Method ComputeInteractionState

Interaction/Widgets/vtkLineRepresentation.cxx:535–597

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int vtkLineRepresentation::ComputeInteractionState(int x, int y, int vtkNotUsed(modify))
{
  // Check if we are on end points. Use the handles to determine this.
  int p1State = this->Point1Representation->ComputeInteractionState(x, y, 0);
  int p2State = this->Point2Representation->ComputeInteractionState(x, y, 0);
  if (p1State == vtkHandleRepresentation::Nearby)
  {
    this->InteractionState = vtkLineRepresentation::OnP1;
    this->SetRepresentationState(vtkLineRepresentation::OnP1);
  }
  else if (p2State == vtkHandleRepresentation::Nearby)
  {
    this->InteractionState = vtkLineRepresentation::OnP2;
    this->SetRepresentationState(vtkLineRepresentation::OnP2);
  }
  else
  {
    this->InteractionState = vtkLineRepresentation::Outside;
  }

  // Okay if we're near a handle return, otherwise test the line
  if (this->InteractionState != vtkLineRepresentation::Outside)
  {
    return this->InteractionState;
  }

  // Check if we are on edges
  double pos1[3], pos2[3];
  this->GetPoint1DisplayPosition(pos1);
  this->GetPoint2DisplayPosition(pos2);

  double p1[3], p2[3], xyz[3];
  double t, closest[3];
  xyz[0] = static_cast<double>(x);
  xyz[1] = static_cast<double>(y);
  p1[0] = pos1[0];
  p1[1] = pos1[1];
  p2[0] = pos2[0];
  p2[1] = pos2[1];
  xyz[2] = p1[2] = p2[2] = 0.0;

  double tol2 = this->Tolerance * this->Tolerance;

  int onLine = (vtkLine::DistanceToLine(xyz, p1, p2, t, closest) <= tol2);
  if (onLine && t < 1.0 && t > 0.0)
  {
    this->InteractionState = vtkLineRepresentation::OnLine;
    this->SetRepresentationState(vtkLineRepresentation::OnLine);
    this->GetPoint1WorldPosition(pos1);
    this->GetPoint2WorldPosition(pos2);

    this->LinePicker->Pick(x, y, 0.0, this->Renderer);
    this->LinePicker->GetPickPosition(closest);
    this->LineHandleRepresentation->SetWorldPosition(closest);
  }
  else
  {
    this->InteractionState = vtkLineRepresentation::Outside;