Nobody's perfect, and thus for our paint application, we need a way of clearing the
canvas. We can invent our own gesture for this, as anything that can be described in code can become a gesture.
For our use case, we will use two fingers swiping up and away from each other over the canvas. This will look like tracing the outline of an upside down equilateral triangle. Have a look at the following photos of the before and after state of the gesture:
We have built upon the basic Finger Painter application with some modifications, so it won't try and draw while the user attempts ...