path: root/PhysX_3.4/Include/extensions/PxJointLimit.h

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#ifndef PX_EXTENSIONS_JOINT_LIMIT
#define PX_EXTENSIONS_JOINT_LIMIT
/** \addtogroup extensions
  @{
*/

#include "foundation/PxMath.h"
#include "PxPhysXConfig.h"
#include "common/PxTolerancesScale.h"
#include "PxJoint.h"

#if !PX_DOXYGEN
namespace physx
{
#endif

/**
\brief Describes the parameters for a joint limit. 

Limits are enabled or disabled by setting flags or other configuration parameters joints, see the
documentation for specific joint types for details.

*/

class PxJointLimitParameters
{
//= ATTENTION! =====================================================================================
// Changing the data layout of this class breaks the binary serialization format.  See comments for 
// PX_BINARY_SERIAL_VERSION.  If a modification is required, please adjust the getBinaryMetaData 
// function.  If the modification is made on a custom branch, please change PX_BINARY_SERIAL_VERSION
// accordingly.
//==================================================================================================
public:
	/**
	\brief Controls the amount of bounce when the joint hits a limit.

	A restitution value of 1.0 causes the joint to bounce back with the velocity which it hit the limit.
	A value of zero causes the joint to stop dead.

	In situations where the joint has many locked DOFs (e.g. 5) the restitution may not be applied 
	correctly. This is due to a limitation in the solver which causes the restitution velocity to become zero 
	as the solver enforces constraints on the other DOFs.

	This limitation applies to both angular and linear limits, however it is generally most apparent with limited
	angular DOFs. Disabling joint projection and increasing the solver iteration count may improve this behavior 
	to some extent.

	Also, combining soft joint limits with joint drives driving against those limits may affect stability.

	<b>Range:</b> [0,1]<br>
	<b>Default:</b> 0.0
	*/
	PxReal restitution;


	/**
	determines the minimum impact velocity which will cause the joint to bounce
	*/

	PxReal bounceThreshold;
	/**
	\brief if greater than zero, the limit is soft, i.e. a spring pulls the joint back to the limit

	<b>Range:</b> [0, PX_MAX_F32)<br>
	<b>Default:</b> 0.0
	*/
	PxReal stiffness;

	/**
	\brief if spring is greater than zero, this is the damping of the limit spring

	<b>Range:</b> [0, PX_MAX_F32)<br>
	<b>Default:</b> 0.0
	*/
	PxReal damping;

	/**
	\brief the distance inside the limit value at which the limit will be considered to be active by the
	solver.  As this value is made larger, the limit becomes active more quickly. It thus becomes less 
	likely to violate the extents of the limit, but more expensive.
	
	The contact distance should be less than the limit angle or distance, and in the case of a pair limit,
	less than half the distance between the upper and lower bounds. Exceeding this value will result in
	the limit being active all the time.

	Making this value too small can result in jitter around the limit.

	<b>Default:</b> depends on the joint

	@see PxPhysics::getTolerancesScale()
	*/

	PxReal contactDistance;



	PxJointLimitParameters()
	: restitution(0)
	, bounceThreshold(0)
	, stiffness(0)
	, damping(0)
	, contactDistance(0)
	{
	}	

	/**
	\brief Returns true if the current settings are valid.

	\return true if the current settings are valid
	*/
	PX_INLINE bool isValid() const
	{
		return	PxIsFinite(restitution) && restitution >= 0 && restitution <= 1 && 
			    PxIsFinite(stiffness) && stiffness >= 0 && 
			    PxIsFinite(damping) && damping >= 0 &&
				PxIsFinite(bounceThreshold) && bounceThreshold >= 0 &&
				PxIsFinite(contactDistance) && contactDistance >= 0;
	}

	PX_INLINE bool isSoft() const
	{
		return damping>0 || stiffness>0;
	}

protected:
	~PxJointLimitParameters() {}
};


/**
\brief Describes a one-sided linear limit.
*/
class PxJointLinearLimit : public PxJointLimitParameters
{
//= ATTENTION! =====================================================================================
// Changing the data layout of this class breaks the binary serialization format.  See comments for 
// PX_BINARY_SERIAL_VERSION.  If a modification is required, please adjust the getBinaryMetaData 
// function.  If the modification is made on a custom branch, please change PX_BINARY_SERIAL_VERSION
// accordingly.
//==================================================================================================
public:
	/**
	\brief the extent of the limit. 

	<b>Range:</b> (0, PX_MAX_F32) <br>
	<b>Default:</b> PX_MAX_F32
	*/
	PxReal value;

	/**
	\brief construct a linear hard limit

	\param[in] scale a PxTolerancesScale struct. Should be the same as used when creating the PxPhysics object.
	\param[in] extent the extent of the limit
	\param[in] contactDist the distance from the limit at which it becomes active. Default is 0.01f scaled by the tolerance length scale

	@see PxJointLimitParameters PxTolerancesScale
	*/

	PxJointLinearLimit(const PxTolerancesScale& scale, PxReal extent, PxReal contactDist = -1)
	: value(extent)
	{
		PxJointLimitParameters::contactDistance = contactDist == -1 ? 0.01f*scale.length : contactDist; 
	}


	/**
	\brief construct a linear soft limit 

	\param[in] extent the extent of the limit
	\param[in] spring the stiffness and damping parameters for the limit spring

	@see PxJointLimitParameters PxTolerancesScale
	*/

	PxJointLinearLimit(PxReal extent, const PxSpring& spring)
	: value(extent)
	{
		stiffness = spring.stiffness;
		damping = spring.damping;
	}



	/**
	\brief Returns true if the limit is valid

	\return true if the current settings are valid
	*/
	PX_INLINE bool isValid() const
	{
		return PxJointLimitParameters::isValid() &&
			   PxIsFinite(value) && 
			   value > 0;
	}
};


/**
\brief Describes a two-sided limit.
*/

class PxJointLinearLimitPair : public PxJointLimitParameters
{
//= ATTENTION! =====================================================================================
// Changing the data layout of this class breaks the binary serialization format.  See comments for 
// PX_BINARY_SERIAL_VERSION.  If a modification is required, please adjust the getBinaryMetaData 
// function.  If the modification is made on a custom branch, please change PX_BINARY_SERIAL_VERSION
// accordingly.
//==================================================================================================
public:
	/**
	\brief the range of the limit. The upper limit must be no lower than the
	lower limit, and if they are equal the limited degree of freedom will be treated as locked.

	<b>Unit:</b> Angular: Radians
	<b>Range:</b> See the joint on which the limit is used for details<br>
	<b>Default:</b> 0.0
	*/
	PxReal upper, lower;


	/**
	\brief Construct a linear hard limit pair. The lower distance value must be less than the upper distance value. 

	\param[in] scale a PxTolerancesScale struct. Should be the same as used when creating the PxPhysics object.
	\param[in] lowerLimit the lower distance of the limit
	\param[in] upperLimit the upper distance of the limit
	\param[in] contactDist the distance from the limit at which it becomes active. Default is the lesser of 0.01f scaled by the tolerance length scale, and 0.49 * (upperLimit - lowerLimit)

	@see PxJointLimitParameters PxTolerancesScale
	*/

	PxJointLinearLimitPair(const PxTolerancesScale& scale, PxReal lowerLimit, PxReal upperLimit, PxReal contactDist = -1)
	: upper(upperLimit)
	, lower(lowerLimit)
	{
		PxJointLimitParameters::contactDistance = contactDist == -1 ? PxMin(scale.length * 0.01f, (upperLimit*0.49f-lowerLimit*0.49f)) : contactDist; 
		bounceThreshold = 2*scale.length;
	}


	/**
	\brief construct a linear soft limit pair

	\param[in] lowerLimit the lower distance of the limit
	\param[in] upperLimit the upper distance of the limit
	\param[in] spring the stiffness and damping parameters of the limit spring

	@see PxJointLimitParameters PxTolerancesScale
	*/

	PxJointLinearLimitPair(PxReal lowerLimit, PxReal upperLimit, const PxSpring& spring)
	: upper(upperLimit)
	, lower(lowerLimit)
	{
		stiffness = spring.stiffness;
		damping = spring.damping;
	}


	/**
	\brief Returns true if the limit is valid.

	\return true if the current settings are valid
	*/
	PX_INLINE bool isValid() const
	{
		return PxJointLimitParameters::isValid() &&
			   PxIsFinite(upper) && PxIsFinite(lower) && upper >= lower &&
			   PxIsFinite(upper - lower) && 
			   PxIsFinite(contactDistance) && contactDistance <= upper - lower;
	}
};


class PxJointAngularLimitPair : public PxJointLimitParameters
{
//= ATTENTION! =====================================================================================
// Changing the data layout of this class breaks the binary serialization format.  See comments for 
// PX_BINARY_SERIAL_VERSION.  If a modification is required, please adjust the getBinaryMetaData 
// function.  If the modification is made on a custom branch, please change PX_BINARY_SERIAL_VERSION
// accordingly.
//==================================================================================================
public:
	/**
	\brief the range of the limit. The upper limit must be no lower than the lower limit.

	<b>Unit:</b> Angular: Radians
	<b>Range:</b> See the joint on which the limit is used for details<br>
	<b>Default:</b> 0.0
	*/
	PxReal upper, lower;


	/**
	\brief construct an angular hard limit pair. 
	
	The lower value must be less than the upper value. 

	\param[in] lowerLimit the lower angle of the limit
	\param[in] upperLimit the upper angle of the limit
	\param[in] contactDist the distance from the limit at which it becomes active. Default is the lesser of 0.1 radians, and 0.49 * (upperLimit - lowerLimit)

	@see PxJointLimitParameters
	*/

	PxJointAngularLimitPair(PxReal lowerLimit, PxReal upperLimit, PxReal contactDist = -1)
	: upper(upperLimit)
	, lower(lowerLimit)
	{
		PxJointLimitParameters::contactDistance = contactDist ==-1 ? PxMin(0.1f, 0.49f*(upperLimit-lowerLimit)) : contactDist;
		bounceThreshold = 0.5f;
	}


	/**
	\brief construct an angular soft limit pair. 
	
	The lower value must be less than the upper value. 

	\param[in] lowerLimit the lower angle of the limit
	\param[in] upperLimit the upper angle of the limit
	\param[in] spring the stiffness and damping of the limit spring

	@see PxJointLimitParameters
	*/

	PxJointAngularLimitPair(PxReal lowerLimit, PxReal upperLimit, const PxSpring& spring)
	: upper(upperLimit)
	, lower(lowerLimit)
	{
		stiffness = spring.stiffness;
		damping = spring.damping;
	}


	/**
	\brief Returns true if the limit is valid.

	\return true if the current settings are valid
	*/
	PX_INLINE bool isValid() const
	{
		return PxJointLimitParameters::isValid() &&
			   PxIsFinite(upper) && PxIsFinite(lower) && upper >= lower &&
			   PxIsFinite(contactDistance) && contactDistance <= upper - lower;
	}
};



/**
\brief Describes an elliptical conical joint limit. Note that very small or highly elliptical limit cones may 
result in jitter.

@see PxD6Joint PxSphericalJoint
*/

class PxJointLimitCone : public PxJointLimitParameters
{
//= ATTENTION! =====================================================================================
// Changing the data layout of this class breaks the binary serialization format.  See comments for 
// PX_BINARY_SERIAL_VERSION.  If a modification is required, please adjust the getBinaryMetaData 
// function.  If the modification is made on a custom branch, please change PX_BINARY_SERIAL_VERSION
// accordingly.
//==================================================================================================
public:
	/**
	\brief the maximum angle from the Y axis of the constraint frame.

	<b>Unit:</b> Angular: Radians
	<b>Range:</b> Angular: (0,PI)<br>
	<b>Default:</b> PI/2
	*/
	PxReal yAngle;


	/**
	\brief the maximum angle from the Z-axis of the constraint frame.

	<b>Unit:</b> Angular: Radians
	<b>Range:</b> Angular: (0,PI)<br>
	<b>Default:</b> PI/2
	*/
	PxReal zAngle;

	/**
	\brief Construct a cone hard limit. 

	\param[in] yLimitAngle the limit angle from the Y-axis of the constraint frame
	\param[in] zLimitAngle the limit angle from the Z-axis of the constraint frame
	\param[in] contactDist the distance from the limit at which it becomes active. 	Default is the lesser of 0.1 radians, and 0.49 * the lower of the limit angles

	@see PxJointLimitParameters
	*/

	PxJointLimitCone(PxReal yLimitAngle, PxReal zLimitAngle, PxReal contactDist = -1):
	  yAngle(yLimitAngle),
	  zAngle(zLimitAngle)
	  {
			PxJointLimitParameters::contactDistance = contactDist == -1 ? PxMin(0.1f, PxMin(yLimitAngle, zLimitAngle)*0.49f) : contactDist;
			bounceThreshold = 0.5f;
	  }


	
	/**
	\brief Construct a cone soft limit. 

	\param[in] yLimitAngle the limit angle from the Y-axis of the constraint frame
	\param[in] zLimitAngle the limit angle from the Z-axis of the constraint frame
	\param[in] spring the stiffness and damping of the limit spring

	@see PxJointLimitParameters
	*/

	  PxJointLimitCone(PxReal yLimitAngle, PxReal zLimitAngle, const PxSpring& spring):
	  yAngle(yLimitAngle),
	  zAngle(zLimitAngle)
	  {
		  stiffness = spring.stiffness;
		  damping = spring.damping;
	  }


	/**
	\brief Returns true if the limit is valid.

	\return true if the current settings are valid
	*/
	PX_INLINE bool isValid() const
	{
		return PxJointLimitParameters::isValid() &&
			   PxIsFinite(yAngle) && yAngle>0 && yAngle<PxPi && 
			   PxIsFinite(zAngle) && zAngle>0 && zAngle<PxPi;
	}
};

#if !PX_DOXYGEN
} // namespace physx
#endif

/** @} */
#endif