# Class List The classes and protocols in Google VR iOS API Reference:

|---|---|
| C[GVRAudioEngine](https://developers.google.com/vr/ios/reference/interface_g_v_r_audio_engine) | High-level Google VR Audio Engine |
| C[GVRCardboardView](https://developers.google.com/vr/ios/reference/interface_g_v_r_cardboard_view) | Defines a view responsible for rendering graphics in VR mode |
| C[\<GVRCardboardViewDelegate\>](https://developers.google.com/vr/ios/reference/protocol_g_v_r_cardboard_view_delegate-p) | Defines a delegate protocol for `https://developers.google.com/vr/ios/reference/interface_g_v_r_cardboard_view` |
| C[GVRFieldOfView](https://developers.google.com/vr/ios/reference/struct_g_v_r_field_of_view) | Defines a struct to hold half field of view angles, in degrees, for an `GVREye` eye |
| C[GVRHeadRotation](https://developers.google.com/vr/ios/reference/struct_g_v_r_head_rotation) | Contains yaw and pitch angles corresponding to where the user is looking |
| C[GVRHeadTransform](https://developers.google.com/vr/ios/reference/interface_g_v_r_head_transform) | Defines a class to represent the head transformation for a render frame |
| C[GVRPanoramaView](https://developers.google.com/vr/ios/reference/interface_g_v_r_panorama_view) | Defines a view that can load and display 360-degree panoramic photos |
| C[GVRVideoView](https://developers.google.com/vr/ios/reference/interface_g_v_r_video_view) | Defines a player view that renders a 360 video using OpenGL |
| C[\<GVRVideoViewDelegate\>](https://developers.google.com/vr/ios/reference/protocol_g_v_r_video_view_delegate-p) | Defines a protocol to notify delegates of change in video playback |
| C[GVRWidgetView](https://developers.google.com/vr/ios/reference/interface_g_v_r_widget_view) | Defines a base class for all widget views, that encapsulates common functionality |
| C[\<GVRWidgetViewDelegate\>](https://developers.google.com/vr/ios/reference/protocol_g_v_r_widget_view_delegate-p) | Defines a delegate for [GVRWidgetView](https://developers.google.com/vr/ios/reference/interface_g_v_r_widget_view "Defines a base class for all widget views, that encapsulates common functionality. ") and its subclasses |