samples.constraints: add the SwingTwistConstraintFrictionTest class

src/test/java/testjoltjni/app/samples/constraints/SwingTwistConstraintFrictionTest.java

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+/*
+Copyright (c) 2024 Stephen Gold
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.
+ */
+package testjoltjni.app.samples.constraints;
+import com.github.stephengold.joltjni.*;
+import com.github.stephengold.joltjni.enumerate.*;
+import com.github.stephengold.joltjni.operator.Op;
+import testjoltjni.app.samples.*;
+/**
+ * A line-for-line Java translation of the Jolt Physics swing-twist constraint friction test.
+ * <p>
+ * Compare with the original by Jorrit Rouwe at
+ * https://github.com/jrouwe/JoltPhysics/blob/master/Samples/Tests/Constraints/SwingTwistConstraintFrictionTest.cpp
+ */
+public class SwingTwistConstraintFrictionTest extends Test{
+float mTime;
+SwingTwistConstraint mConstraint;
+
+public void Initialize()
+{
+	// Floor
+	CreateFloor();
+
+	// Create group filter
+	GroupFilterTableRef group_filter = new GroupFilterTable().toRef();
+
+	float half_cylinder_height = 1.5f;
+	ShapeRefC capsule = new CapsuleShape(half_cylinder_height, 0.5f).toRefC();
+
+	RVec3 body1_position=new RVec3(0, 10, 0);
+	Body body1 = mBodyInterface.createBody(new BodyCreationSettings(capsule, body1_position, Quat.sIdentity(), EMotionType.Static, Layers.NON_MOVING));
+	body1.setCollisionGroup(new CollisionGroup(group_filter, 0, 0));
+	mBodyInterface.addBody(body1.getId(), EActivation.DontActivate);
+
+	RVec3 body2_position = Op.add(body1_position ,new Vec3(0, -2.0f * half_cylinder_height, 0));
+	Body body2 = mBodyInterface.createBody(new BodyCreationSettings(capsule, body2_position, Quat.sIdentity(), EMotionType.Dynamic, Layers.MOVING));
+	body2.setCollisionGroup(new CollisionGroup(group_filter, 0, 0));
+	body2.getMotionProperties().setLinearDamping(0.0f);
+	body2.getMotionProperties().setAngularDamping(0.0f);
+	body2.setAllowSleeping(false);
+	mBodyInterface.addBody(body2.getId(), EActivation.Activate);
+
+	SwingTwistConstraintSettings settings=new SwingTwistConstraintSettings();
+	settings.setPosition1 ( settings.setPosition2 ( Op.add(body1_position ,new Vec3(0, -half_cylinder_height, 0))));
+	settings.setTwistAxis1 ( settings.setTwistAxis2 (new Vec3(0, -1, 0)));
+	settings.setPlaneAxis1 ( settings.setPlaneAxis2 (Vec3.sAxisX()));
+	settings.setNormalHalfConeAngle ( Jolt.degreesToRadians(90));
+	settings.setPlaneHalfConeAngle ( Jolt.degreesToRadians(90));
+	settings.setTwistMinAngle ( -Jolt.JPH_PI);
+	settings.setTwistMaxAngle ( Jolt.JPH_PI);
+
+	float body2_inertia = Op.multiply(body2.getMotionProperties().getLocalSpaceInverseInertia().inversed3x3() , Vec3.sAxisY()).length();
+	final float max_angular_acceleration = Jolt.degreesToRadians(90.0f); // rad/s^2
+	settings.setMaxFrictionTorque ( body2_inertia * max_angular_acceleration);
+
+	settings.setTwistMotorSettings ( settings.setSwingMotorSettings (new MotorSettings(10.0f, 2.0f)));
+
+	mConstraint = (SwingTwistConstraint) (settings.create(body1, body2));
+	mPhysicsSystem.addConstraint(mConstraint);
+}
+
+public void PrePhysicsUpdate(PreUpdateParams inParams)
+{
+	mTime += inParams.mDeltaTime;
+
+	boolean pause = Jolt.fmod(mTime, 5.0f) > 2.5f;
+
+	if (pause)
+	{
+		mConstraint.setSwingMotorState(EMotorState.Off);
+		mConstraint.setTwistMotorState(EMotorState.Off);
+	}
+	else
+	{
+		mConstraint.setSwingMotorState(EMotorState.Velocity);
+		mConstraint.setTwistMotorState(EMotorState.Velocity);
+		mConstraint.setTargetAngularVelocityCs(new Vec3(Jolt.degreesToRadians(180.0f), 0, 0));
+	}
+}
+
+void SaveState(StateRecorder inStream)
+{
+	inStream.write(mTime);
+}
+
+void RestoreState(StateRecorder inStream)
+{
+	mTime=inStream.readFloat(mTime);
+}
+}