void setup(){

 size(400, 400);
 background(0);
 stroke(100,50,255);
 strokeWeight(20);
 smooth();

 }

 int mrX = 0;

 void draw(){

 background(450
 );
 point(mrX, 200);
 mrX = mrX + 1;


 if (mrX > 400){

 mrX = 0;

 }

 }