Is there any way to get processing to act as if the canvas is periodic?

For instance make it so  line(-20,10,20,10) on a canvas of width 400 would draw a line from x 0  to x 20 and a line from x 380 to x 399? Also, having filters() use the pixels on the other side of the canvas as their nieghbors would be important.

Obvioulsy I can do some of it myself using modulo, but tha requires re-implementing everything I want to use.

Not in your example when you draw one object, like PhiLho said.

But it depends on what you wanna do. If you want moving objects its pretty simple. Look at the stayincanvas part of the code


Code:

Wanderer[] wanderer = new Wanderer[11];

void setup(){
  size(200, 200);
  background(50);
  fill(200);
  noStroke();

  for (int i=0; i<wanderer.length; i++)  {
    wanderer[i] = new Wanderer(random(width), random(height));
  }
}

void draw(){
  fill(0,40);
  rect(0,0,width,height);

  for (int i=0; i<wanderer.length; i++)  {
    wanderer[i].stayInsideCanvas();
    wanderer[i].move();
  }
}
class Wanderer{
  float x;
  float y;
  float wander_theta;
  float wander_radius;
  float max_wander_offset = 0.3;
  float max_wander_radius = 3.5;

  Wanderer(float _x, float _y){
    x = _x;
    y = _y;

    wander_theta = random(TWO_PI);
    wander_radius = random(max_wander_radius);
  }

  void stayInsideCanvas()  {
    if(x<0)x=width;
    if(y<0)y=height;
    if(x>width)x=0;
    if(y>height)y=0;
  }

  void move(){
    float wander_offset = random(-max_wander_offset, max_wander_offset);
    wander_theta += wander_offset;
    x += cos(wander_theta);
    y += sin(wander_theta);
    fill(255);
    ellipse(x, y, 2, 2);
  }

}