I am using a draggable knob along an svg path. The path is a quadratic bezier curve which has the y coordinates going up and then down. How should I progress the draggable instance so that I am able to fill the path while dragging the knob on the path?   To simply put it, I want the path to be filled while dragging the knob and the portion of the path to be filled should be only upto the knob. Also the mouse pointer should be in sync with the draggable knob. Any suggesti