Rendering/OpenGL2/vtkCompositePolyDataMapper2.cxx

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

  Program:   Visualization Toolkit
  Module:    vtkCompositePolyDataMapper2.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 "vtkCompositePolyDataMapper2.h"

#include "vtk_glew.h"

#include "vtkBoundingBox.h"
#include "vtkCellData.h"
#include "vtkColorTransferFunction.h"
#include "vtkCommand.h"
#include "vtkCompositeDataDisplayAttributes.h"
#include "vtkCompositeDataIterator.h"
#include "vtkCompositeDataPipeline.h"
#include "vtkCompositeDataSet.h"
#include "vtkDataObjectTreeIterator.h"
#include "vtkFloatArray.h"
#include "vtkHardwareSelector.h"
#include "vtkImageData.h"
#include "vtkInformation.h"
#include "vtkLookupTable.h"
#include "vtkMultiBlockDataSet.h"
#include "vtkMultiPieceDataSet.h"
#include "vtkObjectFactory.h"
#include "vtkOpenGLIndexBufferObject.h"
#include "vtkOpenGLRenderWindow.h"
#include "vtkOpenGLRenderer.h"
#include "vtkOpenGLTexture.h"
#include "vtkOpenGLVertexBufferObject.h"
#include "vtkOpenGLVertexBufferObjectGroup.h"
#include "vtkPointData.h"
#include "vtkPolyData.h"
#include "vtkProperty.h"
#include "vtkScalarsToColors.h"
#include "vtkShaderProgram.h"
#include "vtkTextureObject.h"
#include "vtkTransform.h"
#include "vtkUnsignedIntArray.h"

#include <algorithm>
#include <sstream>

#include "vtkCompositePolyDataMapper2Internal.h"

typedef std::map<vtkPolyData *, vtkCompositeMapperHelperData *>::iterator dataIter;
typedef std::map<const std::string, vtkCompositeMapperHelper2 *>::iterator helpIter;

vtkStandardNewMacro(vtkCompositeMapperHelper2);

vtkCompositeMapperHelper2::~vtkCompositeMapperHelper2()
{
  for (dataIter it = this->Data.begin(); it != this->Data.end(); ++it)
  {
    delete it->second;
  }
  this->Data.clear();
}

void vtkCompositeMapperHelper2::SetShaderValues(
  vtkShaderProgram *prog,
  vtkCompositeMapperHelperData *hdata,
  size_t primOffset)
{
  if (this->PrimIDUsed)
  {
    prog->SetUniformi("PrimitiveIDOffset",
      static_cast<int>(primOffset));
  }

  if (this->CurrentSelector)
  {
    if (this->CurrentSelector->GetCurrentPass() ==
        vtkHardwareSelector::COMPOSITE_INDEX_PASS &&
        prog->IsUniformUsed("mapperIndex"))
    {
      this->CurrentSelector->RenderCompositeIndex(hdata->FlatIndex);
      prog->SetUniform3f("mapperIndex",
        this->CurrentSelector->GetPropColorValue());
    }
    return;
  }

  // If requested, color partial / missing arrays with NaN color.
  bool useNanColor = false;
  double nanColor[4] = { -1., -1., -1., -1 };
  if (this->Parent->GetColorMissingArraysWithNanColor() &&
      this->GetScalarVisibility())
  {
    int cellFlag = 0;
    vtkAbstractArray *scalars = vtkAbstractMapper::GetAbstractScalars(
          hdata->Data, this->ScalarMode, this->ArrayAccessMode, this->ArrayId,
          this->ArrayName, cellFlag);
    if (scalars == nullptr)
    {
      vtkLookupTable *lut = vtkLookupTable::SafeDownCast(this->GetLookupTable());
      vtkColorTransferFunction *ctf = lut ? nullptr :
           vtkColorTransferFunction::SafeDownCast(this->GetLookupTable());
      if (lut)
      {
        lut->GetNanColor(nanColor);
        useNanColor = true;
      }
      else if (ctf)
      {
        ctf->GetNanColor(nanColor);
        useNanColor = true;
      }
    }
  }

  // override the opacity and color
  prog->SetUniformf("opacityUniform", hdata->Opacity);

  if (useNanColor)
  {
    float fnancolor[3] = {
      static_cast<float>(nanColor[0]),
      static_cast<float>(nanColor[1]),
      static_cast<float>(nanColor[2])
    };
    prog->SetUniform3f("ambientColorUniform", fnancolor);
    prog->SetUniform3f("diffuseColorUniform", fnancolor);
  }
  else
  {
    vtkColor3d &aColor = hdata->AmbientColor;
    float ambientColor[3] = {
      static_cast<float>(aColor[0]),
      static_cast<float>(aColor[1]),
      static_cast<float>(aColor[2])
    };
    vtkColor3d &dColor = hdata->DiffuseColor;
    float diffuseColor[3] = {
      static_cast<float>(dColor[0]),
      static_cast<float>(dColor[1]),
      static_cast<float>(dColor[2])
    };
    prog->SetUniform3f("ambientColorUniform", ambientColor);
    prog->SetUniform3f("diffuseColorUniform", diffuseColor);
    if (this->OverideColorUsed)
    {
      prog->SetUniformi("OverridesColor", hdata->OverridesColor);
    }
  }
}

void vtkCompositeMapperHelper2::UpdateShaders(
  vtkOpenGLHelper &cellBO, vtkRenderer *ren, vtkActor *act)
{
  Superclass::UpdateShaders(cellBO, ren, act);
  if (cellBO.Program && this->Parent)
  {
    // allow the program to set what it wants
    this->Parent->InvokeEvent(vtkCommand::UpdateShaderEvent, cellBO.Program);
  }
}

void vtkCompositeMapperHelper2::ReplaceShaderColor(
  std::map<vtkShader::Type, vtkShader *> shaders,
  vtkRenderer *ren, vtkActor *actor)
{
  if (!this->CurrentSelector)
  {
    std::string FSSource = shaders[vtkShader::Fragment]->GetSource();

    vtkShaderProgram::Substitute(FSSource,"//VTK::Color::Dec",
      "uniform bool OverridesColor;\n"
      "//VTK::Color::Dec",false);

    vtkShaderProgram::Substitute(FSSource,"//VTK::Color::Impl",
      "//VTK::Color::Impl\n"
      "  if (OverridesColor) {\n"
      "    ambientColor = ambientColorUniform * ambientIntensity;\n"
      "    diffuseColor = diffuseColorUniform * diffuseIntensity; }\n",
      false);

    shaders[vtkShader::Fragment]->SetSource(FSSource);
  }

  this->Superclass::ReplaceShaderColor(shaders,ren,actor);
}

void vtkCompositeMapperHelper2::ClearMark()
{
  for (dataIter it = this->Data.begin(); it != this->Data.end(); ++it)
  {
    it->second->Marked = false;
  }
  this->Marked = false;
}

void vtkCompositeMapperHelper2::RemoveUnused()
{
  for (dataIter it = this->Data.begin(); it != this->Data.end(); )
  {
    if (!it->second->Marked)
    {
      delete it->second;
      this->Data.erase(it++);
      this->Modified();
    }
    else
    {
      ++it;
    }
  }
}

//-----------------------------------------------------------------------------
// 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 vtkCompositeMapperHelper2::CanUseTextureMapForColoring(vtkDataObject*)
{
  if (!this->InterpolateScalarsBeforeMapping)
  {
    return 0; // user doesn't want us to use texture maps at all.
  }

  int cellFlag=0;
  vtkScalarsToColors *scalarsLookupTable = nullptr;
  for (dataIter it = this->Data.begin(); it != this->Data.end(); ++it)
  {
    vtkPolyData *pd = it->second->Data;
    vtkDataArray* scalars = vtkAbstractMapper::GetScalars(pd,
      this->ScalarMode, this->ArrayAccessMode, this->ArrayId,
      this->ArrayName, cellFlag);

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

      if (scalarsLookupTable && scalars->GetLookupTable() &&
          (scalarsLookupTable != scalars->GetLookupTable()))
      {
        // Two datasets are requesting different lookup tables to color with.
        // We don't handle this case right now for composite datasets.
        return 0;
      }
      if (scalars->GetLookupTable())
      {
        scalarsLookupTable = scalars->GetLookupTable();
      }
    }
  }

  if ((scalarsLookupTable &&
       scalarsLookupTable->GetIndexedLookup()) ||
      (!scalarsLookupTable &&
       this->LookupTable &&
       this->LookupTable->GetIndexedLookup()))
  {
      return 0;
  }

  return 1;
}

//-----------------------------------------------------------------------------
void vtkCompositeMapperHelper2::RenderPiece(vtkRenderer* ren, vtkActor *actor)
{
  // Make sure that we have been properly initialized.
  if (ren->GetRenderWindow()->CheckAbortStatus())
  {
    return;
  }

  this->CurrentInput = this->Data.begin()->first;

  this->RenderPieceStart(ren, actor);
  this->RenderPieceDraw(ren, actor);
  this->RenderPieceFinish(ren, actor);
}

void vtkCompositeMapperHelper2::DrawIBO(
  vtkRenderer* ren, vtkActor *actor,
  int primType,
  vtkOpenGLHelper &CellBO,
  GLenum mode,
  int pointSize)
{
  if (CellBO.IBO->IndexCount)
  {
    if (pointSize > 0)
    {
#if GL_ES_VERSION_3_0 != 1
      glPointSize(pointSize); // need to use shader value
#endif
    }
    // First we do the triangles, update the shader, set uniforms, etc.
    this->UpdateShaders(CellBO, ren, actor);
    vtkShaderProgram *prog = CellBO.Program;
    if (!prog)
    {
      return;
    }
    this->PrimIDUsed = prog->IsUniformUsed("PrimitiveIDOffset");
    this->OverideColorUsed = prog->IsUniformUsed("OverridesColor");
    CellBO.IBO->Bind();

    if (!this->HaveWideLines(ren,actor) && mode == GL_LINES)
    {
      glLineWidth(actor->GetProperty()->GetLineWidth());
    }

    // if (this->DrawingEdgesOrVetices && !this->DrawingTubes(CellBO, actor))
    // {
    //   vtkProperty *ppty = actor->GetProperty();
    //   float diffuseColor[3] = {0.0, 0.0, 0.0};
    //   float ambientColor[3];
    //   double *acol = ppty->GetEdgeColor();
    //   ambientColor[0] = acol[0];
    //   ambientColor[1] = acol[1];
    //   ambientColor[2] = acol[2];
    //   prog->SetUniform3f("diffuseColorUniform", diffuseColor);
    //   prog->SetUniform3f("ambientColorUniform", ambientColor);
    // }

    this->RenderedList.clear();
    bool selecting = (this->CurrentSelector ? true : false);
    for (dataIter it = this->Data.begin(); it != this->Data.end(); ++it)
    {
      vtkCompositeMapperHelperData *starthdata = it->second;
      if (starthdata->Visibility &&
          ((selecting && starthdata->Pickability) || !selecting) &&
          starthdata->NextIndex[primType] > starthdata->StartIndex[primType])
      {
        //compilers think this can exceed the bounds so we also
        // test against primType even though we should not need to
        if (primType <= PrimitiveTriStrips)
        {
          this->SetShaderValues(prog, starthdata,
            starthdata->PrimOffsets[primType]);
        }
        glDrawRangeElements(mode,
          static_cast<GLuint>(starthdata->StartVertex),
          static_cast<GLuint>(starthdata->NextVertex > 0 ? starthdata->NextVertex - 1 : 0),
          static_cast<GLsizei>(starthdata->NextIndex[primType] - starthdata->StartIndex[primType]),
          GL_UNSIGNED_INT,
          reinterpret_cast<const GLvoid *>(starthdata->StartIndex[primType]*sizeof(GLuint)));
      }
    }
    CellBO.IBO->Release();
  }
}

//-----------------------------------------------------------------------------
void vtkCompositeMapperHelper2::RenderPieceDraw(
  vtkRenderer* ren, vtkActor *actor)
{
  int representation = actor->GetProperty()->GetRepresentation();

  // render points for point picking in a special way
  // all cell types should be rendered as points
  this->CurrentSelector = ren->GetSelector();
  bool pointPicking = false;
  if (this->CurrentSelector && this->PopulateSelectionSettings &&
      this->CurrentSelector->GetFieldAssociation() == vtkDataObject::FIELD_ASSOCIATION_POINTS)
  {
    representation = VTK_POINTS;
    pointPicking = true;
  }

  this->PrimitiveIDOffset = 0;

  // draw IBOs
  for (int i = PrimitiveStart;
    i < (this->CurrentSelector ? PrimitiveTriStrips + 1 : PrimitiveEnd); i++)
  {
    this->DrawingEdgesOrVertices =
     (i > PrimitiveTriStrips ? true :false);
    GLenum mode = this->GetOpenGLMode(representation, i);
    this->DrawIBO(ren, actor, i, this->Primitives[i], mode,
      pointPicking ? this->GetPointPickingPrimitiveSize(i) : 0);
  }

  if (this->CurrentSelector && (
        this->CurrentSelector->GetCurrentPass() == vtkHardwareSelector::CELL_ID_LOW24 ||
        this->CurrentSelector->GetCurrentPass() == vtkHardwareSelector::CELL_ID_HIGH24))
  {
    this->CurrentSelector->SetPropColorValue(this->PrimitiveIDOffset);
  }
}

vtkCompositeMapperHelperData *vtkCompositeMapperHelper2::AddData(
  vtkPolyData *pd, unsigned int flatIndex)
{
  dataIter found = this->Data.find(pd);
  if (found == this->Data.end())
  {
    vtkCompositeMapperHelperData *hdata =
      new vtkCompositeMapperHelperData();
    hdata->FlatIndex = flatIndex;
    hdata->Data = pd;
    hdata->Marked = true;
    this->Data.insert(std::make_pair(pd, hdata));
    this->Modified();
    return hdata;
  }
  found->second->Marked = true;
  return found->second;
}

//-------------------------------------------------------------------------
void vtkCompositeMapperHelper2::BuildBufferObjects(
  vtkRenderer *ren,
  vtkActor *act)
{
  // render using the composite data attributes

  // create the cell scalar array adjusted for ogl Cells
  std::vector<unsigned char> newColors;
  std::vector<float> newNorms;

  // check if this system is subject to the apple/amd primID bug
  this->HaveAppleBug =
    static_cast<vtkOpenGLRenderer *>(ren)->HaveApplePrimitiveIdBug();
  if (this->HaveAppleBugForce == 1)
  {
    this->HaveAppleBug = false;
  }
  if (this->HaveAppleBugForce == 2)
  {
    this->HaveAppleBug = true;
  }
  this->AppleBugPrimIDs.resize(0);

  dataIter iter;
  this->VBOs->ClearAllVBOs();

  if (this->Data.begin() == this->Data.end())
  {
    this->VBOBuildTime.Modified();
    return;
  }

  vtkBoundingBox bbox;
  double bounds[6];
  this->Data.begin()->second->Data->GetPoints()->GetBounds(bounds);
  bbox.SetBounds(bounds);
  for (iter = this->Data.begin(); iter != this->Data.end(); ++iter)
  {
    vtkCompositeMapperHelperData *hdata = iter->second;

    hdata->Data->GetPoints()->GetBounds(bounds);
    bbox.AddBounds(bounds);

    for (int i = 0; i < PrimitiveEnd; i++)
    {
      hdata->StartIndex[i] =
        static_cast<unsigned int>(this->IndexArray[i].size());
    }

    vtkIdType voffset = 0;
    this->AppendOneBufferObject(ren, act, hdata,
      voffset, newColors, newNorms);
    hdata->StartVertex = static_cast<unsigned int>(voffset);
    hdata->NextVertex = hdata->StartVertex + hdata->Data->GetPoints()->GetNumberOfPoints();
    for (int i = 0; i < PrimitiveEnd; i++)
    {
      hdata->NextIndex[i] =
        static_cast<unsigned int>(this->IndexArray[i].size());
    }
  }

  // clear color cache
  for (auto& c : this->ColorArrayMap)
  {
    c.second->Delete();
  }
  this->ColorArrayMap.clear();

  vtkOpenGLVertexBufferObject *posVBO = this->VBOs->GetVBO("vertexMC");
  if (posVBO && this->ShiftScaleMethod ==
      vtkOpenGLVertexBufferObject::AUTO_SHIFT_SCALE)
  {
    posVBO->SetCoordShiftAndScaleMethod(vtkOpenGLVertexBufferObject::MANUAL_SHIFT_SCALE);
    bbox.GetBounds(bounds);
    std::vector<double> shift;
    std::vector<double> scale;
    for (int i = 0; i < 3; i++)
    {
      shift.push_back(0.5*(bounds[i*2] + bounds[i*2+1]));
      scale.push_back((bounds[i*2+1] - bounds[i*2]) ? 1.0/(bounds[i*2+1] - bounds[i*2]) : 1.0);
    }
    posVBO->SetShift(shift);
    posVBO->SetScale(scale);
    // If the VBO coordinates were shifted and scaled, prepare the inverse transform
    // for application to the model->view matrix:
    if (posVBO->GetCoordShiftAndScaleEnabled())
    {
      this->VBOInverseTransform->Identity();
      this->VBOInverseTransform->Translate(shift[0], shift[1], shift[2]);
      this->VBOInverseTransform->Scale(1.0/scale[0], 1.0/scale[1], 1.0/scale[2]);
      this->VBOInverseTransform->GetTranspose(this->VBOShiftScale);
    }
  }

  this->VBOs->BuildAllVBOs(ren);

  for (int i = PrimitiveStart; i < PrimitiveEnd; i++)
  {
    this->Primitives[i].IBO->IndexCount = this->IndexArray[i].size();
    if (this->Primitives[i].IBO->IndexCount)
    {
      this->Primitives[i].IBO->Upload(this->IndexArray[i],
       vtkOpenGLBufferObject::ElementArrayBuffer);
      this->IndexArray[i].resize(0);
    }
  }

  // allocate as needed
  if (this->HaveCellScalars)
  {
    if (!this->CellScalarTexture)
    {
      this->CellScalarTexture = vtkTextureObject::New();
      this->CellScalarBuffer = vtkOpenGLBufferObject::New();
    }
    this->CellScalarTexture->SetContext(
      static_cast<vtkOpenGLRenderWindow*>(ren->GetVTKWindow()));
    this->CellScalarBuffer->Upload(newColors,
      vtkOpenGLBufferObject::TextureBuffer);
    this->CellScalarTexture->CreateTextureBuffer(
      static_cast<unsigned int>(newColors.size()/4),
      4,
      VTK_UNSIGNED_CHAR,
      this->CellScalarBuffer);
  }

  if (this->HaveCellNormals)
  {
    if (!this->CellNormalTexture)
    {
      this->CellNormalTexture = vtkTextureObject::New();
      this->CellNormalBuffer = vtkOpenGLBufferObject::New();
      this->CellNormalBuffer->SetType(vtkOpenGLBufferObject::TextureBuffer);
    }
    this->CellNormalTexture->SetContext(
      static_cast<vtkOpenGLRenderWindow*>(ren->GetVTKWindow()));

    // do we have float texture support ?
    int ftex =
      static_cast<vtkOpenGLRenderWindow *>(ren->GetRenderWindow())->
        GetDefaultTextureInternalFormat(VTK_FLOAT, 4, false, true, false);

    if (ftex)
    {
      this->CellNormalBuffer->Upload(newNorms,
        vtkOpenGLBufferObject::TextureBuffer);
      this->CellNormalTexture->CreateTextureBuffer(
        static_cast<unsigned int>(newNorms.size()/4),
        4, VTK_FLOAT,
        this->CellNormalBuffer);
    }
    else
    {
      // have to convert to unsigned char if no float support
      std::vector<unsigned char> ucNewNorms;
      ucNewNorms.resize(newNorms.size());
      for (size_t i = 0; i < newNorms.size(); i++)
      {
        ucNewNorms[i] = 127.0*(newNorms[i] + 1.0);
      }
      this->CellNormalBuffer->Upload(ucNewNorms,
        vtkOpenGLBufferObject::TextureBuffer);
      this->CellNormalTexture->CreateTextureBuffer(
        static_cast<unsigned int>(newNorms.size()/4),
        4, VTK_UNSIGNED_CHAR,
        this->CellNormalBuffer);
    }
  }

  if (this->HaveAppleBug &&
      (this->HaveCellNormals || this->HaveCellScalars))
  {
    if (!this->AppleBugPrimIDBuffer)
    {
      this->AppleBugPrimIDBuffer = vtkOpenGLBufferObject::New();
    }
    this->AppleBugPrimIDBuffer->Bind();
    this->AppleBugPrimIDBuffer->Upload(
     this->AppleBugPrimIDs, vtkOpenGLBufferObject::ArrayBuffer);
    this->AppleBugPrimIDBuffer->Release();
  }

  this->VBOBuildTime.Modified();
}

//-------------------------------------------------------------------------
void vtkCompositeMapperHelper2::AppendOneBufferObject(
  vtkRenderer *ren,
  vtkActor *act,
  vtkCompositeMapperHelperData *hdata,
  vtkIdType &voffset,
  std::vector<unsigned char> &newColors,
  std::vector<float> &newNorms
  )
{
  vtkPolyData *poly = hdata->Data;

  // if there are no points then skip this piece
  if (!poly->GetPoints() || poly->GetPoints()->GetNumberOfPoints() == 0)
  {
    return;
  }

  // Get rid of old texture color coordinates if any
  if ( this->ColorCoordinates )
  {
    this->ColorCoordinates->UnRegister(this);
    this->ColorCoordinates = nullptr;
  }
  // Get rid of old texture color coordinates if any
  if ( this->Colors )
  {
    this->Colors->UnRegister(this);
    this->Colors = nullptr;
  }

  // For vertex coloring, this sets this->Colors as side effect.
  // For texture map coloring, this sets ColorCoordinates
  // and ColorTextureMap as a side effect.
  // I moved this out of the conditional because it is fast.
  // Color arrays are cached. If nothing has changed,
  // then the scalars do not have to be regenerted.
  this->MapScalars(poly, 1.0);

  // If we are coloring by texture, then load the texture map.
  if (this->ColorTextureMap)
  {
    if (this->InternalColorTexture == nullptr)
    {
      this->InternalColorTexture = vtkOpenGLTexture::New();
      this->InternalColorTexture->RepeatOff();
    }
    this->InternalColorTexture->SetInputData(this->ColorTextureMap);
  }

  this->HaveCellScalars = false;
  vtkDataArray *c = this->Colors;
  if (this->ScalarVisibility)
  {
    // We must figure out how the scalars should be mapped to the polydata.
    if ( (this->ScalarMode == VTK_SCALAR_MODE_USE_CELL_DATA ||
          this->ScalarMode == VTK_SCALAR_MODE_USE_CELL_FIELD_DATA ||
          this->ScalarMode == VTK_SCALAR_MODE_USE_FIELD_DATA ||
          !poly->GetPointData()->GetScalars() )
         && this->ScalarMode != VTK_SCALAR_MODE_USE_POINT_FIELD_DATA
         && this->Colors)
    {
      this->HaveCellScalars = true;
      c = nullptr;
    }
  }

  this->HaveCellNormals = false;
  // Do we have cell normals?
  vtkDataArray *n =
    (act->GetProperty()->GetInterpolation() != VTK_FLAT) ? poly->GetPointData()->GetNormals() : nullptr;
  if (n == nullptr && poly->GetCellData()->GetNormals())
  {
    this->HaveCellNormals = true;
    n = nullptr;
  }

  int representation = act->GetProperty()->GetRepresentation();
  vtkHardwareSelector* selector = ren->GetSelector();

  if (selector && this->PopulateSelectionSettings &&
      selector->GetFieldAssociation() == vtkDataObject::FIELD_ASSOCIATION_POINTS)
  {
    representation = VTK_POINTS;
  }

  // if we have cell scalars then we have to
  // explode the data
  vtkCellArray *prims[4];
  prims[0] =  poly->GetVerts();
  prims[1] =  poly->GetLines();
  prims[2] =  poly->GetPolys();
  prims[3] =  poly->GetStrips();

  // vert cell offset starts at the end of the last block
  hdata->PrimOffsets[0] = (!newColors.empty() ? newColors.size()/4 : newNorms.size()/4);
  hdata->PrimOffsets[1] = hdata->PrimOffsets[0] +
    prims[0]->GetNumberOfConnectivityEntries() -
    prims[0]->GetNumberOfCells();

  this->AppendCellTextures(ren, act, prims, representation,
    newColors, newNorms, poly);

  hdata->PrimOffsets[2] = hdata->PrimOffsets[1] +
    prims[1]->GetNumberOfConnectivityEntries() -
    2*prims[1]->GetNumberOfCells();

  hdata->PrimOffsets[4] = (!newColors.empty() ? newColors.size()/4 : newNorms.size()/4);

  // we back compute the strip number
  size_t triCount = prims[3]->GetNumberOfConnectivityEntries()
    - 3*prims[3]->GetNumberOfCells();
  hdata->PrimOffsets[3] = hdata->PrimOffsets[4] - triCount;

  // on Apple Macs with the AMD PrimID bug <rdar://20747550>
  // we use a slow painful approach to work around it (pre 10.11).
  if (this->HaveAppleBug &&
      (this->HaveCellNormals || this->HaveCellScalars))
  {
    poly = this->HandleAppleBug(poly, this->AppleBugPrimIDs);
    prims[0] =  poly->GetVerts();
    prims[1] =  poly->GetLines();
    prims[2] =  poly->GetPolys();
    prims[3] =  poly->GetStrips();

#ifndef NDEBUG
    static bool warnedAboutBrokenAppleDriver = false;
    if (!warnedAboutBrokenAppleDriver)
    {
      vtkWarningMacro("VTK is working around a bug in Apple-AMD hardware related to gl_PrimitiveID.  This may cause significant memory and performance impacts. Your hardware has been identified as vendor "
        << (const char *)glGetString(GL_VENDOR) << " with renderer of "
        << (const char *)glGetString(GL_RENDERER) << " and version "
        << (const char *)glGetString(GL_VERSION));
      warnedAboutBrokenAppleDriver = true;
    }
#endif
    if (n)
    {
      n = (act->GetProperty()->GetInterpolation() != VTK_FLAT) ?
            poly->GetPointData()->GetNormals() : nullptr;
    }
    if (c)
    {
      this->Colors->Delete();
      this->Colors = nullptr;
      this->MapScalars(poly,1.0);
      c = this->Colors;
    }
  }


  // do we have texture maps?
  bool haveTextures = (this->ColorTextureMap || act->GetTexture() || act->GetProperty()->GetNumberOfTextures());

  // Set the texture if we are going to use texture
  // for coloring with a point attribute.
  // fixme ... make the existence of the coordinate array the signal.
  vtkDataArray *tcoords = nullptr;
  if (haveTextures)
  {
    if (this->InterpolateScalarsBeforeMapping && this->ColorCoordinates)
    {
      tcoords = this->ColorCoordinates;
    }
    else
    {
      tcoords = poly->GetPointData()->GetTCoords();
    }
  }

  // Check if color array is already computed for the current array.
  // This step is mandatory otherwise the test ArrayExists will fail for "scalarColor" even if
  // the array used to map the color has already been added.
  if (c)
  {
    int cellFlag = 0; // not used
    vtkAbstractArray* abstractArray = this->GetAbstractScalars(poly, this->ScalarMode,
      this->ArrayAccessMode, this->ArrayId, this->ArrayName, cellFlag);

    auto iter = this->ColorArrayMap.find(abstractArray);
    if (iter != this->ColorArrayMap.end())
    {
      c = iter->second;
    }
    else
    {
      this->ColorArrayMap[abstractArray] = c;
      c->Register(this);
    }
  }

  // Build the VBO
  vtkIdType offsetPos = 0;
  vtkIdType offsetNorm = 0;
  vtkIdType offsetColor = 0;
  vtkIdType offsetTex = 0;
  vtkIdType totalOffset = 0;
  vtkIdType dummy = 0;
  bool exists =
    this->VBOs->ArrayExists("vertexMC", poly->GetPoints()->GetData(), offsetPos, totalOffset) &&
    this->VBOs->ArrayExists("normalMC", n, offsetNorm, dummy) &&
    this->VBOs->ArrayExists("scalarColor", c, offsetColor,dummy) &&
    this->VBOs->ArrayExists("tcoord", tcoords, offsetTex, dummy);

  // if all used arrays have the same offset and have already been added,
  // we can reuse them and save memory
  if (exists &&
    (offsetNorm == 0 || offsetPos == offsetNorm) &&
    (offsetColor == 0 || offsetPos == offsetColor) &&
    (offsetTex == 0 || offsetPos == offsetTex))
  {
    voffset = offsetPos;
  }
  else
  {
    this->VBOs->AppendDataArray("vertexMC", poly->GetPoints()->GetData(), VTK_FLOAT);
    this->VBOs->AppendDataArray("normalMC", n, VTK_FLOAT);
    this->VBOs->AppendDataArray("scalarColor", c, VTK_UNSIGNED_CHAR);
    this->VBOs->AppendDataArray("tcoord", tcoords, VTK_FLOAT);

    voffset = totalOffset;
  }

  // now create the IBOs
  vtkOpenGLIndexBufferObject::AppendPointIndexBuffer(
    this->IndexArray[0], prims[0], voffset);

  vtkDataArray *ef = poly->GetPointData()->GetAttribute(
                    vtkDataSetAttributes::EDGEFLAG);

  if (representation == VTK_POINTS)
  {
    vtkOpenGLIndexBufferObject::AppendPointIndexBuffer(
      this->IndexArray[1], prims[1], voffset);

    vtkOpenGLIndexBufferObject::AppendPointIndexBuffer(
      this->IndexArray[2], prims[2], voffset);

    vtkOpenGLIndexBufferObject::AppendPointIndexBuffer(
      this->IndexArray[3], prims[3], voffset);
  }
  else // WIREFRAME OR SURFACE
  {
    vtkOpenGLIndexBufferObject::AppendLineIndexBuffer(
      this->IndexArray[1], prims[1], voffset);

    if (representation == VTK_WIREFRAME)
    {
      if (ef)
      {
        if (ef->GetNumberOfComponents() != 1)
        {
          vtkDebugMacro(<< "Currently only 1d edge flags are supported.");
          ef = nullptr;
        }
        if (ef && !ef->IsA("vtkUnsignedCharArray"))
        {
          vtkDebugMacro(<< "Currently only unsigned char edge flags are supported.");
          ef = nullptr;
        }
      }
      if (ef)
      {
        vtkOpenGLIndexBufferObject::AppendEdgeFlagIndexBuffer(
          this->IndexArray[2], prims[2], voffset, ef);
      }
      else
      {
        vtkOpenGLIndexBufferObject::AppendTriangleLineIndexBuffer(
          this->IndexArray[2], prims[2], voffset);
      }
      vtkOpenGLIndexBufferObject::AppendStripIndexBuffer(
        this->IndexArray[3], prims[3], voffset, true);
    }
    else // SURFACE
    {
      vtkOpenGLIndexBufferObject::AppendTriangleIndexBuffer(
        this->IndexArray[2],
        prims[2],
        poly->GetPoints(),
        voffset);
      vtkOpenGLIndexBufferObject::AppendStripIndexBuffer(
        this->IndexArray[3], prims[3], voffset, false);
    }
  }

  // when drawing edges also build the edge IBOs
  vtkProperty *prop = act->GetProperty();
  bool draw_surface_with_edges =
    (prop->GetEdgeVisibility() && prop->GetRepresentation() == VTK_SURFACE);
  if (draw_surface_with_edges)
  {
    if (ef)
    {
      if (ef->GetNumberOfComponents() != 1)
      {
        vtkDebugMacro(<< "Currently only 1d edge flags are supported.");
        ef = nullptr;
      }
      if (!ef->IsA("vtkUnsignedCharArray"))
      {
        vtkDebugMacro(<< "Currently only unsigned char edge flags are supported.");
        ef = nullptr;
      }
    }
    if (ef)
    {
      vtkOpenGLIndexBufferObject::AppendEdgeFlagIndexBuffer(
        this->IndexArray[4], prims[2], voffset, ef);
    }
    else
    {
      vtkOpenGLIndexBufferObject::AppendTriangleLineIndexBuffer(
        this->IndexArray[4], prims[2], voffset);
    }
    vtkOpenGLIndexBufferObject::AppendStripIndexBuffer(
      this->IndexArray[5], prims[3], voffset, false);
  }

  if (prop->GetVertexVisibility())
  {
    vtkOpenGLIndexBufferObject::AppendVertexIndexBuffer(
      this->IndexArray[PrimitiveVertices], prims, voffset);
  }

  // free up polydata if allocated due to apple bug
  if (poly != hdata->Data)
  {
    poly->Delete();
  }
}

void vtkCompositeMapperHelper2::ProcessSelectorPixelBuffers(
  vtkHardwareSelector *sel,
  std::vector<unsigned int> &pixeloffsets,
  vtkProp *prop)
{
  if (!this->PopulateSelectionSettings)
  {
    return;
  }

  if (sel->GetCurrentPass() == vtkHardwareSelector::ACTOR_PASS)
  {
    this->PickPixels.clear();
    return;
  }

  if (PickPixels.size() == 0 && pixeloffsets.size())
  {
    // preprocess the image to find matching pixels and
    // store them in a map of vectors based on flat index
    // this makes the block processing far faster as we just
    // loop over the pixels for our block
    unsigned char *compositedata =
      sel->GetRawPixelBuffer(vtkHardwareSelector::COMPOSITE_INDEX_PASS);

    if (!compositedata)
    {
      return;
    }

    size_t maxFlatIndex = 0;
    for (dataIter it = this->Data.begin(); it != this->Data.end(); ++it)
    {
      maxFlatIndex = (it->second->FlatIndex > maxFlatIndex) ? it->second->FlatIndex : maxFlatIndex;
    }

    this->PickPixels.resize(maxFlatIndex + 1);

    for (auto pos : pixeloffsets)
    {
      unsigned int compval = compositedata[pos+2];
      compval = compval << 8;
      compval |= compositedata[pos+1];
      compval = compval << 8;
      compval |= compositedata[pos];
      compval -= 1;
      if (compval <= maxFlatIndex)
      {
        this->PickPixels[compval].push_back(pos);
      }
    }
  }

  // for each block update the image
  for (dataIter it = this->Data.begin(); it != this->Data.end(); ++it)
  {
    if (this->PickPixels[it->second->FlatIndex].size())
    {
      this->ProcessCompositePixelBuffers(sel, prop, it->second,
        this->PickPixels[it->second->FlatIndex]);
    }
  }
}

namespace
{
  unsigned int convertToCells(
    unsigned int *offset,
    unsigned int *stride,
    unsigned int inval )
  {
    if (inval < offset[0])
    {
      return inval;
    }
    if (inval < offset[1])
    {
      return offset[0] + (inval - offset[0]) / stride[0];
    }
    return offset[0] + (offset[1] - offset[0]) / stride[0] + (inval - offset[1]) / stride[1];
  }
}

void vtkCompositeMapperHelper2::ProcessCompositePixelBuffers(
  vtkHardwareSelector *sel,
  vtkProp *prop,
  vtkCompositeMapperHelperData *hdata,
  std::vector<unsigned int> &pixeloffsets)
{
  vtkPolyData *poly = hdata->Data;

  if (!poly)
  {
    return;
  }

  // which pass are we processing ?
  int currPass = sel->GetCurrentPass();

  // get some common useful values
  bool pointPicking =
    sel->GetFieldAssociation() == vtkDataObject::FIELD_ASSOCIATION_POINTS;
  vtkPointData *pd = poly->GetPointData();
  vtkCellData *cd = poly->GetCellData();

  // get some values
  unsigned char *rawplowdata = sel->GetRawPixelBuffer(vtkHardwareSelector::POINT_ID_LOW24);
  unsigned char *rawphighdata = sel->GetRawPixelBuffer(vtkHardwareSelector::POINT_ID_HIGH24);

  // do we need to do anything to the process pass data?
  if (currPass == vtkHardwareSelector::PROCESS_PASS)
  {
    unsigned char *processdata = sel->GetPixelBuffer(vtkHardwareSelector::PROCESS_PASS);
    vtkUnsignedIntArray* processArray = nullptr;

    if (sel->GetUseProcessIdFromData())
    {
      processArray = this->ProcessIdArrayName ?
        vtkArrayDownCast<vtkUnsignedIntArray>(
          pd->GetArray(this->ProcessIdArrayName)) : nullptr;
    }

    if (processArray && processdata && rawplowdata)
    {
      for (auto pos : pixeloffsets)
      {
        unsigned int inval = 0;
        if (rawphighdata)
        {
          inval = rawphighdata[pos];
          inval = inval << 8;
        }
        inval |= rawplowdata[pos + 2];
        inval = inval << 8;
        inval |= rawplowdata[pos + 1];
        inval = inval << 8;
        inval |= rawplowdata[pos];
        inval -= 1;
        inval -= hdata->StartVertex;
        unsigned int outval =  processArray->GetValue(inval) + 1;
        processdata[pos] = outval & 0xff;
        processdata[pos + 1] = (outval & 0xff00) >> 8;
        processdata[pos + 2] = (outval & 0xff0000) >> 16;
      }
    }
  }

  // do we need to do anything to the point id data?
  if (currPass == vtkHardwareSelector::POINT_ID_LOW24)
  {
    vtkIdTypeArray* pointArrayId = this->PointIdArrayName ?
      vtkArrayDownCast<vtkIdTypeArray>(
        pd->GetArray(this->PointIdArrayName)) : nullptr;

    // do we need to do anything to the point id data?
    if (rawplowdata)
    {
      unsigned char *plowdata = sel->GetPixelBuffer(vtkHardwareSelector::POINT_ID_LOW24);

      for (auto pos : pixeloffsets)
      {
        unsigned int inval = 0;
        if (rawphighdata)
        {
          inval = rawphighdata[pos];
          inval = inval << 8;
        }
        inval |= rawplowdata[pos + 2];
        inval = inval << 8;
        inval |= rawplowdata[pos + 1];
        inval = inval << 8;
        inval |= rawplowdata[pos];
        inval -= 1;
        inval -= hdata->StartVertex;
        vtkIdType outval =  inval + 1;
        if (pointArrayId)
        {
          outval = pointArrayId->GetValue(inval) + 1;
        }
        plowdata[pos] = outval & 0xff;
        plowdata[pos + 1] = (outval & 0xff00) >> 8;
        plowdata[pos + 2] = (outval & 0xff0000) >> 16;
      }
    }
  }

  if (currPass == vtkHardwareSelector::POINT_ID_HIGH24)
  {
    vtkIdTypeArray *pointArrayId = this->PointIdArrayName ?
      vtkArrayDownCast<vtkIdTypeArray>(
        pd->GetArray(this->PointIdArrayName)) : nullptr;

    // do we need to do anything to the point id data?
    if (rawphighdata)
    {
      unsigned char *phighdata = sel->GetPixelBuffer(vtkHardwareSelector::POINT_ID_HIGH24);

      for (auto pos : pixeloffsets)
      {
        unsigned int inval = 0;
        inval = rawphighdata[pos];
        inval = inval << 8;
        inval |= rawplowdata[pos + 2];
        inval = inval << 8;
        inval |= rawplowdata[pos + 1];
        inval = inval << 8;
        inval |= rawplowdata[pos];
        inval -= 1;
        inval -= hdata->StartVertex;
        vtkIdType outval =  inval + 1;
        if (pointArrayId)
        {
          outval = pointArrayId->GetValue(inval) + 1;
        }
        phighdata[pos] = (outval & 0xff000000) >> 24;
        phighdata[pos + 1] = (outval & 0xff00000000) >> 32;
        phighdata[pos + 2] = (outval & 0xff0000000000) >> 40;
      }
    }
  }

  // vars for cell based indexing
  vtkCellArray *prims[4];
  prims[0] =  poly->GetVerts();
  prims[1] =  poly->GetLines();
  prims[2] =  poly->GetPolys();
  prims[3] =  poly->GetStrips();

  int representation =
    static_cast<vtkActor *>(prop)->GetProperty()->GetRepresentation();

  unsigned char *rawclowdata = sel->GetRawPixelBuffer(vtkHardwareSelector::CELL_ID_LOW24);
  unsigned char *rawchighdata = sel->GetRawPixelBuffer(vtkHardwareSelector::CELL_ID_HIGH24);

  // build the mapping of point primID to cell primID
  // aka when we render triangles in point picking mode
  // how do we map primid to what would normally be primid
  unsigned int offset[2];
  unsigned int stride[2];
  offset[0] = static_cast<unsigned int>(this->Primitives[PrimitiveVertices].IBO->IndexCount);
  stride[0] = representation == VTK_POINTS ? 1 : 2;
  offset[1] = offset[0] + static_cast<unsigned int>(
    this->Primitives[PrimitiveLines].IBO->IndexCount);
  stride[1] = representation == VTK_POINTS ? 1 : representation == VTK_WIREFRAME ? 2 : 3;

  // do we need to do anything to the composite pass data?
  if (currPass == vtkHardwareSelector::COMPOSITE_INDEX_PASS)
  {
    unsigned char *compositedata =
      sel->GetPixelBuffer(vtkHardwareSelector::COMPOSITE_INDEX_PASS);

    vtkUnsignedIntArray *compositeArray = this->CompositeIdArrayName ?
      vtkArrayDownCast<vtkUnsignedIntArray>(
        cd->GetArray(this->CompositeIdArrayName)) : nullptr;

    if (compositedata && compositeArray && rawclowdata)
    {
      this->UpdateCellMaps(this->HaveAppleBug,
        poly,
        prims,
        representation,
        poly->GetPoints());

      for (auto pos : pixeloffsets)
      {
        unsigned int inval = 0;
        if (rawchighdata)
        {
          inval = rawchighdata[pos];
          inval = inval << 8;
        }
        inval |= rawclowdata[pos + 2];
        inval = inval << 8;
        inval |= rawclowdata[pos + 1];
        inval = inval << 8;
        inval |= rawclowdata[pos];
        inval -= 1;
        inval -= static_cast<int>(hdata->PrimOffsets[0]);
        if (pointPicking)
        {
          inval = convertToCells(offset, stride, inval);
        }
        vtkIdType vtkCellId = this->CellCellMap[inval];
        unsigned int outval =  compositeArray->GetValue(vtkCellId) + 1;
        compositedata[pos] = outval & 0xff;
        compositedata[pos + 1] = (outval & 0xff00) >> 8;
        compositedata[pos + 2] = (outval & 0xff0000) >> 16;
      }
    }
  }

  if (currPass == vtkHardwareSelector::CELL_ID_LOW24)
  {
    vtkIdTypeArray *cellArrayId = this->CellIdArrayName ?
      vtkArrayDownCast<vtkIdTypeArray>(
        cd->GetArray(this->CellIdArrayName)) : nullptr;
    unsigned char *clowdata = sel->GetPixelBuffer(vtkHardwareSelector::CELL_ID_LOW24);

    if (rawclowdata)
    {
      this->UpdateCellMaps(this->HaveAppleBug,
        poly,
        prims,
        representation,
        poly->GetPoints());

      for (auto pos : pixeloffsets)
      {
        unsigned int inval = 0;
        if (rawchighdata)
        {
          inval = rawchighdata[pos];
          inval = inval << 8;
        }
        inval |= rawclowdata[pos + 2];
        inval = inval << 8;
        inval |= rawclowdata[pos + 1];
        inval = inval << 8;
        inval |= rawclowdata[pos];
        inval -= 1;
        inval -= static_cast<int>(hdata->PrimOffsets[0]);
        if (pointPicking)
        {
          inval = convertToCells(offset, stride, inval);
        }
        vtkIdType outval = this->CellCellMap[inval];
        if (cellArrayId)
        {
          outval = cellArrayId->GetValue(outval);
        }
        outval++;
        clowdata[pos] = outval & 0xff;
        clowdata[pos + 1] = (outval & 0xff00) >> 8;
        clowdata[pos + 2] = (outval & 0xff0000) >> 16;
      }
    }
  }

  if (currPass == vtkHardwareSelector::CELL_ID_HIGH24)
  {
    vtkIdTypeArray *cellArrayId = this->CellIdArrayName ?
      vtkArrayDownCast<vtkIdTypeArray>(
        cd->GetArray(this->CellIdArrayName)) : nullptr;
    unsigned char *chighdata = sel->GetPixelBuffer(vtkHardwareSelector::CELL_ID_HIGH24);

    if (rawchighdata)
    {
      this->UpdateCellMaps(this->HaveAppleBug,
        poly,
        prims,
        representation,
        poly->GetPoints());

      for (auto pos : pixeloffsets)
      {
        unsigned int inval = 0;
        inval = rawchighdata[pos];
        inval = inval << 8;
        inval |= rawclowdata[pos + 2];
        inval = inval << 8;
        inval |= rawclowdata[pos + 1];
        inval = inval << 8;
        inval |= rawclowdata[pos];
        inval -= 1;
        inval -= static_cast<int>(hdata->PrimOffsets[0]);
        if (pointPicking)
        {
          inval = convertToCells(offset, stride, inval);
        }
        vtkIdType outval = this->CellCellMap[inval];
        if (cellArrayId)
        {
          outval = cellArrayId->GetValue(outval);
        }
        outval++;
        chighdata[pos] = (outval & 0xff000000) >> 24;
        chighdata[pos + 1] = (outval & 0xff00000000) >> 32;
        chighdata[pos + 2] = (outval & 0xff0000000000) >> 40;
      }
    }
  }

}

//===================================================================
// Now the main class methods

vtkStandardNewMacro(vtkCompositePolyDataMapper2);
//----------------------------------------------------------------------------
vtkCompositePolyDataMapper2::vtkCompositePolyDataMapper2()
{
  this->LastOpaqueCheckTime = 0;
  this->CurrentFlatIndex = 0;
  this->LastOpaqueCheckValue = true;
  this->ColorMissingArraysWithNanColor = false;
}

//----------------------------------------------------------------------------
vtkCompositePolyDataMapper2::~vtkCompositePolyDataMapper2()
{
  helpIter miter = this->Helpers.begin();
  for (;miter != this->Helpers.end(); ++miter)
  {
    miter->second->Delete();
  }
  this->Helpers.clear();
}

//----------------------------------------------------------------------------
int vtkCompositePolyDataMapper2::FillInputPortInformation(
  int vtkNotUsed(port), vtkInformation* info)
{
  info->Set(vtkAlgorithm::INPUT_REQUIRED_DATA_TYPE(), "vtkPolyData");
  info->Append(vtkAlgorithm::INPUT_REQUIRED_DATA_TYPE(), "vtkCompositeDataSet");
  return 1;
}

//----------------------------------------------------------------------------
vtkExecutive* vtkCompositePolyDataMapper2::CreateDefaultExecutive()
{
  return vtkCompositeDataPipeline::New();
}

//-----------------------------------------------------------------------------
//Looks at each DataSet and finds the union of all the bounds
void vtkCompositePolyDataMapper2::ComputeBounds()
{
  vtkCompositeDataSet *input = vtkCompositeDataSet::SafeDownCast(
    this->GetInputDataObject(0, 0));

  // If we don't have hierarchical data, test to see if we have
  // plain old polydata. In this case, the bounds are simply
  // the bounds of the input polydata.
  if (!input)
  {
    this->Superclass::ComputeBounds();
    return;
  }

  if (input->GetMTime() < this->BoundsMTime &&
      this->GetMTime() < this->BoundsMTime)
  {
    return;
  }

  // computing bounds with only visible blocks
  vtkCompositeDataDisplayAttributes::ComputeVisibleBounds(
    this->CompositeAttributes, input, this->Bounds);
  this->BoundsMTime.Modified();
}

//-----------------------------------------------------------------------------
bool vtkCompositePolyDataMapper2::GetIsOpaque()
{
  vtkCompositeDataSet *input = vtkCompositeDataSet::SafeDownCast(
    this->GetInputDataObject(0, 0));
  vtkMTimeType lastMTime = std::max(input ? input->GetMTime() : 0, this->GetMTime());
  if (lastMTime <= this->LastOpaqueCheckTime)
  {
    return this->LastOpaqueCheckValue;
  }
  this->LastOpaqueCheckTime = lastMTime;
  if (this->ScalarVisibility && input &&
      (this->ColorMode == VTK_COLOR_MODE_DEFAULT ||
       this->ColorMode == VTK_COLOR_MODE_DIRECT_SCALARS))
  {
    vtkSmartPointer<vtkCompositeDataIterator> iter;
    iter.TakeReference(input->NewIterator());
    for (iter->InitTraversal(); !iter->IsDoneWithTraversal(); iter->GoToNextItem())
    {
      vtkPolyData *pd = vtkPolyData::SafeDownCast(iter->GetCurrentDataObject());
      if (pd)
      {
        int cellFlag;
        vtkDataArray* scalars = this->GetScalars(pd,
          this->ScalarMode, this->ArrayAccessMode, this->ArrayId,
          this->ArrayName, cellFlag);
        if (scalars &&
            (scalars->IsA("vtkUnsignedCharArray")  ||
             this->ColorMode == VTK_COLOR_MODE_DIRECT_SCALARS) &&
            (scalars->GetNumberOfComponents() ==  4 /*(RGBA)*/ ||
             scalars->GetNumberOfComponents() == 2 /*(LuminanceAlpha)*/))
        {
          int opacityIndex = scalars->GetNumberOfComponents() - 1;
          unsigned char opacity = 0;
          switch (scalars->GetDataType())
          {
            vtkTemplateMacro(
              vtkScalarsToColors::ColorToUChar(
                static_cast<VTK_TT>(scalars->GetRange(opacityIndex)[0]),
                &opacity));
          }
          if (opacity < 255)
          {
            // If the opacity is 255, despite the fact that the user specified
            // RGBA, we know that the Alpha is 100% opaque. So treat as opaque.
            this->LastOpaqueCheckValue = false;
            return false;
          }
        }
      }
    }
  }
  else if(this->CompositeAttributes &&
    this->CompositeAttributes->HasBlockOpacities())
  {
    this->LastOpaqueCheckValue = false;
    return false;
  }

  this->LastOpaqueCheckValue = this->Superclass::GetIsOpaque();
  return this->LastOpaqueCheckValue;
}

//----------------------------------------------------------------------------
void vtkCompositePolyDataMapper2::SetBlockVisibility(unsigned int index, bool visible)
{
  if(this->CompositeAttributes)
  {
    unsigned int start_index = 0;
    auto dataObj = vtkCompositeDataDisplayAttributes::DataObjectFromIndex(index,
      this->GetInputDataObject(0, 0), start_index);
    if (dataObj)
    {
      this->CompositeAttributes->SetBlockVisibility(dataObj, visible);
      this->Modified();
    }
  }
}

//----------------------------------------------------------------------------
bool vtkCompositePolyDataMapper2::GetBlockVisibility(unsigned int index)
{
  if(this->CompositeAttributes)
  {
    unsigned int start_index = 0;
    auto dataObj = vtkCompositeDataDisplayAttributes::DataObjectFromIndex(index,
      this->GetInputDataObject(0, 0), start_index);
    if (dataObj)
    {
      return this->CompositeAttributes->GetBlockVisibility(dataObj);
    }
  }

  return true;
}

//----------------------------------------------------------------------------
void vtkCompositePolyDataMapper2::RemoveBlockVisibility(unsigned int index)
{
  if(this->CompositeAttributes)
  {
    unsigned int start_index = 0;
    auto dataObj = vtkCompositeDataDisplayAttributes::DataObjectFromIndex(index,
      this->GetInputDataObject(0, 0), start_index);
    if (dataObj)
    {
      this->CompositeAttributes->RemoveBlockVisibility(dataObj);
      this->Modified();
    }
  }
}

//----------------------------------------------------------------------------
void vtkCompositePolyDataMapper2::RemoveBlockVisibilities()
{
  if(this->CompositeAttributes)
  {
    this->CompositeAttributes->RemoveBlockVisibilities();
    this->Modified();
  }
}

#ifndef VTK_LEGACY_REMOVE
void vtkCompositePolyDataMapper2::RemoveBlockVisibilites()
{
  this->RemoveBlockVisibilities();
}
#endif

//----------------------------------------------------------------------------
void vtkCompositePolyDataMapper2::SetBlockColor(unsigned int index, double color[3])
{
  if(this->CompositeAttributes)
  {
    unsigned int start_index = 0;
    auto dataObj = vtkCompositeDataDisplayAttributes::DataObjectFromIndex(index,
      this->GetInputDataObject(0, 0), start_index);

    if (dataObj)
    {
      this->CompositeAttributes->SetBlockColor(dataObj, color);
      this->Modified();
    }
  }
}

//----------------------------------------------------------------------------
double* vtkCompositePolyDataMapper2::GetBlockColor(unsigned int index)
{
  static double white[3] = {1.0,1.0,1.0};

  if(this->CompositeAttributes)
  {
    unsigned int start_index = 0;
    auto dataObj = vtkCompositeDataDisplayAttributes::DataObjectFromIndex(index,
      this->GetInputDataObject(0, 0), start_index);
    if (dataObj)
    {
      this->CompositeAttributes->GetBlockColor(dataObj, this->ColorResult);
    }

    return this->ColorResult;
  }
  else
  {
    return white;
  }
}

//----------------------------------------------------------------------------
void vtkCompositePolyDataMapper2::RemoveBlockColor(unsigned int index)
{
  if(this->CompositeAttributes)
  {
    unsigned int start_index = 0;
    auto dataObj = vtkCompositeDataDisplayAttributes::DataObjectFromIndex(index,
      this->GetInputDataObject(0, 0), start_index);
    if (dataObj)
    {
      this->CompositeAttributes->RemoveBlockColor(dataObj);
      this->Modified();
    }
  }
}

//----------------------------------------------------------------------------
void vtkCompositePolyDataMapper2::RemoveBlockColors()
{
  if(this->CompositeAttributes)
  {
    this->CompositeAttributes->RemoveBlockColors();
    this->Modified();
  }
}

//----------------------------------------------------------------------------
void vtkCompositePolyDataMapper2::SetBlockOpacity(unsigned int index, double opacity)
{
  if(this->CompositeAttributes)
  {
    unsigned int start_index = 0;
    auto dataObj = vtkCompositeDataDisplayAttributes::DataObjectFromIndex(index,
      this->GetInputDataObject(0, 0), start_index);
    if (dataObj)
    {
      this->CompositeAttributes->SetBlockOpacity(dataObj, opacity);
      this->Modified();
    }
  }
}

//----------------------------------------------------------------------------
double vtkCompositePolyDataMapper2::GetBlockOpacity(unsigned int index)
{
  if(this->CompositeAttributes)
  {
    unsigned int start_index = 0;
    auto dataObj = vtkCompositeDataDisplayAttributes::DataObjectFromIndex(index,
      this->GetInputDataObject(0, 0), start_index);
    if (dataObj)
    {
      return this->CompositeAttributes->GetBlockOpacity(dataObj);
    }
  }
  return 1.;
}

//----------------------------------------------------------------------------
void vtkCompositePolyDataMapper2::RemoveBlockOpacity(unsigned int index)
{
  if(this->CompositeAttributes)
  {
    unsigned int start_index = 0;
    auto dataObj = vtkCompositeDataDisplayAttributes::DataObjectFromIndex(index,
      this->GetInputDataObject(0, 0), start_index);
    if (dataObj)
    {
      this->CompositeAttributes->RemoveBlockOpacity(dataObj);
      this->Modified();
    }
  }
}

//----------------------------------------------------------------------------
void vtkCompositePolyDataMapper2::RemoveBlockOpacities()
{
  if(this->CompositeAttributes)
  {
    this->CompositeAttributes->RemoveBlockOpacities();
    this->Modified();
  }
}

//----------------------------------------------------------------------------
void vtkCompositePolyDataMapper2::SetCompositeDataDisplayAttributes(
  vtkCompositeDataDisplayAttributes *attributes)
{
  if(this->CompositeAttributes != attributes)
  {
    this->CompositeAttributes = attributes;
    this->Modified();
  }
}

//----------------------------------------------------------------------------
vtkCompositeDataDisplayAttributes*
vtkCompositePolyDataMapper2::GetCompositeDataDisplayAttributes()
{
  return this->CompositeAttributes;
}

//----------------------------------------------------------------------------
void vtkCompositePolyDataMapper2::PrintSelf(ostream& os, vtkIndent indent)
{
  this->Superclass::PrintSelf(os, indent);
}

void vtkCompositePolyDataMapper2::CopyMapperValuesToHelper(vtkCompositeMapperHelper2 *helper)
{
  // We avoid PolyDataMapper::ShallowCopy because it copies the input
  helper->vtkMapper::ShallowCopy(this);
  helper->SetPointIdArrayName(this->GetPointIdArrayName());
  helper->SetCompositeIdArrayName(this->GetCompositeIdArrayName());
  helper->SetProcessIdArrayName(this->GetProcessIdArrayName());
  helper->SetCellIdArrayName(this->GetCellIdArrayName());
  helper->ClearAllShaderReplacements();
  helper->SetVertexShaderCode(this->GetVertexShaderCode());
  helper->SetGeometryShaderCode(this->GetGeometryShaderCode());
  helper->SetFragmentShaderCode(this->GetFragmentShaderCode());
  helper->SetStatic(1);
  for (auto& repl : this->UserShaderReplacements)
  {
    const vtkShader::ReplacementSpec& spec = repl.first;
    const vtkShader::ReplacementValue& values = repl.second;

    helper->AddShaderReplacement(spec.ShaderType, spec.OriginalValue, spec.ReplaceFirst,
      values.Replacement, values.ReplaceAll);
  }
}

//-----------------------------------------------------------------------------
void vtkCompositePolyDataMapper2::ReleaseGraphicsResources(vtkWindow* win)
{
  helpIter miter = this->Helpers.begin();
  for (;miter != this->Helpers.end(); ++miter)
  {
    miter->second->ReleaseGraphicsResources(win);
  }
  miter = this->Helpers.begin();
  for (;miter != this->Helpers.end(); ++miter)
  {
    miter->second->Delete();
  }
  this->Helpers.clear();
  this->Modified();
  this->Superclass::ReleaseGraphicsResources(win);
}

// ---------------------------------------------------------------------------
// Description:
// Method initiates the mapping process. Generally sent by the actor
// as each frame is rendered.
void vtkCompositePolyDataMapper2::Render(
  vtkRenderer *ren, vtkActor *actor)
{
  this->RenderedList.clear();

  // Make sure that we have been properly initialized.
  if (ren->GetRenderWindow()->CheckAbortStatus())
  {
    return;
  }

  if (this->GetInputAlgorithm() == nullptr)
  {
    return;
  }

  if (!this->Static)
  {
    this->InvokeEvent(vtkCommand::StartEvent,nullptr);
    this->GetInputAlgorithm()->Update();
    this->InvokeEvent(vtkCommand::EndEvent,nullptr);
  }

  if (this->GetInputDataObject(0, 0) == nullptr)
  {
    vtkErrorMacro(<< "No input!");
    return;
  }

  // the first step is to gather up the polydata based on their
  // signatures (aka have normals, have scalars etc)
  if (this->HelperMTime < this->GetInputDataObject(0, 0)->GetMTime() ||
      this->HelperMTime < this->GetMTime())
  {
    // clear old helpers
    for (helpIter hiter = this->Helpers.begin(); hiter != this->Helpers.end(); ++hiter)
    {
      hiter->second->ClearMark();
    }
    this->HelperDataMap.clear();

    vtkCompositeDataSet *input = vtkCompositeDataSet::SafeDownCast(
      this->GetInputDataObject(0, 0));

    if (input)
    {
      vtkSmartPointer<vtkDataObjectTreeIterator> iter =
        vtkSmartPointer<vtkDataObjectTreeIterator>::New();
      iter->SetDataSet(input);
      iter->SkipEmptyNodesOn();
      iter->VisitOnlyLeavesOn();
      for (iter->InitTraversal(); !iter->IsDoneWithTraversal();
          iter->GoToNextItem())
      {
        unsigned int flatIndex = iter->GetCurrentFlatIndex();
        vtkDataObject *dso = iter->GetCurrentDataObject();
        vtkPolyData *pd = vtkPolyData::SafeDownCast(dso);

        if (!pd || !pd->GetPoints())
        {
          continue;
        }
        int cellFlag = 0;
        bool hasScalars = this->ScalarVisibility &&
          (vtkAbstractMapper::GetAbstractScalars(
            pd, this->ScalarMode, this->ArrayAccessMode,
            this->ArrayId, this->ArrayName,
            cellFlag) != nullptr);

        bool hasNormals =
          (pd->GetPointData()->GetNormals() || pd->GetCellData()->GetNormals());

        bool hasTCoords = (pd->GetPointData()->GetTCoords() != nullptr);

        std::ostringstream toString;
        toString.str("");
        toString.clear();
        toString <<
          'A' << (hasScalars ? 1 : 0) <<
          'B' << (hasNormals ? 1 : 0) <<
          'C' << (hasTCoords ? 1 : 0);

        vtkCompositeMapperHelper2 *helper = nullptr;
        helpIter found = this->Helpers.find(toString.str());
        if (found == this->Helpers.end())
        {
          helper = this->CreateHelper();
          helper->SetParent(this);
          this->Helpers.insert(std::make_pair(toString.str(), helper));
        }
        else
        {
          helper = found->second;
        }
        this->CopyMapperValuesToHelper(helper);
        helper->SetMarked(true);
        this->HelperDataMap[pd] =
          helper->AddData(pd, flatIndex);
      }
    }
    else
    {
      vtkPolyData *pd = vtkPolyData::SafeDownCast(
        this->GetInputDataObject(0, 0));
      if (pd && pd->GetPoints())
      {
        int cellFlag = 0;
        bool hasScalars = this->ScalarVisibility &&
          (vtkAbstractMapper::GetAbstractScalars(
            pd, this->ScalarMode, this->ArrayAccessMode,
            this->ArrayId, this->ArrayName,
            cellFlag) != nullptr);

        bool hasNormals =
          (pd->GetPointData()->GetNormals() || pd->GetCellData()->GetNormals());

        bool hasTCoords = (pd->GetPointData()->GetTCoords() != nullptr);

        std::ostringstream toString;
        toString.str("");
        toString.clear();
        toString <<
          'A' << (hasScalars ? 1 : 0) <<
          'B' << (hasNormals ? 1 : 0) <<
          'C' << (hasTCoords ? 1 : 0);

        vtkCompositeMapperHelper2 *helper = nullptr;
        helpIter found = this->Helpers.find(toString.str());
        if (found == this->Helpers.end())
        {
          helper = this->CreateHelper();
          helper->SetParent(this);
          this->Helpers.insert(std::make_pair(toString.str(), helper));
        }
        else
        {
          helper = found->second;
        }
        this->CopyMapperValuesToHelper(helper);
        helper->SetMarked(true);
        this->HelperDataMap[pd] =
          helper->AddData(pd, 0);
      }
    }

    // delete unused old helpers/data
    for (helpIter hiter = this->Helpers.begin(); hiter != this->Helpers.end(); )
    {
      hiter->second->RemoveUnused();
      if (!hiter->second->GetMarked())
      {
        hiter->second->ReleaseGraphicsResources(ren->GetVTKWindow());
        hiter->second->Delete();
        this->Helpers.erase(hiter++);
      }
      else
      {
        ++hiter;
      }
    }
    this->HelperMTime.Modified();
  }

  // rebuild the render values if needed
  if (this->RenderValuesBuildTime < this->GetMTime() ||
      this->RenderValuesBuildTime < actor->GetProperty()->GetMTime() ||
      this->RenderValuesBuildTime < this->VBOBuildTime ||
      this->RenderValuesBuildTime < this->HelperMTime)
  {
    vtkProperty* prop = actor->GetProperty();

    // Push base-values on the state stack.
    this->BlockState.Visibility.push(true);
    this->BlockState.Pickability.push(true);
    this->BlockState.Opacity.push(prop->GetOpacity());
    this->BlockState.AmbientColor.push(vtkColor3d(prop->GetAmbientColor()));
    this->BlockState.DiffuseColor.push(vtkColor3d(prop->GetDiffuseColor()));
    this->BlockState.SpecularColor.push(vtkColor3d(prop->GetSpecularColor()));

    unsigned int flat_index = 0;
    this->BuildRenderValues(ren, actor,
      this->GetInputDataObject(0, 0), flat_index);

    this->BlockState.Visibility.pop();
    this->BlockState.Pickability.pop();
    this->BlockState.Opacity.pop();
    this->BlockState.AmbientColor.pop();
    this->BlockState.DiffuseColor.pop();
    this->BlockState.SpecularColor.pop();

    this->RenderValuesBuildTime.Modified();
  }

  this->InitializeHelpersBeforeRendering(ren, actor);

  for (helpIter hiter = this->Helpers.begin(); hiter != this->Helpers.end(); ++hiter)
  {
    vtkCompositeMapperHelper2 *helper = hiter->second;
    helper->RenderPiece(ren,actor);

    std::vector<vtkPolyData *> pdl = helper->GetRenderedList();
    for (unsigned int i = 0; i < pdl.size(); ++i)
    {
      this->RenderedList.push_back(pdl[i]);
    }
  }
}

vtkCompositeMapperHelper2 *vtkCompositePolyDataMapper2::CreateHelper()
{
  return vtkCompositeMapperHelper2::New();
}

//-----------------------------------------------------------------------------
void vtkCompositePolyDataMapper2::BuildRenderValues(
  vtkRenderer *renderer,
  vtkActor *actor,
  vtkDataObject *dobj,
  unsigned int &flat_index)
{
  vtkCompositeDataDisplayAttributes* cda = this->GetCompositeDataDisplayAttributes();
  bool overrides_visibility = (cda && cda->HasBlockVisibility(dobj));
  if (overrides_visibility)
  {
    this->BlockState.Visibility.push(cda->GetBlockVisibility(dobj));
  }
  bool overrides_pickability = (cda && cda->HasBlockPickability(dobj));
  if (overrides_pickability)
  {
    this->BlockState.Pickability.push(cda->GetBlockPickability(dobj));
  }

  bool overrides_opacity = (cda && cda->HasBlockOpacity(dobj));
  if (overrides_opacity)
  {
    this->BlockState.Opacity.push(cda->GetBlockOpacity(dobj));
  }

  bool overrides_color = (cda && cda->HasBlockColor(dobj));
  if (overrides_color)
  {
    vtkColor3d color = cda->GetBlockColor(dobj);
    this->BlockState.AmbientColor.push(color);
    this->BlockState.DiffuseColor.push(color);
    this->BlockState.SpecularColor.push(color);
  }

  // Advance flat-index. After this point, flat_index no longer points to this
  // block.
  flat_index++;

  vtkMultiBlockDataSet *mbds = vtkMultiBlockDataSet::SafeDownCast(dobj);
  vtkMultiPieceDataSet *mpds = vtkMultiPieceDataSet::SafeDownCast(dobj);
  if (mbds || mpds)
  {
    unsigned int numChildren = mbds? mbds->GetNumberOfBlocks() :
      mpds->GetNumberOfPieces();
    for (unsigned int cc=0 ; cc < numChildren; cc++)
    {
      vtkDataObject* child = mbds ? mbds->GetBlock(cc) : mpds->GetPiece(cc);
      if (child == nullptr)
      {
        // speeds things up when dealing with nullptr blocks (which is common with
        // AMRs).
        flat_index++;
        continue;
      }
      this->BuildRenderValues(renderer, actor, child, flat_index);
    }
  }
  else
  {
    vtkPolyData *pd = vtkPolyData::SafeDownCast(dobj);
    dataIter dit = this->HelperDataMap.find(pd);
    if (dit != this->HelperDataMap.end())
    {
      vtkCompositeMapperHelperData *helperData = dit->second;
      helperData->Opacity = this->BlockState.Opacity.top();
      helperData->Visibility = this->BlockState.Visibility.top();
      helperData->Pickability = this->BlockState.Pickability.top();
      helperData->AmbientColor = this->BlockState.AmbientColor.top();
      helperData->DiffuseColor = this->BlockState.DiffuseColor.top();
      helperData->OverridesColor = (this->BlockState.AmbientColor.size() > 1);
    }
  }
  if (overrides_color)
  {
    this->BlockState.AmbientColor.pop();
    this->BlockState.DiffuseColor.pop();
    this->BlockState.SpecularColor.pop();
  }
  if (overrides_opacity)
  {
    this->BlockState.Opacity.pop();
  }
  if (overrides_pickability)
  {
    this->BlockState.Pickability.pop();
  }
  if (overrides_visibility)
  {
    this->BlockState.Visibility.pop();
  }
}

//----------------------------------------------------------------------------
void vtkCompositePolyDataMapper2::SetInputArrayToProcess(int idx, vtkInformation* inInfo)
{
  this->Superclass::SetInputArrayToProcess(idx, inInfo);

  // set inputs to helpers
  for (auto& helper : this->Helpers)
  {
    helper.second->SetInputArrayToProcess(idx, inInfo);
  }
}

//----------------------------------------------------------------------------
void vtkCompositePolyDataMapper2::SetInputArrayToProcess(
  int idx, int port, int connection, int fieldAssociation, int attributeType)
{
  this->Superclass::SetInputArrayToProcess(idx, port, connection, fieldAssociation, attributeType);

  // set inputs to helpers
  for (auto& helper : this->Helpers)
  {
    helper.second->SetInputArrayToProcess(idx, port, connection, fieldAssociation, attributeType);
  }
}

//-----------------------------------------------------------------------------
void vtkCompositePolyDataMapper2::SetInputArrayToProcess(
  int idx, int port, int connection, int fieldAssociation, const char* name)
{
  this->Superclass::SetInputArrayToProcess(idx, port, connection, fieldAssociation, name);

  // set inputs to helpers
  for (auto& helper : this->Helpers)
  {
    helper.second->SetInputArrayToProcess(idx, port, connection, fieldAssociation, name);
  }
}

void vtkCompositePolyDataMapper2::ProcessSelectorPixelBuffers(
  vtkHardwareSelector *sel,
  std::vector<unsigned int> &pixeloffsets,
  vtkProp *prop)
{
  // forward to helper
  for (auto& helper : this->Helpers)
  {
    helper.second->ProcessSelectorPixelBuffers(sel, pixeloffsets, prop);
  }
}