Android Camera API 1.0, 2.0, 3.0 知多少

看到源码里面有诸如Camera.h , Camera2.h， Camera3.h的文件，觉得奇怪，后面在Camera3.h

中找到了对前后3个版本的概要性描述。

BTW， 我们看代码的过程中，如何避免不需要的文件被添加到工程？

我是指： 我只想看Camera3.0的代码，怎么去除掉其他版本的呢？

不知道各位是否知道这些牵涉到哪些文件？ 谢谢！！

 * S1. Version history:
 * 1.0: Initial Android camera HAL (Android 4.0) [camera.h]:
 *
 *   - Converted from C++ CameraHardwareInterface abstraction layer.
 *
 *   - Supports android.hardware.Camera API.
 *
 * 2.0: Initial release of expanded-capability HAL (Android 4.2) [camera2.h]:
 *
 *   - Sufficient for implementing existing android.hardware.Camera API.
 *
 *   - Allows for ZSL queue in camera service layer
 *
 *   - Not tested for any new features such manual capture control, Bayer RAW
 *     capture, reprocessing of RAW data.
 * 3.0: First revision of expanded-capability HAL:
 *
 *   - Major version change since the ABI is completely different. No change to
 *     the required hardware capabilities or operational model from 2.0.
 *
 *   - Reworked input request and stream queue interfaces: Framework calls into
 *     HAL with next request and stream buffers already dequeued. Sync framework
 *     support is included, necessary for efficient implementations.
 *
 *   - Moved triggers into requests, most notifications into results.
 *
 *   - Consolidated all callbacks into framework into one structure, and all
 *     setup methods into a single initialize() call.
 *   - Made stream configuration into a single call to simplify stream
 *     management. Bidirectional streams replace STREAM_FROM_STREAM construct.