Camera2 实现重力感应四个方向调试相机预览

Camera2API 实现重力感应四个方向调试相机预览

---

需求

Camera2 相机预览实现四个重力感应方向预览方向正常

场景

• 实际有个客户需求，用到了四个方向的重力感应，但是之前的工程代码只有两个方向，导致屏幕无法四个方向正常显示
• 相机预览两个重力感应方向已经满足了需求，但是客户重力感应模块、板卡 实际物理装配时候不可能按照要求装配的，不同厂家的磨具不一样导致板卡方向装配不一样。基于这样的实际情况，软件就需要适配四个方向，两个重力感应预览方向就无法满足实际要求了。
• 实际产品案例：监控、HDMIN、车载Camera…

需求实现

setAspectRatio 设置显示长宽

设置显示组件长宽
textureView.setAspectRatio(width, height)

 private void setupCamera(int width, int height) {
   
   
        CameraManager manager = (CameraManager) getSystemService(Context.CAMERA_SERVICE);
        try {
   
   
            for (String cameraId : manager.getCameraIdList()) {
   
   
              ...............
                int orientation = getResources().getConfiguration().orientation;
                if (orientation == Configuration.ORIENTATION_LANDSCAPE) {
   
   
                    Log.d(TAG, "setupCamera: ORIENTATION_LANDSCAPE  " + mPreviewSize.getWidth() + " x " + mPreviewSize.getHeight());
                    textureView.setAspectRatio(1920, 1080);
                } else {
   
   
                    textureView.setAspectRatio(mPreviewSize.getHeight(), mPreviewSize.getWidth());
                    Log.d(TAG, "setupCamera:  ORIENTATION_PORT  " + mPreviewSize.getWidth() + " x " + mPreviewSize.getHeight());
                }

                break;
            }
        } catch (CameraAccessException e) {
   
   
            e.printStackTrace();
        }
    }

使用位置：在View 组件流传递过来时候， onSurfaceTextureAvailable 方法中，去设置 setupCamera

 TextureView.SurfaceTextureListener textureListener = new TextureView.SurfaceTextureListener() {
   
   
        @Override
        public void onSurfaceTextureAvailable(SurfaceTexture surface, int width, int height) {
   
   
            setupCamera(width, height);
            configureTransform(width, height);
            openCamera();
        }


        @Override
        public void onSurfaceTextureSizeChanged(SurfaceTexture surface, int width, int height) {
   
   
            configureTransform(width, height);
        }

        @Override
        public boolean onSurfaceTextureDestroyed(SurfaceTexture surface) {
   
   
            return false;
        }

        @Override
        public void onSurfaceTextureUpdated(SurfaceTexture surface) {
   
   

        }
    };
				

postScale postRotate 设置缩放和旋转

比如长宽肯定是1920*1080，根据实际产品长宽进行设置，但是如果是竖屏状态下，还是需要这个图像输出流的比例数出来，那么就必须进行缩放，才能完全显示出来的。

补充下基本知识点：
Matrix的操作，总共分为translate（平移），rotate（旋转），scale（缩放）和skew（倾斜）四种，每一种变换在Android的API里都提供了set, post和pre三种操作方式,除了translate，其他三种操作都可以指定中心点。

set是直接设置Matrix的值，每次set一次，整个Matrix的数组都会变掉，这也就意味着你对同一个矩阵先调用setScale，再调用setTranslate,那么矩阵只会执行Translate的操作，前面的scale操作是无效的。

post是后乘，当前的矩阵乘以参数给出的矩阵。可以连续多次使用post，来完成所需的整个变换。例如，要将一个图片先缩放，再平移则可以通过：

同样的道理，如上面设置显示长宽的后面就需要又缩放和旋转逻辑了， 输出流的地方是不会变的，那么接收的地方就需要根据实际情况如重力感应和物理场景【竖屏-横屏】进行流显示的变化了->缩放、旋转操作

onSurfaceTextureAvailable ->  configureTransform(width, height) -> Configuration config =  getResources().getConfiguration()【根据重力感应方向，计算缩放比例和旋转角度及选择方向了】

核心代码如下：
private void configureTransform(int viewWidth, int viewHeight) {
   
   
        if (null == textureView || null == mPreviewSize) {
   
   
            return;
        }
        int rotation = getWindowManager().getDefaultDisplay().getRotation();
        Configuration config =  getResources().getConfiguration();
        if (config.orientation == Configuration.ORIENTATION_PORTRAIT) {
   
   
            Log.d(TAG, "configureTransform: ORIENTATION_PORTRAIT");
            if(Surface.ROTATION_90 == rotation || Surface.ROTATION_270 == rotation){
   
   
              isRotation = true;
            }
        } else if (config.orientation == Configuration.ORIENTATION_LANDSCAPE) {
   
   
            Log.d(TAG, "configureTransform: ORIENTATION_LANDSCAPE");
            if(Surface.ROTATION_0 == rotation || Surface.ROTATION_180 == rotation){
   
   
              isRotation = true;
            }
        }
        Log.d(TAG, "configureTransform: isRotation = "+isRotation);
        if(isRotation){
   
   
            rotation = rotation + 1;
            if(rotation > 3){
   
   
               rotation = rotation - 3;
            }
        }
        Log.d(TAG," aaaaaaaaaaaa rotation:"+rotation);
        Matrix matrix = new Matrix();
        RectF viewRect = new RectF(0, 0, viewWidth, viewHeight);
        RectF bufferRect = new RectF(0, 0, mPreviewSize.getHeight(), mPreviewSize.getWidth());
        float centerX = viewRect.centerX();
        float centerY = viewRect.centerY();
        if (Surface.ROTATION_90 == rotation) {
   
   
            bufferRect.offset(centerX - bufferRect.centerX(), centerY - bufferRect.centerY());
            matrix.setRectToRect(viewRect, bufferRect, Matrix.ScaleToFit.FILL);
            float scale = Math.max(
                    (float) viewHeight / mPreviewSize.getHeight(),
                    (float) viewWidth / mPreviewSize.getWidth());
            matrix.postScale(scale, scale, centerX, centerY);
            matrix.postRotate(90 * (rotation - 2), centerX, centerY);
            Log.d(TAG," 00000000000000  ");
        }else  if ( Surface.ROTATION_270 == rotation) {
   
   
            bufferRect.offset(centerX - bufferRect.centerX(), centerY - bufferRect.centerY());
            matrix.setRectToRect(viewRect, bufferRect, Matrix.ScaleToFit.FILL);
            float scale = Math.max(
                    (float) viewHeight / mPreviewSize.getHeight(),
                    (float) viewWidth / mPreviewSize.getWidth());
            matrix.postScale(scale, scale, centerX, centerY);
            matrix.postRotate(270, centerX, centerY);
            Log.d(TAG," bbbbbbbbbbbbbbbb  ");
        }  else if (Surface.ROTATION_180 == rotation) {
   
   
            float scale = (float)1080/ 1920;
            Log.d(TAG, "configureTransform: rizhi xianshi port state  scale:"+scale+"    centerX:"+centerX+"   centerY:"+centerY);
            matrix.postScale(scale, scale, centerX, centerY);
            textureView.setRotation(270f);
            Log.d(TAG, "configureTransform:   "+"    centerX:"+centerX+"   centerY:"+centerY);
            Log.d(TAG," 111111111111111  ");
        }else if(Surface.ROTATION_0 == rotation){
   
   
            float scale = (float)1080/ 1920;

            Log.d(TAG, "configureTransform: rizhi xianshi port state  scale:"+scale+"    centerX:"+centerX+"   centerY:"+centerY);
            matrix.postScale(scale, scale, centerX, centerY);
            textureView.setRotation(270f);
            Log.d(TAG," 222222222222222222  ");

        }
        textureView.setTransform(matrix);
    }

manager.openCamera 打开相机

打开相机就是一个比较常规操作了，如上显示组件 已经准备好，进行了算转和缩放操作，就是显示组件已经设置好了参数，接下来就打开相机，让流数据进来。
打开相机基本代码如下：

 public void onSurfaceTextureAvailable(SurfaceTexture surface, int width, int height) {
   
   
            setupCamera(width