question: private void cubicTo ( float x1 , float y1 , float x2 , float y2 , float x3 , float y3 ) { mPath . curveTo ( x1 , y1 , x2 , y2 , mLastX = x3 , mLastY = y3 ) ; }
target:  Add a cubic bezier from the last point, approaching control points (x1,y1) and (x2,y2), and ending at (x3,y3). If no moveTo() call has been made for this contour, the first point is automatically set to (0,0).