0028404: DRAW - avoid useless preparation of display data when shape is not shown

Class DBRep_DrawableShape is changed to postpone generation of display data until the shape is actually displayed (for the first time).

Test perf draw bug28404 is added.

src/DBRep/DBRep_DrawableShape.cxx

@@ -104,18 +104,16 @@ DBRep_DrawableShape::DBRep_DrawableShape
   myRgN(Standard_False),
   myHid(Standard_False)
 {
-  Set(aShape);
+  myShape = aShape;
 }
 
 //=======================================================================
-//function : Set
+//function : updateDisplayData
 //purpose  : 
 //=======================================================================
 
-void  DBRep_DrawableShape::Set(const TopoDS_Shape& aShape)
+void DBRep_DrawableShape::updateDisplayData () const
 {
-  myShape = aShape;
-  
   myFaces.Clear();
   myEdges.Clear();
   
@@ -154,7 +152,7 @@ void  DBRep_DrawableShape::Set(const TopoDS_Shape& aShape)
   //==============================================================
   
   TopTools_IndexedDataMapOfShapeListOfShape edgemap;
-  TopExp::MapShapesAndAncestors(aShape,TopAbs_EDGE,TopAbs_FACE,edgemap);
+  TopExp::MapShapesAndAncestors(myShape,TopAbs_EDGE,TopAbs_FACE,edgemap);
   Standard_Integer iedge;
   
   for (iedge = 1; iedge <= edgemap.Extent(); iedge++) {
@@ -358,6 +356,9 @@ void  DBRep_DrawableShape::DrawOn(Draw_Display& dis) const
     return;
   }
 
+  if (myFaces.IsEmpty() || myEdges.IsEmpty())
+    updateDisplayData();
+
   // hidden lines
   if (myHLR) {
     DBRep_DrawableShape* p = (DBRep_DrawableShape*) this;
@@ -610,7 +611,7 @@ void  DBRep_DrawableShape::DrawOn(Draw_Display& dis) const
     if (aSurf.IsNull() || mytriangulations) {
       Tr = BRep_Tool::Triangulation(F->Face(), loc);
       if (!Tr.IsNull()) {
-	Display(Tr, loc.Transformation(), dis);
+	display(Tr, loc.Transformation(), dis);
       }
     }
     itf.Next();
@@ -1093,11 +1094,11 @@ void  DBRep_DrawableShape::LastPick(TopoDS_Shape& s,
 
 
 //=======================================================================
-//function : Display
+//function : display
 //purpose  : 
 //=======================================================================
 
-void  DBRep_DrawableShape::Display(const Handle(Poly_Triangulation)& T,
+void  DBRep_DrawableShape::display(const Handle(Poly_Triangulation)& T,
 				   const gp_Trsf&                    tr,
 				   Draw_Display&                     dis) const
 {

src/DBRep/DBRep_DrawableShape.hxx

@@ -53,8 +53,6 @@ public:
   
   Standard_EXPORT DBRep_DrawableShape(const TopoDS_Shape& C, const Draw_Color& FreeCol, const Draw_Color& ConnCol, const Draw_Color& EdgeCol, const Draw_Color& IsosCol, const Standard_Real size, const Standard_Integer nbisos, const Standard_Integer discret);
   
-  Standard_EXPORT void Set (const TopoDS_Shape& C);
-  
   //! Changes the number of isoparametric curves in a shape.
   Standard_EXPORT void ChangeNbIsos (const Standard_Integer NbIsos);
   
@@ -113,20 +111,21 @@ public:
 
   DEFINE_STANDARD_RTTIEXT(DBRep_DrawableShape,Draw_Drawable3D)
 
-protected:
-
+private:
 
+  void display (const Handle(Poly_Triangulation)& T, const gp_Trsf& tr, Draw_Display& dis) const;
 
+  //! Updates internal data necessary for display
+  void updateDisplayData () const;
 
 private:
 
-  
-  Standard_EXPORT void Display (const Handle(Poly_Triangulation)& T, const gp_Trsf& tr, Draw_Display& dis) const;
-
   TopoDS_Shape myShape;
-  DBRep_ListOfEdge myEdges;
-  DBRep_ListOfFace myFaces;
+
+  mutable DBRep_ListOfEdge myEdges;
+  mutable DBRep_ListOfFace myFaces;
   DBRep_ListOfHideData myHidData;
+
   Standard_Real mySize;
   Standard_Integer myDiscret;
   Draw_Color myFreeCol;

tests/perf/draw/bug28404

@@ -0,0 +1,38 @@
+puts "0028404: DRAW is slow"
+
+# Test performance of code generating deep nested compound 
+# involving simple shape (box) around 93 K times
+
+pload MODELING
+
+# replicate shape nb times, adding rotation and translation to each copy
+# (except first) 
+proc replicate {result shape nb cx cy cz rx ry rz angle tx ty tz} {
+  upvar $result res
+  upvar $shape s
+
+  copy s a0
+  set ll a0
+  for {set i 1} {$i < $nb} {incr i} {
+    copy "a[expr $i - 1]" a$i
+    trotate a$i $cx $cy $cz $rx $ry $rz $angle
+    ttranslate a$i $tx $ty $tz
+    lappend ll a$i
+  }
+  eval compound $ll res
+  return $result
+}
+
+# switch off autodisplay of shapes
+autodisplay 0
+
+chrono s restart
+box b 10 10 10 
+replicate r1 b  12    0    0 0  0  0 1 30   15  20  3
+replicate r2 r1 36   50  -50 0  1  1 0 10    0   0  0 
+replicate r3 r2 18  250  250 0  1 -1 0 20  100 100 20
+replicate r4 r3 12 -300 -300 0  0  0 1 30  300 300  0
+chrono s stop counter "huge compound generation CPU"
+
+# return autodisplay
+autodisplay 1

tests/perf/grids.list

@@ -9,4 +9,5 @@
 009 modalg
 010 moddata
 011 sewing
-012 vis
+012 vis
+013 draw