Processing: Creative Coding and Computational Art

introduced to become larger, more complex, and more independent entities. OOP facilitates
code reuse—which will become more important as you get more experienced—and
enforces certain programming rules. OOP is a much more complex approach to programming
that delves into very interesting but quite challenging abstractions. I will cover OOP
in Chapter 8, although I include a brief overview of it in the next chapter, which focuses on
code grammar. OOP is such a big subject that it would be worthwhile to devote an entire
book to creative OOP with processing—maybe if I’m still standing when I’m done writing
this one . . .
If you’re interested, here is a Processing OOP version of the little rectangle program, with
some comments—the descriptions following the two forward slashes (//). I am not going
to do a full analysis of the program here, as I’ll be covering these concepts in painstaking
detail later in the book.
// Processing Object-Oriented approach: Create a rectangle
void setup(){
// set display window to 400 x 400
size(400, 400);
// set background color to light gray
background(225);
//instantiate a MyRect object and assign it to the reference ➥
variable rectangle1
MyRect rectangle1 = new MyRect(width/8, height/8, width/4, ➥
height/4, 200, -1);
/* call drawRect() method using MyRect object reference, rectangle1
calls the method using dot syntax (literally
the period between the object and the method call).*/
rectangle1.drawRect();
}
// MyRect class definition
class MyRect {
// public instance fields - each MyRect object will have
// their own set of these properties
float x, y, wdth, ht;
int fillCol, strokeCol;
/*constructor - called when the object is instantiated, using the new
operator. the parameter list between the parentheses needs to match
the argument list in the instantiation call */
MyRect(float x, float y, float wdth, float ht, int fillCol, ➥
int strokeCol){
// initialize instance fields - assignment happens form
// right to left, e.g. the value of x is assigned to the
// instance property this.x
this.x = x;
CREATIVE CODING
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