PointerLockControls: sensitivity const (mrdoob#30966)

Author: satelllte

examples/jsm/controls/PointerLockControls.js

@@ -31,6 +31,7 @@ const _lockEvent = { type: 'lock' };
  */
 const _unlockEvent = { type: 'unlock' };
 
+const _MOUSE_SENSITIVITY = 0.002;
 const _PI_2 = Math.PI / 2;
 
 /**
@@ -233,8 +234,8 @@ function onMouseMove( event ) {
 	const camera = this.object;
 	_euler.setFromQuaternion( camera.quaternion );
 
-	_euler.y -= event.movementX * 0.002 * this.pointerSpeed;
-	_euler.x -= event.movementY * 0.002 * this.pointerSpeed;
+	_euler.y -= event.movementX * _MOUSE_SENSITIVITY * this.pointerSpeed;
+	_euler.x -= event.movementY * _MOUSE_SENSITIVITY * this.pointerSpeed;
 
 	_euler.x = Math.max( _PI_2 - this.maxPolarAngle, Math.min( _PI_2 - this.minPolarAngle, _euler.x ) );