Added distance-based LOD for titles and labels.

This is ON by default

Change-Id: I1cdb875643c3e97f13ddb09a1e0cf7bb1f327a3f

Hybrid/vtkPolarAxesActor.cxx

@@ -169,17 +169,11 @@ vtkPolarAxesActor::vtkPolarAxesActor() : vtkActor()
   // Base offset for followers
   double offset = this->LabelScreenOffset + this->ScreenSize * 0.5;
 
-  // Using twice the base offset and a little for the title of the polar axis.
+  // Set polar axis title follower (label followers not built yet)
   vtkAxisFollower* follower = this->PolarAxis->GetTitleActor();
   follower->SetAxis( this->PolarAxis );
   follower->SetScreenOffset( 2.0 * offset + 5 );
-
-  vtkAxisFollower** labelActors = this->PolarAxis->GetLabelActors();
-  int numberOfLabels = this->PolarAxis->GetNumberOfLabelsBuilt();
-  for( int i = 0; i < numberOfLabels; ++ i )
-    {
-    labelActors[i]->SetScreenOffset( offset );
-    }
+  follower->SetEnableDistanceLOD( this->EnableDistanceLOD );
 
   // Properties of the radial axes, with default color black
   this->RadialAxesProperty = vtkProperty::New();
@@ -197,9 +191,10 @@ vtkPolarAxesActor::vtkPolarAxesActor() : vtkActor()
     axis->SetCalculateTitleOffset( 0 );
     axis->SetCalculateLabelOffset( 0 );
 
-    // Using 2/3 of base offset if not for non-polar radial axes.
+    // Set radial axis title follower
     axis->GetTitleActor()->SetAxis( axis );
     axis->GetTitleActor()->SetScreenOffset( .67 * offset );
+    axis->GetTitleActor()->SetEnableDistanceLOD( this->EnableDistanceLOD );
     } // for ( int i = 0; i < VTK_MAXIMUM_NUMBER_OF_RADIAL_AXES; ++ i )
 
   // Create and set polar arcs and ancillary objects, with default color white
@@ -426,7 +421,6 @@ double *vtkPolarAxesActor::GetBounds()
 //-----------------------------------------------------------------------------
 void vtkPolarAxesActor::BuildAxes( vtkViewport *viewport )
 {
-  cerr << "In BuildAxes\n";
   double bounds[6];
 
   if ( ( this->GetMTime() < this->BuildTime.GetMTime() ))
@@ -538,6 +532,7 @@ void vtkPolarAxesActor::SetCommonAxisAttributes( vtkAxisActor* axis )
   prop->SetDiffuse( 0.0 );
   axis->SetProperty( prop );
 
+  // Common space and range attributes
   axis->SetCamera( this->Camera );
   axis->SetBounds( this->Bounds );
   axis->SetRange( 0., this->MaximumRadius );
@@ -546,12 +541,6 @@ void vtkPolarAxesActor::SetCommonAxisAttributes( vtkAxisActor* axis )
   axis->SetMinorTicksVisible( 0 );
 }
 
-//-----------------------------------------------------------------------------
-double vtkPolarAxesActor::MaxOf( double a, double b )
-{
-  return ( a > b ? a : b );
-}
-
 //-----------------------------------------------------------------------------
 inline double vtkPolarAxesActor::FFix( double value )
 {
@@ -573,7 +562,6 @@ inline double vtkPolarAxesActor::FSign( double value, double sign )
 //-----------------------------------------------------------------------------
 void vtkPolarAxesActor::BuildPolarAxisTicks( double x0 )
 {
-  cerr << "In BuildPolarAxisTicks\n";
   double delta;
 
   if ( this->AutoSubdividePolarAxis
@@ -643,7 +631,6 @@ void vtkPolarAxesActor::BuildPolarAxisTicks( double x0 )
 //-----------------------------------------------------------------------------
 void vtkPolarAxesActor::BuildPolarAxisLabelsArcs( double* O )
 {
-  cerr << "In BuildPolarAxisLabelsArcs\n";
   // Prepare storage for polar axis labels
   vtkStringArray *labels = vtkStringArray::New();
   labels->SetNumberOfValues( this->NumberOfPolarAxisTicks );
@@ -660,12 +647,12 @@ void vtkPolarAxesActor::BuildPolarAxisLabelsArcs( double* O )
     = static_cast<vtkIdType>( angularSector * VTK_POLAR_ARC_RESOLUTION_PER_DEG );
 
   // Arc points
-  vtkPoints *polarArcsPoints = vtkPoints::New();
+  vtkPoints* polarArcsPoints = vtkPoints::New();
   this->PolarArcs->SetPoints( polarArcsPoints );
   polarArcsPoints->Delete();
 
   // Arc lines
-  vtkCellArray *polarArcsLines = vtkCellArray::New();
+  vtkCellArray* polarArcsLines = vtkCellArray::New();
   this->PolarArcs->SetLines( polarArcsLines );
   polarArcsLines->Delete();
 
@@ -734,6 +721,7 @@ void vtkPolarAxesActor::BuildPolarAxisLabelsArcs( double* O )
     {
     labelActors[i]->SetAxis( axis );
     labelActors[i]->SetScreenOffset( this->LabelScreenOffset );
+    labelActors[i]->SetEnableDistanceLOD( EnableDistanceLOD );
     }
 }
 

Hybrid/vtkPolarAxesActor.h

@@ -146,23 +146,33 @@ public:
   // resources to release.
   void ReleaseGraphicsResources( vtkWindow* );
 
+  // Description:
+  // Enable and disable the use of distance based LOD for titles and labels. 
+  vtkSetMacro( EnableDistanceLOD, int );
+  vtkGetMacro( EnableDistanceLOD, int );
+  
+  // Description:a
+  // Set distance LOD threshold [0.0 - 1.0] for titles and labels. 
+  vtkSetClampMacro( DistanceLODThreshold, double, 0.0, 1.0 );
+  vtkGetMacro( DistanceLODThreshold, double);
+
   // Description:
   // Turn on and off the visibility of the polar axis.
-  vtkSetMacro( PolarAxisVisibility,int );
-  vtkGetMacro( PolarAxisVisibility,int );
-  vtkBooleanMacro( PolarAxisVisibility,int );
+  vtkSetMacro( PolarAxisVisibility, int );
+  vtkGetMacro( PolarAxisVisibility, int );
+  vtkBooleanMacro( PolarAxisVisibility, int );
 
   // Description:
   // Turn on and off the visibility of titles for polar axis.
-  vtkSetMacro( PolarTitleVisibility,int );
-  vtkGetMacro( PolarTitleVisibility,int );
-  vtkBooleanMacro( PolarTitleVisibility,int );
+  vtkSetMacro( PolarTitleVisibility, int );
+  vtkGetMacro( PolarTitleVisibility, int );
+  vtkBooleanMacro( PolarTitleVisibility, int );
 
   // Description:
   // Turn on and off the visibility of labels for polar axis.
-  vtkSetMacro( PolarLabelVisibility,int );
-  vtkGetMacro( PolarLabelVisibility,int );
-  vtkBooleanMacro( PolarLabelVisibility,int );
+  vtkSetMacro( PolarLabelVisibility, int );
+  vtkGetMacro( PolarLabelVisibility, int );
+  vtkBooleanMacro( PolarLabelVisibility, int );
 
   // Description:
   // Turn on and off the visibility of ticks for polar axis.
@@ -172,15 +182,15 @@ public:
 
   // Description:
   // Turn on and off the visibility of non-polar radial axes.
-  vtkSetMacro( RadialAxesVisibility,int );
-  vtkGetMacro( RadialAxesVisibility,int );
-  vtkBooleanMacro( RadialAxesVisibility,int );
+  vtkSetMacro( RadialAxesVisibility, int );
+  vtkGetMacro( RadialAxesVisibility, int );
+  vtkBooleanMacro( RadialAxesVisibility, int );
 
   // Description:
   // Turn on and off the visibility of titles for non-polar radial axes.
-  vtkSetMacro( RadialTitleVisibility,int );
-  vtkGetMacro( RadialTitleVisibility,int );
-  vtkBooleanMacro( RadialTitleVisibility,int );
+  vtkSetMacro( RadialTitleVisibility, int );
+  vtkGetMacro( RadialTitleVisibility, int );
+  vtkBooleanMacro( RadialTitleVisibility, int );
 
   // Description:
   // Turn on and off the visibility of arcs for polar axis.
@@ -247,7 +257,6 @@ protected:
 
   // Description:
   // Convenience methods
-  double MaxOf(double, double );
   double FFix(double );
   double FSign(double, double );
 
@@ -318,19 +327,33 @@ protected:
   char  *PolarLabelFormat;
 
   // Description:
-  // Use angle units (degrees) to label radial axes
+  // Display angle units (degrees) to label radial axes
+  // Default is true
   bool RadialUnits;
 
+  // Description:
+  // If enabled the actor will not be visible at a certain distance from the camera.
+  // Default is true
+  int EnableDistanceLOD;
+
+  // Description:
+  // Default is 0.80.
+  // This determines at what fraction of camera far clip range, actor is not visible.
+  double DistanceLODThreshold;
+
+  // Description:
   // Visibility of polar axis and its title, labels, ticks (major only)
   int PolarAxisVisibility;
   int PolarTitleVisibility;
   int PolarLabelVisibility;
   int PolarTickVisibility;
 
+  // Description:
   // Visibility of radial axes and their titles
   int RadialAxesVisibility;
   int RadialTitleVisibility;
 
+  // Description:
   // Visibility of polar arcs
   int PolarArcsVisibility;
 
@@ -338,23 +361,35 @@ protected:
 
   int RenderSomething;
 
-  double LabelScreenOffset;
-
+  // Description:
   // Text properties of polar axis title and labels
   vtkTextProperty   *PolarAxisTitleTextProperty;
   vtkTextProperty   *PolarAxisLabelTextProperty;
 
+  // Description:
   // General properties of polar axis
   vtkProperty* PolarAxisProperty;
 
+  // Description:
   // General properties of radial axes
   vtkProperty* RadialAxesProperty;
 
   vtkTimeStamp BuildTime;
 
-  double LabelScale;
+  // Description:
+  // Title scale factor
   double TitleScale;
 
+  // Description:
+  // Label scale factor
+  double LabelScale;
+
+  // Description:
+  // Label screen offset
+  double LabelScreenOffset;
+
+  // Description:
+  // Text screen size
   double ScreenSize;
 
 private: