
+
+ int curr_base_len = nb;
+ int next_base_len = 0;
+
+ if ( true )
+ { // ------------------------------------------------------------------
+ // New algorithm implemented by request of IPAL22856
+ // "2D quadrangle mesher of reduced type works wrong"
+ // http://bugtracker.opencascade.com/show_bug.cgi?id=22856
+
+ // the algorithm is following: all reduces are centred in horizontal
+ // direction and are distributed among all rows
+
+ if (ncol_bot > max_tree42) {
+ is_lin_31 = true;
+ }
+ else {
+ if ((ncol_top/3)*3 == ncol_top ) {
+ is_lin_31 = true;
+ }
+ else {
+ is_lin_42 = true;
+ }
+ }
+
+ const int col_top_size = is_lin_42 ? 2 : 1;
+ const int col_base_size = is_lin_42 ? 4 : 3;
+
+ // Compute nb of "columns" (like in "linear" simple reducing) in all rows
+
+ vector<int> nb_col_by_row;
+
+ int delta_all = nb - nt;
+ int delta_one_col = nrows * 2;
+ int nb_col = delta_all / delta_one_col;
+ int remainder = delta_all - nb_col * delta_one_col;
+ if (remainder > 0) {
+ nb_col++;
+ }
+ if ( nb_col * col_top_size >= nt ) // == "tree" reducing situation
+ {
+ // top row is full (all elements reduced), add "columns" one by one
+ // in rows below until all bottom elements are reduced
+ nb_col = ( nt - 1 ) / col_top_size;
+ nb_col_by_row.resize( nrows, nb_col );
+ int nbrows_not_full = nrows - 1;
+ int cur_top_size = nt - 1;
+ remainder = delta_all - nb_col * delta_one_col;
+ while ( remainder > 0 )
+ {
+ delta_one_col = nbrows_not_full * 2;
+ int nb_col_add = remainder / delta_one_col;
+ cur_top_size += 2 * nb_col_by_row[ nbrows_not_full ];
+ int nb_col_free = cur_top_size / col_top_size - nb_col_by_row[ nbrows_not_full-1 ];
+ if ( nb_col_add > nb_col_free )
+ nb_col_add = nb_col_free;
+ for ( int irow = 0; irow < nbrows_not_full; ++irow )
+ nb_col_by_row[ irow ] += nb_col_add;
+ nbrows_not_full --;
+ remainder -= nb_col_add * delta_one_col;
+ }
+ }
+ else // == "linear" reducing situation
+ {
+ nb_col_by_row.resize( nrows, nb_col );
+ if (remainder > 0)
+ for ( int irow = remainder / 2; irow < nrows; ++irow )
+ nb_col_by_row[ irow ]--;
+ }
+
+ // Make elements
+
+ PReduceFunction reduceFunction = & ( is_lin_42 ? reduce42 : reduce31 );
+
+ const int reduce_grp_size = is_lin_42 ? 4 : 3;
+
+ for (i = 1; i < nr; i++) // layer by layer
+ {
+ nb_col = nb_col_by_row[ i-1 ];
+ int nb_next = curr_base_len - nb_col * 2;
+ if (nb_next < nt) nb_next = nt;
+
+ const double y = uv_el[ i ].normParam;
+
+ if ( i + 1 == nr ) // top
+ {
+ next_base = uv_et;
+ }
+ else
+ {
+ next_base.clear();
+ next_base.resize( nb_next, nullUVPtStruct );
+ next_base.front() = uv_el[i];
+ next_base.back() = uv_er[i];
+
+ // compute normalized param u
+ double du = 1. / ( nb_next - 1 );
+ next_base[0].normParam = 0.;
+ for ( j = 1; j < nb_next; ++j )
+ next_base[j].normParam = next_base[j-1].normParam + du;
+ }
+ uv[ UV_L ].SetCoord( next_base.front().u, next_base.front().v );
+ uv[ UV_R ].SetCoord( next_base.back().u, next_base.back().v );
+
+ int free_left = ( curr_base_len - 1 - nb_col * col_base_size ) / 2;
+ int free_middle = curr_base_len - 1 - nb_col * col_base_size - 2 * free_left;
+
+ // not reduced left elements
+ for (j = 0; j < free_left; j++)
+ {
+ // f (i + 1, j + 1)
+ const SMDS_MeshNode*& Nf = next_base[++next_base_len].node;
+ if ( !Nf )
+ Nf = makeNode( next_base[ next_base_len ], y, quad, uv, myHelper, S );
+
+ myHelper->AddFace(curr_base[ j ].node,
+ curr_base[ j+1 ].node,
+ Nf,
+ next_base[ next_base_len-1 ].node);
+ }
+
+ for (int icol = 1; icol <= nb_col; icol++)
+ {
+ // add "H"
+ reduceFunction( curr_base, next_base, j, next_base_len, quad, uv, y, myHelper, S );
+
+ j += reduce_grp_size;
+
+ // elements in the middle of "columns" added for symmetry
+ if ( free_middle > 0 && ( nb_col % 2 == 0 ) && icol == nb_col / 2 )
+ {
+ for (int imiddle = 1; imiddle <= free_middle; imiddle++) {
+ // f (i + 1, j + imiddle)
+ const SMDS_MeshNode*& Nf = next_base[++next_base_len].node;
+ if ( !Nf )
+ Nf = makeNode( next_base[ next_base_len ], y, quad, uv, myHelper, S );
+
+ myHelper->AddFace(curr_base[ j-1+imiddle ].node,
+ curr_base[ j +imiddle ].node,
+ Nf,
+ next_base[ next_base_len-1 ].node);
+ }
+ j += free_middle;
+ }
+ }
+
+ // not reduced right elements
+ for (; j < curr_base_len-1; j++) {
+ // f (i + 1, j + 1)
+ const SMDS_MeshNode*& Nf = next_base[++next_base_len].node;
+ if ( !Nf )
+ Nf = makeNode( next_base[ next_base_len ], y, quad, uv, myHelper, S );
+
+ myHelper->AddFace(curr_base[ j ].node,
+ curr_base[ j+1 ].node,
+ Nf,
+ next_base[ next_base_len-1 ].node);
+ }
+
+ curr_base_len = next_base_len + 1;
+ next_base_len = 0;
+ curr_base.swap( next_base );
+ }
+
+ }
+ else if ( is_tree_42 || is_tree_31 )
+ {
+ // "tree" simple reduce "42": 2->4->8->16->32->...
+ //
+ // .-------------------------------.-------------------------------. nr
+ // | \ | / |
+ // | \ .---------------.---------------. / |
+ // | | | | |
+ // .---------------.---------------.---------------.---------------.
+ // | \ | / | \ | / |
+ // | \ .-------.-------. / | \ .-------.-------. / |
+ // | | | | | | | | |
+ // .-------.-------.-------.-------.-------.-------.-------.-------. i
+ // |\ | /|\ | /|\ | /|\ | /|
+ // | \.---.---./ | \.---.---./ | \.---.---./ | \.---.---./ |
+ // | | | | | | | | | | | | | | | | |
+ // .---.---.---.---.---.---.---.---.---.---.---.---.---.---.---.---.
+ // |\ | /|\ | /|\ | /|\ | /|\ | /|\ | /|\ | /|\ | /|
+ // | .-.-. | .-.-. | .-.-. | .-.-. | .-.-. | .-.-. | .-.-. | .-.-. |
+ // | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
+ // .-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-. 1
+ // 1 j nb
+
+ // "tree" simple reduce "31": 1->3->9->27->...
+ //
+ // .-----------------------------------------------------. nr
+ // | \ / |
+ // | .-----------------. |
+ // | | | |
+ // .-----------------.-----------------.-----------------.
+ // | \ / | \ / | \ / |
+ // | .-----. | .-----. | .-----. | i
+ // | | | | | | | | | |
+ // .-----.-----.-----.-----.-----.-----.-----.-----.-----.
+ // |\ /|\ /|\ /|\ /|\ /|\ /|\ /|\ /|\ /|
+ // | .-. | .-. | .-. | .-. | .-. | .-. | .-. | .-. | .-. |
+ // | | | | | | | | | | | | | | | | | | | | | | | | | | | |
+ // .-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-. 1
+ // 1 j nb
+
+ PReduceFunction reduceFunction = & ( is_tree_42 ? reduce42 : reduce31 );
+
+ const int reduce_grp_size = is_tree_42 ? 4 : 3;
+
+ for (i = 1; i < nr; i++) // layer by layer
+ {
+ // to stop reducing, if number of nodes reaches nt
+ int delta = curr_base_len - nt;
+
+ // to calculate normalized parameter, we must know number of points in next layer
+ int nb_reduce_groups = (curr_base_len - 1) / reduce_grp_size;
+ int nb_next = nb_reduce_groups * (reduce_grp_size-2) + (curr_base_len - nb_reduce_groups*reduce_grp_size);
+ if (nb_next < nt) nb_next = nt;
+
+ const double y = uv_el[ i ].normParam;
+
+ if ( i + 1 == nr ) // top
+ {
+ next_base = uv_et;
+ }
+ else
+ {
+ next_base.clear();
+ next_base.resize( nb_next, nullUVPtStruct );
+ next_base.front() = uv_el[i];
+ next_base.back() = uv_er[i];
+
+ // compute normalized param u
+ double du = 1. / ( nb_next - 1 );
+ next_base[0].normParam = 0.;
+ for ( j = 1; j < nb_next; ++j )
+ next_base[j].normParam = next_base[j-1].normParam + du;
+ }
+ uv[ UV_L ].SetCoord( next_base.front().u, next_base.front().v );
+ uv[ UV_R ].SetCoord( next_base.back().u, next_base.back().v );
+
+ for (j = 0; j+reduce_grp_size < curr_base_len && delta > 0; j+=reduce_grp_size, delta-=2)
+ {
+ reduceFunction( curr_base, next_base, j, next_base_len, quad, uv, y, myHelper, S );
+ }
+
+ // not reduced side elements (if any)
+ for (; j < curr_base_len-1; j++)
+ {
+ // f (i + 1, j + 1)
+ const SMDS_MeshNode*& Nf = next_base[++next_base_len].node;
+ if ( !Nf )
+ Nf = makeNode( next_base[ next_base_len ], y, quad, uv, myHelper, S );
+
+ myHelper->AddFace(curr_base[ j ].node,
+ curr_base[ j+1 ].node,
+ Nf,
+ next_base[ next_base_len-1 ].node);
+ }
+ curr_base_len = next_base_len + 1;
+ next_base_len = 0;
+ curr_base.swap( next_base );
+ }
+ } // end "tree" simple reduce
+
+ else if ( is_lin_42 || is_lin_31 ) {
+ // "linear" simple reduce "31": 2->6->10->14
+ //
+ // .-----------------------------.-----------------------------. nr
+ // | \ / | \ / |
+ // | .---------. | .---------. |
+ // | | | | | | |
+ // .---------.---------.---------.---------.---------.---------.
+ // | / \ / \ | / \ / \ |
+ // | / .-----. \ | / .-----. \ | i
+ // | / | | \ | / | | \ |
+ // .-----.-----.-----.-----.-----.-----.-----.-----.-----.-----.
+ // | / / \ / \ \ | / / \ / \ \ |
+ // | / / .-. \ \ | / / .-. \ \ |
+ // | / / / \ \ \ | / / / \ \ \ |
+ // .--.----.---.-----.---.-----.-.--.----.---.-----.---.-----.-. 1
+ // 1 j nb
+
+ // "linear" simple reduce "42": 4->8->12->16
+ //
+ // .---------------.---------------.---------------.---------------. nr
+ // | \ | / | \ | / |
+ // | \ .-------.-------. / | \ .-------.-------. / |
+ // | | | | | | | | |
+ // .-------.-------.-------.-------.-------.-------.-------.-------.
+ // | / \ | / \ | / \ | / \ |
+ // | / \.----.----./ \ | / \.----.----./ \ | i
+ // | / | | | \ | / | | | \ |
+ // .-----.----.----.----.----.-----.-----.----.----.----.----.-----.
+ // | / / \ | / \ \ | / / \ | / \ \ |
+ // | / / .-.-. \ \ | / / .-.-. \ \ |
+ // | / / / | \ \ \ | / / / | \ \ \ |
+ // .---.---.---.---.---.---.---.---.---.---.---.---.---.---.---.---. 1
+ // 1 j nb
+
+ // nt = 5, nb = 7, nr = 4
+ //int delta_all = 2;
+ //int delta_one_col = 6;
+ //int nb_col = 0;
+ //int remainder = 2;
+ //if (remainder > 0) nb_col++;
+ //nb_col = 1;
+ //int free_left = 1;
+ //free_left += 2;
+ //int free_middle = 4;
+
+ int delta_all = nb - nt;
+ int delta_one_col = (nr - 1) * 2;
+ int nb_col = delta_all / delta_one_col;
+ int remainder = delta_all - nb_col * delta_one_col;
+ if (remainder > 0) {
+ nb_col++;
+ }
+ const int col_top_size = is_lin_42 ? 2 : 1;
+ int free_left = ((nt - 1) - nb_col * col_top_size) / 2;
+ free_left += nr - 2;
+ int free_middle = (nr - 2) * 2;
+ if (remainder > 0 && nb_col == 1) {
+ int nb_rows_short_col = remainder / 2;
+ int nb_rows_thrown = (nr - 1) - nb_rows_short_col;
+ free_left -= nb_rows_thrown;
+ }
+
+ // nt = 5, nb = 17, nr = 4
+ //int delta_all = 12;
+ //int delta_one_col = 6;
+ //int nb_col = 2;
+ //int remainder = 0;
+ //int free_left = 2;
+ //int free_middle = 4;
+
+ PReduceFunction reduceFunction = & ( is_lin_42 ? reduce42 : reduce31 );
+
+ const int reduce_grp_size = is_lin_42 ? 4 : 3;
+
+ for (i = 1; i < nr; i++, free_middle -= 2, free_left -= 1) // layer by layer
+ {
+ // to calculate normalized parameter, we must know number of points in next layer
+ int nb_next = curr_base_len - nb_col * 2;
+ if (remainder > 0 && i > remainder / 2)
+ // take into account short "column"
+ nb_next += 2;
+ if (nb_next < nt) nb_next = nt;
+
+ const double y = uv_el[ i ].normParam;
+
+ if ( i + 1 == nr ) // top
+ {
+ next_base = uv_et;
+ }
+ else
+ {
+ next_base.clear();
+ next_base.resize( nb_next, nullUVPtStruct );
+ next_base.front() = uv_el[i];
+ next_base.back() = uv_er[i];
+
+ // compute normalized param u
+ double du = 1. / ( nb_next - 1 );
+ next_base[0].normParam = 0.;
+ for ( j = 1; j < nb_next; ++j )
+ next_base[j].normParam = next_base[j-1].normParam + du;
+ }
+ uv[ UV_L ].SetCoord( next_base.front().u, next_base.front().v );
+ uv[ UV_R ].SetCoord( next_base.back().u, next_base.back().v );
+
+ // not reduced left elements
+ for (j = 0; j < free_left; j++)
+ {
+ // f (i + 1, j + 1)
+ const SMDS_MeshNode*& Nf = next_base[++next_base_len].node;
+ if ( !Nf )
+ Nf = makeNode( next_base[ next_base_len ], y, quad, uv, myHelper, S );
+
+ myHelper->AddFace(curr_base[ j ].node,
+ curr_base[ j+1 ].node,
+ Nf,
+ next_base[ next_base_len-1 ].node);
+ }
+
+ for (int icol = 1; icol <= nb_col; icol++) {
+
+ if (remainder > 0 && icol == nb_col && i > remainder / 2)
+ // stop short "column"
+ break;
+
+ // add "H"
+ reduceFunction( curr_base, next_base, j, next_base_len, quad, uv, y, myHelper, S );
+
+ j += reduce_grp_size;
+
+ // not reduced middle elements
+ if (icol < nb_col) {
+ if (remainder > 0 && icol == nb_col - 1 && i > remainder / 2)
+ // pass middle elements before stopped short "column"
+ break;
+
+ int free_add = free_middle;
+ if (remainder > 0 && icol == nb_col - 1)
+ // next "column" is short
+ free_add -= (nr - 1) - (remainder / 2);
+
+ for (int imiddle = 1; imiddle <= free_add; imiddle++) {
+ // f (i + 1, j + imiddle)
+ const SMDS_MeshNode*& Nf = next_base[++next_base_len].node;
+ if ( !Nf )
+ Nf = makeNode( next_base[ next_base_len ], y, quad, uv, myHelper, S );
+
+ myHelper->AddFace(curr_base[ j-1+imiddle ].node,
+ curr_base[ j +imiddle ].node,
+ Nf,
+ next_base[ next_base_len-1 ].node);
+ }
+ j += free_add;
+ }
+ }
+
+ // not reduced right elements
+ for (; j < curr_base_len-1; j++) {
+ // f (i + 1, j + 1)
+ const SMDS_MeshNode*& Nf = next_base[++next_base_len].node;
+ if ( !Nf )
+ Nf = makeNode( next_base[ next_base_len ], y, quad, uv, myHelper, S );
+
+ myHelper->AddFace(curr_base[ j ].node,
+ curr_base[ j+1 ].node,
+ Nf,
+ next_base[ next_base_len-1 ].node);
+ }
+
+ curr_base_len = next_base_len + 1;
+ next_base_len = 0;
+ curr_base.swap( next_base );
+ }
+
+ } // end "linear" simple reduce
+
+ else {
+ return false;
+ }
+ } // end Simple Reduce implementation
+
+ bool isOk = true;
+ return isOk;
+}
+
+//================================================================================
+namespace // data for smoothing