fisica

Class FRevoluteJoint

java.lang.Object

fisica.FDrawable

fisica.FJoint

fisica.FRevoluteJoint

public class FRevoluteJoint
extends FJoint

Represents a revolute joint that restricts the movement of one body with respect to another to rotation around a given anchor. The rotation can be further limited given a lower and un upper angles. Additionally the user can enable a motor in order to apply a constant rotation force (torque) to the joint in order to reach the desired rotation speed.

Field Summary

Fields

Modifier and Type	Field and Description
protected org.jbox2d.common.Vec2	m_anchor
protected FBody	m_body1
protected FBody	m_body2
protected boolean	m_enableLimit A flag to enable joint limits.
protected boolean	m_enableMotor A flag to enable the joint motor.
protected org.jbox2d.common.Vec2	m_localAnchor1 The local anchor point relative to body1's origin.
protected org.jbox2d.common.Vec2	m_localAnchor2 The local anchor point relative to body2's origin.
protected float	m_lowerAngle The lower angle for the joint limit (radians).
protected float	m_maxMotorTorque The maximum motor torque used to achieve the desired motor speed.
protected float	m_motorSpeed The desired motor speed.
protected float	m_referenceAngle The body2 angle minus body1 angle in the reference state (radians).
protected float	m_upperAngle The upper angle for the joint limit (radians).

Fields inherited from class fisica.FJoint

m_collideConnected, m_joint, m_world

Fields inherited from class fisica.FDrawable

m_drawable, m_fill, m_fillColor, m_image, m_imageAlpha, m_mask, m_stroke, m_strokeColor, m_strokeWeight

Constructor Summary

Constructors

Constructor and Description
FRevoluteJoint(FBody body1, FBody body2) Construct a revolute joint between two bodies.
FRevoluteJoint(FBody body1, FBody body2, float x, float y) Construct a revolute joint between two bodies given an anchor position.

Method Summary

Modifier and Type	Method and Description
void	draw(def.processing.core.PGraphics applet) This method is called when calling world.draw().
void	drawDebug(def.processing.core.PGraphics applet) This method is called when calling world.drawDebug().
float	getAnchorX() Get the horizontal coordinate of the anchor of the joint around which the bodies can rotate.
float	getAnchorY() Get the vertical coordinate of the anchor of the joint around which the bodies can rotate.
protected org.jbox2d.dynamics.joints.JointDef	getJointDef(FWorld world)
void	setAnchor(float x, float y) Sets the position of the anchor of the joint around which the bodies rotate.
void	setEnableLimit(boolean value) Set limits to the allowed rotation of one body respect to the other.
void	setEnableMotor(boolean value) Set the state of the motor in order to generate a rotation force (torque) on the joint.
void	setLowerAngle(float a) Set the lowest angle allowed.
void	setMaxMotorTorque(float a) Set the maximum torque that the joint's motor can apply in order to acheive the desired speed.
void	setMotorSpeed(float a) Set the desired rotation speed of the joint.
void	setReferenceAngle(float ang)
void	setUpperAngle(float a) Set the highest angle allowed.
protected void	updateLocalAnchors()

Methods inherited from class fisica.FJoint

addToWorld, getBody1, getBody2, getBox2dJoint, getReactionForceX, getReactionForceY, getReactionTorque, postDraw, postDrawDebug, preDraw, preDrawDebug, processJoint, removeFromWorld, setCollideConnected

Methods inherited from class fisica.FDrawable

appletFill, appletFillStroke, appletStroke, attachImage, dettachImage, drawImage, getFillColor, getImageAlpha, isDrawable, setDrawable, setFill, setFill, setFill, setFill, setFillColor, setImageAlpha, setNoFill, setNoStroke, setStroke, setStroke, setStroke, setStroke, setStrokeColor, setStrokeWeight, updateStyle

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

m_body1

protected FBody m_body1

m_body2

protected FBody m_body2

m_anchor

protected org.jbox2d.common.Vec2 m_anchor

m_localAnchor1

protected org.jbox2d.common.Vec2 m_localAnchor1

The local anchor point relative to body1's origin.

m_localAnchor2

protected org.jbox2d.common.Vec2 m_localAnchor2

The local anchor point relative to body2's origin.

m_referenceAngle

protected float m_referenceAngle

The body2 angle minus body1 angle in the reference state (radians).

m_enableLimit

protected boolean m_enableLimit

A flag to enable joint limits.

m_lowerAngle

protected float m_lowerAngle

The lower angle for the joint limit (radians).

m_upperAngle

protected float m_upperAngle

The upper angle for the joint limit (radians).

m_enableMotor

protected boolean m_enableMotor

A flag to enable the joint motor.

m_motorSpeed

protected float m_motorSpeed

The desired motor speed. Usually in radians per second.

m_maxMotorTorque

protected float m_maxMotorTorque

The maximum motor torque used to achieve the desired motor speed. Usually in N-m.

Constructor Detail

FRevoluteJoint

public FRevoluteJoint(FBody body1,
                      FBody body2,
                      float x,
                      float y)

Construct a revolute joint between two bodies given an anchor position.

Parameters:

body1 - first body of the joint

body2 - second body of the joint

x - horizontal coordinate of the anchor given in global coordinates, relative to the canvas' center

y - vertical coordinate of the anchor given in global coordinates, relative to the canvas' center

FRevoluteJoint

public FRevoluteJoint(FBody body1,
                      FBody body2)

Construct a revolute joint between two bodies.

Parameters:

body1 - first body of the joint

body2 - second body of the joint

Method Detail

updateLocalAnchors

protected void updateLocalAnchors()

getJointDef

protected org.jbox2d.dynamics.joints.JointDef getJointDef(FWorld world)

Overrides:

getJointDef in class FJoint

setLowerAngle

public void setLowerAngle(float a)

Set the lowest angle allowed. This property only has effect if the enableLimit has been set to true using setEnableLimit(boolean).

Parameters:

a - lowest angle allowed in radians

setUpperAngle

public void setUpperAngle(float a)

Set the highest angle allowed. This property only has effect if the enableLimit has been set to true using setEnableLimit(boolean).

Parameters:

a - highest angle allowed in radians

setEnableLimit

public void setEnableLimit(boolean value)

Set limits to the allowed rotation of one body respect to the other. If set to true the limits imposed using setLowerAngle and setLowerAngle are enforced.

Parameters:

value - if true the bodies will be able to rotate around the anchor only between certain limits

setMotorSpeed

public void setMotorSpeed(float a)

Set the desired rotation speed of the joint. This property only has effect if the enableMotor has been set to true using setEnableMotor(boolean). The speed is given in radians per second.

Parameters:

a - the desired speed in radians per second

setMaxMotorTorque

public void setMaxMotorTorque(float a)

Set the maximum torque that the joint's motor can apply in order to acheive the desired speed. This property only has effect if the enableMotor has been set to true using setEnableMotor(boolean).

Parameters:

a - the maximum torque of the joint's motor

setEnableMotor

public void setEnableMotor(boolean value)

Set the state of the motor in order to generate a rotation force (torque) on the joint. If set to true the desired motor speed, set using setMotorSpeed, will try to be matched using a motor with a maximum rotation force (torque) set using setMaxMotorTorque.

Parameters:

value - if true the joint will receive the rotation force (torque) of a motor

setAnchor

public void setAnchor(float x,
                      float y)

Sets the position of the anchor of the joint around which the bodies rotate. This position is given global coordinates, relative to the center of the canvas.

Parameters:

x - the horizontal coordinate of the anchor in global coordinates, relative to the center of the canvas

y - the vertical coordinate of the anchor in global coordinates, relative to the center of the canvas

getAnchorX

public float getAnchorX()

Get the horizontal coordinate of the anchor of the joint around which the bodies can rotate. This position is given global coordinates, relative to the center of the canvas.

Returns:

the horizontal coordinate of the anchor in global coordinates, relative to the center of the canvas

getAnchorY

public float getAnchorY()

Get the vertical coordinate of the anchor of the joint around which the bodies can rotate. This position is given global coordinates, relative to the center of the canvas.

Returns:

the vertical coordinate of the anchor in global coordinates, relative to the center of the canvas

setReferenceAngle

public void setReferenceAngle(float ang)

draw

public void draw(def.processing.core.PGraphics applet)

Description copied from class: FDrawable

This method is called when calling world.draw(). This method may be overriden to allow custom drawing of the object.

Overrides:

draw in class FDrawable

Parameters:

applet - the graphics onto which the object must be drawn.

drawDebug

public void drawDebug(def.processing.core.PGraphics applet)

Description copied from class: FDrawable

This method is called when calling world.drawDebug(). This method may be overriden to allow custom debug drawing of the object.

Overrides:

drawDebug in class FDrawable

Parameters:

applet - the graphics onto which the object must be drawn.