Smoke Brush

function setup() {

background(255);

createCanvas(windowWidth,windowHeight);  

}  

​

var PY, PX;

var x = [20];

var y = [20];

var segLength = 5;

​

for(var i=0; i<60; i++) {

    x[i]=1;

    y[i]=1;

}

​

function segment( x, y,  a) {

  strokeWeight(1);

  stroke(0, 0, 0,50);

  push();

  translate(x, y);

  rotate(a);

  line(0, 0, segLength, 0);

  pop();

};

​

function dragSegment( i,  xin,  yin) {

  var dx = xin - x[i];

  var dy = yin - y[i];

  var angle = atan2(dy, dx);  

  x[i] = xin - cos(angle) * segLength;

  y[i] = yin - sin(angle) * segLength;

  segment(x[i], y[i], angle);

};

​

function draw() {

 PX=mouseX;

 PY=mouseY;

  dragSegment(0, PX, PY);

  for(var i=0; i<x.length-1; i++) {

    dragSegment(i+1, x[i], y[i]);

  }

};