Processing: Creative Coding and Computational Art

yspeed*=-1;
}
}
Within the draw() function of this last sketch, I include very simple collision detection,
used to reverse the direction of the box if it collides with any of the edges of the display
window. Imagine if there were a lot more detection code—it could get pretty confusing
looking. A better way to organize this would be to write a separate block of code (a function)
to check the collisions. Not only will this code be cleaner looking, but the detection
will be in a sense encapsulated (a word I’ll discuss more when I get to OOP). Modularizing
the code like this in a function gives the ability to potentially plug the function into other
programs. Also, once I develop a template for this collision detection, I can develop variations
on it, building a cool detection library—but I’m getting a bit carried way. Here’s the
sketch with the collision detection function added:
int xpos, ypos;
int xspeed=3;
int yspeed=5;
void setup(){
size(400, 400);
}
void draw(){
background(0);
rect(xpos, ypos, 10, 10);
xpos+=xspeed;
ypos+=yspeed;
checkCollisions(xpos, ypos);
}
void checkCollisions(int xp, int yp){
if (xp>=width-10 || xp=width-10 || yp