Method DrawLines

Rendering/ContextOpenGL2/vtkOpenGLContextDevice2D.cxx:839–985

------------------------------------------------------------------------------

//------------------------------------------------------------------------------
void vtkOpenGLContextDevice2D::DrawLines(float* f, int n, unsigned char* colors, int nc)
{
  assert("f must be non-null" && f != nullptr);
  assert("n must be greater than 0" && n > 0);

  if (SkipDraw())
  {
    return;
  }

  if (this->Pen->GetLineType() == vtkPen::NO_PEN)
  {
    return;
  }

  // Skip transparent elements.
  if (!colors && this->Pen->GetColorObject().GetAlpha() == 0)
  {
    return;
  }

  vtkOpenGLClearErrorMacro();

  this->SetLineType(this->Pen->GetLineType());

  vtkOpenGLHelper* cbo = nullptr;
  if (colors)
  {
    this->ReadyLinesCBOProgram();
    cbo = this->LinesCBO;
  }
  else
  {
    this->ReadyLinesBOProgram();
    cbo = this->LinesBO;
    if (!cbo->Program)
    {
      return;
    }
    cbo->Program->SetUniform4uc("vertexColor", this->Pen->GetColor());
  }
  if (!cbo->Program)
  {
    return;
  }

  cbo->Program->SetUniformi("stipple", this->LinePattern);

  this->SetMatrices(cbo->Program);

  // for line stipple we need to compute the scaled
  // cumulative linear distance
  double* scale = this->ModelMatrix->GetScale();
  std::vector<float> distances;
  distances.resize(n * 2);
  float totDist = 0.0;
  distances[0] = 0.0;
  for (int i = 1; i < n; i++)