Processing: Creative Coding and Computational Art

PROCESSING: CREATIVE CODING AND COMPUTATIONAL ART
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inverse of these functions (referred to as the arc functions) to go in the other direction
(find the angle of rotation beginning with some Cartesian coordinates).
Next I’ll add an Orb class, which is very simple and self-explanatory. Add the following code
to a new tab named Orb:
class Orb{
float x, y, r;
// default constructor
Orb() {
}
Orb(float x, float y, float r) {
this.x = x;
this.y = y;
this.r = r;
}
}
I created a really simple 2D vector class for the orb’s velocity. Create a tab named Vect2D
and enter the following code:
class Vect2D{
float vx, vy;
// default constructor
Vect2D() {
}
Vect2D(float vx, float vy) {
this.vx = vx;
this.vy = vy;
}
}
These are all the classes you’ll need. To handle the collision detection between the orb and
the non-orthogonal surface, as well as the display window edges, you’ll use two functions.
First you’ll tackle the easier, orthogonal (display window edge) collision. Create a new tab
called checkWallCollision and enter the following code:
void checkWallCollision(){
if (orb.x > width-orb.r){
orb.x = width-orb.r;
velocity.vx *= -1;
velocity.vx *= damping;
}
else if (orb.x < orb.r){
orb.x = orb.r;
velocity.vx *= -1;