0210 - Very basic interaction: A mouse-sensitive canvas
In a program with a setup() and draw() structure, create an extremely simple interaction in which the mouseX is used to govern the color of the background of the entire canvas. For example, the canvas might become more red in direct proportion to the mouseX. (Optionally, you may connect both the mouseX and the mouseY.) I recommend setting the size of your canvas to 256*256 pixels (why?).