int nowMx = 0;
int nowMy = 0;
int prevMx = 0;
int prevMy = 0;

void setup() {
	size(800, 600);
	smooth();
}

void draw(){
	int mx = nowMx - prevMx;
	int my = nowMy - prevMy;
	float d = sqrt(mx*mx + my*my);
	float r1 = random(d * -1, 0);
	float r2 = random(d * -2, d * 1);
	int n = floor(random(10,50));
   
	drawStar(nowMx,nowMy,r1,r2,n);
	prevMx = nowMx;
	prevMy = nowMy;
	nowMx = mouseX;
	nowMy = mouseY;
}

void clear(){
	stroke(200);
	fill(200);
	rect(0,0,width,height);
}

void drawStar(int x , int y , float r1,float r2 , int num){
	stroke(0,0,0,100);
	float rad = TWO_PI / num;
	for ( int i=0; i< num; i++){
		float p1x = r1 * cos(rad * i) +x;
		float p1y = r1 * sin(rad * i) +y;
		float p2x = r2 * cos(rad * (i + 0.5)) +x;
		float p2y = r2 * sin(rad * (i + 0.5)) +y;
		float p3x = r1 * cos(rad * (i+1)) +x;
		float p3y = r1 * sin(rad * (i+1)) +y;
		line(p1x,p1y,p2x,p2y);
		line(p2x,p2y,p3x,p3y);
	}
}