vtkMapper.cxx

/*=========================================================================

  Program:   Visualization Toolkit
  Module:    vtkMapper.cxx

  Copyright (c) Ken Martin, Will Schroeder, Bill Lorensen
  All rights reserved.
  See Copyright.txt or http://www.kitware.com/Copyright.htm for details.

     This software is distributed WITHOUT ANY WARRANTY; without even
     the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
     PURPOSE.  See the above copyright notice for more information.

=========================================================================*/
#include "vtkMapper.h"

#include "vtkAbstractArray.h"
#include "vtkColorSeries.h"
#include "vtkCompositeDataSet.h"
#include "vtkDataArray.h"
#include "vtkDataSet.h"
#include "vtkDataObjectTreeIterator.h"
#include "vtkDoubleArray.h"
#include "vtkDoubleArray.h"
#include "vtkExecutive.h"
#include "vtkFloatArray.h"
#include "vtkImageData.h"
#include "vtkLookupTable.h"
#include "vtkMath.h"
#include "vtkPointData.h"
#include "vtkPolyData.h"
#include "vtkVariantArray.h"


// Initialize static member that controls global immediate mode rendering
static int vtkMapperGlobalImmediateModeRendering = 0;

// Initialize static member that controls global coincidence resolution
static int vtkMapperGlobalResolveCoincidentTopology = VTK_RESOLVE_OFF;
static double vtkMapperGlobalResolveCoincidentTopologyZShift = 0.01;
static int vtkMapperGlobalResolveCoincidentTopologyPolygonOffsetFaces = 1;

static double vtkMapperGlobalResolveCoincidentTopologyPolygonOffsetFactor = 2.0;
static double vtkMapperGlobalResolveCoincidentTopologyPolygonOffsetUnits = 2.0;
static double vtkMapperGlobalResolveCoincidentTopologyLineOffsetFactor = 1.0;
static double vtkMapperGlobalResolveCoincidentTopologyLineOffsetUnits = 1.0;
static double vtkMapperGlobalResolveCoincidentTopologyPointOffsetUnits = 0.0;

vtkScalarsToColors *vtkMapper::InvertibleLookupTable = NULL;

// Construct with initial range (0,1).
vtkMapper::vtkMapper()
{
  this->Colors = 0;
  this->Static = 0;
  this->LookupTable = 0;

  this->ScalarVisibility = 1;
  this->ScalarRange[0] = 0.0; this->ScalarRange[1] = 1.0;
  this->UseLookupTableScalarRange = 0;

  this->ImmediateModeRendering = 0;

  this->ColorMode = VTK_COLOR_MODE_DEFAULT;
  this->ScalarMode = VTK_SCALAR_MODE_DEFAULT;
  this->ScalarMaterialMode = VTK_MATERIALMODE_DEFAULT;

  vtkMath::UninitializeBounds(this->Bounds);
  this->Center[0] = this->Center[1] = this->Center[2] = 0.0;

  this->RenderTime = 0.0;

  strcpy(this->ArrayName, "");
  this->ArrayId = -1;
  this->ArrayComponent = 0;
  this->ArrayAccessMode = VTK_GET_ARRAY_BY_ID;

  this->FieldDataTupleId = -1;

  this->InterpolateScalarsBeforeMapping = 0;
  this->ColorCoordinates = 0;
  this->ColorTextureMap = 0;

  this->ForceCompileOnly=0;

  this->UseInvertibleColors = false;
  this->InvertibleScalars = NULL;

  this->CoincidentPolygonFactor = 0.0;
  this->CoincidentPolygonOffset = 0.0;
  this->CoincidentLineFactor = 0.0;
  this->CoincidentLineOffset = 0.0;
  this->CoincidentPointOffset = 0.0;

  this->AcquireInvertibleLookupTable();
}

vtkMapper::~vtkMapper()
{
  if (this->LookupTable)
  {
    this->LookupTable->UnRegister(this);
  }
  assert(vtkMapper::InvertibleLookupTable);
  bool clear = vtkMapper::InvertibleLookupTable->GetReferenceCount() == 1;
  vtkMapper::InvertibleLookupTable->UnRegister(this);
  if (clear)
  {
    vtkMapper::InvertibleLookupTable = NULL;
  }

  if ( this->Colors != 0 )
  {
    this->Colors->UnRegister(this);
  }
  if ( this->ColorCoordinates != 0 )
  {
    this->ColorCoordinates->UnRegister(this);
  }
  if ( this->ColorTextureMap != 0 )
  {
    this->ColorTextureMap->UnRegister(this);
  }
  if (this->InvertibleScalars != NULL)
  {
    this->InvertibleScalars->UnRegister(this);
  }
}

// Get the bounds for the input of this mapper as
// (Xmin,Xmax,Ymin,Ymax,Zmin,Zmax).
double *vtkMapper::GetBounds()
{
  if (!this->Static)
  {
    this->Update();
  }
  vtkDataSet *input = this->GetInput();
  if (!input)
  {
    vtkMath::UninitializeBounds(this->Bounds);
  }
  else
  {
    input->GetBounds(this->Bounds);
  }
  return this->Bounds;
}

vtkDataSet *vtkMapper::GetInput()
{
  if (this->GetNumberOfInputConnections(0) < 1)
  {
    return 0;
  }
  return vtkDataSet::SafeDownCast(
    this->GetExecutive()->GetInputData(0, 0));
}

void vtkMapper::SetForceCompileOnly(int value)
{
  if(this->ForceCompileOnly!=value)
  {
      this->ForceCompileOnly=value;
      // make sure we don't call this->Modified();
      //      this->Modified();
  }
}

void vtkMapper::SetGlobalImmediateModeRendering(int val)
{
  if (val == vtkMapperGlobalImmediateModeRendering)
  {
    return;
  }
  vtkMapperGlobalImmediateModeRendering = val;
}

int vtkMapper::GetGlobalImmediateModeRendering()
{
  return vtkMapperGlobalImmediateModeRendering;
}

void vtkMapper::SetResolveCoincidentTopology(int val)
{
  if (val == vtkMapperGlobalResolveCoincidentTopology)
  {
    return;
  }
  vtkMapperGlobalResolveCoincidentTopology = val;
}

int vtkMapper::GetResolveCoincidentTopology()
{
  return vtkMapperGlobalResolveCoincidentTopology;
}

void vtkMapper::SetResolveCoincidentTopologyToDefault()
{
  vtkMapperGlobalResolveCoincidentTopology = VTK_RESOLVE_OFF;
}

void vtkMapper::SetResolveCoincidentTopologyZShift(double val)
{
  if (val == vtkMapperGlobalResolveCoincidentTopologyZShift)
  {
    return;
  }
  vtkMapperGlobalResolveCoincidentTopologyZShift = val;
}

double vtkMapper::GetResolveCoincidentTopologyZShift()
{
  return vtkMapperGlobalResolveCoincidentTopologyZShift;
}

void vtkMapper::SetResolveCoincidentTopologyPolygonOffsetParameters(
                                            double factor, double units)
{
  if (factor == vtkMapperGlobalResolveCoincidentTopologyPolygonOffsetFactor &&
      units == vtkMapperGlobalResolveCoincidentTopologyPolygonOffsetUnits )
  {
    return;
  }
  vtkMapperGlobalResolveCoincidentTopologyPolygonOffsetFactor = factor;
  vtkMapperGlobalResolveCoincidentTopologyPolygonOffsetUnits = units;
}

void vtkMapper::GetResolveCoincidentTopologyPolygonOffsetParameters(
                           double& factor, double& units)
{
  factor = vtkMapperGlobalResolveCoincidentTopologyPolygonOffsetFactor;
  units = vtkMapperGlobalResolveCoincidentTopologyPolygonOffsetUnits;
}

void vtkMapper::SetRelativeCoincidentTopologyPolygonOffsetParameters(
                                          double factor, double units)
{
  if (factor == this->CoincidentPolygonFactor &&
      units == this->CoincidentPolygonOffset )
  {
    return;
  }
  this->CoincidentPolygonFactor = factor;
  this->CoincidentPolygonOffset = units;
}

void vtkMapper::GetRelativeCoincidentTopologyPolygonOffsetParameters(
                           double& factor, double& units)
{
  factor = this->CoincidentPolygonFactor;
  units = this->CoincidentPolygonOffset;
}

void vtkMapper::GetCoincidentTopologyPolygonOffsetParameters(
                           double& factor, double& units)
{
  factor = vtkMapperGlobalResolveCoincidentTopologyPolygonOffsetFactor
    + this->CoincidentPolygonFactor;
  units = vtkMapperGlobalResolveCoincidentTopologyPolygonOffsetUnits
    + this->CoincidentPolygonOffset;
}

void vtkMapper::SetResolveCoincidentTopologyLineOffsetParameters(
                                            double factor, double units)
{
  if (factor == vtkMapperGlobalResolveCoincidentTopologyLineOffsetFactor &&
      units == vtkMapperGlobalResolveCoincidentTopologyLineOffsetUnits )
  {
    return;
  }
  vtkMapperGlobalResolveCoincidentTopologyLineOffsetFactor = factor;
  vtkMapperGlobalResolveCoincidentTopologyLineOffsetUnits = units;
}

void vtkMapper::GetResolveCoincidentTopologyLineOffsetParameters(
                           double& factor, double& units)
{
  factor = vtkMapperGlobalResolveCoincidentTopologyLineOffsetFactor;
  units = vtkMapperGlobalResolveCoincidentTopologyLineOffsetUnits;
}

void vtkMapper::SetRelativeCoincidentTopologyLineOffsetParameters(
                                          double factor, double units)
{
  if (factor == this->CoincidentLineFactor &&
      units == this->CoincidentLineOffset )
  {
    return;
  }
  this->CoincidentLineFactor = factor;
  this->CoincidentLineOffset = units;
}

void vtkMapper::GetRelativeCoincidentTopologyLineOffsetParameters(
                           double& factor, double& units)
{
  factor = this->CoincidentLineFactor;
  units = this->CoincidentLineOffset;
}

void vtkMapper::GetCoincidentTopologyLineOffsetParameters(
                           double& factor, double& units)
{
  factor = vtkMapperGlobalResolveCoincidentTopologyLineOffsetFactor
    + this->CoincidentLineFactor;
  units = vtkMapperGlobalResolveCoincidentTopologyLineOffsetUnits
    + this->CoincidentLineOffset;
}

void vtkMapper::SetResolveCoincidentTopologyPointOffsetParameter(
                                            double units)
{
  if (units == vtkMapperGlobalResolveCoincidentTopologyPointOffsetUnits )
  {
    return;
  }
  vtkMapperGlobalResolveCoincidentTopologyPointOffsetUnits = units;
}

void vtkMapper::GetResolveCoincidentTopologyPointOffsetParameter(
                           double& units)
{
  units = vtkMapperGlobalResolveCoincidentTopologyPointOffsetUnits;
}

void vtkMapper::SetRelativeCoincidentTopologyPointOffsetParameter(
                                            double units)
{
  if (units == this->CoincidentPointOffset )
  {
    return;
  }
  this->CoincidentPointOffset = units;
}

void vtkMapper::GetRelativeCoincidentTopologyPointOffsetParameter(
                           double& units)
{
  units = this->CoincidentPointOffset;
}

void vtkMapper::GetCoincidentTopologyPointOffsetParameter(double& units)
{
  units = vtkMapperGlobalResolveCoincidentTopologyPointOffsetUnits
    + this->CoincidentPointOffset;
}

void vtkMapper::SetResolveCoincidentTopologyPolygonOffsetFaces(int faces)
{
  vtkMapperGlobalResolveCoincidentTopologyPolygonOffsetFaces = faces;
}

int vtkMapper::GetResolveCoincidentTopologyPolygonOffsetFaces()
{
  return vtkMapperGlobalResolveCoincidentTopologyPolygonOffsetFaces;
}

// Overload standard modified time function. If lookup table is modified,
// then this object is modified as well.
vtkMTimeType vtkMapper::GetMTime()
{
  //vtkMTimeType mTime=this->MTime.GetMTime();
  vtkMTimeType mTime=vtkAbstractMapper::GetMTime();
  vtkMTimeType lutMTime;

  if ( this->LookupTable != NULL )
  {
    lutMTime = this->LookupTable->GetMTime();
    mTime = ( lutMTime > mTime ? lutMTime : mTime );
  }

  return mTime;
}

void vtkMapper::ShallowCopy(vtkAbstractMapper *mapper)
{
  vtkMapper *m = vtkMapper::SafeDownCast(mapper);
  if ( m != NULL )
  {
    this->SetLookupTable(m->GetLookupTable());
    this->SetScalarVisibility(m->GetScalarVisibility());
    this->SetScalarRange(m->GetScalarRange());
    this->SetColorMode(m->GetColorMode());
    this->SetScalarMode(m->GetScalarMode());
    this->SetScalarMaterialMode(m->GetScalarMaterialMode());
    this->SetImmediateModeRendering(m->GetImmediateModeRendering());
    this->SetUseLookupTableScalarRange(m->GetUseLookupTableScalarRange());
    this->SetInterpolateScalarsBeforeMapping(
      m->GetInterpolateScalarsBeforeMapping());
    this->SetFieldDataTupleId(m->GetFieldDataTupleId());

    if ( m->GetArrayAccessMode() == VTK_GET_ARRAY_BY_ID )
    {
      this->ColorByArrayComponent(m->GetArrayId(),m->GetArrayComponent());
    }
    else
    {
      this->ColorByArrayComponent(m->GetArrayName(),m->GetArrayComponent());
    }
  }

  // Now do superclass
  this->vtkAbstractMapper3D::ShallowCopy(mapper);

}

// a side effect of this is that this->Colors is also set
// to the return value
vtkUnsignedCharArray *vtkMapper::MapScalars(double alpha)
{
  vtkDataSet *input = this->GetInput();
  int cellFlag; //not used
  return this->MapScalars(input,alpha,cellFlag);
}

// a side effect of this is that this->Colors is also set
// to the return value
vtkUnsignedCharArray *vtkMapper::MapScalars(double alpha, int &cellFlag)
{
  vtkDataSet *input = this->GetInput();
  return this->MapScalars(input,alpha,cellFlag);
}

//-----------------------------------------------------------------------------
// Returns if we can use texture maps for scalar coloring. Note this doesn't say
// we "will" use scalar coloring. It says, if we do use scalar coloring, we will
// use a texture.
// When rendering multiblock datasets, if any 2 blocks provide different
// lookup tables for the scalars, then also we cannot use textures. This case can
// be handled if required.
int vtkMapper::CanUseTextureMapForColoring(vtkDataObject* input)
{
  if (!this->InterpolateScalarsBeforeMapping)
  {
    return 0; // user doesn't want us to use texture maps at all.
  }

  // index color does not use textures
  if (this->LookupTable &&
      this->LookupTable->GetIndexedLookup())
  {
    return 0;
  }

  if (input->IsA("vtkDataSet"))
  {
    int cellFlag=0;
    vtkDataSet* ds = static_cast<vtkDataSet*>(input);
    vtkDataArray* scalars = vtkAbstractMapper::GetScalars(ds,
      this->ScalarMode, this->ArrayAccessMode, this->ArrayId,
      this->ArrayName, cellFlag);

    if (!scalars)
    {
      // no scalars on  this dataset, we don't care if texture is used at all.
      return 1;
    }

    if (cellFlag)
    {
      return 0; // cell data colors, don't use textures.
    }

    if ((this->ColorMode == VTK_COLOR_MODE_DEFAULT &&
         vtkArrayDownCast<vtkUnsignedCharArray>(scalars)) ||
        this->ColorMode == VTK_COLOR_MODE_DIRECT_SCALARS)
    {
      // Don't use texture is direct coloring using RGB unsigned chars is
      // requested.
      return 0;
    }
  }

  return 1;
}

vtkUnsignedCharArray *vtkMapper::MapScalars(vtkDataSet *input,
                                            double alpha)
{
  int cellFlag = 0;
  return this->MapScalars(input, alpha, cellFlag);
}

// a side effect of this is that this->Colors is also set
// to the return value
vtkUnsignedCharArray *vtkMapper::MapScalars(vtkDataSet *input,
                                            double alpha,
                                            int &cellFlag)
{
  vtkAbstractArray *scalars = NULL;
  if (!this->UseInvertibleColors)
  {
    scalars = vtkAbstractMapper::
      GetAbstractScalars(input, this->ScalarMode, this->ArrayAccessMode,
                         this->ArrayId, this->ArrayName, cellFlag);

    // This is for a legacy feature: selection of the array component to color by
    // from the mapper.  It is now in the lookuptable.  When this feature
    // is removed, we can remove this condition.
    if (scalars == 0 || scalars->GetNumberOfComponents() <= this->ArrayComponent)
    {
      this->ArrayComponent = 0;
    }

    if ( !this->ScalarVisibility || scalars==0 || input==0)
    { // No scalar colors.
      if ( this->ColorCoordinates )
      {
        this->ColorCoordinates->UnRegister(this);
        this->ColorCoordinates = 0;
      }
      if ( this->ColorTextureMap )
      {
        this->ColorTextureMap->UnRegister(this);
        this->ColorTextureMap = 0;
      }
      if ( this->Colors )
      {
        this->Colors->UnRegister(this);
        this->Colors = 0;
      }
      return 0;
    }

    // Get the lookup table.
    vtkDataArray *dataArray = vtkArrayDownCast<vtkDataArray>(scalars);
    if (dataArray && dataArray->GetLookupTable())
    {
      this->SetLookupTable(dataArray->GetLookupTable());
    }
    else
    {
      // make sure we have a lookup table
      if ( this->LookupTable == 0 )
      {
        this->CreateDefaultLookupTable();
      }
      this->LookupTable->Build();
    }
    if ( !this->UseLookupTableScalarRange )
    {
      this->LookupTable->SetRange(this->ScalarRange);
    }
  }
  else
  {
    scalars = this->InvertibleScalars;
    this->LookupTable->SetRange(this->ScalarRange);
  }

  // Decide betweeen texture color or vertex color.
  // Cell data always uses vertex color.
  // Only point data can use both texture and vertex coloring.
  if (this->CanUseTextureMapForColoring(input))
  {
    this->MapScalarsToTexture(scalars, alpha);
    return 0;
  }

  // Vertex colors are being used.
  // Get rid of texure Color arrays.  Only texture or vertex coloring
  // can be active at one time.  The existence of the array is the
  // signal to use that technique.
  if ( this->ColorCoordinates )
  {
    this->ColorCoordinates->UnRegister(this);
    this->ColorCoordinates = 0;
  }
  if ( this->ColorTextureMap )
  {
    this->ColorTextureMap->UnRegister(this);
    this->ColorTextureMap = 0;
  }

  // Lets try to resuse the old colors.
  if (this->Colors)
  {
    if (this->LookupTable && this->LookupTable->GetAlpha() == alpha)
    {
      if (this->GetMTime() < this->Colors->GetMTime() &&
          input->GetMTime() < this->Colors->GetMTime() &&
          this->LookupTable->GetMTime() < this->Colors->GetMTime())
      {
        return this->Colors;
      }
    }
  }

  // Get rid of old colors
  if ( this->Colors )
  {
    this->Colors->UnRegister(this);
    this->Colors = 0;
  }

  // map scalars
  double orig_alpha = this->LookupTable->GetAlpha();
  this->LookupTable->SetAlpha(alpha);
  this->Colors = this->LookupTable->
    MapScalars(scalars, this->ColorMode, this->ArrayComponent);
  this->LookupTable->SetAlpha(orig_alpha);
  // Consistent register and unregisters
  this->Colors->Register(this);
  this->Colors->Delete();

  return this->Colors;
}


void vtkMapper::SelectColorArray(int arrayNum)
{
  this->ColorByArrayComponent(arrayNum, -1);
}


void vtkMapper::SelectColorArray(const char* arrayName)
{
  this->ColorByArrayComponent(arrayName, -1);
}


void vtkMapper::ColorByArrayComponent(int arrayNum, int component)
{
  if (this->ArrayId == arrayNum && component == this->ArrayComponent &&
      this->ArrayAccessMode == VTK_GET_ARRAY_BY_ID)
  {
    return;
  }
  this->Modified();

  this->ArrayId = arrayNum;
  this->ArrayComponent = component;
  this->ArrayAccessMode = VTK_GET_ARRAY_BY_ID;
}

void vtkMapper::ColorByArrayComponent(const char* arrayName, int component)
{
  if (!arrayName ||
      ( strcmp(this->ArrayName, arrayName) == 0 &&
        component == this->ArrayComponent &&
        this->ArrayAccessMode == VTK_GET_ARRAY_BY_NAME ))
  {
    return;
  }
  this->Modified();

  strncpy(this->ArrayName, arrayName, sizeof(this->ArrayName) - 1);
  this->ArrayName[sizeof(this->ArrayName) - 1] = '\0';
  this->ArrayComponent = component;
  this->ArrayAccessMode = VTK_GET_ARRAY_BY_NAME;
}

// Specify a lookup table for the mapper to use.
void vtkMapper::SetLookupTable(vtkScalarsToColors *lut)
{
  if ( this->LookupTable != lut )
  {
    if ( this->LookupTable)
    {
      this->LookupTable->UnRegister(this);
    }
    this->LookupTable = lut;
    if (lut)
    {
      lut->Register(this);
    }
    this->Modified();
  }
}

vtkScalarsToColors *vtkMapper::GetLookupTable()
{
  if ( this->LookupTable == 0 )
  {
    this->CreateDefaultLookupTable();
  }
  return this->LookupTable;
}

void vtkMapper::CreateDefaultLookupTable()
{
  if ( this->LookupTable)
  {
    this->LookupTable->UnRegister(this);
  }
  vtkLookupTable* table = vtkLookupTable::New();
  this->LookupTable = table;
  this->LookupTable->Register(this);
  this->LookupTable->Delete();

  int cellFlag = 0; // not used
  vtkAbstractArray* abstractArray = vtkAbstractMapper::
    GetAbstractScalars(this->GetInput(), this->ScalarMode, this->ArrayAccessMode,
                       this->ArrayId, this->ArrayName, cellFlag);

  vtkDataArray *dataArray = vtkArrayDownCast<vtkDataArray>(abstractArray);
  if (abstractArray && !dataArray)
  {
    // Use indexed lookup for non-numeric arrays
    this->LookupTable->IndexedLookupOn();

    // Get prominent values from array and set them up as annotations in the color map.
    vtkVariantArray* prominentValues = vtkVariantArray::New();
    abstractArray->GetProminentComponentValues(0, prominentValues);
    vtkIdType numProminentValues = prominentValues->GetNumberOfValues();
    table->SetNumberOfTableValues(numProminentValues);
    for (vtkIdType i = 0; i < numProminentValues; ++i)
    {
      vtkVariant & variant = prominentValues->GetValue(i);
      this->LookupTable->SetAnnotation(variant, variant.ToString());
    }
    prominentValues->Delete();

    // Set colors for annotations
    vtkColorSeries* colorSeries = vtkColorSeries::New();
    colorSeries->SetColorScheme(vtkColorSeries::BREWER_QUALITATIVE_PAIRED);
    colorSeries->BuildLookupTable(table, vtkColorSeries::CATEGORICAL);
    colorSeries->Delete();
  }
}

void vtkMapper::AcquireInvertibleLookupTable()
{
  if (!vtkMapper::InvertibleLookupTable)
  {
    vtkLookupTable *table = vtkLookupTable::New();
    const int MML = 0x1000;
    table->SetNumberOfTableValues(MML);
    table->SetBelowRangeColor(0.0, 0.0, 0.0, 1.0);
    table->SetAboveRangeColor(0.0, 0.0, 0.0, 1.0);
    table->SetNanColor(0.0, 0.0, 0.0, 1.0);
    unsigned char color[3] = { 0 };
    for (int i = 0; i < MML; ++i)
    {
      ValueToColor(i, 0, MML, color);
      table->SetTableValue(i,
          (double)color[0] / 255.0,
          (double)color[1] / 255.0,
          (double)color[2] / 255.0,
          1);
    }
    table->Register(this);
    table->Delete();
    vtkMapper::InvertibleLookupTable = table;
  }
  else
  {
    vtkMapper::InvertibleLookupTable->Register(this);
  }
}

void vtkMapper::ValueToColor(double value, double min, double scale,
  unsigned char *color)
{
  //TODO: make this configurable
  double valueS = (value - min)/scale;
  valueS = (valueS<0.0?0.0:valueS); //prevent underflow
  valueS = (valueS>1.0?1.0:valueS); //prevent overflow
  int valueI = valueS * 0xfffffe + 0x1; //0 is reserved as "nothing"

  color[0] = (unsigned char)((valueI & 0xff0000)>>16);
  color[1] = (unsigned char)((valueI & 0x00ff00)>>8);
  color[2] = (unsigned char)((valueI & 0x0000ff));
}

void vtkMapper::ColorToValue(unsigned char *color, double min, double scale,
  double &value)
{
  //TODO: make this configurable
  int valueI = ((int)(*(color+0)))<<16 | ((int)(*(color+1)))<<8 | ((int)(*(color+2)));
  double valueS = (valueI-0x1)/(double)0xfffffe; // 0 is reserved as "nothing"
  value = valueS * scale + min;
}

//-------------------------------------------------------------------
void vtkMapper::UseInvertibleColorFor(int scalarMode,
                                      int arrayAccessMode,
                                      int arrayId,
                                      const char *arrayName,
                                      int arrayComponent,
                                      double *scalarRange)
{
  vtkDataObject *dataObject = this->GetExecutive()->GetInputData(0, 0);
  this->UseInvertibleColorFor(dataObject,
    scalarMode, arrayAccessMode, arrayId,
    arrayName, arrayComponent, scalarRange);
}

//-------------------------------------------------------------------
void vtkMapper::UseInvertibleColorFor(vtkDataObject *dataObject,
                                      int scalarMode,
                                      int arrayAccessMode,
                                      int arrayId,
                                      const char *arrayName,
                                      int arrayComponent,
                                      double *scalarRange)
{
  //find and hold onto the array to use later
  int cellFlag = 0; // not used

  vtkAbstractArray *abstractArray = NULL;

  // Check for a regular data set
  vtkDataSet *input = vtkDataSet::SafeDownCast(dataObject);
  if (input)
  {
    abstractArray = vtkAbstractMapper::
      GetAbstractScalars(input, scalarMode, arrayAccessMode,
                         arrayId, arrayName, cellFlag);
  }

  // Check for a composite data set
  vtkCompositeDataSet *compositeInput =
    vtkCompositeDataSet::SafeDownCast(dataObject);
  if (compositeInput)
  {
    vtkSmartPointer<vtkDataObjectTreeIterator> iter =
      vtkSmartPointer<vtkDataObjectTreeIterator>::New();
    iter->SetDataSet(compositeInput);
    iter->SkipEmptyNodesOn();
    iter->VisitOnlyLeavesOn();
    for (iter->InitTraversal();
         !iter->IsDoneWithTraversal();
         iter->GoToNextItem())
    {
      vtkDataObject *dso = iter->GetCurrentDataObject();
      vtkPolyData *pd = vtkPolyData::SafeDownCast(dso);
      if (pd)
      {
        abstractArray = vtkAbstractMapper::
          GetAbstractScalars(pd, scalarMode, arrayAccessMode,
                             arrayId, arrayName, cellFlag);
        if (abstractArray)
        {
          break;
        }
      }
    }
  }

  if (!abstractArray)
  {
    vtkErrorMacro(<< "Scalar array " << arrayName
                  << "with Id = " << arrayId << " not found.");
  }

  this->Modified();

  // Ensure the scalar range is initialized
  vtkDataArray *dataArray = vtkArrayDownCast<vtkDataArray>(abstractArray);
  if (dataArray && scalarRange[0] > scalarRange[1])
  {
    scalarRange = dataArray->GetRange();
  }

  this->ScalarMode = scalarMode;
  this->ArrayComponent = arrayComponent;
  this->SetScalarRange(scalarRange);

  // Set the new array, if present
  if (this->InvertibleScalars)
  {
    this->InvertibleScalars->UnRegister(this);
  }
  this->InvertibleScalars = abstractArray;
  if (this->InvertibleScalars)
  {
    this->InvertibleScalars->Register(this);
  }

  // Determine whether to use invertible colors
  this->UseInvertibleColors = this->InvertibleScalars != NULL;
  if (!this->UseInvertibleColors)
  {
      return;
  }

  //make up new table
  if (this->LookupTable)
  {
    this->LookupTable->UnRegister(this);
    this->LookupTable = NULL;
  }

  if (!dataArray)
  {
    vtkLookupTable* table = vtkLookupTable::New();
    this->LookupTable = table;
    this->LookupTable->Register(this);
    this->LookupTable->Delete();
    table->SetNumberOfTableValues(1);
    table->SetTableValue(0, 0.0, 0.0, 0.0, 1);
  }
  else
  {
    // Just grab a reference to the invertible lookup table
    this->LookupTable = vtkMapper::InvertibleLookupTable;
    this->LookupTable->Register(this);
  }

    // Update the component in either case.
    this->LookupTable->SetVectorComponent(arrayComponent);
}

//-------------------------------------------------------------------
void vtkMapper::ClearInvertibleColor()
{
  if (!this->UseInvertibleColors)
  {
    return;
  }
  this->Modified();
  this->UseInvertibleColors = false;
  if (this->LookupTable)
  {
    this->LookupTable->UnRegister(this);
    this->LookupTable = NULL;
  }
}

//-------------------------------------------------------------------
// Return the method of coloring scalar data.
const char *vtkMapper::GetColorModeAsString(void)
{
  if ( this->ColorMode == VTK_COLOR_MODE_MAP_SCALARS )
  {
    return "MapScalars";
  }
  else
  {
    return "Default";
  }
}

// Return the method for obtaining scalar data.
const char *vtkMapper::GetScalarModeAsString(void)
{
  if ( this->ScalarMode == VTK_SCALAR_MODE_USE_CELL_DATA )
  {
    return "UseCellData";
  }
  else if ( this->ScalarMode == VTK_SCALAR_MODE_USE_POINT_DATA )
  {
    return "UsePointData";
  }
  else if ( this->ScalarMode == VTK_SCALAR_MODE_USE_POINT_FIELD_DATA )
  {
    return "UsePointFieldData";
  }
  else if ( this->ScalarMode == VTK_SCALAR_MODE_USE_CELL_FIELD_DATA )
  {
    return "UseCellFieldData";
  }
  else if ( this->ScalarMode == VTK_SCALAR_MODE_USE_FIELD_DATA )
  {
    return "UseFieldData";
  }
  else
  {
    return "Default";
  }
}

const char *vtkMapper::GetScalarMaterialModeAsString(void)
{
  if ( this->ScalarMaterialMode == VTK_MATERIALMODE_AMBIENT )
  {
    return "Ambient";
  }
  else if ( this->ScalarMaterialMode == VTK_MATERIALMODE_DIFFUSE )
  {
    return "Diffuse";
  }
  else if ( this->ScalarMaterialMode == VTK_MATERIALMODE_AMBIENT_AND_DIFFUSE )
  {
    return "Ambient and Diffuse";
  }
  else
  {
    return "Default";
  }
}

//-----------------------------------------------------------------------------
bool vtkMapper::GetIsOpaque()
{
  vtkScalarsToColors* lut = this->GetLookupTable();
  if (lut)
  {
    // Ensure that the lookup table is built
    lut->Build();
    return (lut->IsOpaque() == 1);
  }

  return true;
}

// anonymous namespace
namespace {

//-----------------------------------------------------------------------------
template<class T>
void ScalarToTextureCoordinate(
                               T scalar_value,         // Input scalar
                               double range_min,       // range[0]
                               double inv_range_width, // 1/(range[1]-range[0])
                               float &tex_coord_s,     // 1st tex coord
                               float &tex_coord_t)     // 2nd tex coord
{
  if (vtkMath::IsNan(scalar_value))
  {
    tex_coord_s = 0.5;  // Scalar value is arbitrary when NaN
    tex_coord_t = 1.0;  // 1.0 in t coordinate means NaN
  }
  else
  {
    // 0.0 in t coordinate means not NaN.  So why am I setting it to 0.49?
    // Because when you are mapping scalars and you have a NaN adjacent to
    // anything else, the interpolation everywhere should be NaN.  Thus, I
    // want the NaN color everywhere except right on the non-NaN neighbors.
    // To simulate this, I set the t coord for the real numbers close to
    // the threshold so that the interpolation almost immediately looks up
    // the NaN value.
    tex_coord_t = 0.49;

    double ranged_scalar = (scalar_value - range_min) * inv_range_width;
    tex_coord_s = static_cast<float>(ranged_scalar);
  }

    // Some implementations apparently don't handle relatively large
    // numbers (compared to the range [0.0, 1.0]) very well. In fact,
    // values above 1122.0f appear to cause texture wrap-around on
    // some systems even when edge clamping is enabled. Why 1122.0f? I
    // don't know. For safety, we'll clamp at +/- 1000. This will
    // result in incorrect images when the texture value should be
    // above or below 1000, but I don't have a better solution.
    if (tex_coord_s > 1000.0f)
    {
      tex_coord_s = 1000.0f;
    }
    else if (tex_coord_s < -1000.0f)
    {
      tex_coord_s = -1000.0f;
    }
}

//-----------------------------------------------------------------------------
template<class T>
void CreateColorTextureCoordinates(T* input, float* output,
                                   vtkIdType numScalars, int numComps,
                                   int component, double* range,
                                   const double* table_range,
                                   int tableNumberOfColors,
                                   bool use_log_scale)
{
  // We have to change the range used for computing texture
  // coordinates slightly to accomodate the special above- and
  // below-range colors that are the first and last texels,
  // respectively.
  double scalar_texel_width = (range[1] - range[0]) / static_cast<double>(tableNumberOfColors);
  double padded_range[2];
  padded_range[0] = range[0] - scalar_texel_width;
  padded_range[1] = range[1] + scalar_texel_width;
  double inv_range_width = 1.0 / (padded_range[1] - padded_range[0]);

  if (component < 0 || component >= numComps)
  {
    for (vtkIdType scalarIdx = 0; scalarIdx < numScalars; ++scalarIdx)
    {
      double sum = 0;
      for (int compIdx = 0; compIdx < numComps; ++compIdx)
      {
        double tmp = static_cast<double>(*input);
        sum += (tmp * tmp);
        ++input;
      }
      double magnitude = sqrt(sum);
      if (use_log_scale)
      {
        magnitude = vtkLookupTable::ApplyLogScale(
          magnitude, table_range, range);
      }
      ScalarToTextureCoordinate(magnitude, padded_range[0], inv_range_width,
                                output[0], output[1]);
      output += 2;
    }
  }
  else
  {
    input += component;
    for (vtkIdType scalarIdx = 0; scalarIdx < numScalars; ++scalarIdx)
    {
      double input_value = static_cast<double>(*input);
      if (use_log_scale)
      {
        input_value = vtkLookupTable::ApplyLogScale(
          input_value, table_range, range);
      }
      ScalarToTextureCoordinate(input_value, padded_range[0], inv_range_width,
                                output[0], output[1]);
      output += 2;
      input = input + numComps;
    }
  }
}

} // end anonymous namespace

// a side effect of this is that this->ColorCoordinates and
// this->ColorTexture are set.
void vtkMapper::MapScalarsToTexture(vtkAbstractArray* scalars, double alpha)
{
  double range[2];
  range[0] = this->LookupTable->GetRange()[0];
  range[1] = this->LookupTable->GetRange()[1];
  bool use_log_scale = (this->LookupTable->UsingLogScale() != 0);
  if (use_log_scale)
  {
    // convert range to log.
    vtkLookupTable::GetLogRange(range, range);
  }

  double orig_alpha = this->LookupTable->GetAlpha();

  // Get rid of vertex color array.  Only texture or vertex coloring
  // can be active at one time.  The existence of the array is the
  // signal to use that technique.
  if ( this->Colors )
  {
    this->Colors->UnRegister(this);
    this->Colors = 0;
  }

  // If the lookup table has changed, the recreate the color texture map.
  // Set a new lookup table changes this->MTime.
  if (this->ColorTextureMap == 0 ||
      this->GetMTime() > this->ColorTextureMap->GetMTime() ||
      this->LookupTable->GetMTime() > this->ColorTextureMap->GetMTime() ||
      this->LookupTable->GetAlpha() != alpha)
  {
    this->LookupTable->SetAlpha(alpha);
    if ( this->ColorTextureMap )
    {
      this->ColorTextureMap->UnRegister(this);
      this->ColorTextureMap = 0;
    }
    // Get the texture map from the lookup table.
    // Create a dummy ramp of scalars.
    // In the future, we could extend vtkScalarsToColors.
    vtkIdType numberOfColors = this->LookupTable->GetNumberOfAvailableColors();
    numberOfColors += 2;
    double k = (range[1]-range[0]) / (numberOfColors-1-2);
    vtkDoubleArray* tmp = vtkDoubleArray::New();
    tmp->SetNumberOfTuples(numberOfColors*2);
    double* ptr = tmp->GetPointer(0);
    for (int i = 0; i < numberOfColors; ++i)
    {
      *ptr = range[0] + i * k - k; // minus k to start at below range color
      if (use_log_scale)
      {
        *ptr = pow(10.0, *ptr);
      }
      ++ptr;
    }
    // Dimension on NaN.
    double nan = vtkMath::Nan();
    for (int i = 0; i < numberOfColors; ++i)
    {
      *ptr = nan;
      ++ptr;
    }
    this->ColorTextureMap = vtkImageData::New();
    this->ColorTextureMap->SetExtent(0,numberOfColors-1,
                                     0,1, 0,0);
    this->ColorTextureMap->GetPointData()->SetScalars(
         this->LookupTable->MapScalars(tmp, this->ColorMode, 0));
    this->LookupTable->SetAlpha(orig_alpha);
    // Do we need to delete the scalars?
    this->ColorTextureMap->GetPointData()->GetScalars()->Delete();
    // Consistent register and unregisters
    this->ColorTextureMap->Register(this);
    this->ColorTextureMap->Delete();
    tmp->Delete();
  }

  // Create new coordinates if necessary.
  // Need to compare lookup table incase the range has changed.
  if (this->ColorCoordinates == 0 ||
      this->GetMTime() > this->ColorCoordinates->GetMTime() ||
      this->GetExecutive()->GetInputData(0, 0)->GetMTime() >
      this->ColorCoordinates->GetMTime() ||
      this->LookupTable->GetMTime() > this->ColorCoordinates->GetMTime())
  {
    // Get rid of old colors
    if ( this->ColorCoordinates )
    {
      this->ColorCoordinates->UnRegister(this);
      this->ColorCoordinates = 0;
    }

    // Now create the color texture coordinates.
    int numComps = scalars->GetNumberOfComponents();
    void* input = scalars->GetVoidPointer(0);
    vtkIdType num = scalars->GetNumberOfTuples();
    this->ColorCoordinates = vtkFloatArray::New();
    this->ColorCoordinates->SetNumberOfComponents(2);
    this->ColorCoordinates->SetNumberOfTuples(num);
    float* output = this->ColorCoordinates->GetPointer(0);
    int scalarComponent;
    // Although I like the feature of applying magnitude to single component
    // scalars, it is not how the old MapScalars for vertex coloring works.
    if (this->LookupTable->GetVectorMode() == vtkScalarsToColors::MAGNITUDE &&
        scalars->GetNumberOfComponents() > 1)
    {
      scalarComponent = -1;
    }
    else
    {
      scalarComponent = this->LookupTable->GetVectorComponent();
    }
    switch (scalars->GetDataType())
    {
      vtkTemplateMacro(
        CreateColorTextureCoordinates(static_cast<VTK_TT*>(input),
          output, num, numComps,
          scalarComponent, range,
          this->LookupTable->GetRange(),
          this->LookupTable->GetNumberOfAvailableColors(),
          use_log_scale)
        );
      case VTK_BIT:
        vtkErrorMacro("Cannot color by bit array.");
        break;
      default:
        vtkErrorMacro(<< "Unknown input ScalarType");
        return;
    }
  }
}

void vtkMapper::PrintSelf(ostream& os, vtkIndent indent)
{
  this->Superclass::PrintSelf(os,indent);

  if ( this->LookupTable )
  {
    os << indent << "Lookup Table:\n";
    this->LookupTable->PrintSelf(os,indent.GetNextIndent());
  }
  else
  {
    os << indent << "Lookup Table: (none)\n";
  }

  os << indent << "Immediate Mode Rendering: "
    << (this->ImmediateModeRendering ? "On\n" : "Off\n");

   os << indent << "Force compile only for display lists: "
    << (this->ForceCompileOnly ? "On\n" : "Off\n");

  os << indent << "Global Immediate Mode Rendering: " <<
    (vtkMapperGlobalImmediateModeRendering ? "On\n" : "Off\n");

  os << indent << "Scalar Visibility: "
    << (this->ScalarVisibility ? "On\n" : "Off\n");

  os << indent << "Static: "
    << (this->Static ? "On\n" : "Off\n");

  double *range = this->GetScalarRange();
  os << indent << "Scalar Range: (" << range[0] << ", " << range[1] << ")\n";

  os << indent << "UseLookupTableScalarRange: "
     << this->UseLookupTableScalarRange << "\n";

  os << indent << "Color Mode: " << this->GetColorModeAsString() << endl;
  os << indent << "InterpolateScalarsBeforeMapping: "
     << (this->InterpolateScalarsBeforeMapping ? "On\n" : "Off\n");

  os << indent << "Scalar Mode: " << this->GetScalarModeAsString() << endl;

  os << indent << "LM Color Mode: "
     << this->GetScalarMaterialModeAsString() << endl;

  os << indent << "RenderTime: " << this->RenderTime << endl;

  os << indent << "Resolve Coincident Topology: ";
  if ( vtkMapperGlobalResolveCoincidentTopology == VTK_RESOLVE_OFF )
  {
    os << "Off" << endl;
  }
  else if ( vtkMapperGlobalResolveCoincidentTopology == VTK_RESOLVE_POLYGON_OFFSET )
  {
    os << "Polygon Offset" << endl;
  }
  else
  {
    os << "Shift Z-Buffer" << endl;
  }

  os << indent << "CoincidentPointOffset: "
     << this->CoincidentPointOffset << "\n";
  os << indent << "CoincidentLineOffset: "
     << this->CoincidentLineOffset << "\n";
  os << indent << "CoincidentPolygonOffset: "
     << this->CoincidentPolygonOffset << "\n";
  os << indent << "CoincidentLineFactor: "
     << this->CoincidentLineFactor << "\n";
  os << indent << "CoincidentPolygonFactor: "
     << this->CoincidentPolygonFactor << "\n";
}

//-------------------------------------------------------------------
void vtkMapper::ClearColorArrays()
{
  if (this->Colors)
  {
    this->Colors->Delete();
    this->Colors = NULL;
  }
  if (this->ColorCoordinates)
  {
    this->ColorCoordinates->Delete();
    this->ColorCoordinates = NULL;
  }
  if (this->ColorTextureMap)
  {
    this->ColorTextureMap->Delete();
    this->ColorTextureMap = NULL;
  }
}

//-------------------------------------------------------------------
vtkUnsignedCharArray *vtkMapper::GetColorMapColors()
{
  return this->Colors;
}

//-------------------------------------------------------------------
vtkFloatArray *vtkMapper::GetColorCoordinates()
{
  return this->ColorCoordinates;
}

//-------------------------------------------------------------------
vtkImageData* vtkMapper::GetColorTextureMap()
{
  return this->ColorTextureMap;
}