How to add an example?

[GanWeaving]

I'm sorry this is surely not the way to go but I'm not sure how to do it otherwise ...

Here's the code for example 1.3 from the book:

/* built with Studio Sketchpad:

• http://sketchpad.cc
• observe the evolution of this sketch:
• http://studio.sketchpad.cc/sp/pad/view/ro.37kmnnDoE91/rev.4
• authors:
• GoToLoop
• license (unless otherwise specified):
• creative commons attribution-share alike 3.0 license.
• http://creativecommons.org/licenses/by-sa/3.0/
  */

// Nature of Code - EXERCISE 1.3 - 3D Bouncing Ball
// Extend the bouncing ball with vectors example into 3D.
// Can you get a sphere to bounce around a box?

// https://forum.processing.org/topic/
// the-nature-of-code-code-solutions-of-the-examples

// studio.processingtogether.com/sp/pad/export/ro.9o1T5z1ghf2s7/latest

final PVector location = new PVector();
final PVector velocity = new PVector(3, 2, 4);

final static int BALL_DIM = 30;
final static int CUBE_DIM = 450, CUBE_RAD = CUBE_DIM >> 1;

int cx, cy;

void setup() {
size(400, 400, P3D);
strokeWeight(2);

cx = width >> 1;
cy = height >> 1;
}

void draw() {
background(-1);

drawCube();
moveSphere();
drawSphere();
}

void drawCube() {
//move cube and ball to center:
translate(cx, cy, -CUBE_DIM);

//rotate cube and ball so it's 3D-ness can be appreciated:
rotateX(-QUARTER_PI);
rotateY(QUARTER_PI);
rotateZ(QUARTER_PI/2);

//draw cube:
noFill();
stroke(0);

box(CUBE_DIM);
}

void moveSphere() {
//move ball:
location.add(velocity);

//detect edges with center at 0,0 and edge minus width of ball:
if ( checkBounce(location.x) ) velocity.x *= -1;
if ( checkBounce(location.y) ) velocity.y *= -1;
if ( checkBounce(location.z) ) velocity.z *= -1;
}

void drawSphere() {
//draw ball, and lights for definition:
translate(location.x, location.y, location.z);

fill(0300);
noStroke();
lights();

sphere(BALL_DIM);
}

static final boolean checkBounce(float coord) {
return coord > CUBE_RAD - BALL_DIM | coord < BALL_DIM - CUBE_RAD;
}