com.jme3.bullet.joints.SixDofSpringJoint Maven / Gradle / Ivy
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/*
* Copyright (c) 2009-2018 jMonkeyEngine
* All rights reserved.
*
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*
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*
* * Redistributions in binary form must reproduce the above copyright
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*
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package com.jme3.bullet.joints;
import com.jme3.bullet.objects.PhysicsRigidBody;
import com.jme3.export.InputCapsule;
import com.jme3.export.JmeExporter;
import com.jme3.export.JmeImporter;
import com.jme3.export.OutputCapsule;
import com.jme3.math.Matrix3f;
import com.jme3.math.Vector3f;
import com.jme3.util.clone.Cloner;
import java.io.IOException;
import java.util.logging.Logger;
import jme3utilities.Validate;
/**
* A 6 degree-of-freedom joint based on Bullet's btGeneric6DofSpringConstraint.
*
* From the Bullet manual:
*
* For each axis:
* - Lowerlimit = Upperlimit → axis is locked
* - Lowerlimit > Upperlimit → axis is free
* - Lowerlimit < Upperlimit → axis is limited in that range
*
*
* It is recommended to use the btGeneric6DofSpring2Constraint, it has some
* improvements over the original btGeneric6Dof(Spring)Constraint.
*
* @see com.jme3.bullet.joints.New6Dof
* @author normenhansen
*/
public class SixDofSpringJoint extends SixDofJoint {
// *************************************************************************
// constants and loggers
/**
* message logger for this class
*/
final public static Logger logger3
= Logger.getLogger(SixDofSpringJoint.class.getName());
/**
* field names for serialization
*/
final private static String tagDof = "Dof";
final private static String tagSpringDamping = "_SpringDamping";
final private static String tagStiffness = "_Stiffness";
// *************************************************************************
// constructors
/**
* No-argument constructor needed by SavableClassUtil.
*/
protected SixDofSpringJoint() {
}
/**
* Instantiate a single-ended SixDofSpringJoint.
*
* To be effective, the joint must be added to the body's PhysicsSpace and
* the body must be dynamic.
*
* @param rigidBodyB the body to constrain (not null, alias created)
* @param pivotInB the pivot location in B's scaled local coordinates (not
* null, unaffected)
* @param pivotInWorld the pivot location in physics-space coordinates (not
* null, unaffected)
* @param rotInB the orientation of the joint in B's local coordinates
* (rotation matrix, not null, unaffected)
* @param rotInWorld the orientation of the joint in physics-space
* coordinates (rotation matrix, not null, unaffected)
* @param linearReferenceFrame which end to use as the linear reference
* frame (not null)
*/
public SixDofSpringJoint(PhysicsRigidBody rigidBodyB, Vector3f pivotInB,
Vector3f pivotInWorld, Matrix3f rotInB, Matrix3f rotInWorld,
JointEnd linearReferenceFrame) {
super(rigidBodyB, pivotInB, pivotInWorld, rotInB, rotInWorld,
linearReferenceFrame);
}
/**
* Instantiate a double-ended SixDofSpringJoint.
*
* To be effective, the joint must be added to the PhysicsSpace of both
* bodies. Also, the bodies must be distinct and at least one of them must
* be dynamic.
*
* @param rigidBodyA the body for the A end (not null, alias created)
* @param rigidBodyB the body for the B end (not null, alias created)
* @param pivotInA the pivot location in A's scaled local coordinates (not
* null, unaffected)
* @param pivotInB the pivot location in B's scaled local coordinates (not
* null, unaffected)
* @param rotInA the orientation of the joint in A's local coordinates (not
* null, unaffected)
* @param rotInB the orientation of the joint in B's local coordinates (not
* null, unaffected)
* @param useLinearReferenceFrameA true→use body A, false→use body
* B
*/
public SixDofSpringJoint(PhysicsRigidBody rigidBodyA,
PhysicsRigidBody rigidBodyB, Vector3f pivotInA, Vector3f pivotInB,
Matrix3f rotInA, Matrix3f rotInB,
boolean useLinearReferenceFrameA) {
super(rigidBodyA, rigidBodyB, pivotInA, pivotInB, rotInA, rotInB,
useLinearReferenceFrameA);
}
// *************************************************************************
// new methods exposed
/**
* Enable or disable the spring for the indexed degree of freedom. Enabling
* a spring also enables the corresponding limit motor. Disabling a spring
* also disables the corresponding limit motor.
*
* @param dofIndex which degree of freedom (0→X translation, 1→Y
* translation, 2→Z translation, 3→X rotation, 4→Y rotation,
* 5→Z rotation)
* @param onOff true → enable, false → disable (default=false)
*/
public void enableSpring(int dofIndex, boolean onOff) {
Validate.inRange(dofIndex, "DOF index", 0, 5);
long constraintId = nativeId();
enableSpring(constraintId, dofIndex, onOff);
}
/**
* Return the damping of the indexed degree of freedom.
*
* @param dofIndex which degree of freedom (0→X translation, 1→Y
* translation, 2→Z translation, 3→X rotation, 4→Y rotation,
* 5→Z rotation)
* @return the viscous damping ratio
*/
public float getDamping(int dofIndex) {
Validate.inRange(dofIndex, "DOF index", 0, 5);
long constraintId = nativeId();
float result = getDamping(constraintId, dofIndex);
return result;
}
/**
* Return the equilibrium point of the indexed degree of freedom.
*
* @param dofIndex which degree of freedom (0→X translation, 1→Y
* translation, 2→Z translation, 3→X rotation, 4→Y rotation,
* 5→Z rotation)
* @return the equilibrium point
*/
public float getEquilibriumPoint(int dofIndex) {
Validate.inRange(dofIndex, "DOF index", 0, 5);
long constraintId = nativeId();
float result = getEquilibriumPoint(constraintId, dofIndex);
return result;
}
/**
* Return the spring stiffness of the indexed degree of freedom.
*
* @param dofIndex which degree of freedom (0→X translation, 1→Y
* translation, 2→Z translation, 3→X rotation, 4→Y rotation,
* 5→Z rotation)
* @return the stiffness
*/
public float getStiffness(int dofIndex) {
Validate.inRange(dofIndex, "DOF index", 0, 5);
long constraintId = nativeId();
float result = getStiffness(constraintId, dofIndex);
return result;
}
/**
* Test whether the spring for the indexed degree of freedom is enabled.
*
* @param dofIndex which degree of freedom (0→X translation, 1→Y
* translation, 2→Z translation, 3→X rotation, 4→Y rotation,
* 5→Z rotation)
* @return true if enabled, otherwise false
*/
public boolean isSpringEnabled(int dofIndex) {
Validate.inRange(dofIndex, "DOF index", 0, 5);
long constraintId = nativeId();
boolean result = isSpringEnabled(constraintId, dofIndex);
return result;
}
/**
* Alter the damping for the indexed degree of freedom.
*
* @param dofIndex which degree of freedom (0→X translation, 1→Y
* translation, 2→Z translation, 3→X rotation, 4→Y rotation,
* 5→Z rotation)
* @param damping the desired viscous damping ratio (0→no damping,
* 1→critically damped, default=1)
*/
public void setDamping(int dofIndex, float damping) {
Validate.inRange(dofIndex, "DOF index", 0, 5);
long constraintId = nativeId();
setDamping(constraintId, dofIndex, damping);
}
/**
* Alter the equilibrium points for all degrees of freedom, based on the
* joint's current location/orientation.
*/
public void setEquilibriumPoint() {
long constraintId = nativeId();
setEquilibriumPoint(constraintId);
}
/**
* Alter the equilibrium point of the indexed degree of freedom, based on
* the joint's current location/orientation.
*
* @param dofIndex which degree of freedom (0→X translation, 1→Y
* translation, 2→Z translation, 3→X rotation, 4→Y rotation,
* 5→Z rotation)
*/
public void setEquilibriumPoint(int dofIndex) {
Validate.inRange(dofIndex, "DOF index", 0, 5);
long constraintId = nativeId();
setEquilibriumPoint(constraintId, dofIndex);
}
/**
* Alter the spring stiffness for the indexed degree of freedom.
*
* @param dofIndex which degree of freedom (0→X translation, 1→Y
* translation, 2→Z translation, 3→X rotation, 4→Y rotation,
* 5→Z rotation)
* @param stiffness the desired stiffness (default=0)
*/
public void setStiffness(int dofIndex, float stiffness) {
Validate.inRange(dofIndex, "DOF index", 0, 5);
long constraintId = nativeId();
setStiffness(constraintId, dofIndex, stiffness);
}
// *************************************************************************
// SixDofJoint methods
/**
* Create a double-ended {@code btGeneric6DofSpringConstraint}.
*
* @param bodyIdA the ID of the body for the A end (not zero)
* @param bodyIdB the ID of the body for the B end (not zero)
* @param pivotInA the pivot location in A's scaled local coordinates (not
* null, unaffected)
* @param rotInA the orientation of the joint in A's local coordinates (not
* null, unaffected)
* @param pivotInB the pivot location in B's scaled local coordinates (not
* null, unaffected)
* @param rotInB the orientation of the joint in B's local coordinates (not
* null, unaffected)
* @param useLinearReferenceFrameA true→use body A, false→use body
* B
* @return the ID of the new joint
*/
@Override
native protected long createJoint(long bodyIdA, long bodyIdB,
Vector3f pivotInA, Matrix3f rotInA, Vector3f pivotInB,
Matrix3f rotInB, boolean useLinearReferenceFrameA);
/**
* Create a single-ended {@code btGeneric6DofSpringConstraint}.
*
* @param bodyIdB the ID of the body for the B end (not zero)
* @param pivotInB the pivot location in B's scaled local coordinates (not
* null, unaffected)
* @param rotInB the orientation of the joint in B's local coordinates (not
* null, unaffected)
* @param useLinearReferenceFrameB true→use body A, false→use body
* B
* @return the ID of the new joint
*/
@Override
native protected long createJoint1(long bodyIdB, Vector3f pivotInB,
Matrix3f rotInB, boolean useLinearReferenceFrameB);
/**
* Callback from {@link com.jme3.util.clone.Cloner} to convert this
* shallow-cloned joint into a deep-cloned one, using the specified Cloner
* and original to resolve copied fields.
*
* @param cloner the Cloner that's cloning this joint (not null)
* @param original the instance from which this joint was shallow-cloned
* (not null, unaffected)
*/
@Override
public void cloneFields(Cloner cloner, Object original) {
assert !hasAssignedNativeObject();
SixDofSpringJoint old = (SixDofSpringJoint) original;
assert old != this;
assert old.hasAssignedNativeObject();
super.cloneFields(cloner, original);
if (hasAssignedNativeObject()) {
return;
}
for (int dofIndex = 0; dofIndex < 6; ++dofIndex) {
setDamping(dofIndex, old.getDamping(dofIndex));
setStiffness(dofIndex, old.getStiffness(dofIndex));
// TODO: enableSpring, equilibrium points
}
}
/**
* De-serialize this joint from the specified importer, for example when
* loading from a J3O file.
*
* @param importer (not null)
* @throws IOException from the importer
*/
@Override
public void read(JmeImporter importer) throws IOException {
super.read(importer);
InputCapsule capsule = importer.getCapsule(this);
for (int dofIndex = 0; dofIndex < 6; ++dofIndex) {
String dofTag = tagDof + dofIndex;
setDamping(dofIndex,
capsule.readFloat(dofTag + tagSpringDamping, 1f));
setStiffness(dofIndex,
capsule.readFloat(dofTag + tagStiffness, 0f));
// TODO: enableSpring, equilibrium points
}
}
/**
* Serialize this joint to the specified exporter, for example when saving
* to a J3O file.
*
* @param exporter (not null)
* @throws IOException from the exporter
*/
@Override
public void write(JmeExporter exporter) throws IOException {
super.write(exporter);
OutputCapsule capsule = exporter.getCapsule(this);
for (int dofIndex = 0; dofIndex < 6; ++dofIndex) {
String dofTag = tagDof + dofIndex;
capsule.write(getDamping(dofIndex), dofTag + tagSpringDamping, 1f);
capsule.write(getStiffness(dofIndex), dofTag + tagStiffness, 0f);
}
}
// *************************************************************************
// native private methods
native private static void
enableSpring(long jointId, int dofIndex, boolean onOff);
native private static float getDamping(long jointId, int dofIndex);
native private static float getEquilibriumPoint(long jointId, int dofIndex);
native private static float getStiffness(long jointId, int dofIndex);
native private static boolean isSpringEnabled(long jointId, int dofIndex);
native private static void
setDamping(long jointId, int dofIndex, float damping);
native private static void setEquilibriumPoint(long jointId);
native private static void setEquilibriumPoint(long jointId, int dofIndex);
native private static void
setStiffness(long jointId, int dofIndex, float stiffness);
}