vtkScalarBarActor in WebAssembly

Web
21

@ken-martin That is funny because that is exactly how I got my code to work. I just thought maybe I should stick with the same #defines used in the vtkTextureObject. Below is the function as I used it:

void vtkScalarBarActor::ConfigureScalarBar()
{
vtkScalarsToColors* lut = this->LookupTable;
const double* range = lut->GetRange();
this->P->NumColors =
lut->GetIndexedLookup() ? lut->GetNumberOfAnnotatedValues() : this->MaximumNumberOfColors;
this->P->NumSwatches = this->P->NumColors + (this->DrawNanAnnotation ? 1 : 0);
int numPts = 2 * (this->P->NumColors + 1) + (this->DrawNanAnnotation ? 4 : 0);

this->P->NumSwatches = this->P->NumColors + (this->DrawBelowRangeSwatch ? 1 : 0);
numPts += (this->DrawBelowRangeSwatch ? 4 : 0);

this->P->SwatchPts = vtkPoints::New();
this->P->SwatchPts->SetNumberOfPoints(numPts);
this->P->Polys = vtkCellArray::New();
this->P->Polys->AllocateEstimate(this->P->NumSwatches, 4);
this->P->SwatchColors = vtkUnsignedCharArray::New();

unsigned int nComponents = ((this->UseOpacity) ? 4 : 3);
this->P->SwatchColors->SetNumberOfComponents(nComponents);
if (!this->UseColorBarPointScalars)
{
this->P->SwatchColors->SetNumberOfTuples(this->P->NumSwatches);
}
else
{
this->P->SwatchColors->SetNumberOfTuples(numPts);
}

this->ScalarBarActor->SetProperty(this->GetProperty());
this->ScalarBar->Initialize();
this->ScalarBar->SetPoints(this->P->SwatchPts);
this->ScalarBar->SetPolys(this->P->Polys);
if (!this->UseColorBarPointScalars)
{
this->ScalarBar->GetCellData()->SetScalars(this->P->SwatchColors);
}
else
{
this->ScalarBar->GetPointData()->SetScalars(this->P->SwatchColors);
}
this->P->SwatchPts->Delete();
this->P->Polys->Delete();
this->P->SwatchColors->Delete();

double delta = static_cast(this->P->ScalarBarBox.Size[1]) / this->P->NumColors;
double x[3];
x[2] = 0.;
for (int i = 0; i < numPts / 2 - (this->DrawNanAnnotation ? 2 : 0) - (this->DrawBelowRangeSwatch ? 2 : 0); ++i)
{
x[this->P->TL[0]] = this->P->ScalarBarBox.Posn[this->P->TL[0]];
x[this->P->TL[1]] = this->P->ScalarBarBox.Posn[this->P->TL[1]] + i * delta;
this->P->SwatchPts->SetPoint(2 * i, x);

x[this->P->TL[0]] = this->P->ScalarBarBox.Posn[this->P->TL[0]] + this->P->ScalarBarBox.Size[0];
this->P->SwatchPts->SetPoint(2 * i + 1, x);

}

// polygons & cell colors
unsigned char* rgb;
double rgba[4];
vtkIdType ptIds[4];
for (int i = 0; i < this->P->NumColors; ++i)
{
ptIds[0] = 2 * i;
ptIds[1] = ptIds[0] + 1;
ptIds[2] = ptIds[1] + 2;
ptIds[3] = ptIds[0] + 2;
this->P->Polys->InsertNextCell(4, ptIds);

double rgbval;
if (this->LookupTable->UsingLogScale())
{
  rgbval = log10(range[0]) + i * (log10(range[1]) - log10(range[0])) / this->P->NumColors;
  rgbval = pow(10.0, rgbval);
}
else
{
  rgbval = range[0] + (range[1] - range[0]) * (i / static_cast<double>(this->P->NumColors));
}
lut->GetColor(rgbval, rgba);
rgba[3] = lut->GetOpacity(rgbval);

// write into array directly

if (!this->UseColorBarPointScalars)
{
rgb = this->P->SwatchColors->GetPointer(nComponents * i);
rgb[0] = static_cast(rgba[0] * 255.);
rgb[1] = static_cast(rgba[1] * 255.);
rgb[2] = static_cast(rgba[2] * 255.);
if (this->P->SwatchColors->GetNumberOfComponents() > 3)
{
rgb[3] = static_cast(this->UseOpacity ? rgba[3] * 255. : 255.);
}
}
else
{

  rgb = this->P->SwatchColors->GetPointer(nComponents * (i * 2));
  rgb[0] = static_cast<unsigned char>(rgba[0] * 255.);
  rgb[1] = static_cast<unsigned char>(rgba[1] * 255.);
  rgb[2] = static_cast<unsigned char>(rgba[2] * 255.);
  if (this->P->SwatchColors->GetNumberOfComponents() > 3)
  {
  	rgb[3] = static_cast<unsigned char>(this->UseOpacity ? rgba[3] * 255. : 255.);
  }

  rgb = this->P->SwatchColors->GetPointer(nComponents * (i * 2 + 1));
  rgb[0] = static_cast<unsigned char>(rgba[0] * 255.);
  rgb[1] = static_cast<unsigned char>(rgba[1] * 255.);
  rgb[2] = static_cast<unsigned char>(rgba[2] * 255.);
  if (this->P->SwatchColors->GetNumberOfComponents() > 3)
  {
  	rgb[3] = static_cast<unsigned char>(this->UseOpacity ? rgba[3] * 255. : 255.);
  }

}

}

// Set up a texture actor as an alternative to the 1-quad-per-color
// scalar bar polydata.
vtkPoints* texturePoints = vtkPoints::New();
texturePoints->SetNumberOfPoints(4);
this->TexturePolyData->SetPoints(texturePoints);
texturePoints->SetPoint(0, 0.0, 0.0, 0.0);

double p1[2], p2[2];
p1[0] = this->P->ScalarBarBox.Posn[0];
p1[1] = this->P->ScalarBarBox.Posn[1];
p2[0] = p1[0] + this->P->ScalarBarBox.Size[this->P->TL[0]];
p2[1] = p1[1] + this->P->ScalarBarBox.Size[this->P->TL[1]];

texturePoints->SetPoint(0, p1[0], p1[1], 0.0);
texturePoints->SetPoint(1, p2[0], p1[1], 0.0);
texturePoints->SetPoint(2, p2[0], p2[1], 0.0);
texturePoints->SetPoint(3, p1[0], p2[1], 0.0);
texturePoints->Delete();

double barWidth = this->P->ScalarBarBox.Size[this->P->TL[0]];
double barHeight = this->P->ScalarBarBox.Size[this->P->TL[1]];
vtkDataArray* tc = this->TexturePolyData->GetPointData()->GetTCoords();
tc->SetTuple2(1, barWidth / this->TextureGridWidth, 0.0);
tc->SetTuple2(2, barWidth / this->TextureGridWidth, barHeight / this->TextureGridWidth);
tc->SetTuple2(3, 0.0, barHeight / this->TextureGridWidth);
}

Here is what I added to the header file:

//@{
/**

  • Set to true to use point scalars on the scalar bar polydata.
  • If set to false the scalar bar polydata will use cell scalars.
  • For use in WebGL and OPENGL ES this must be set to true.
  • [Default: off]
    */
    vtkSetMacro(UseColorBarPointScalars, vtkTypeBool);
    vtkGetMacro(UseColorBarPointScalars, vtkTypeBool);
    vtkBooleanMacro(UseColorBarPointScalars, vtkTypeBool);
    //@}

Thanks!

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