写一个UVCCamera的类，继承UVCCameraTextureView类上面扩展出一个类支持多点触碰支持放大缩小和旋转的类

下面是一个简单的示例代码，实现了继承自UVCCameraTextureView类的多点触碰支持放大缩小和旋转的UVCCamera类：

public class UVCCamera extends UVCCameraTextureView {
    private float mPrevX, mPrevY;
    private float mScaleFactor = 1f;
    private float mRotationDegree = 0f;

    public UVCCamera(Context context, AttributeSet attrs) {
        super(context, attrs);
    }

    @Override
    public boolean onTouchEvent(MotionEvent event) {
        switch (event.getActionMasked()) {
            case MotionEvent.ACTION_DOWN:
                mPrevX = event.getX(0);
                mPrevY = event.getY(0);
                break;
            case MotionEvent.ACTION_MOVE:
                if (event.getPointerCount() == 1) {
                    float x = event.getX(0);
                    float y = event.getY(0);
                    float dx = x - mPrevX;
                    float dy = y - mPrevY;
                    mRotationDegree += Math.atan2(dy, dx) * 180 / Math.PI;
                    setRotation(mRotationDegree);
                    mPrevX = x;
                    mPrevY = y;
                } else if (event.getPointerCount() == 2) {
                    float x1 = event.getX(0);
                    float y1 = event.getY(0);
                    float x2 = event.getX(1);
                    float y2 = event.getY(1);
                    float distance = (float) Math.sqrt((x1 - x2) * (x1 - x2) + (y1 - y2) * (y1 - y2));
                    if (distance > 10f) {
                        float scaleFactor = distance / mPrevDistance;
                        mScaleFactor *= scaleFactor;
                        mScaleFactor = Math.max(0.1f, Math.min(mScaleFactor, 10.0f));
                        setScaleX(mScaleFactor);
                        setScaleY(mScaleFactor);
                    }
                    float angle = (float) Math.atan2(y2 - y1, x2 - x1) * 180 / (float) Math.PI;
                    setRotation(angle);
                    mPrevDistance = distance;
                }
                break;
            case MotionEvent.ACTION_UP:
            case MotionEvent.ACTION_CANCEL:
                break;
        }
        return true;
    }
}

这个类继承自UVCCameraTextureView，重写了onTouchEvent方法，实现了多点触碰支持放大缩小和旋转的功能。当手指只有一个触点时，根据手指移动的方向来旋转图像；当手指有两个触点时，根据两个触点之间的距离来缩放图像，并根据两个触点之间的角度来旋转图像。