这是我使用 OnScaleGestureListener 和 SimpleOnGestureListener-onScroll 输出制作的来自 Camera2 的平移和缩放对象。如果您的相机支持级别 > LEGACY，这只会按预期工作，因为 LEGACY 仅支持裁剪到中心。
两个警告：一个是当前未设置为输出到 JPEG 输出，因为 JPEG 输出的矩形的尺寸必须是 16 的倍数（请参阅此处的原因）。第二个是我已将屏幕锁定为横向模式，并且我的相机也锁定为横向模式，但经过一些调整后应该可以处理屏幕旋转。
您需要传入屏幕尺寸
DisplayMetrics displayMetrics = new DisplayMetrics();
((Activity) mView.getContext()).getWindowManager().getDefaultDisplay().getMetrics(displayMetrics);
最大相机数码变焦
try {
CameraManager manager = (CameraManager) mView.getContext().getSystemService(Context.CAMERA_SERVICE);
CameraCharacteristics characteristics = manager.getCameraCharacteristics(mCameraID);
float maxZoom = (characteristics.get(CameraCharacteristics.SCALER_AVAILABLE_MAX_DIGITAL_ZOOM));
} catch (CameraAccessException e) {
e.printStackTrace();
}
相机传感器的有源阵列大小
try {
CameraManager manager = (CameraManager) mView.getContext().getSystemService(Context.CAMERA_SERVICE);
CameraCharacteristics characteristics = manager.getCameraCharacteristics(mCameraID);
Rect rectInit = characteristics.get(CameraCharacteristics.SENSOR_INFO_ACTIVE_ARRAY_SIZE);
} catch (CameraAccessException e) {
e.printStackTrace();
}
这是我的对象初始化
mScaler = new CamScaler(maxZoom, rectInit.width(), rectInit.height(), displayMetrics.heightPixels, displayMetrics.widthPixels);
CamScaler 类
public class CamScaler {
private final float ZOOM_MIN = 1.0f;
private final int X_MIN = 0;
private final int Y_MIN = 0;
private int displayWidth;
private int displayHeight;
private Rect current_rect;
private int xCenter;
private int yCenter;
private int xWidth;
private int yHeight;
private int xMax;
private int yMax;
private float zoomMax;
private float zoomCurrent;
public CamScaler(float zoomMax, int xMax, int yMax, int displayHeight, int displayWidth) {
this.xMax = xMax;
this.yMax = yMax;
this.zoomMax = zoomMax;
current_rect = new Rect(X_MIN,Y_MIN, xMax, yMax); //(0,0,xMax,yMax) as the starting rectangle
zoomCurrent = ZOOM_MIN;
xWidth = current_rect.width();
yHeight = current_rect.height();
xCenter = current_rect.centerX();
yCenter = current_rect.centerY();
this.displayHeight = displayHeight;
this.displayWidth = displayWidth;
}
public void pan(float distanceX, float distanceY){
//calculate the shift in the we want to take on the camera sensor with respect to the distance moved on the screen
int xShift = Math.round((distanceX/displayWidth)*xWidth); //scales down to a percentage of the current view width->converts to a pixel shift
int yShift = Math.round((distanceY/displayHeight)*yHeight); //scales down to a percentage of the current view height->converts to a pixel shift
//check if the shift will push us pass our maximums, this should account for both negative and positive values of xShift and yShift correctly
if ( !((xCenter + Math.round(xWidth/2.0) + xShift < xMax) && (xCenter - Math.round(xWidth/2.0) + xShift > 0))) { //if not within xBounds, set xShift to 0
xShift = 0;
}
if ( !((yCenter + Math.round(yHeight/2) + yShift < yMax) && (yCenter - Math.round(yHeight/2.0) + yShift > 0))) { //if not within yBounds, set yShift to 0
yShift = 0;
}
Log.d("Scaler", "pan: xShift" + xShift + " yShift " + yShift);
current_rect.offset(xShift,yShift);
Log.d("Scaler", "pan: current_rect" + current_rect.toString());
xCenter = current_rect.centerX(); //update center
yCenter = current_rect.centerY(); //update center
}
public void zoom(float scale_change){
if ( (zoomCurrent*scale_change < zoomMax) && (zoomCurrent*scale_change > ZOOM_MIN) ){ //if we are within zoom bounds
zoomCurrent *= scale_change; //update the zoom factor
int newWidthHalf = (int)Math.floor(xMax/zoomCurrent/2.0);
int newHeightHalf = (int)Math.floor(yMax/zoomCurrent/2.0);
int xTempCenter = xCenter;
int yTempCenter = yCenter;
//if at edge we need to shift and scale
if (xCenter + newWidthHalf > xMax) { //if at right edge
xTempCenter = xMax - newWidthHalf; //shift center to the left
} else if (xCenter - newWidthHalf < 0) { //if at left edge
xTempCenter = newWidthHalf; //shift center to the right
}
if (yCenter + newHeightHalf > yMax) { //if at bottom
yTempCenter = yMax - newHeightHalf; //shift center up
} else if (yCenter - newHeightHalf < 0) { //if at top
yTempCenter = newHeightHalf; //shift center down
}
Log.d("Scaler", "zoom: " + zoomCurrent);
Log.d(TAG, "current center(x,y) " + xTempCenter + " " + yTempCenter + "current halfwidths(x,y) " + newWidthHalf + " " + newHeightHalf);
current_rect.set(xTempCenter - newWidthHalf, yTempCenter - newHeightHalf,xTempCenter + newWidthHalf, yTempCenter + newHeightHalf);
Log.d("Scaler", "zoom: current_rect" + current_rect.toString());
xWidth = current_rect.width();
yHeight = current_rect.height();
xCenter = current_rect.centerX(); //update center
yCenter = current_rect.centerY(); //update center
} //if not in digital zoom bounds, do nothing
}
public Rect getCurrentView() {
return current_rect;
}
}
以及如何使用它
public void pan(float distanceX, float distanceY){
if (mScaler != null) {
synchronized (mScaler) {
mScaler.pan(distanceX, distanceY);
try {
mPreviewRequestBuilder.set(CaptureRequest.SCALER_CROP_REGION, mScaler.getCurrentView());
mCaptureSession.setRepeatingRequest(mPreviewRequestBuilder.build(), mCaptureCallback, mBackgroundHandler);
} catch (CameraAccessException e) {
e.printStackTrace();
}
}
}
}
public void zoom(float scale_factor) {
if (mScaler!= null) {
synchronized (mScaler) {
mScaler.zoom(scale_factor);
try {
mPreviewRequestBuilder.set(CaptureRequest.SCALER_CROP_REGION, mScaler.getCurrentView());
mCaptureSession.setRepeatingRequest(mPreviewRequestBuilder.build(), mCaptureCallback, mBackgroundHandler);
} catch (CameraAccessException e) {
e.printStackTrace();
}
}
}
}
这些函数的输入直接从手势侦听器传递
我希望这可以帮助别人！
