VR开发--CardboardSDK解析

using UnityEngine;

/// in order to reset its cache.
[RequireComponent(typeof(Camera))]
[AddComponentMenu("Cardboard/CardboardEye")]
public class CardboardEye : MonoBehaviour {
  /// Whether this is the left eye or the right eye.
  /// Determines which stereo eye to render, that is, which `EyeOffset` and
  /// `Projection` matrix to use and which half of the screen to render to.
  /// 确定要渲染的立体眼睛,就是用EyeOffset和projecttion 矩阵并且去渲染到屏幕的哪一半
  public Cardboard.Eye eye;

  /// Allows you to flip on or off specific culling mask layers for just this
  /// eye.  The mask is a toggle:  The eye's culling mask is first copied from
  /// the parent mono camera, and then the layers specified here are flipped.
  /// Each eye has its own toggle mask.
  /// 允许你为这个眼睛打开或关闭特定的剔除层.是一个触发器,这个层首先从父相机复制,然后在此制定那些层被启用,每只眼睛有它自己的剔除层
  [Tooltip("Culling mask layers that this eye should toggle relative to the parent camera.")]
  public LayerMask toggleCullingMask = 0;

    /// The StereoController in charge of this eye (and whose mono camera
    /// we will copy settings from).
    /// 返回StereoController 控制这个眼睛
    public StereoController Controller {
    // This property is set up to work both in editor and in player.
    get {
      if (transform.parent == null) { // Should not happen.
        return null;
      }
      if ((Application.isEditor && !Application.isPlaying) || controller == null) {
        // Go find our controller.
        return transform.parent.GetComponentInParent<StereoController>();
      }
      return controller;
    }
  }

    /// Returns the closest ancestor CardboardHead.
    /// @note Uses GetComponentInParent(), so the result will be null if no active ancestor is found.
    /// 返回父类CardboardHead
    public CardboardHead Head {
    get {
      return GetComponentInParent<CardboardHead>();
    }
  }

 public override void Process() {
    // Save the previous Game Object
    GameObject gazeObjectPrevious = GetCurrentGameObject();

    CastRayFromGaze();   // 控制射线发射，先将3D坐标转换为2D UI坐标系，发出射线
    UpdateCurrentObject(); // 更新选中物体的状态，比如按钮会设置选中状态等
    UpdateReticle(gazeObjectPrevious); // 

    // Get the camera
    Camera camera = pointerData.enterEventCamera;

    // Handle input
    if (!Cardboard.SDK.TapIsTrigger && !Input.GetMouseButtonDown(0) && Input.GetMouseButton(0)) {
      // Drag is only supported if TapIsTrigger is false.
      HandleDrag();           // 拖动状态
    } else if (Time.unscaledTime - pointerData.clickTime < clickTime) {
      // Delay new events until clickTime has passed.
    } else if (!pointerData.eligibleForClick &&
               (Cardboard.SDK.Triggered || !Cardboard.SDK.TapIsTrigger && Input.GetMouseButtonDown(0))) {
     
      HandleTrigger();           //触发事件
      if (cardboardPointer != null) {
        cardboardPointer.OnGazeTriggerStart(camera);
      }
    } else if (!Cardboard.SDK.Triggered && !Input.GetMouseButton(0)) {
      HandlePendingClick(); // 就是光标选中，啥也没干
    }
  }