int WIDTH = 400;
int HEIGHT = 400;

int c1, c2, s1, s2;
int RANGE = 1;

int STILLRUNNING = 0;

class Edge {
	Edge e1;
	Edge e2;
	
	int startx, starty, endx, endy;
	int x, y;
	int dir; // -2/2 : y | -1/1 : x
	int running = 0;
	int exists = 0;
	int spawned = 0;
	int age;
	int col;
	
	Edge(int xIn, int yIn, int dirIn, int ageIn, int colIn) {
		running = 1;
		startx = xIn;
		starty = yIn;
		x = xIn;
		y = yIn;
		dir = dirIn;
		
		exists = 1;
		spawned = 0;
		age = ageIn+1;
		col = colIn;
		
		}
	
	void posupdate() {
		int next;
	
		x += (dir == -1 || dir == 1) ? dir : 0;
		y += (dir == -2 || dir == 2) ? (dir/2) : 0;
		
		next = y*width+x;
		
		if(x >= WIDTH || x <= 0 || y <= 0 || y >= HEIGHT || next <= 0 || next >= WIDTH*HEIGHT || pixels[next] != 0xffffffff) {
			borked();
			}
		else if(next < WIDTH*HEIGHT && next > 0) {
			pixels[next] = col;
			STILLRUNNING = 1;
			}
		}

	void borked() {
		running = 0;
		endx = x;
		endy = y;
		if(((dir == -1 || dir == 1) && Math.abs(endx - startx) > RANGE) || ((dir == -2 || dir == 2) && Math.abs(endy - starty) > RANGE) ) {
			spawn();
			}
		}
	
	void spawn() {
		int dir1;
		spawned = 1;
		if(dir == 2 || dir == -2) {dir1 = -1;}
		else {dir1 = -2;}
		
		int brightness;
		brightness = (age < 32) ? 190 + age*2:255;
		
		e1 = new Edge((int)random(startx, endx), (int)random(starty, endy), dir1, age, color(c1, s1, brightness));
		e2 = new Edge((int)random(startx, endx), (int)random(starty, endy), -1*dir1, age, color(c2, s2, brightness)); 
		}
	
	void update() {
		if(running == 1) posupdate();
		if(spawned == 1) {
			e1.update();
			e2.update();
			}
		}
	}

Edge e1;

void setup() {
	size(400,400);
	colorMode(HSB);
	background(#ffffff);
	noBackground();
	startup();
	}
	
void startup() {
	c1 = (int)random(255);
	c2 = (int)random(255);
	s1 = (int)random(128,240);
	s2 = (int)random(60);
	
	for(int i = 0; i < WIDTH*HEIGHT; i++) {
		pixels[i] = 0xffffffff;
		}
	int dir;
	dir = (random(2) < 1) ? ((random(2) < 1) ? -2:2) : ((random(2) < 1) ? -1:1);
	
	e1 = new Edge((int)random(WIDTH), (int)random(HEIGHT), dir, 0, color((int)random(255), 255, 196));
	}
	
void loop() {
	STILLRUNNING = 0;
	e1.update();
	
	if(STILLRUNNING == 0) {
		delay(5000);
		startup();
		}
	}