WheelJoint.java

/*******************************************************************************
 * Copyright 2011 See AUTHORS file.
 * 
 * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with
 * the License. You may obtain a copy of the License at
 * 
 * http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on
 * an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the
 * specific language governing permissions and limitations under the License.
 ******************************************************************************/

package com.badlogic.gdx.physics.box2d.joints;

import com.badlogic.gdx.physics.box2d.Joint;
import com.badlogic.gdx.physics.box2d.World;

/**
 * A wheel joint. This joint provides two degrees of freedom: translation along an axis fixed in body1 and rotation in
 * the plane. You can use a joint limit to restrict the range of motion and a joint motor to drive the rotation or to
 * model rotational friction. This joint is designed for vehicle suspensions.
 */
public class WheelJoint extends Joint {
	// @off
	/*JNI
	#include <Box2D/Box2D.h> 
	 */

	public WheelJoint(World world, long addr) {
		super(world, addr);
	}

	/** Get the current joint translation, usually in meters. */
	public float getJointTranslation() {
		return jniGetJointTranslation(addr);
	}

	private native float jniGetJointTranslation(long addr); /*
															b2WheelJoint* joint = (b2WheelJoint*)addr;
															return joint->GetJointTranslation();
															*/

	/** Get the current joint translation speed, usually in meters per second. */
	public float getJointSpeed() {
		return jniGetJointSpeed(addr);
	}

	private native float jniGetJointSpeed(long addr); /*
														b2WheelJoint* joint = (b2WheelJoint*)addr;
														return joint->GetJointSpeed();
														*/

	/** Is the joint motor enabled? */
	private boolean isMotorEnabled() {
		return jniIsMotorEnabled(addr);
	}

	private native boolean jniIsMotorEnabled(long addr); /*
															b2WheelJoint* joint = (b2WheelJoint*)addr;
															return joint->IsMotorEnabled();
															*/

	/** Enable/disable the joint motor. */
	public void enableMotor(boolean flag) {
		jniEnableMotor(addr, flag);
	}

	private native void jniEnableMotor(long addr, boolean flag); /*
																	b2WheelJoint* joint = (b2WheelJoint*)addr;
																	joint->EnableMotor(flag);
																	*/

	/** Set the motor speed, usually in radians per second. */
	public void setMotorSpeed(float speed) {
		jniSetMotorSpeed(addr, speed);
	}

	private native void jniSetMotorSpeed(long addr, float speed); /*
																	b2WheelJoint* joint = (b2WheelJoint*)addr;
																	joint->SetMotorSpeed(speed);
																	*/

	/** Get the motor speed, usually in radians per second. */
	public float getMotorSpeed() {
		return jniGetMotorSpeed(addr);
	}

	private native float jniGetMotorSpeed(long addr); /*
														b2WheelJoint* joint = (b2WheelJoint*)addr;
														return joint->GetMotorSpeed();
														*/

	/** Set/Get the maximum motor force, usually in N-m. */
	public void setMaxMotorTorque(float torque) {
		jniSetMaxMotorTorque(addr, torque);
	}

	private native void jniSetMaxMotorTorque(long addr, float torque); /*
																		b2WheelJoint* joint = (b2WheelJoint*)addr;
																		joint->SetMaxMotorTorque(torque);
																		*/

	public float getMaxMotorTorque() {
		return jniGetMaxMotorTorque(addr);
	}

	private native float jniGetMaxMotorTorque(long addr); /*
															b2WheelJoint* joint = (b2WheelJoint*)addr;
															return joint->GetMaxMotorTorque();
															*/

	/** Get the current motor torque given the inverse time step, usually in N-m. */
	public float getMotorTorque(float invDt) {
		return jniGetMotorTorque(addr, invDt);
	}

	private native float jniGetMotorTorque(long addr, float invDt); /*
																	b2WheelJoint* joint = (b2WheelJoint*)addr;
																	return joint->GetMotorTorque(invDt);
																	*/

	/** Set/Get the spring frequency in hertz. Setting the frequency to zero disables the spring. */
	public void setSpringFrequencyHz(float hz) {
		jniSetSpringFrequencyHz(addr, hz);
	}

	private native void jniSetSpringFrequencyHz(long addr, float hz); /*
																		b2WheelJoint* joint = (b2WheelJoint*)addr;
																		joint->SetSpringFrequencyHz(hz);
																		*/

	public float getSpringFrequencyHz() {
		return jniGetSpringFrequencyHz(addr);
	}

	private native float jniGetSpringFrequencyHz(long addr); /*
																b2WheelJoint* joint = (b2WheelJoint*)addr;
																return joint->GetSpringFrequencyHz();
																*/

	/** Set/Get the spring damping ratio */
	public void setSpringDampingRatio(float ratio) {
		jniSetSpringDampingRatio(addr, ratio);
	}

	private native void jniSetSpringDampingRatio(long addr, float ratio); /*
																			b2WheelJoint* joint = (b2WheelJoint*)addr;
																			joint->SetSpringDampingRatio(ratio);
																			*/

	public float getSpringDampingRatio() {
		return jniGetSpringDampingRatio(addr);
	}

	private native float jniGetSpringDampingRatio(long addr); /*
																b2WheelJoint* joint = (b2WheelJoint*)addr;
																return joint->GetSpringDampingRatio();
																*/
}