TermApp/app/src/main/cpp/camera2/image_reader.h

/*
 * Copyright (C) 2017 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#ifndef CAMERA_IMAGE_READER_H
#define CAMERA_IMAGE_READER_H
#include <media/NdkImageReader.h>

#include <functional>
/*
 * ImageFormat:
 *     A Data Structure to communicate resolution between camera and ImageReader
 */
struct ImageFormat {
  int32_t width;
  int32_t height;

  int32_t format;  // Through out this demo, the format is fixed to
                   // YUV_420 format
};

class ImageReader {
 public:
  /**
   * Ctor and Dtor()
   */
  explicit ImageReader(ImageFormat* res, enum AIMAGE_FORMATS format);

  ~ImageReader();

  /**
   * Report cached ANativeWindow, which was used to create camera's capture
   * session output.
   */
  ANativeWindow* GetNativeWindow(void);

  /**
   * Retrieve Image on the top of Reader's queue
   */
  AImage* GetNextImage(void);

  /**
   * Retrieve Image on the back of Reader's queue, dropping older images
   */
  AImage* GetLatestImage(void);

  /**
   * Delete Image
   * @param image {@link AImage} instance to be deleted
   */
  void DeleteImage(AImage* image);

  /**
   * AImageReader callback handler. Called by AImageReader when a frame is
   * captured
   * (Internal function, not to be called by clients)
   */
  void ImageCallback(AImageReader* reader);

  /**
   * DisplayImage()
   *   Present camera image to the given display buffer. Avaliable image is
   * converted
   *   to display buffer format. Supported display format:
   *      WINDOW_FORMAT_RGBX_8888
   *      WINDOW_FORMAT_RGBA_8888
   *   @param buf {@link ANativeWindow_Buffer} for image to display to.
   *   @param image a {@link AImage} instance, source of image conversion.
   *            it will be deleted via {@link AImage_delete}
   *   @return true on success, false on failure
   */
  bool DisplayImage(ANativeWindow_Buffer* buf, AImage* image);
  /**
   * Configure the rotation angle necessary to apply to
   * Camera image when presenting: all rotations should be accumulated:
   *    CameraSensorOrientation + Android Device Native Orientation +
   *    Human Rotation (rotated degree related to Phone native orientation
   */
  void SetPresentRotation(int32_t angle);

  /**
   * regsiter a callback function for client to be notified that jpeg already
   * written out.
   * @param ctx is client context when callback is invoked
   * @param callback is the actual callback function
   */
  void RegisterCallback(void* ctx,
                        std::function<void(void* ctx, const char* fileName)>);

 private:
  int32_t presentRotation_;
  AImageReader* reader_;

  std::function<void(void* ctx, const char* fileName)> callback_;
  void* callbackCtx_;

  void PresentImage(ANativeWindow_Buffer* buf, AImage* image);
  void PresentImage90(ANativeWindow_Buffer* buf, AImage* image);
  void PresentImage180(ANativeWindow_Buffer* buf, AImage* image);
  void PresentImage270(ANativeWindow_Buffer* buf, AImage* image);

  void WriteFile(AImage* image);
};

#endif  // CAMERA_IMAGE_READER_H