opennurbs_plane.h

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/* $NoKeywords: $ */
/*
//
// Copyright (c) 1993-2012 Robert McNeel & Associates. All rights reserved.
// OpenNURBS, Rhinoceros, and Rhino3D are registered trademarks of Robert
// McNeel & Associates.
//
// THIS SOFTWARE IS PROVIDED "AS IS" WITHOUT EXPRESS OR IMPLIED WARRANTY.
// ALL IMPLIED WARRANTIES OF FITNESS FOR ANY PARTICULAR PURPOSE AND OF
// MERCHANTABILITY ARE HEREBY DISCLAIMED.
//                              
// For complete openNURBS copyright information see <http://www.opennurbs.org>.
//
*/

#if !defined(ON_PLANE_INC_)
#define ON_PLANE_INC_

class ON_CLASS ON_Plane
{
public:

  /*
  Description:
    The default constructor creates a plane
    with orgin=(0,0,0), xaxis=(1,0,0), yaxis=(0,1,0)
    zaxis=(0,0,1), and equation=(0,0,1,0).
  */
  ON_Plane();

  /*
  Description:
    Construct a plane from a point and normal vector.
  Parameters:
    origin - [in] point on the plane
    normal - [in] non-zero normal to the plane
  Remarks:
    origin = point, zaxis = unitized normal, xaxis
    xaxis set with xaxis.PerpindicularTo(zaxis).
  See Also:
    ON_Plane::CreateFromNormal
  */
  ON_Plane(
    const ON_3dPoint& origin,
    const ON_3dVector& normal
    );

  /*
  Description:
    Construct a plane from a point, and two vectors in
    the plane.
  Parameters:
    origin - [in] point on the plane
    x_dir - [in] non-zero vector in the plane that
        determines the xaxis direction.
    y_dir - [in] non-zero vector not parallel to x_dir
        that is used to determine the yaxis direction.
        y_dir does not have to be perpendicular to x_dir.
  */
  ON_Plane(
    const ON_3dPoint& origin,
    const ON_3dVector& x_dir,
    const ON_3dVector& y_dir
    );

  /*
  Description:
    Construct a plane from three non-colinear points.
  Parameters:
    origin - [in] point on the plane
    x_point - [in] second point in the plane.
        The xaxis will be parallel to x_point-origin.
    y_point - [in] third point on the plane that is
        not colinear with the first two points.
        yaxis*(y_point-origin) will be > 0.
  */
  ON_Plane(
    const ON_3dPoint& origin,
    const ON_3dPoint& x_point,
    const ON_3dPoint& y_point
    );

  /*
  Description:
    Construct a plane from an equation.
  Parameters:
    equation - [in] an array of 4 doubles with
       one of equation[0], equation[1], or equation[2]
       being non-zero.
  */
  ON_Plane(
    const double equation[4]
    );

  ~ON_Plane();

  bool operator==(const ON_Plane&) const;
  bool operator!=(const ON_Plane&) const;

  /*
  Description:
    Create a plane from a point and normal vector.
  Parameters:
    origin - [in] point on the plane
    normal - [in] non-zero normal to the plane
  Remarks:
    origin = point, zaxis = unitized normal, xaxis
    xaxis set with xaxis.PerpindicularTo(zaxis).
  Returns:
    true if valid plane is created.
  */
  bool CreateFromNormal(
    const ON_3dPoint& origin,
    const ON_3dVector& normal
    );

  /*
  Description:
    Construct a plane from a point, and two vectors in
    the plane.
  Parameters:
    origin - [in] point on the plane
    x_dir - [in] non-zero vector in the plane that
        determines the xaxis direction.
    y_dir - [in] non-zero vector not parallel to x_dir
        that is used to determine the yaxis direction.
        y_dir does not have to be perpendicular to x_dir.
  Returns:
    true if valid plane is created.
  */
  bool CreateFromFrame(
    const ON_3dPoint& origin,
    const ON_3dVector& x_dir,
    const ON_3dVector& y_dir
    );

  /*
  Description:
    Construct a plane from three non-colinear points.
  Parameters:
    origin - [in] point on the plane
    point_on_x - [in] second point in the plane.
        The xaxis will be parallel to x_point-origin.
    point_on - [in] third point on the plane that is
        not colinear with the first two points.
        yaxis*(y_point-origin) will be > 0.
  Returns:
    true if valid plane is created.
  */
  bool CreateFromPoints(
    const ON_3dPoint& origin,
    const ON_3dPoint& point_on_x,
    const ON_3dPoint& point_on
    );

  /*
  Description:
    Construct a plane from an equation.
  Parameters:
    equation - [in] an array of 4 doubles with
       one of equation[0], equation[1], or equation[2]
       being non-zero.
  Remarks:
    points on the plane will satisfy 
    x*equation[0] +y*equation[1] + z*equation[2] + equation[3] = 0
  Returns:
    true if valid plane is created.
  */
  bool CreateFromEquation( 
    const double equation[4]
    );

  /*
  Description:
    Test plane to see if it is valid.
  Returns:
    true if all fields contain reasonable
    information and equation jibes with point and zaxis.
  */
  bool IsValid() const;

  /*
  Returns:
    Plane origin.
  */
  const ON_3dPoint& Origin() const;

  /*
  Returns:
    Plane unit x-axis.
  */
  const ON_3dVector& Xaxis() const;

  /*
  Returns:
    Plane unit y-axis.
  */
  const ON_3dVector& Yaxis() const;

  /*
  Returns:
    Plane unit normal.
  */
  const ON_3dVector& Normal() const;


  /*
  Description:
    Set the origin and update the plane equation
  Parameters:
    origin - [in] the new origin
  */
  void SetOrigin( const ON_3dPoint& origin );
  
  /*
  Description:
    Evaluate a point on the plane
  Parameters:
    u - [in]
    v - [in] evaulation parameters
  Returns:
    plane.origin + u*plane.xaxis + v*plane.yaxis
  */
  ON_3dPoint PointAt(
    double u,
    double v
    ) const;

  /*
  Description:
    Evaluate a point on the plane
  Parameters:
    u - [in]
    v - [in] evaluation parameters
    w - [in] elevation parameter
  Returns:
    plane.origin + u*plane.xaxis + v*plane.yaxis + z*plane.zaxis
  */
  ON_3dPoint PointAt(
    double u,
    double v,
    double w
    ) const;

  /*
  Description:
    Get an isoparameteric line on the plane.
  Parameters:
    dir - [in] direction of iso-parametric line
        0: first parameter varies and second parameter is constant
           e.g., line(t) = plane(t,c)
        1: first parameter is constant and second parameter varies
           e.g., line(t) = plane(c,t)
    c - [in] value of constant parameter 
  Returns:
    iso-parametric line
  */
  ON_Line IsoLine(
         int dir,
         double c
         ) const;

  /*
  Description:
    Get signed distance from the plane to a point.
  Parameters:
    point - [in]
  Returns:
    Signed distance from a point to a plane.
  Remarks:
    If the point is on the plane, the distance is 0.
    If the point is above the plane, the distance is > 0.
    If the point is below the plane the distance is < 0.
    The zaxis determines the plane's orientation.
  */
  double DistanceTo( 
        const ON_3dPoint& point
        ) const;


  bool GetDistanceToBoundingBox(
           //returns false if plane has zero length normal
                                   const ON_BoundingBox&, // Box

           //output
                                   double* min,    // min signed dist from plane to box 
           double* max     //max signed dist from plane to box
           ) const;

  /*
  Description:
    Update the plane equation based on the current values
    of the origin and zaxis.
  Returns:
    true if successful.  false if zaxis is zero.
  Remarks:
    If you modify a plane's origin or zaxis, call UpdateEquation()
    to set equation[]. 
  */
  bool UpdateEquation();

  /*
  Description:
    Get point on plane that is closest to a given point.
  Parameters:
    world_point - [in] 3d point
    u - [out] 
    v - [out] The point ON_Plane::PointAt(*u,*v) is the point
              on the plane that is closest to world_point.
  Returns:
    true if successful.
  */
  bool ClosestPointTo( 
         ON_3dPoint world_point,
         double* u,
         double* v
         ) const;

  /*
  Description:
    Get point on plane that is closest to a given point.
  Parameters:
    point - [in]
  Returns:
    A 3d point on the plane that is closest to world_point.
  */
  ON_3dPoint ClosestPointTo( 
         ON_3dPoint point
         ) const;

  // For intersections see ON_Intersect();

  /*
  Description:
    Transform plane.
  Parameters:
    xform - [in] transformation to apply to plane
  Returns:
    true if successful
  */
  bool Transform( 
        const ON_Xform& xform
        );

  /*
  Description:
    Transform a plane by swapping coordinates.
  Parameters:
    i - [in]
    j - [in] indices of coordinates to swap.
        0 = x coordinate, 1 = y coordinate, 2 = z coordinate.
  Returns:
    true if successful.
  */
  bool SwapCoordinates(
        int i,
        int j
        );

  /*
  Description:
    Rotate a plane about its origin.
  Parameters:
    sin_angle - [in] sine of rotation angle
    cos_angle - [in] cosine of rotation angle
    axis - [in] axis of rotation
  Returns:
    true if successful
  */
  bool Rotate(
        double sin_angle,
        double cos_angle,
        const ON_3dVector& axis
        );

  /*
  Description:
    Rotate a plane about its origin.
  Parameters:
    angle - [in] rotation angle in radians
    axis - [in] axis of rotation
  Returns:
    true if successful
  */
  bool Rotate(
        double angle,
        const ON_3dVector& axis
        );

  /*
  Description:
    Rotate a plane about a point.
  Parameters:
    sin_angle - [in] sine of rotation angle
    cos_angle - [in] cosine of rotation angle
    axis - [in] axis of rotation
    center - [in] center of rotation
  Returns:
    true if successful
  */
  bool Rotate(
        double sin_angle,
        double cos_angle,
        const ON_3dVector& axis,
        const ON_3dPoint&  center
        );

  /*
  Description:
    Rotate a plane about a point.
  Parameters:
    angle - [in] rotation angle in radians
    axis - [in] axis of rotation
    center - [in] center of rotation
  Returns:
    true if successful
  */
  bool Rotate(
        double angle,
        const ON_3dVector& axis,
        const ON_3dPoint& center
        );

  /*
  Description:
    Translate a plane.
  Parameters:
    delta - [in] translation vector
  Returns:
    true if successful
  */
  bool Translate(
        const ON_3dVector&  delta
        );

  /*
  Description:
    Flip plane orientation by swapping x and y axes,
    reversing the zaxis, and updating the equation.
  Returns:
    true if successful
  */
  bool Flip();

// world plane coordinate system ON_Plane(ON_origin, ON_xaxis, ON_yaxis); 
        const static
        ON_Plane World_xy;      

public:
  // origin of plane
  ON_3dPoint  origin;

  // unit X axis of plane
  ON_3dVector xaxis;

  // unit Y axis of plane
  ON_3dVector yaxis;

  // unit Z axis of plane
  ON_3dVector zaxis;

  // equation of plane
  ON_PlaneEquation plane_equation;
  //double equation[4];
};

class ON_CLASS ON_ClippingPlaneInfo
{
public:
  // C++ defaults for construction, destruction, copy construction
  // and operator= work fine.

  // A point is visible if m_plane_equation.ValueAt(point) <= 0.
  // (This is the opposite convention from what OpenGL uses.)
  ON_PlaneEquation m_plane_equation;
  ON_UUID m_plane_id;
  bool m_bEnabled;

  void Default();
  bool Write( ON_BinaryArchive& ) const;
  bool Read( ON_BinaryArchive& );
};

class ON_CLASS ON_ClippingPlane
{
public:
  ON_ClippingPlane();
  ~ON_ClippingPlane();

  void Default();

  ON_Plane m_plane;
  ON_UuidList m_viewport_ids; //ids of viewports that this clipping plane "clips"
  ON_UUID m_plane_id;
  bool m_bEnabled; // true if this clipping plane is active

  ON_ClippingPlaneInfo ClippingPlaneInfo() const;

  bool Read( class ON_BinaryArchive& );
  bool Write( class ON_BinaryArchive& ) const;
};


#if defined(ON_DLL_TEMPLATE)

// This stuff is here because of a limitation in the way Microsoft
// handles templates and DLLs.  See Microsoft's knowledge base 
// article ID Q168958 for details.
#pragma warning( push )
#pragma warning( disable : 4231 )
ON_DLL_TEMPLATE template class ON_CLASS ON_SimpleArray<ON_Plane>;
ON_DLL_TEMPLATE template class ON_CLASS ON_ClassArray<ON_ClippingPlane>;
ON_DLL_TEMPLATE template class ON_CLASS ON_SimpleArray<ON_ClippingPlaneInfo>;
#pragma warning( pop )

#endif

extern ON_EXTERN_DECL const ON_Plane ON_xy_plane;
extern ON_EXTERN_DECL const ON_Plane ON_yz_plane;
extern ON_EXTERN_DECL const ON_Plane ON_zx_plane;

/*
Description:
  Get a convex hull of a set of 3d points.
Parameters:
  points - [in]
    List of points.  This function can handle tens of points
    but is too slow for hundreds of points.
  hull -[out]
    Equations of the sides of the convex hull are appended to
    this list.  
    A point P is inside the hull if hull[i].ValueAt(P) <= 0 for
    every plane equation.
Returns:
  Number of equations appended to hull[] array.
  If 0, then the points are coincident or colinear.
  If 2, then the points are coplanar and the returned
  planes are parallel.
  If >= 4, then the points are in a 3d convex hull.
*/
ON_DECL
int ON_Get3dConvexHull( 
          const ON_SimpleArray<ON_3dPoint> & points, 
          ON_SimpleArray<ON_PlaneEquation> & hull 
          );

#endif