Processing: Creative Coding and Computational Art

ectBackground = color(255, 0, 0);
}
else if (key == 's') {
rectBackground = color(255, 255, 0);
}
else if (key == 'w') {
rectBackground = color(0, 255, 0);
}
else if (key == 'z') {
rectBackground = color(255, 0, 255);
}
}
Finally, instead of using the keyPressed() function, you can use a keyPressed Boolean
variable directly within the draw() function. We already looked at this multiple approach
to solving a problem earlier in the chapter, when I discussed the mousePressed() function
vs. the mousePressed Boolean variable. Here’s the code:
color rectBackground = color(0, 0, 255);
void setup(){
size(400, 400);
background(255);
rectMode(CENTER);
}
void draw(){
fill(rectBackground);
rect(width/2, height/2, 200, 200);
// keyPressed boolean variable
if (keyPressed){
if(key == 'a'){
rectBackground = color(255, 0, 0);
}
else if (key == 's') {
rectBackground = color(255, 255, 0);
}
else if (key == 'w') {
rectBackground = color(0, 255, 0);
}
else if (key == 'z') {
rectBackground = color(255, 0, 255);
}
}
}
I’ve included one more somewhat lengthy interactive example that takes advantage of
Processing’s easy-to-use key event detection (see Figure 12-4). The piece is a motion painting
application that uses an animated brush, which is completely controlled by the keyboard.
I’ve killed enough trees this chapter, so I’ve added my descriptions about the sketch
INTERACTIVITY
605
12