refactor: clean up wheel joint

Author: AlmasB

fxgl-entity/src/main/java/com/almasb/fxgl/physics/box2d/dynamics/joints/WheelJoint.java

@@ -39,22 +39,21 @@
  */
 public class WheelJoint extends Joint {
 
-    private float m_frequencyHz;
-    private float m_dampingRatio;
-
     // Solver shared
     private final Vec2 m_localAnchorA = new Vec2();
     private final Vec2 m_localAnchorB = new Vec2();
     private final Vec2 m_localXAxisA = new Vec2();
     private final Vec2 m_localYAxisA = new Vec2();
 
     private float m_impulse;
-    private float m_motorImpulse;
+    private float m_motorImpulse = 0.0f;
     private float m_springImpulse;
 
     private float m_maxMotorTorque;
     private float m_motorSpeed;
     private boolean m_enableMotor;
+    private float m_frequencyHz;
+    private float m_dampingRatio;
 
     // Solver temp
     private int m_indexA;
@@ -68,11 +67,13 @@ public class WheelJoint extends Joint {
 
     private final Vec2 m_ax = new Vec2();
     private final Vec2 m_ay = new Vec2();
-    private float m_sAx, m_sBx;
-    private float m_sAy, m_sBy;
+    private float m_sAx;
+    private float m_sBx;
+    private float m_sAy;
+    private float m_sBy;
 
     private float m_mass;
-    private float m_motorMass;
+    private float m_motorMass = 0.0f;
     private float m_springMass;
 
     private float m_bias;
@@ -85,14 +86,9 @@ protected WheelJoint(IWorldPool argPool, WheelJointDef def) {
         m_localXAxisA.set(def.localAxisA);
         Vec2.crossToOutUnsafe(1.0f, m_localXAxisA, m_localYAxisA);
 
-
-        m_motorMass = 0.0f;
-        m_motorImpulse = 0.0f;
-
         m_maxMotorTorque = def.maxMotorTorque;
         m_motorSpeed = def.motorSpeed;
         m_enableMotor = def.enableMotor;
-
         m_frequencyHz = def.frequencyHz;
         m_dampingRatio = def.dampingRatio;
     }
@@ -340,9 +336,7 @@ public void initVelocityConstraints(SolverData data) {
         pool.pushRot(2);
         pool.pushVec2(1);
 
-        // data.velocities[m_indexA].v = vA;
         data.velocities[m_indexA].w = wA;
-        // data.velocities[m_indexB].v = vB;
         data.velocities[m_indexB].w = wB;
     }
 
@@ -414,9 +408,7 @@ public void solveVelocityConstraints(SolverData data) {
         }
         pool.pushVec2(2);
 
-        // data.velocities[m_indexA].v = vA;
         data.velocities[m_indexA].w = wA;
-        // data.velocities[m_indexB].v = vB;
         data.velocities[m_indexB].w = wB;
     }
 
@@ -470,9 +462,7 @@ public boolean solvePositionConstraints(SolverData data) {
 
         pool.pushVec2(3);
         pool.pushRot(2);
-        // data.positions[m_indexA].c = cA;
         data.positions[m_indexA].a = aA;
-        // data.positions[m_indexB].c = cB;
         data.positions[m_indexB].a = aB;
 
         return FXGLMath.abs(C) <= JBoxSettings.linearSlop;

fxgl-entity/src/main/java/com/almasb/fxgl/physics/box2d/dynamics/joints/WheelJointDef.java

@@ -36,39 +36,32 @@ public class WheelJointDef extends JointDef<WheelJoint> {
     /**
      * The local translation axis in body1.
      */
-    public final Vec2 localAxisA = new Vec2();
+    public final Vec2 localAxisA = new Vec2(1, 0);
 
     /**
      * Enable/disable the joint motor.
      */
-    public boolean enableMotor;
+    public boolean enableMotor = false;
 
     /**
      * The maximum motor torque, usually in N-m.
      */
-    public float maxMotorTorque;
+    public float maxMotorTorque = 0f;
 
     /**
      * The desired motor speed in radians per second.
      */
-    public float motorSpeed;
+    public float motorSpeed = 0f;
 
     /**
      * Suspension frequency, zero indicates no suspension
      */
-    public float frequencyHz;
+    public float frequencyHz = 0f;
 
     /**
      * Suspension damping ratio, one indicates critical damping
      */
-    public float dampingRatio;
-
-    public WheelJointDef() {
-        localAxisA.set(1, 0);
-        enableMotor = false;
-        maxMotorTorque = 0f;
-        motorSpeed = 0f;
-    }
+    public float dampingRatio = 0f;
 
     public void initialize(Body b1, Body b2, Vec2 anchor, Vec2 axis) {
         setBodyA(b1);