class Shape
{
  Position[] points;
  color c = shapeColor;
  int fade = 0, fadeSteps = 50;
  
  boolean down = false, kill = false;
  
  Shape() {}
  
  void set(Position[] p, int index, float ix, float iy)
  {
    down = true;
    points = new Position[p.length - index + 1];
    int j = 1;
    points[0] = new Position(ix, iy);
    for (int i = index; i < p.length-1; i++) {
      points[j] = new Position(p[i]);
      j++;
    }
  }
  
  void be()
  {
    if (points != null && down) {
      if (!kill) {
        draw();
      } else {
        fade();
      }
    }
  }
  
  void kill()
  {
    kill = true;
  }
  
  void draw()
  {
    stroke(255);
    fill(shapeColor);
    draw_shape();   
  }
  
  void fade()
  {
    float alfa = 255 - ((float)fade/(float)fadeSteps*255);
    c = color(red(c), green(c), blue(c), alfa);
    noStroke();
    fill(c);
    draw_shape();
    
    fade++;
    if (fade > fadeSteps) {
      fade = 0;
      c = shapeColor;
      kill = false;
      down = false;
    }
  }
  
  void draw_shape()
  {
    beginShape(POLYGON);
    curveVertex(points[0].x, points[0].y);
    for (int i = 1; i < points.length-9; i = i + 10) {
      if (points[i] != null && points[i].on_screen()) {
        curveVertex(points[i].x, points[i].y);
      }
    }
    curveVertex(points[0].x, points[0].y);
    endShape();
  }
}