vtkBoxWidgetRestricted.cpp

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// ----------------------------------------------------------------------------
// -                        CloudViewer: www.cloudViewer.org                  -
// ----------------------------------------------------------------------------
// Copyright (c) 2018-2024 www.cloudViewer.org
// SPDX-License-Identifier: MIT
// ----------------------------------------------------------------------------
 
#include "vtkBoxWidgetRestricted.h"
 
#include <vtkDoubleArray.h>
#include <vtkMath.h>
#include <vtkPoints.h>
#include <vtkRenderWindowInteractor.h>
#include <vtkRenderer.h>
#include <vtkTransform.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 Y axis in current view
    double y[3] = {0, 1, 0};  // restrict to y rotation
    double m[3];
    vtkMath::Cross(y, 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);
    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->RotateY(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();
}