Module org.dyn4j

Package org.dyn4j.dynamics.joint

Interface LinearSpringJoint

All Known Implementing Classes:

DistanceJoint, PinJoint, PrismaticJoint, WheelJoint

public interface LinearSpringJoint

Represents a linear spring joint.

Since:

5.0.0

Version:

5.0.0

Author:

William Bittle

Method Summary

Modifier and Type	Method	Description
double	getMaximumSpringForce()	Returns the maximum spring force that will be applied.
double	getSpringDampingRatio()	Returns the damping ratio for the spring's damper.
double	getSpringForce(double invdt)	Returns the force in netwons applied by the spring in the last timestep.
double	getSpringFrequency()	Returns the spring frequency.
int	getSpringMode()	Returns the current spring mode.
double	getSpringStiffness()	Returns the spring stiffness.
boolean	isMaximumSpringForceEnabled()	Returns true if the spring force is limited to the maximum.
boolean	isSpringDamperEnabled()	Returns true if the damper is enabled for the spring.
boolean	isSpringEnabled()	Returns true if the spring is enabled.
void	setMaximumSpringForce(double maximum)	Sets the maximum force the spring can apply.
void	setMaximumSpringForceEnabled(boolean enabled)	Sets whether the spring force is limited to the maximum.
void	setSpringDamperEnabled(boolean enabled)	Sets whether the spring's damper is enabled or not.
void	setSpringDampingRatio(double dampingRatio)	Sets the damping ratio.
void	setSpringEnabled(boolean enabled)	Sets whether the spring is enabled or not.
void	setSpringFrequency(double frequency)	Sets the spring frequency.
void	setSpringStiffness(double stiffness)	Sets the spring stiffness.

Method Detail

setSpringEnabled

void setSpringEnabled(boolean enabled)

Sets whether the spring is enabled or not.

Parameters:

enabled - true if the spring should be enabled

isSpringEnabled

boolean isSpringEnabled()

Returns true if the spring is enabled.

Returns:

boolean

setSpringDamperEnabled

void setSpringDamperEnabled(boolean enabled)

Sets whether the spring's damper is enabled or not.

NOTE: for the damper to have any effect, the spring must be enabled.

Parameters:

enabled - true if the damper should be enabled

See Also:

setSpringEnabled(boolean)

isSpringDamperEnabled

boolean isSpringDamperEnabled()

Returns true if the damper is enabled for the spring.

NOTE: for the damper to have any effect, the spring must be enabled.

Returns:

boolean

Since:

4.0.0

See Also:

isSpringEnabled()

getSpringDampingRatio

double getSpringDampingRatio()

Returns the damping ratio for the spring's damper.

Returns:

double

setSpringDampingRatio

void setSpringDampingRatio(double dampingRatio)

Sets the damping ratio.

Larger values reduce the oscillation of the spring.

Parameters:

dampingRatio - the damping ratio; in the range (0, 1]

Throws:

IllegalArgumentException - if damping ratio is less than or equal to zero or greater than 1

getSpringFrequency

double getSpringFrequency()

Returns the spring frequency.

Returns:

double

setSpringFrequency

void setSpringFrequency(double frequency)

Sets the spring frequency.

Larger values increase the stiffness of the spring.

Calling this method puts the spring into fixed frequency mode. In this mode, the spring stiffness is computed based on the frequency.

Parameters:

frequency - the spring frequency in hz; must be greater than zero

Throws:

IllegalArgumentException - if frequency is less than or equal to zero

getSpringStiffness

double getSpringStiffness()

Returns the spring stiffness.

Returns:

double

setSpringStiffness

void setSpringStiffness(double stiffness)

Sets the spring stiffness.

Larger values increase the stiffness of the spring.

Calling this method puts the spring into fixed stiffness mode. In this mode, the spring frequency is computed based on the stiffness.

Parameters:

stiffness - the spring stiffness (k); must be greater than zero

Throws:

IllegalArgumentException - if stiffness is less than or equal to zero

isMaximumSpringForceEnabled

boolean isMaximumSpringForceEnabled()

Returns true if the spring force is limited to the maximum.

Returns:

boolean

setMaximumSpringForceEnabled

void setMaximumSpringForceEnabled(boolean enabled)

Sets whether the spring force is limited to the maximum.

Parameters:

enabled - true if the spring force should be limited

getMaximumSpringForce

double getMaximumSpringForce()

Returns the maximum spring force that will be applied.

Returns:

double

setMaximumSpringForce

void setMaximumSpringForce(double maximum)

Sets the maximum force the spring can apply.

Parameters:

maximum - the maximum force

Throws:

IllegalArgumentException - if maximum is less than or equal to zero

getSpringForce

double getSpringForce(double invdt)

Returns the force in netwons applied by the spring in the last timestep.

Parameters:

invdt - the inverse delta time

Returns:

double

getSpringMode

int getSpringMode()

Returns the current spring mode.

NOTE: The spring mode is set automatically when you call either setSpringFrequency(double) or setSpringStiffness(double). Use this method to store the spring mode when saving the simulation state and use the value to call either setSpringFrequency(double) or setSpringStiffness(double).

Returns:

int

See Also:

Joint.SPRING_MODE_FREQUENCY, Joint.SPRING_MODE_STIFFNESS