Processing: Creative Coding and Computational Art

PROCESSING: CREATIVE CODING AND COMPUTATIONAL ART
96
Functions
Figure 3-6. Screen capture of an alternative rendering of
the Many Bouncing Balls program
I mentioned functions briefly in Chapter 2, so let’s look at them again in a little more
detail. Functions add structure and flexibility to your sketches, but also a little complexity.
Try not to worry if some of the material seems too abstract—you’ll be using functions
throughout the rest of the book. My main goal here is to give you an overview of basic
programming structures and a glimpse into the potential of creative coding.
In the simplest sense, functions just organize code into reusable blocks. They also have the
ability to receive arguments and return a value. Here are some examples.
This first sketch draws a rectangle based on the x, y, width, and height properties passed to
the drawRectangle() function:
void setup(){
size(400, 400);
background(255);
drawRectangle(150, 150, 100, 100);
}
void drawRectangle(float x, float y, float w, float h){
rect(x, y, w, h);
}