C++ ON_Line::Length方法代码示例

int ON_Intersect( // returns 0 = no intersections, 
                  // 1 = one intersection, 
                  // 2 = 2 intersections
                  // 3 = line lies on cylinder
                  // If 0 is returned, first point is point 
                  // on line closest to cylinder and 2nd point is the point
                  // on the sphere closest to the line.
                  // If 1 is returned, first point is obtained by evaluating
                  // the line and the second point is obtained by evaluating
                  // the cylinder.
                  const ON_Line& line, 
                  const ON_Cylinder& cylinder, // if cylinder.height[0]==cylinder.height[1],
                                               // then infinite cyl is used.  Otherwise
                                               // finite cyl is used.
                  ON_3dPoint& A, ON_3dPoint& B // intersection point(s) returned here
                  )
{
  ON_BOOL32 bFiniteCyl = true;
  int rc = 0;
  const double cylinder_radius = fabs(cylinder.circle.radius);
  double tol = cylinder_radius*ON_SQRT_EPSILON;
  if ( tol < ON_ZERO_TOLERANCE )
    tol = ON_ZERO_TOLERANCE;

  ON_Line axis;
  axis.from = cylinder.circle.plane.origin + cylinder.height[0]*cylinder.circle.plane.zaxis;
  axis.to   = cylinder.circle.plane.origin + cylinder.height[1]*cylinder.circle.plane.zaxis;
  if ( axis.Length() <= tol ) {
    axis.to = cylinder.circle.plane.origin + cylinder.circle.plane.zaxis;
    bFiniteCyl = false;
  }


  //ON_BOOL32 bIsParallel = false;
  double line_t, axis_t;
  if ( !ON_Intersect(line,axis,&line_t,&axis_t) ) {
    axis.ClosestPointTo( cylinder.circle.plane.origin, &axis_t );
    line.ClosestPointTo( cylinder.circle.plane.origin, &line_t );
  }
  ON_3dPoint line_point = line.PointAt(line_t);
  ON_3dPoint axis_point = axis.PointAt(axis_t);
  double d = line_point.DistanceTo(axis_point);
  if ( bFiniteCyl ) {
    if ( axis_t < 0.0 )
      axis_t = 0.0;
    else if ( axis_t > 1.0 )
      axis_t = 1.0;
    axis_point = axis.PointAt(axis_t);
  }
  
  if ( d >= cylinder_radius-tol) {
    rc = ( d <= cylinder_radius+tol ) ? 1 : 0;
    A = line_point;
    ON_3dVector V = line_point - axis_point;
    if ( bFiniteCyl ) {
      V = V - (V*cylinder.circle.plane.zaxis)*cylinder.circle.plane.zaxis;
    }
    V.Unitize();
    B = axis_point + cylinder_radius*V;
    if ( rc == 1 ) {
      // check for overlap
      ON_3dPoint P = axis.ClosestPointTo(line.from);
      d = P.DistanceTo(line.from);
      if ( fabs(d-cylinder_radius) <= tol ) {
        P = axis.ClosestPointTo(line.to);
        d = P.DistanceTo(line.to);
        if ( fabs(d-cylinder_radius) <= tol ) {
          rc = 3;
          A = cylinder.ClosestPointTo(line.from);
          B = cylinder.ClosestPointTo(line.to);
        }
      }
    }
  }
  else {
    // transform to coordinate system where equation of cyl
    // is x^2 + y^2 = R^2 and solve for line parameter(s).
    ON_Xform xform;
    xform.Rotation( cylinder.circle.plane, ON_xy_plane );
    ON_Line L = line;
    L.Transform(xform);

    const double x0 = L.from.x;
    const double x1 = L.to.x;
    const double x1mx0 = x1-x0;
    double ax = x1mx0*x1mx0;
    double bx = 2.0*x1mx0*x0;
    double cx = x0*x0;

    const double y0 = L.from.y;
    const double y1 = L.to.y;
    const double y1my0 = y1-y0;
    double ay = y1my0*y1my0;
    double by = 2.0*y1my0*y0;
    double cy = y0*y0;

    double t0, t1;
    int qerc = ON_SolveQuadraticEquation(ax+ay, bx+by, cx+cy-cylinder_radius*cylinder_radius,
                                         &t0,&t1);
    if ( qerc == 2 ) {
//.........这里部分代码省略.........

CRhinoCommand::result CCommandSampleCageEdit::RunCommand( const CRhinoCommandContext& context )
{
  ON_Workspace ws;
  CRhinoCommand::result rc = CRhinoCommand::success;
 
  // Get the captive object
  CRhinoGetObject go;
  go.SetCommandPrompt( L"Select captive surface or polysurface" );
  go.SetGeometryFilter( CRhinoGetObject::surface_object | CRhinoGetObject::polysrf_object );
  go.GetObjects( 1, 1 );
  rc = go.CommandResult();
  if( CRhinoCommand::success != rc )
    return rc;
 
  const CRhinoObject* captive = go.Object(0).Object();
  if( 0 == captive )
    return CRhinoCommand::failure;
 
  // Define the control line
  ON_Line line;
  CArgsRhinoGetLine args;
  rc = RhinoGetLine( args, line );
  if( CRhinoCommand::success != rc )
    return rc;
 
  // Get the curve parameters
  int degree = 3;
  int cv_count = 4;
  for(;;)
  {
    CRhinoGetOption gl;
    gl.SetCommandPrompt( L"NURBS Parameters" );
    gl.AcceptNothing();
    int d_opt = gl.AddCommandOptionInteger( RHCMDOPTNAME(L"Degree"), &degree, L"Curve degree", 1.0, 100.0 );
    int p_opt = gl.AddCommandOptionInteger( RHCMDOPTNAME(L"PointCount"), &cv_count, L"Number of control points", 2.0, 100.0 );
    gl.GetOption();
    rc = gl.CommandResult();
    if( CRhinoCommand::success != rc )
      return rc;
 
    if( CRhinoGet::nothing == gl.Result() )
      break;
 
    if( cv_count <= degree )
    {
      if( CRhinoGet::option != gl.Result() )
        continue;
      const CRhinoCommandOption* opt = go.Option();
      if( 0 == opt )
        continue;
      if( d_opt == opt->m_option_index )
        cv_count = degree + 1;
      else 
        degree = cv_count - 1;
    }
  }
 
  // Set up morph control
  ON_MorphControl* control = new ON_MorphControl();
  control->m_varient = 1; // 1= curve
 
  // Specify the source line curve
  control->m_nurbs_curve0.Create( 3, false, 2, 2 );
  control->m_nurbs_curve0.MakeClampedUniformKnotVector();
  control->m_nurbs_curve0.SetCV( 0, line.from );
  control->m_nurbs_curve0.SetCV( 1, line.to );
 
  // Specify the destination NURBS curve
  control->m_nurbs_curve.Create( 3, false, degree + 1, cv_count );
  control->m_nurbs_curve.MakeClampedUniformKnotVector();
  double* g = ws.GetDoubleMemory( control->m_nurbs_curve.m_cv_count );
  control->m_nurbs_curve.GetGrevilleAbcissae( g );
  ON_Interval d = control->m_nurbs_curve.Domain();
  double s = 0.0;
  int i;
  for( i = 0; i < control->m_nurbs_curve.m_cv_count; i++ )
  {
    s = d.NormalizedParameterAt( g[i] );
    control->m_nurbs_curve.SetCV( i, line.PointAt(s) );
  }
 
  // Make sure domains match
  s = line.Length();
  if( s > ON_SQRT_EPSILON )
    control->m_nurbs_curve0.SetDomain( 0.0, s );
  d = control->m_nurbs_curve0.Domain();
  control->m_nurbs_curve.SetDomain( d[0], d[1] );
 
  // Create the morph control object
  CRhinoMorphControl* control_object = new CRhinoMorphControl();
  control_object->SetControl( control );
  context.m_doc.AddObject( control_object );
 
  // Set up the capture
  RhinoCaptureObject( control_object, const_cast<CRhinoObject*>(captive) );
 
  // Clean up display
  context.m_doc.UnselectAll();
 
  // Turn on the control grips
//.........这里部分代码省略.........