// This program draws a quadrilateral to the screen // in black and white. When the user presses keys, // it toggles the program between white on black and // black on white. void setup(){ size(500,200); } void draw(){ background(255); stroke(0); fill(0); quad(20,20,20,70,60,90,60,40); } // REMINDER: Three ways to have memory // 1. Implicitly: Do things with permanent effects // 2. Parameters: Define a parameter that stores the value that // changes, and use that parameter in your drawing code. // 3. Modes: Define a variable that stores the 'mode' your // program is in. Test for the parameter and do different // things depending on its value.