vpPoint Class Reference

#include <visp3/core/vpPoint.h>

Inheritance diagram for vpPoint:

Public Types
enum	vpForwardProjectionDeallocatorType { user, vpDisplayForwardProjection }

Public Member Functions
	vpPoint ()
	vpPoint (double oX, double oY, double oZ)
	vpPoint (const vpColVector &oP)
	vpPoint (const std::vector< double > &oP)
virtual	~vpPoint ()
void	changeFrame (const vpHomogeneousMatrix &cMo, vpColVector &cP) const
void	changeFrame (const vpHomogeneousMatrix &cMo)
void	display (const vpImage< unsigned char > &I, const vpCameraParameters &cam, const vpColor &color=vpColor::green, unsigned int thickness=1)
void	display (const vpImage< vpRGBa > &I, const vpCameraParameters &cam, const vpColor &color=vpColor::green, unsigned int thickness=1)
void	display (const vpImage< unsigned char > &I, const vpHomogeneousMatrix &cMo, const vpCameraParameters &cam, const vpColor &color=vpColor::green, unsigned int thickness=1)
void	display (const vpImage< vpRGBa > &I, const vpHomogeneousMatrix &cMo, const vpCameraParameters &cam, const vpColor &color=vpColor::green, unsigned int thickness=1)
vpPoint *	duplicate () const
double	get_X () const
double	get_Y () const
double	get_Z () const
double	get_W () const
double	get_oX () const
double	get_oY () const
double	get_oZ () const
double	get_oW () const
double	get_x () const
double	get_y () const
double	get_w () const
void	getWorldCoordinates (double &oX, double &oY, double &oZ)
void	getWorldCoordinates (vpColVector &oP)
vpColVector	getWorldCoordinates (void)
void	getWorldCoordinates (std::vector< double > &oP)
vpPoint &	operator= (const vpPoint &vpp)=default
void	projection (const vpColVector &_cP, vpColVector &_p) const
void	projection ()
void	set_X (double cX)
void	set_Y (double cY)
void	set_Z (double cZ)
void	set_W (double cW)
void	set_oX (double oX)
void	set_oY (double oY)
void	set_oZ (double oZ)
void	set_oW (double oW)
void	set_x (double x)
void	set_y (double y)
void	set_w (double w)
void	setWorldCoordinates (double oX, double oY, double oZ)
void	setWorldCoordinates (const vpColVector &oP)
void	setWorldCoordinates (const std::vector< double > &oP)
Public Member Functions Inherited from vpForwardProjection
vpColVector	get_oP () const
vpForwardProjectionDeallocatorType	getDeallocate ()
virtual void	print () const
void	project ()
void	project (const vpHomogeneousMatrix &cMo)
void	setDeallocate (vpForwardProjectionDeallocatorType d)
void	track (const vpHomogeneousMatrix &cMo)
Public Member Functions Inherited from vpTracker
vpColVector	get_p () const
vpColVector	get_cP () const

Public Attributes
Public Attributes Inherited from vpForwardProjection
vpColVector	oP
Public Attributes Inherited from vpTracker
vpColVector	p
vpColVector	cP
bool	cPAvailable

Protected Member Functions
void	init ()

Friends
VISP_EXPORT std::ostream &	operator<< (std::ostream &os, const vpPoint &vpp)

Detailed Description

Class that defines a 3D point in the object frame and allows forward projection of a 3D point in the camera frame and in the 2D image plane by perspective projection. All the parameters must be set in meter.

A 3D point has the followings parameters:

• in the object frame: the normalized 3D coordinates oX, oY, oZ, oW of the point. These parameters registered in vpForwardProjection::oP internal 4-dim vector are set using the constructors vpPoint(double oX, double oY, double oZ), vpPoint(const vpColVector &oP) and vpPoint(const std::vector<double> &oP) or the fonctions setWorldCoordinates(double oX, double oY, double oZ), setWorldCoordinates(const vpColVector &oP) and setWorldCoordinates(const std::vector<double> &oP). To get theses parameters use get_oP().
• in the camera frame: the normalized coordinates cX, cY, cZ, 1 of the point. These parameters registered in vpTracker::cP internal 4-dim vector are computed using changeFrame(const vpHomogeneousMatrix &cMo, vpColVector &cP) const or changeFrame(const vpHomogeneousMatrix &cMo). These parameters could be retrieved using get_X(), get_Y() and get_Z(). To get theses parameters use get_cP().
• in the image plane: the 2D normalized coordinates (x, y, 1) corresponding to the perspective projection of the point. These parameters are registered in vpTracker::p internal 3-dim vector and computed using projection() and projection(const vpColVector &cP, vpColVector &p) const. They could be retrieved using get_x() and get_y(). They correspond to 2D normalized point parameters with values expressed in meters. To get theses parameters use get_p().

Examples:

AROgre.cpp, AROgreBasic.cpp, homographyHartleyDLT2DObject.cpp, homographyHLM2DObject.cpp, homographyHLM3DObject.cpp, manGeometricFeatures.cpp, manServo4PointsDisplay.cpp, manServoMomentsSimple.cpp, manSimu4Dots.cpp, manSimu4Points.cpp, mbot-apriltag-ibvs.cpp, poseVirtualVS.cpp, servoAfma62DhalfCamVelocity.cpp, servoAfma6FourPoints2DCamVelocityLs_cur.cpp, servoAfma6FourPoints2DCamVelocityLs_des.cpp, servoAfma6Points2DCamVelocityEyeToHand.cpp, servoBebop2.cpp, servoMomentPoints.cpp, servoMomentPolygon.cpp, servoPioneerPanSegment3D.cpp, servoSimu4Points.cpp, servoSimuAfma6FourPoints2DCamVelocity.cpp, servoSimuFourPoints2DCamVelocity.cpp, servoSimuFourPoints2DCamVelocityDisplay.cpp, servoSimuFourPoints2DPolarCamVelocityDisplay.cpp, servoSimuPoint2DCamVelocity1.cpp, servoSimuPoint2DCamVelocity2.cpp, servoSimuPoint2DCamVelocity3.cpp, servoSimuPoint2DhalfCamVelocity1.cpp, servoSimuPoint2DhalfCamVelocity2.cpp, servoSimuPoint2DhalfCamVelocity3.cpp, servoSimuPoint3DCamVelocity.cpp, servoSimuViper850FourPoints2DCamVelocity.cpp, servoViper850FourPoints2DArtVelocityLs_cur.cpp, servoViper850FourPoints2DCamVelocityLs_cur.cpp, servoViper850FourPointsKinect.cpp, simulateFourPoints2DCartesianCamVelocity.cpp, simulateFourPoints2DPolarCamVelocity.cpp, testAprilTag.cpp, testConvert.cpp, testFeatureSegment.cpp, testFindMatch.cpp, testKeyPoint-4.cpp, testPoseFeatures.cpp, testPoseRansac.cpp, testRobotAfma6Pose.cpp, testRobotViper850Pose.cpp, tutorial-chessboard-pose.cpp, tutorial-count-coins.cpp, tutorial-homography-from-points.cpp, tutorial-ibvs-4pts-display.cpp, tutorial-ibvs-4pts-image-tracking.cpp, tutorial-ibvs-4pts-ogre-tracking.cpp, tutorial-ibvs-4pts-ogre.cpp, tutorial-ibvs-4pts-plotter-continuous-gain-adaptive.cpp, tutorial-ibvs-4pts-plotter-gain-adaptive.cpp, tutorial-ibvs-4pts-plotter.cpp, tutorial-ibvs-4pts-wireframe-robot-afma6.cpp, tutorial-ibvs-4pts-wireframe-robot-viper.cpp, tutorial-ibvs-4pts.cpp, tutorial-pose-from-points-image.cpp, tutorial-pose-from-points-live.cpp, tutorial-pose-from-points-realsense-T265.cpp, tutorial-pose-from-qrcode-image.cpp, tutorial-simu-pioneer-continuous-gain-adaptive.cpp, tutorial-simu-pioneer-continuous-gain-constant.cpp, tutorial-simu-pioneer-pan.cpp, and tutorial-simu-pioneer.cpp.

Definition at line 81 of file vpPoint.h.

Member Enumeration Documentation

vpForwardProjectionDeallocatorType

enum vpForwardProjection::vpForwardProjectionDeallocatorType

inherited

Used for memory issue especially in the vpServo class.

Enumerator
user
vpDisplayForwardProjection

Definition at line 73 of file vpForwardProjection.h.

Constructor & Destructor Documentation

vpPoint() [1/4]

vpPoint::vpPoint

(

)

Basic constructor.

Definition at line 64 of file vpPoint.cpp.

References init().

Referenced by changeFrame().

vpPoint() [2/4]

vpPoint::vpPoint	(	double	oX,
		double	oY,
		double	oZ
	)

Construction from a 3D point with coordinates in object frame.

Parameters

oX,oY,oZ

Coordinates of a 3D point in object frame.

Definition at line 70 of file vpPoint.cpp.

References init(), and setWorldCoordinates().

vpPoint() [3/4]

vpPoint::vpPoint ( const vpColVector &  oP_ )

explicit

Construction from a 3D point with coordinates in object frame.

Parameters

oP_

Vector containing the coordinates of the 3D point in the object frame. This vector could be of dimension 3 or 4. If dimension is 3, oP corresponds to the normalized coordinates oP = (oX, oY, oZ, 1) where oP[0]=oX, oP[1]=oY, oP[2]=oZ. If dimension is 4, oP corresponds to the normalized coordinates oP = (oX, oY, oZ, oW) where oP[0]=oX, oP[1]=oY, oP[2]=oZ and oP[3]=oW.

Definition at line 86 of file vpPoint.cpp.

References init(), and setWorldCoordinates().

vpPoint() [4/4]

vpPoint::vpPoint ( const std::vector< double > &  oP_ )

explicit

Construction from a 3D point with coordinates in object frame.

Parameters

oP_

Vector containing the coordinates of the 3D point in the object frame. This vector could be of dimension 3 or 4. If dimension is 3, oP corresponds to the normalized coordinates oP = (oX, oY, oZ, 1) where oP[0]=oX, oP[1]=oY, oP[2]=oZ. If dimension is 4, oP corresponds to the normalized coordinates oP = (oX, oY, oZ, oW) where oP[0]=oX, oP[1]=oY, oP[2]=oZ and oP[3]=oW.

Definition at line 102 of file vpPoint.cpp.

References init(), and setWorldCoordinates().

~vpPoint()

virtual vpPoint::~vpPoint ( )

inlinevirtual

Destructor.

Definition at line 91 of file vpPoint.h.

References vpForwardProjection::changeFrame(), vpForwardProjection::display(), vpForwardProjection::duplicate(), vpColor::green, vpForwardProjection::init(), vpTracker::operator=(), vpForwardProjection::projection(), and vpForwardProjection::setWorldCoordinates().

Member Function Documentation

changeFrame() [1/2]

void vpPoint::changeFrame ( const vpHomogeneousMatrix &  cMo, vpColVector &  _cP  ) const

virtual

From the 3D coordinates of the point in the object frame oP that are set using for example setWorldCoordinates() or set_oX(), set_oY(), set_oZ(), compute the 3D coordinates of the point in the camera frame cP = cMo * oP.

Parameters

cMo	: Transformation from camera to object frame.
_cP	: 3D normalized coordinates of the point in the camera frame cP = (cX, cY, cZ, 1).

Implements vpForwardProjection.

Examples:

servoAfma6FourPoints2DCamVelocityLs_cur.cpp, servoAfma6FourPoints2DCamVelocityLs_des.cpp, servoAfma6Points2DCamVelocityEyeToHand.cpp, servoPioneerPanSegment3D.cpp, servoViper850FourPoints2DArtVelocityLs_cur.cpp, servoViper850FourPoints2DCamVelocityLs_cur.cpp, servoViper850FourPointsKinect.cpp, and simulateFourPoints2DPolarCamVelocity.cpp.

Definition at line 239 of file vpPoint.cpp.

References vpForwardProjection::oP, and vpColVector::resize().

Referenced by vpPolygon3D::changeFrame(), vpMbtDistanceKltCylinder::computeInteractionMatrixAndResidu(), display(), vpMbtFaceDepthNormal::displayFeature(), vpMbtFaceDepthNormal::getFeaturesForDisplay(), vpMbtDistanceLine::getModelForDisplay(), vpMbtDistanceCylinder::getModelForDisplay(), vpMbtDistanceLine::initMovingEdge(), vpMbtDistanceCylinder::initMovingEdge(), vpMbtDistanceLine::updateMovingEdge(), and vpMbtDistanceCylinder::updateMovingEdge().

changeFrame() [2/2]

void vpPoint::changeFrame ( const vpHomogeneousMatrix &  cMo )

virtual

From the 3D coordinates of the point in the object frame oP that are set using for example setWorldCoordinates() or set_oX(), set_oY(), set_oZ(), compute the 3D coordinates of the point in the camera frame cP = cMo * oP.

Parameters

cMo	: Transformation from camera to object frame.

Implements vpForwardProjection.

Definition at line 263 of file vpPoint.cpp.

References vpTracker::cP, duplicate(), get_W(), get_w(), get_X(), get_x(), get_Y(), get_y(), get_Z(), vpForwardProjection::oP, operator*(), set_oW(), set_oX(), set_oY(), set_oZ(), set_W(), set_w(), set_X(), set_x(), set_Y(), set_y(), set_Z(), and vpPoint().

display() [1/4]

void vpPoint::display ( const vpImage< unsigned char > &  I, const vpCameraParameters &  cam, const vpColor &  color = vpColor::green, unsigned int  thickness = 1  )

virtual

Display the projection of a 3D point in image I.

Parameters

I	: Image used as background.
cam	: Camera parameters.
color	: Color used to draw the point.
thickness	: Thickness used to draw the point.

Implements vpForwardProjection.

Examples:

manGeometricFeatures.cpp, and servoAfma6Points2DCamVelocityEyeToHand.cpp.

Definition at line 430 of file vpPoint.cpp.

References vpFeatureDisplay::displayPoint(), and vpTracker::p.

display() [2/4]

void vpPoint::display	(	const vpImage< vpRGBa > &	I,
		const vpCameraParameters &	cam,
		const vpColor &	color = vpColor::green,
		unsigned int	thickness = 1
	)

Display the projection of a 3D point in image I.

Parameters

I	: Image used as background.
cam	: Camera parameters.
color	: Color used to draw the point.
thickness	: Thickness used to draw the point.

Definition at line 444 of file vpPoint.cpp.

References vpFeatureDisplay::displayPoint(), and vpTracker::p.

display() [3/4]

void vpPoint::display ( const vpImage< unsigned char > &  I, const vpHomogeneousMatrix &  cMo, const vpCameraParameters &  cam, const vpColor &  color = vpColor::green, unsigned int  thickness = 1  )

virtual

Display the projection of a 3D point in image I. This method is non destructive wrt. cP and p internal 3D point parameters.

Parameters

I	: Image used as background.
cMo	: Homogeneous transformation from camera frame to object frame. The point is considered as viewed from this camera position.
cam	: Camera parameters.
color	: Color used to draw the sphere.
thickness	: Thickness used to draw the sphere.

Implements vpForwardProjection.

Definition at line 370 of file vpPoint.cpp.

References changeFrame(), vpFeatureDisplay::displayPoint(), and projection().

display() [4/4]

void vpPoint::display	(	const vpImage< vpRGBa > &	I,
		const vpHomogeneousMatrix &	cMo,
		const vpCameraParameters &	cam,
		const vpColor &	color = vpColor::green,
		unsigned int	thickness = 1
	)

Display the projection of a 3D point in image I. This method is non destructive wrt. cP and p internal 3D point parameters.

Parameters

I	: Image used as background.
cMo	: Homogeneous transformation from camera frame to object frame. The point is considered as viewed from this camera position.
cam	: Camera parameters.
color	: Color used to draw the sphere.
thickness	: Thickness used to draw the sphere.

Definition at line 395 of file vpPoint.cpp.

References changeFrame(), vpFeatureDisplay::displayPoint(), and projection().

duplicate()

vpPoint * vpPoint::duplicate ( ) const

virtual

For memory issue (used by the vpServo class only).

Implements vpForwardProjection.

Definition at line 353 of file vpPoint.cpp.

Referenced by changeFrame().

get_cP()

vpColVector vpTracker::get_cP ( ) const

inlineinherited

Return object parameters expressed in the 3D camera frame.

Definition at line 99 of file vpTracker.h.

get_oP()

vpColVector vpForwardProjection::get_oP ( ) const

inlineinherited

Return object parameters expressed in the 3D object frame.

Definition at line 165 of file vpForwardProjection.h.

get_oW()

double vpPoint::get_oW

(

)

const

Get the point oW coordinate in the object frame.

Definition at line 467 of file vpPoint.cpp.

References vpForwardProjection::oP.

get_oX()

double vpPoint::get_oX

(

)

const

Get the point oX coordinate in the object frame.

Examples:

testConvert.cpp.

Definition at line 461 of file vpPoint.cpp.

References vpForwardProjection::oP.

Referenced by vpMbTracker::addPolygon(), vpMbTracker::addProjectionErrorPolygon(), vpMbtDistanceCircle::buildFrom(), vpMbtDistanceKltCylinder::buildFrom(), vpMbtDistanceLine::buildFrom(), vpMbtDistanceCylinder::buildFrom(), vpKeyPoint::compute3DForPointsOnCylinders(), vpPose::coplanar(), vpMbTracker::createCylinderBBox(), vpMbTracker::extractCylinders(), vpMbTracker::getGravityCenter(), vpPlane::init(), vpPose::poseDementhonNonPlan(), vpPose::poseDementhonPlan(), vpPose::poseLagrangeNonPlan(), vpPose::poseLagrangePlan(), vpPose::poseLowe(), vpMbtFaceDepthDense::samePoint(), vpMbtFaceDepthNormal::samePoint(), vpMbTracker::samePoint(), vpPlane::vpPlane(), and vpMbtDistanceLine::~vpMbtDistanceLine().

get_oY()

double vpPoint::get_oY

(

)

const

Get the point oY coordinate in the object frame.

Examples:

testConvert.cpp.

Definition at line 463 of file vpPoint.cpp.

References vpForwardProjection::oP.

Referenced by vpMbTracker::addPolygon(), vpMbTracker::addProjectionErrorPolygon(), vpMbtDistanceCircle::buildFrom(), vpMbtDistanceKltCylinder::buildFrom(), vpMbtDistanceLine::buildFrom(), vpMbtDistanceCylinder::buildFrom(), vpKeyPoint::compute3DForPointsOnCylinders(), vpPose::coplanar(), vpMbTracker::createCylinderBBox(), vpMbTracker::extractCylinders(), vpPlane::init(), vpPose::poseDementhonNonPlan(), vpPose::poseDementhonPlan(), vpPose::poseLagrangeNonPlan(), vpPose::poseLagrangePlan(), vpPose::poseLowe(), vpMbtFaceDepthDense::samePoint(), vpMbtFaceDepthNormal::samePoint(), vpMbTracker::samePoint(), vpPlane::vpPlane(), and vpMbtDistanceLine::~vpMbtDistanceLine().

get_oZ()

double vpPoint::get_oZ

(

)

const

Get the point oZ coordinate in the object frame.

Examples:

testConvert.cpp.

Definition at line 465 of file vpPoint.cpp.

References vpForwardProjection::oP.

Referenced by vpMbTracker::addPolygon(), vpMbTracker::addProjectionErrorPolygon(), vpMbtDistanceCircle::buildFrom(), vpMbtDistanceKltCylinder::buildFrom(), vpMbtDistanceLine::buildFrom(), vpMbtDistanceCylinder::buildFrom(), vpKeyPoint::compute3DForPointsOnCylinders(), vpPose::coplanar(), vpMbTracker::createCylinderBBox(), vpMbTracker::extractCylinders(), vpPlane::init(), vpPose::poseDementhonNonPlan(), vpPose::poseDementhonPlan(), vpPose::poseLagrangeNonPlan(), vpPose::poseLagrangePlan(), vpPose::poseLowe(), vpMbtFaceDepthDense::samePoint(), vpMbtFaceDepthNormal::samePoint(), vpMbTracker::samePoint(), vpPlane::vpPlane(), and vpMbtDistanceLine::~vpMbtDistanceLine().

get_p()

vpColVector vpTracker::get_p ( ) const

inlineinherited

Return object parameters expressed in the 2D image plane computed by perspective projection.

Definition at line 97 of file vpTracker.h.

get_W()

double vpPoint::get_W

(

)

const

Get the point cW coordinate in the camera frame.

Definition at line 458 of file vpPoint.cpp.

References vpTracker::cP.

Referenced by changeFrame(), vpHomogeneousMatrix::operator*(), and vpPlane::projectionPointOnPlan().

get_w()

double vpPoint::get_w

(

)

const

Get the point w coordinate in the image plane.

Examples:

homographyHartleyDLT2DObject.cpp, homographyHLM2DObject.cpp, and homographyHLM3DObject.cpp.

Definition at line 474 of file vpPoint.cpp.

References vpTracker::p.

Referenced by changeFrame(), and vpHomography::operator*().

get_X()

double vpPoint::get_X

(

)

const

Get the point cX coordinate in the camera frame.

Definition at line 452 of file vpPoint.cpp.

References vpTracker::cP.

Referenced by changeFrame(), vpMbtFaceDepthNormal::computeNormalVisibility(), vpMbtFaceDepthNormal::computePolygonCentroid(), vpPolygon3D::computePolygonClipped(), vpMbtFaceDepthDense::computeROI(), vpMbtFaceDepthNormal::displayFeature(), vpMbtFaceDepthNormal::getFeaturesForDisplay(), vpPlane::init(), vpMbtPolygon::isVisible(), vpHomogeneousMatrix::operator*(), vpPlane::projectionPointOnPlan(), vpPlane::rayIntersection(), and vpPlane::vpPlane().

get_x()

double vpPoint::get_x

(

)

const

Get the point x coordinate in the image plane.

Examples:

homographyHartleyDLT2DObject.cpp, homographyHLM2DObject.cpp, homographyHLM3DObject.cpp, servoAfma62DhalfCamVelocity.cpp, servoSimuFourPoints2DPolarCamVelocityDisplay.cpp, and testFindMatch.cpp.

Definition at line 470 of file vpPoint.cpp.

References vpTracker::p.

Referenced by changeFrame(), vpMbtDistanceKltCylinder::computeInteractionMatrixAndResidu(), vpKeyPoint::computePose(), vpPose::computeResidual(), vpFeatureBuilder::create(), vpMbtFaceDepthNormal::displayFeature(), vpMbtFaceDepthNormal::getFeaturesForDisplay(), vpKeyPoint::matchPointAndDetect(), vpHomography::operator*(), vpPose::poseFromRectangle(), vpPose::poseLagrangeNonPlan(), vpPose::poseLagrangePlan(), vpPose::poseLowe(), vpPose::poseVirtualVS(), vpPose::poseVirtualVSrobust(), vpHomography::project(), vpWireFrameSimulator::projectCameraTrajectory(), vpSimulatorAfma6::updateArticularPosition(), and vpSimulatorViper850::updateArticularPosition().

get_Y()

double vpPoint::get_Y

(

)

const

Get the point cY coordinate in the camera frame.

Definition at line 454 of file vpPoint.cpp.

References vpTracker::cP.

Referenced by changeFrame(), vpMbtFaceDepthNormal::computeNormalVisibility(), vpPolygon3D::computePolygonClipped(), vpMbtFaceDepthDense::computeROI(), vpMbtFaceDepthNormal::displayFeature(), vpMbtFaceDepthNormal::getFeaturesForDisplay(), vpPlane::init(), vpMbtPolygon::isVisible(), vpHomogeneousMatrix::operator*(), vpPlane::projectionPointOnPlan(), vpPlane::rayIntersection(), and vpPlane::vpPlane().

get_y()

double vpPoint::get_y

(

)

const

Get the point y coordinate in the image plane.

Examples:

homographyHartleyDLT2DObject.cpp, homographyHLM2DObject.cpp, homographyHLM3DObject.cpp, servoAfma62DhalfCamVelocity.cpp, servoSimuFourPoints2DPolarCamVelocityDisplay.cpp, and testFindMatch.cpp.

Definition at line 472 of file vpPoint.cpp.

References vpTracker::p.

Referenced by changeFrame(), vpMbtDistanceKltCylinder::computeInteractionMatrixAndResidu(), vpKeyPoint::computePose(), vpPose::computeResidual(), vpFeatureBuilder::create(), vpMbtFaceDepthNormal::displayFeature(), vpMbtFaceDepthNormal::getFeaturesForDisplay(), vpKeyPoint::matchPointAndDetect(), vpHomography::operator*(), vpPose::poseFromRectangle(), vpPose::poseLagrangeNonPlan(), vpPose::poseLagrangePlan(), vpPose::poseLowe(), vpPose::poseVirtualVS(), vpPose::poseVirtualVSrobust(), vpHomography::project(), vpWireFrameSimulator::projectCameraTrajectory(), vpSimulatorAfma6::updateArticularPosition(), and vpSimulatorViper850::updateArticularPosition().

get_Z()

double vpPoint::get_Z

(

)

const

Get the point cZ coordinate in the camera frame.

Examples:

servoAfma62DhalfCamVelocity.cpp, tutorial-simu-pioneer-continuous-gain-adaptive.cpp, tutorial-simu-pioneer-continuous-gain-constant.cpp, tutorial-simu-pioneer-pan.cpp, and tutorial-simu-pioneer.cpp.

Definition at line 456 of file vpPoint.cpp.

References vpTracker::cP.

Referenced by changeFrame(), vpMbtFaceDepthNormal::computeNormalVisibility(), vpPolygon3D::computePolygonClipped(), vpMbtFaceDepthDense::computeROI(), vpFeatureBuilder::create(), vpProjectionDisplay::displayCamera(), vpMbtFaceDepthNormal::displayFeature(), vpMbtFaceDepthNormal::getFeaturesForDisplay(), vpPlane::init(), vpMbtPolygon::isVisible(), vpHomogeneousMatrix::operator*(), vpPose::poseVirtualVS(), vpPose::poseVirtualVSrobust(), vpPlane::projectionPointOnPlan(), vpPlane::rayIntersection(), and vpPlane::vpPlane().

getDeallocate()

vpForwardProjectionDeallocatorType vpForwardProjection::getDeallocate ( )

inlineinherited

Definition at line 167 of file vpForwardProjection.h.

getWorldCoordinates() [1/4]

void vpPoint::getWorldCoordinates	(	double &	oX,
		double &	oY,
		double &	oZ
	)

Get the point object frame coordinates.

Definition at line 178 of file vpPoint.cpp.

References vpForwardProjection::oP.

getWorldCoordinates() [2/4]

void vpPoint::getWorldCoordinates

(

vpColVector &

oP_

)

Get the point object frame normalized coordinates.

Parameters

oP_	Normalized coordinates of the point in the object frame oP = (oX, oY, oZ, oW) as a 4-dim vector.

Definition at line 191 of file vpPoint.cpp.

References vpForwardProjection::oP.

getWorldCoordinates() [3/4]

vpColVector vpPoint::getWorldCoordinates

(

void

)

Return the point object frame normalized coordinates.

Returns

Normalized coordinates of the point in the object frame oP = (oX, oY, oZ, oW) as a 4-dim vector.

Definition at line 212 of file vpPoint.cpp.

References vpForwardProjection::oP.

getWorldCoordinates() [4/4]

void vpPoint::getWorldCoordinates

(

std::vector< double > &

oP_

)

Get the point object frame normalized coordinates.

Parameters

oP_	Normalized coordinates of the point in the object frame oP = (oX, oY, oZ, oW) as a 4-dim vector.

Definition at line 199 of file vpPoint.cpp.

References vpForwardProjection::oP, vpColVector::resize(), and vpArray2D< Type >::size().

init()

void vpPoint::init ( )

protectedvirtual

Basic construction.

Implements vpForwardProjection.

Definition at line 48 of file vpPoint.cpp.

References vpTracker::cP, vpForwardProjection::oP, vpTracker::p, vpColVector::resize(), and set_Z().

Referenced by vpPoint().

operator=()

vpPoint& vpPoint::operator= ( const vpPoint &  vpp )

default

print()

void vpForwardProjection::print ( ) const

virtualinherited

Print to stdout the feature parameters in:

• the object frame
• the camera frame
• the image plane.

Examples:

servoSimuCircle2DCamVelocityDisplay.cpp, servoSimuLine2DCamVelocityDisplay.cpp, and servoSimuSquareLine2DCamVelocityDisplay.cpp.

Definition at line 53 of file vpForwardProjection.cpp.

References vpTracker::cP, vpForwardProjection::oP, vpTracker::p, and vpColVector::t().

project() [1/2]

void vpForwardProjection::project ( )

inherited

Compute the feature parameters in the image plane (vpTracker::p) from the parameters in the camera frame (vpTracker::cP).

Warning

Be careful to update vpTracker::p and vpTracker::cP public attributes before the call of this method.

Examples:

homographyHartleyDLT2DObject.cpp, homographyHLM2DObject.cpp, homographyHLM3DObject.cpp, manGeometricFeatures.cpp, manServo4PointsDisplay.cpp, manSimu4Points.cpp, servoAfma62DhalfCamVelocity.cpp, servoAfma6Cylinder2DCamVelocity.cpp, servoAfma6Cylinder2DCamVelocitySecondaryTask.cpp, servoAfma6Line2DCamVelocity.cpp, servoAfma6SquareLines2DCamVelocity.cpp, servoAfma6TwoLines2DCamVelocity.cpp, servoPioneerPanSegment3D.cpp, simulateFourPoints2DPolarCamVelocity.cpp, testFeatureSegment.cpp, testFindMatch.cpp, and testPoseFeatures.cpp.

Definition at line 68 of file vpForwardProjection.cpp.

References vpTracker::cP, vpTracker::p, and vpForwardProjection::projection().

Referenced by vpMbtDistanceKltCylinder::computeInteractionMatrixAndResidu(), vpMbtFaceDepthNormal::computeNormalVisibility(), vpKeyPoint::computePose(), vpMbtFaceDepthDense::computeROI(), vpMbtFaceDepthNormal::displayFeature(), vpMbtFaceDepthNormal::getFeaturesForDisplay(), vpKeyPoint::matchPointAndDetect(), vpForwardProjection::track(), vpMbtDistanceCircle::~vpMbtDistanceCircle(), vpMbtDistanceCylinder::~vpMbtDistanceCylinder(), and vpMbtDistanceLine::~vpMbtDistanceLine().

project() [2/2]

void vpForwardProjection::project ( const vpHomogeneousMatrix &  cMo )

inherited

Compute the feature parameters in the camera frame (vpTracker::cP) and than compute the projection of these parameters in the image plane (vpTracker::p).

Warning

The feature parameters in the object frame (vpForwardProjection:oP) need to be set prior the use of this method. To initialize these parameters see setWorldCoordinates().

Parameters

cMo	: The homogeneous matrix corresponding to the pose between the camera frame and the object frame.

Definition at line 84 of file vpForwardProjection.cpp.

References vpForwardProjection::changeFrame(), and vpForwardProjection::projection().

projection() [1/2]

void vpPoint::projection ( const vpColVector &  _cP, vpColVector &  _p  ) const

virtual

Projection onto the image plane of a point. Input: the 3D coordinates in the camera frame _cP, output : the 2D coordinates _p.

Compute the perspective projection of a point _cP.

Parameters

_cP	: 3-dim vector cP = (cX, cY, cZ) or 4-dim vector cP = (cX, cY, cZ, 1) corresponding to the normalized coordinates of the 3D point in the camera frame.
_p	: Coordinates of the point in the image plane obtained by perspective projection.

Implements vpForwardProjection.

Examples:

servoAfma6FourPoints2DCamVelocityLs_cur.cpp, servoAfma6FourPoints2DCamVelocityLs_des.cpp, servoAfma6Points2DCamVelocityEyeToHand.cpp, servoViper850FourPoints2DArtVelocityLs_cur.cpp, servoViper850FourPoints2DCamVelocityLs_cur.cpp, and servoViper850FourPointsKinect.cpp.

Definition at line 222 of file vpPoint.cpp.

References vpColVector::resize().

Referenced by vpPolygon3D::changeFrame(), vpPolygon3D::computePolygonClipped(), vpMbtDistanceCylinder::getModelForDisplay(), vpMbtDistanceCylinder::initMovingEdge(), and vpMbtDistanceCylinder::updateMovingEdge().

projection() [2/2]

void vpPoint::projection ( )

virtual

Perspective projection of the 3D point.

Projection onto the image plane of the point. Update the object attribute p (2D homogeneous coordinates) according to object attribute cP (current 3D coordinates in the camera frame).

Implements vpForwardProjection.

Definition at line 484 of file vpPoint.cpp.

References vpTracker::cP, and vpTracker::p.

Referenced by display().

set_oW()

void vpPoint::set_oW

(

double

oW

)

Set the point oW coordinate in the object frame.

Definition at line 508 of file vpPoint.cpp.

References vpForwardProjection::oP.

Referenced by changeFrame(), and vpHomogeneousMatrix::operator*().

set_oX()

void vpPoint::set_oX

(

double

oX

)

Set the point oX coordinate in the object frame.

Examples:

testConvert.cpp, and tutorial-chessboard-pose.cpp.

Definition at line 502 of file vpPoint.cpp.

References vpForwardProjection::oP.

Referenced by changeFrame(), vpKeyPoint::computePose(), vpHomogeneousMatrix::operator*(), vpPose::poseDementhonNonPlan(), and vpPose::poseDementhonPlan().

set_oY()

void vpPoint::set_oY

(

double

oY

)

Set the point oY coordinate in the object frame.

Examples:

testConvert.cpp, and tutorial-chessboard-pose.cpp.

Definition at line 504 of file vpPoint.cpp.

References vpForwardProjection::oP.

Referenced by changeFrame(), vpKeyPoint::computePose(), vpHomogeneousMatrix::operator*(), vpPose::poseDementhonNonPlan(), and vpPose::poseDementhonPlan().

set_oZ()

void vpPoint::set_oZ

(

double

oZ

)

Set the point oZ coordinate in the object frame.

Examples:

testConvert.cpp, and tutorial-chessboard-pose.cpp.

Definition at line 506 of file vpPoint.cpp.

References vpForwardProjection::oP.

Referenced by changeFrame(), vpKeyPoint::computePose(), vpHomogeneousMatrix::operator*(), vpPose::poseDementhonNonPlan(), and vpPose::poseDementhonPlan().

set_W()

void vpPoint::set_W

(

double

cW

)

Set the point cW coordinate in the camera frame.

Definition at line 499 of file vpPoint.cpp.

References vpTracker::cP.

Referenced by changeFrame(), vpHomogeneousMatrix::operator*(), and vpPlane::projectionPointOnPlan().

set_w()

void vpPoint::set_w

(

double

w

)

Set the point w coordinate in the image plane.

Definition at line 515 of file vpPoint.cpp.

References vpTracker::p.

Referenced by changeFrame(), and vpHomography::operator*().

set_X()

void vpPoint::set_X

(

double

cX

)

Set the point cX coordinate in the camera frame.

Definition at line 493 of file vpPoint.cpp.

References vpTracker::cP.

Referenced by changeFrame(), vpMbtFaceDepthNormal::computeNormalVisibility(), vpMbtFaceDepthNormal::computePolygonCentroid(), vpPolygon3D::computePolygonClipped(), vpMbtFaceDepthDense::computeROI(), vpMbtFaceDepthNormal::displayFeature(), vpMbtFaceDepthNormal::getFeaturesForDisplay(), vpMbtPolygon::isVisible(), vpHomogeneousMatrix::operator*(), and vpPlane::projectionPointOnPlan().

set_x()

void vpPoint::set_x

(

double

x

)

Set the point x coordinate in the image plane.

Examples:

AROgre.cpp, AROgreBasic.cpp, mbot-apriltag-ibvs.cpp, poseVirtualVS.cpp, servoAfma62DhalfCamVelocity.cpp, servoAfma6FourPoints2DCamVelocityLs_cur.cpp, servoAfma6Points2DCamVelocityEyeToHand.cpp, servoBebop2.cpp, servoViper850FourPoints2DArtVelocityLs_cur.cpp, servoViper850FourPoints2DCamVelocityLs_cur.cpp, servoViper850FourPointsKinect.cpp, testAprilTag.cpp, testRobotAfma6Pose.cpp, testRobotViper850Pose.cpp, and tutorial-count-coins.cpp.

Definition at line 511 of file vpPoint.cpp.

References vpTracker::p.

Referenced by vpCalibration::addPoint(), changeFrame(), vpPose::findMatch(), vpMbTracker::initFromPoints(), vpKeyPoint::matchPoint(), vpHomography::operator*(), and vpHomography::project().

set_Y()

void vpPoint::set_Y

(

double

cY

)

Set the point cY coordinate in the camera frame.

Definition at line 495 of file vpPoint.cpp.

References vpTracker::cP.

Referenced by changeFrame(), vpMbtFaceDepthNormal::computeNormalVisibility(), vpMbtFaceDepthNormal::computePolygonCentroid(), vpPolygon3D::computePolygonClipped(), vpMbtFaceDepthDense::computeROI(), vpMbtFaceDepthNormal::displayFeature(), vpMbtFaceDepthNormal::getFeaturesForDisplay(), vpMbtPolygon::isVisible(), vpHomogeneousMatrix::operator*(), and vpPlane::projectionPointOnPlan().

set_y()

void vpPoint::set_y

(

double

y

)

Set the point y coordinate in the image plane.

Examples:

AROgre.cpp, AROgreBasic.cpp, mbot-apriltag-ibvs.cpp, poseVirtualVS.cpp, servoAfma62DhalfCamVelocity.cpp, servoAfma6FourPoints2DCamVelocityLs_cur.cpp, servoAfma6Points2DCamVelocityEyeToHand.cpp, servoBebop2.cpp, servoViper850FourPoints2DArtVelocityLs_cur.cpp, servoViper850FourPoints2DCamVelocityLs_cur.cpp, servoViper850FourPointsKinect.cpp, testAprilTag.cpp, testRobotAfma6Pose.cpp, testRobotViper850Pose.cpp, and tutorial-count-coins.cpp.

Definition at line 513 of file vpPoint.cpp.

References vpTracker::p.

Referenced by vpCalibration::addPoint(), changeFrame(), vpPose::findMatch(), vpMbTracker::initFromPoints(), vpKeyPoint::matchPoint(), vpHomography::operator*(), and vpHomography::project().

set_Z()

void vpPoint::set_Z

(

double

cZ

)

Set the point cZ coordinate in the camera frame.

Definition at line 497 of file vpPoint.cpp.

References vpTracker::cP.

Referenced by changeFrame(), vpMbtFaceDepthNormal::computeNormalVisibility(), vpMbtFaceDepthNormal::computePolygonCentroid(), vpPolygon3D::computePolygonClipped(), vpMbtFaceDepthDense::computeROI(), vpMbtFaceDepthNormal::displayFeature(), vpMbtFaceDepthNormal::getFeaturesForDisplay(), init(), vpMbtPolygon::isVisible(), vpHomogeneousMatrix::operator*(), and vpPlane::projectionPointOnPlan().

setDeallocate()

void vpForwardProjection::setDeallocate ( vpForwardProjectionDeallocatorType  d )

inlineinherited

Definition at line 196 of file vpForwardProjection.h.

References vpTracker::init().

setWorldCoordinates() [1/3]

void vpPoint::setWorldCoordinates	(	double	oX,
		double	oY,
		double	oZ
	)

Set the 3D point object frame coordinates oP = (oX, oY, oZ, 1).

Parameters

oX,oY,oZ

Coordinates of a 3D point in the object frame.

Examples:

AROgre.cpp, AROgreBasic.cpp, homographyHartleyDLT2DObject.cpp, homographyHLM2DObject.cpp, homographyHLM3DObject.cpp, manGeometricFeatures.cpp, manServo4PointsDisplay.cpp, manSimu4Dots.cpp, manSimu4Points.cpp, poseVirtualVS.cpp, servoAfma62DhalfCamVelocity.cpp, servoAfma6FourPoints2DCamVelocityLs_cur.cpp, servoAfma6FourPoints2DCamVelocityLs_des.cpp, servoAfma6Points2DCamVelocityEyeToHand.cpp, servoPioneerPanSegment3D.cpp, servoSimu4Points.cpp, servoSimuAfma6FourPoints2DCamVelocity.cpp, servoSimuFourPoints2DCamVelocity.cpp, servoSimuFourPoints2DCamVelocityDisplay.cpp, servoSimuFourPoints2DPolarCamVelocityDisplay.cpp, servoSimuViper850FourPoints2DCamVelocity.cpp, servoViper850FourPoints2DArtVelocityLs_cur.cpp, servoViper850FourPoints2DCamVelocityLs_cur.cpp, servoViper850FourPointsKinect.cpp, simulateFourPoints2DCartesianCamVelocity.cpp, simulateFourPoints2DPolarCamVelocity.cpp, testFeatureSegment.cpp, testRobotAfma6Pose.cpp, testRobotViper850Pose.cpp, tutorial-ibvs-4pts-ogre.cpp, tutorial-ibvs-4pts-plotter-continuous-gain-adaptive.cpp, tutorial-ibvs-4pts-plotter-gain-adaptive.cpp, tutorial-ibvs-4pts-plotter.cpp, and tutorial-ibvs-4pts.cpp.

Definition at line 113 of file vpPoint.cpp.

References vpForwardProjection::oP.

Referenced by vpMbTracker::addPolygon(), vpMbTracker::addProjectionErrorPolygon(), vpKeyPoint::compute3D(), vpKeyPoint::compute3DForPointsOnCylinders(), vpMbtFaceDepthNormal::computeDesiredNormalAndCentroid(), vpMbTracker::extractCylinders(), vpMbTracker::extractFaces(), vpMbTracker::extractLines(), vpMbTracker::getGravityCenter(), vpProjectionDisplay::init(), vpMbtDistanceKltCylinder::init(), vpMbTracker::initFromPoints(), vpMbTracker::loadCAOModel(), vpKeyPoint::matchPoint(), vpPose::poseFromRectangle(), vpWireFrameSimulator::projectCameraTrajectory(), and vpPoint().

setWorldCoordinates() [2/3]

void vpPoint::setWorldCoordinates ( const vpColVector &  oP_ )

virtual

Set the 3D point object frame coordinates.

Parameters

oP_

Vector containing the coordinates of the 3D point in the object frame. This vector could be of dimension 3 or 4. If dimension is 3, oP corresponds to the normalized coordinates oP = (oX, oY, oZ, 1) where oP[0]=oX, oP[1]=oY, oP[2]=oZ. If dimension is 4, oP corresponds to the normalized coordinates oP = (oX, oY, oZ, oW) where oP[0]=oX, oP[1]=oY, oP[2]=oZ and oP[3]=oW.

Implements vpForwardProjection.

Definition at line 131 of file vpPoint.cpp.

References vpException::dimensionError, vpForwardProjection::oP, and vpArray2D< Type >::size().

setWorldCoordinates() [3/3]

void vpPoint::setWorldCoordinates

(

const std::vector< double > &

oP_

)

Set the 3D point object frame coordinates.

Parameters

oP_

Vector containing the coordinates of the 3D point in the object frame. This vector could be of dimension 3 or 4. If dimension is 3, oP corresponds to the normalized coordinates oP = (oX, oY, oZ, 1) where oP[0]=oX, oP[1]=oY, oP[2]=oZ. If dimension is 4, oP corresponds to the normalized coordinates oP = (oX, oY, oZ, oW) where oP[0]=oX, oP[1]=oY, oP[2]=oZ and oP[3]=oW.

Definition at line 159 of file vpPoint.cpp.

References vpException::dimensionError, and vpForwardProjection::oP.

track()

void vpForwardProjection::track ( const vpHomogeneousMatrix &  cMo )

inherited

Track the feature parameters in the camera frame (vpTracker::cP) and than compute the projection of these parameters in the image plane (vpTracker::p).

This method is similar to project(const vpHomogeneousMatrix &).

Warning

The feature parameters in the object frame (vpForwardProjection:oP) need to be set prior the use of this method. To initialize these parameters see setWorldCoordinates().

Parameters

cMo	: The homogeneous matrix corresponding to the pose between the camera frame and the object frame.

Examples:

mbot-apriltag-ibvs.cpp, servoBebop2.cpp, servoMomentPoints.cpp, servoMomentPolygon.cpp, servoSimu4Points.cpp, servoSimuAfma6FourPoints2DCamVelocity.cpp, servoSimuCircle2DCamVelocity.cpp, servoSimuCircle2DCamVelocityDisplay.cpp, servoSimuCylinder.cpp, servoSimuFourPoints2DCamVelocity.cpp, servoSimuFourPoints2DCamVelocityDisplay.cpp, servoSimuFourPoints2DPolarCamVelocityDisplay.cpp, servoSimuLine2DCamVelocityDisplay.cpp, servoSimuSphere.cpp, servoSimuSphere2DCamVelocity.cpp, servoSimuSphere2DCamVelocityDisplay.cpp, servoSimuSphere2DCamVelocityDisplaySecondaryTask.cpp, servoSimuSquareLine2DCamVelocityDisplay.cpp, servoSimuViper850FourPoints2DCamVelocity.cpp, simulateCircle2DCamVelocity.cpp, simulateFourPoints2DCartesianCamVelocity.cpp, simulateFourPoints2DPolarCamVelocity.cpp, tutorial-ibvs-4pts-ogre.cpp, tutorial-ibvs-4pts-plotter-continuous-gain-adaptive.cpp, tutorial-ibvs-4pts-plotter-gain-adaptive.cpp, tutorial-ibvs-4pts-plotter.cpp, tutorial-ibvs-4pts.cpp, tutorial-simu-pioneer-continuous-gain-adaptive.cpp, tutorial-simu-pioneer-continuous-gain-constant.cpp, tutorial-simu-pioneer-pan.cpp, and tutorial-simu-pioneer.cpp.

Definition at line 106 of file vpForwardProjection.cpp.

References vpForwardProjection::project().

Referenced by vpPoseFeatures::addFeatureSegment(), vpPose::computeResidual(), vpProjectionDisplay::displayCamera(), vpImageDraw::drawFrame(), vpPose::poseVirtualVS(), vpPose::poseVirtualVSrobust(), vpWireFrameSimulator::projectCameraTrajectory(), vpSimulatorAfma6::updateArticularPosition(), and vpSimulatorViper850::updateArticularPosition().

Friends And Related Function Documentation

operator<<

VISP_EXPORT std::ostream& operator<< ( std::ostream &  os, const vpPoint &  vpp  )

friend

Definition at line 408 of file vpPoint.cpp.

Member Data Documentation

cP

vpColVector vpTracker::cP

inherited

Feature coordinates expressed in the camera frame cP.

Definition at line 77 of file vpTracker.h.

Referenced by vpFeaturePoint3D::buildFrom(), vpSphere::changeFrame(), changeFrame(), vpCircle::changeFrame(), vpLine::changeFrame(), vpCylinder::changeFrame(), vpFeatureBuilder::create(), get_W(), get_X(), get_Y(), get_Z(), vpSphere::init(), vpCircle::init(), init(), vpLine::init(), vpCylinder::init(), vpMbtPolygon::isVisible(), vpTracker::operator=(), vpForwardProjection::print(), vpPose::printPoint(), vpForwardProjection::project(), vpSphere::projection(), vpCircle::projection(), projection(), vpLine::projection(), vpCylinder::projection(), set_W(), set_X(), set_Y(), and set_Z().

cPAvailable

bool vpTracker::cPAvailable

inherited

Flag used to indicate if the feature parameters cP expressed in the camera frame are available.

Definition at line 83 of file vpTracker.h.

Referenced by vpTracker::init(), and vpTracker::operator=().

oP

vpColVector vpForwardProjection::oP

inherited

Feature coordinates expressed in the object frame.

Definition at line 228 of file vpForwardProjection.h.

Referenced by vpSphere::changeFrame(), changeFrame(), vpCircle::changeFrame(), vpLine::changeFrame(), vpCylinder::changeFrame(), get_oW(), get_oX(), get_oY(), get_oZ(), getWorldCoordinates(), vpSphere::init(), vpCircle::init(), init(), vpLine::init(), vpCylinder::init(), vpForwardProjection::print(), vpPose::printPoint(), set_oW(), set_oX(), set_oY(), set_oZ(), vpSphere::setWorldCoordinates(), vpCircle::setWorldCoordinates(), setWorldCoordinates(), vpLine::setWorldCoordinates(), and vpCylinder::setWorldCoordinates().

p

vpColVector vpTracker::p

inherited

Feature coordinates expressed in the image plane p. They correspond to 2D normalized coordinates expressed in meters.

Definition at line 73 of file vpTracker.h.

Referenced by vpMbtDistanceCircle::computeInteractionMatrixError(), vpCircle::computeIntersectionPoint(), vpMeterPixelConversion::convertEllipse(), vpFeatureBuilder::create(), vpSphere::display(), display(), vpCircle::display(), vpLine::display(), vpProjectionDisplay::display(), vpCylinder::display(), vpProjectionDisplay::displayCamera(), vpFeatureDisplay::displayEllipse(), vpPose::displayModel(), vpImageDraw::drawFrame(), get_w(), get_x(), get_y(), vpSphere::init(), vpMeTracker::init(), vpCircle::init(), init(), vpLine::init(), vpCylinder::init(), vpTracker::operator=(), vpForwardProjection::print(), vpPose::printPoint(), vpForwardProjection::project(), vpSphere::projection(), vpCircle::projection(), projection(), vpLine::projection(), vpCylinder::projection(), set_w(), set_x(), and set_y().