text: // https://www.khanacademy.org/computer-programming/perspective/5537308149284864
  
  var draw = function() {
      background(218, 240, 216);
      background(0, 0, 0);
      stroke(255, 255, 255);
      for(var y = 1; y < 500; y+= 1 + y/4) {
          for(var x = -50 - y*3.4; x < 500; x += 20 + abs(200 - x)/23 + (y)/4) {
              pushMatrix();
              translate(x, y);
              
              var xdiff = mouseX - x;
              var ydiff = mouseY - y;
              
              var dot = xdiff;
              var mags = dist(0, 0, xdiff, ydiff);
              
              var angle = acos(dot/mags);
              
              if(ydiff < 0) {
                  angle = 1 - angle;
              }
              
              rotate(angle);
              strokeWeight(1 + y/100);
              line(0, 0, (1 + y/5.1), 0);
              popMatrix();
          }
      }
  };
  