question: private void rLineTo ( float dx , float dy ) { if ( isEmpty ( ) ) { mPath . moveTo ( mLastX = 0 , mLastY = 0 ) ; } dx += mLastX ; dy += mLastY ; mPath . lineTo ( mLastX = dx , mLastY = dy ) ; }
target:  Same as lineTo, but the coordinates are considered relative to the last point on this contour. If there is no previous point, then a moveTo(0,0) is inserted automatically.