OCC22529 FitALL works incorrectly for small flat shapes

src/V3d/V3d_View.cxx

@@ -1748,118 +1748,178 @@ void V3d_View::FitAll(const Standard_Real Coef, const Standard_Boolean FitZ,
 {
   Standard_Real Umin, Umax, Vmin, Vmax, Xrp, Yrp, Zrp, U, V, W, U1, V1, W1;
   Standard_Real Xmin, Ymin, Zmin, Xmax, Ymax, Zmax;
-  Standard_Real DxvOld,DyvOld,DxvNew,DyvNew,RapOld,RapNew ;
+  Standard_Real DxvOld, DyvOld, DxvNew, DyvNew;
-  Standard_Integer Xpixel,Ypixel;
-  // CAL 6/11/98
   Standard_Integer Nstruct = MyView->NumberOfDisplayedStructures();
-  Standard_Integer nbPasse = 2;
 
-  if( (Nstruct <= 0) || (Coef < 0.) || (Coef > 1.) ) {
+  if ((Nstruct <= 0) || (Coef < 0.0) || (Coef > 1.0))
+  {
 #ifndef IMP020300
     ImmediateUpdate();
 #endif
     return;
   }
+
   MyProjReferencePoint = MyViewMapping.ProjectionReferencePoint();
   MyProjReferencePoint.Coord (Xrp, Yrp, Zrp);
-  if( MyView->IsDefined() ) {
+  if (MyView->IsDefined())
+  {
+    Standard_Integer Xpixel, Ypixel;
     MyWindow->Size (Xpixel, Ypixel);
-    DxvOld = Xpixel; DyvOld = Ypixel;
+    DxvOld = Xpixel;
-  } else {
+    DyvOld = Ypixel;
+  }
+  else
+  {
     MyViewMapping.WindowLimit (Umin, Vmin, Umax, Vmax);
-    DxvOld = Abs(Umax - Umin) ; DyvOld = Abs(Vmax - Vmin) ;
+    DxvOld = Abs (Umax - Umin);
+    DyvOld = Abs (Vmax - Vmin);
   }
-  if( (DxvOld == 0.) || (DyvOld == 0.) ) return ;
+  if ((DxvOld == 0.0) || (DyvOld == 0.0))
-  RapOld = DxvOld/DyvOld ;
+  {
-
+    return;
-  MyView->MinMaxValues(Xmin,Ymin,Zmin,Xmax,Ymax,Zmax) ;
-
-  //Object with null bounding box for anyone axis has been
-  //obtained unit bounding interval
-  if( Xmin == Xmax ) {
-    Xmin--; Xmax++;
-  }
-  if( Ymin == Ymax ) {
-    Ymin--; Ymax++;
-  }
-  if( Zmin == Zmax ) {
-    Zmin--; Zmax++;
   }
 
-  Standard_Real LIM = ShortRealLast() -1.;
+  Standard_Real aWinRatio = DxvOld / DyvOld;
+
+  // retrieve min / max values for current displayed objects
+  MyView->MinMaxValues (Xmin, Ymin, Zmin,
+                        Xmax, Ymax, Zmax);
+
+  Standard_Real LIM = ShortRealLast() - 1.0;
   if  (Abs(Xmin) > LIM || Abs(Ymin) > LIM || Abs(Zmin) > LIM
-    ||  Abs(Xmax) > LIM || Abs(Ymax) > LIM || Abs(Zmax) > LIM ) {
+    || Abs(Xmax) > LIM || Abs(Ymax) > LIM || Abs(Zmax) > LIM)
+  {
 #ifndef IMP020300
     ImmediateUpdate();
 #endif
     return;
   }
 
-    while (nbPasse != 0)
+  // eliminate fluctuations between sequential FitAll() calls
+  MyViewMapping.SetWindowLimit (-1.0 * aWinRatio, -1.0, 1.0 * aWinRatio, 1.0);
+  if (MyType != V3d_PERSPECTIVE)
+  {
+    MyProjReferencePoint.SetCoord (0.0, 0.0, Zrp);
+    MyViewMapping.SetProjectionReferencePoint (MyProjReferencePoint);
+  }
+  MyView->SetViewMapping (MyViewMapping);
+
+  // iterate 2 times to find optimal view plane size
+  // (use view plane values computed on previous iteration)
+  for (Standard_Integer aIteration = 2; aIteration > 0; --aIteration)
   {
     MyView->Projects (Xmin, Ymin, Zmin,  U,  V,  W);
     MyView->Projects (Xmax, Ymax, Zmax, U1, V1, W1);
     Umin = Min (U, U1); Umax = Max (U, U1);
     Vmin = Min (V, V1); Vmax = Max (V, V1);
+
     MyView->Projects (Xmin, Ymin, Zmax, U, V, W);
     Umin = Min (U, Umin); Umax = Max (U, Umax);
     Vmin = Min (V, Vmin); Vmax = Max (V, Vmax);
+
     MyView->Projects (Xmax, Ymin, Zmax, U, V, W);
     Umin = Min (U, Umin); Umax = Max (U, Umax);
     Vmin = Min (V, Vmin); Vmax = Max (V, Vmax);
+
     MyView->Projects (Xmax, Ymin, Zmin, U, V, W);
     Umin = Min (U, Umin); Umax = Max (U, Umax);
     Vmin = Min (V, Vmin); Vmax = Max (V, Vmax);
+
     MyView->Projects (Xmax, Ymax, Zmin, U, V, W);
     Umin = Min (U, Umin); Umax = Max (U, Umax);
     Vmin = Min (V, Vmin); Vmax = Max (V, Vmax);
+
     MyView->Projects (Xmin, Ymax, Zmax, U, V, W);
     Umin = Min (U, Umin); Umax = Max (U, Umax);
     Vmin = Min (V, Vmin); Vmax = Max (V, Vmax);
+
     MyView->Projects (Xmin, Ymax, Zmin, U, V, W);
     Umin = Min (U, Umin); Umax = Max (U, Umax);
     Vmin = Min (V, Vmin); Vmax = Max (V, Vmax);
-      if( (Umax > Umin) && (Vmax > Vmin) ) {
-        DxvNew = Abs(Umax - Umin) ; DyvNew = Abs(Vmax - Vmin) ;
 
-        RapNew = DxvNew/DyvNew ;
+    DxvNew = Abs (Umax - Umin);
-        if( RapNew >= RapOld ) {
+    DyvNew = Abs (Vmax - Vmin);
+
+    if (DyvNew < 10.0 * Precision::Confusion())
+    {
+      if (DxvNew < 10.0 * Precision::Confusion())
+      {
+        // whole scene projected to point
+        DxvNew = Max (Abs (Zmax - Zmin), (Max (Abs (Xmax - Xmin), Abs (Ymax - Ymin))));
+        if (DxvNew < 10.0 * Precision::Confusion())
+        {
+          // this is really just one (!) point and zooming has no any effect
+          // just center the view
+          DyvNew = DyvOld;
+          DxvNew = DxvOld;
+        }
+        else
+        {
+          // we look along some line
+          // fit view like that to see whole scene on rotation
           DxvNew += Coef * DxvNew;
-          DyvNew = DxvNew/RapOld ;
+          DyvNew = DxvNew / aWinRatio;
-        } else {
+        }
+      }
+      else
+      {
+        // whole scene projected to horizontal line
+        DxvNew += Coef * DxvNew;
+        DyvNew = DxvNew / aWinRatio;
+      }
+    }
+    else
+    {
+      // general case (or DxvNew == 0.0 - vertical line)
+      // safe original ratio
+      Standard_Real aFitRatio = DxvNew / DyvNew;
+      if (aFitRatio >= aWinRatio)
+      {
+        DxvNew += Coef * DxvNew;
+        DyvNew = DxvNew / aWinRatio;
+      }
+      else
+      {
         DyvNew += Coef * DyvNew;
-          DxvNew = DyvNew*RapOld ;
+        DxvNew = DyvNew * aWinRatio;
+      }
     }
 
-        Xrp = (Umin + Umax)/2. ; Yrp = (Vmin + Vmax)/2. ;
+    // new scene center
-        Umin = Xrp - DxvNew/2. ; Umax = Xrp + DxvNew/2. ;
+    Xrp = 0.5 * (Umin + Umax);
-        Vmin = Yrp - DyvNew/2. ; Vmax = Yrp + DyvNew/2. ;
+    Yrp = 0.5 * (Vmin + Vmax);
+
+    // new window limits
+    Umin = Xrp - 0.5 * DxvNew;
+    Umax = Xrp + 0.5 * DxvNew;
+    Vmin = Yrp - 0.5 * DyvNew;
+    Vmax = Yrp + 0.5 * DyvNew;
     MyViewMapping.SetWindowLimit (Umin, Vmin, Umax, Vmax);
 
-#ifdef OCC280
+    if (MyType != V3d_PERSPECTIVE)
-        if( MyType != V3d_PERSPECTIVE ) {
+    {
+      // center the view
       MyProjReferencePoint.SetCoord (Xrp, Yrp, Zrp);
       MyViewMapping.SetProjectionReferencePoint (MyProjReferencePoint);
     }
-#else
-        MyProjReferencePoint.SetCoord(Xrp,Yrp,Zrp) ;
-        MyViewMapping.SetProjectionReferencePoint(MyProjReferencePoint);
-#endif
     MyView->SetViewMapping (MyViewMapping);
   }
 
-      nbPasse--;
+  if (FitZ)
-    } // while
+  {
-
-    if(FitZ) {
     ZFitAll (Zmargin);
 #ifdef IMP020300
-    } else {
+  }
+  else
+  {
     ImmediateUpdate();
 #endif
   }
 #ifdef IMP020300
-    if( !myImmediateUpdate && update ) Update();
+  if (!myImmediateUpdate && update)
+  {
+    Update();
+  }
 #endif
 }
 
@@ -1889,18 +1949,6 @@ void V3d_View::ZFitAll(const Standard_Real Coef) {
       return ;
     }
 
-  //Object with null bounding box for anyone axis has been
-  //obtained unit bounding interval
-  if( Xmin == Xmax ) {
-    Xmin--; Xmax++;
-  }
-  if( Ymin == Ymax ) {
-    Ymin--; Ymax++;
-  }
-  if( Zmin == Zmax ) {
-    Zmin--; Zmax++;
-  }
-
     // CAL 6/11/98
     // Case when view contains only a point
     if (Xmin == Xmax && Ymin == Ymax && Zmin == Zmax) {
@@ -1954,18 +2002,6 @@ void V3d_View::DepthFitAll(const Quantity_Coefficient Aspect,
       return ;
     }
 
-  //Object with null bounding box for anyone axis has been
-  //obtained unit bounding interval
-  if( Xmin == Xmax ) {
-    Xmin--; Xmax++;
-  }
-  if( Ymin == Ymax ) {
-    Ymin--; Ymax++;
-  }
-  if( Zmin == Zmax ) {
-    Zmin--; Zmax++;
-  }
-
     if (Xmin == Xmax && Ymin == Ymax && Zmin == Zmax) {
       ImmediateUpdate();
       return ;