Method AppendCellTextures

Rendering/OpenGL2/vtkOpenGLPolyDataMapper.cxx:3799–3859

------------------------------------------------------------------------------ create the cell scalar array adjusted for ogl Cells

//------------------------------------------------------------------------------
// create the cell scalar array adjusted for ogl Cells
void vtkOpenGLPolyDataMapper::AppendCellTextures(vtkRenderer* /*ren*/, vtkActor*,
  vtkCellArray* prims[4], int representation, std::vector<unsigned char>& newColors,
  std::vector<float>& newNorms, vtkPolyData* poly, vtkOpenGLCellToVTKCellMap* ccmap)
{
  vtkPoints* points = poly->GetPoints();

  if (this->HaveCellScalars || this->HaveCellNormals)
  {
    ccmap->Update(prims, representation, points);

    if (this->HaveCellScalars)
    {
      int numComp = this->Colors->GetNumberOfComponents();
      unsigned char* colorPtr = this->Colors->GetPointer(0);
      assert(numComp == 4);
      newColors.reserve(numComp * ccmap->GetSize());
      // use a single color value?
      if (this->FieldDataTupleId > -1 && this->ScalarMode == VTK_SCALAR_MODE_USE_FIELD_DATA)
      {
        for (size_t i = 0; i < ccmap->GetSize(); i++)
        {
          for (int j = 0; j < numComp; j++)
          {
            newColors.push_back(colorPtr[this->FieldDataTupleId * numComp + j]);
          }
        }
      }
      else
      {
        for (size_t i = 0; i < ccmap->GetSize(); i++)
        {
          for (int j = 0; j < numComp; j++)
          {
            newColors.push_back(colorPtr[ccmap->GetValue(i) * numComp + j]);
          }
        }
      }
    }

    if (this->HaveCellNormals)
    {
      // create the cell scalar array adjusted for ogl Cells
      vtkDataArray* n = poly->GetCellData()->GetNormals();
      // Allocate memory to allow for faster direct access methods instead of using push_back to
      // populate the array.
      size_t nnSize = newNorms.size(); // Composite mappers can already have values in the array
      newNorms.resize(nnSize + 4 * ccmap->GetSize(), 0.0f);
      for (size_t i = 0; i < ccmap->GetSize(); i++)
      {
        // RGB32F requires a later version of OpenGL than 3.2
        // with 3.2 we know we have RGBA32F hence the extra value
        double* norms = n->GetTuple(ccmap->GetValue(i));
        newNorms[nnSize + i * 4 + 0] = (norms[0]);
        newNorms[nnSize + i * 4 + 1] = (norms[1]);
        newNorms[nnSize + i * 4 + 2] = (norms[2]);
        /* newNorms[nnSize + i * 4 + 3] = (0); */
        // Don't set the final value because it is already set faster by the vector resize above.
      }