[Click and drag the mouse on the stage] [hover over the top-left corner for settings] It might seem simple, but look inside ;) The write sprite basically is the whole interface. You drag your mouse; it draws what your current line. What it does is it takes all info of the line you drew and stores it in lists. The read sprite goes through all the lists and draws all the past lines. The reason the read sprite exists it that while you drag your mouse, the write sprite needs to refresh the line again and again. Which is a problem while drawing past lines on one sprite. See the naming convention? Read-write? Haha...?
