vtkBoxWidgetRestricted.cpp

#include <vtkBoxWidgetRestricted.h>

vtkStandardNewMacro(vtkBoxWidgetRestricted);

void vtkBoxWidgetRestricted::Rotate(int X, int Y, double *p1, double *p2, double *vpn){
    double *pts =
            static_cast<vtkDoubleArray *>(this->Points->GetData())->GetPointer(0);
    double *center =
            static_cast<vtkDoubleArray *>(this->Points->GetData())->GetPointer(3*14);
    double v[3]; //vector of motion
    //        double axis[3]; //axis of rotation
    double theta; //rotation angle
    int i;

    v[0] = p2[0] - p1[0];
    v[1] = p2[1] - p1[1];
    v[2] = p2[2] - p1[2];

    // Create axis of rotation and angle of rotation
    // compute the vector which perpendicular to Z axis in current view
    double z[3]={0,0,1}; //restrict to Z rotation
    double m[3];
    vtkMath::Cross(z,vpn,m);
    if ( vtkMath::Normalize(m) == 0.0 ||  vtkMath::Normalize(v) == 0.0)
    {
        return;
    }
    // alpha is the angle between the motion vector and vector m
    double cos_alpha=vtkMath::Dot(m,v);
//    std::cout<<cos_alpha<<endl;
    int *size = this->CurrentRenderer->GetSize();
    double l2 = (X-this->Interactor->GetLastEventPosition()[0])*(X-this->Interactor->GetLastEventPosition()[0]) + (Y-this->Interactor->GetLastEventPosition()[1])*(Y-this->Interactor->GetLastEventPosition()[1]);
    theta = 360.0 * cos_alpha *sqrt(l2/(size[0]*size[0]+size[1]*size[1]));

    //Manipulate the transform to reflect the rotation
    this->Transform->Identity();
    this->Transform->Translate(center[0],center[1],center[2]);
    this->Transform->RotateZ(theta);
    this->Transform->Translate(-center[0],-center[1],-center[2]);

    //Set the corners
    vtkPoints *newPts = vtkPoints::New(VTK_DOUBLE);
    this->Transform->TransformPoints(this->Points,newPts);

    for (i=0; i<8; i++, pts+=3)
    {
        this->Points->SetPoint(i, newPts->GetPoint(i));
    }

    newPts->Delete();
    this->PositionHandles();
}