GPUImage front camera Tap to focus not working why?

Question

I have implemented the code below to enable tap to focus camera. It is working fine with the back camera but is fails when using the front camera because of _videoCamera.inputCamera.isFocusPointOfInterestSupported being false.

GOT FALSE why ? please help me.

- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event {

    UITouch *touch = [touches anyObject];
    CGPoint touchPoint = [touch locationInView:self.view];

    if([_videoCamera.inputCamera isFocusPointOfInterestSupported]&&[_videoCamera.inputCamera isFocusModeSupported:AVCaptureFocusModeAutoFocus])
    {

        if([_videoCamera.inputCamera lockForConfiguration :nil])
        {
            [_videoCamera.inputCamera setFocusPointOfInterest :touchPoint];
            [_videoCamera.inputCamera setFocusMode :AVCaptureFocusModeLocked];

            if([_videoCamera.inputCamera isExposurePointOfInterestSupported])
            {    CGRect screenRect = [[UIScreen mainScreen] bounds];
                CGFloat screenWidth = screenRect.size.width;
                CGFloat screenHeight = screenRect.size.height;
                double focus_x = touchPoint.x/screenWidth;
                double focus_y = touchPoint.y/screenHeight;
                [_videoCamera.inputCamera setExposurePointOfInterest:CGPointMake(focus_x,focus_y)];
                [_videoCamera.inputCamera setFocusMode:AVCaptureFocusModeAutoFocus];
                if ([_videoCamera.inputCamera isExposureModeSupported:AVCaptureExposureModeAutoExpose]){
                    [_videoCamera.inputCamera setExposureMode:AVCaptureExposureModeAutoExpose];
                }

            }
            [_videoCamera.inputCamera unlockForConfiguration];
        }
    }

}

Answer 1

The front-facing camera is fixed focus. No auto-focus, no focus on point of interest. This is exactly what iOS tells you by returning NO when you call isFocusPointOfInterestSupported.