//---------------------------------------------
class Trail {

  int[] trailX;
  int[] trailY;
  int trailLength, trailDensity;
  int r, g, b;

//---------------------------------------------
  Trail(int inLength, int inDensity, int ir, int ig, int ib){
    trailLength = inLength;
    trailDensity = inDensity;
    trailX = new int[trailLength];
    trailY = new int[trailLength];
    r = ir;
    g = ig;
    b = ib;
  }

//---------------------------------------------
  void update(float x, float y){
    //Updates the trail
    if(timer%trailDensity==0){
      for(int i=0; i<trailLength-1; i++) {
        trailX[i] = trailX[i+1];
        trailY[i] = trailY[i+1];
      }
      trailX[trailLength-1] = (int) x;
      trailY[trailLength-1] = (int) y;
    }
    visualize();
  }

//---------------------------------------------
  void visualize(){
    //Draws the trail
    for(int i=trailLength-1; i>=0; i--) {
      stroke(i*r/trailLength,i*g/trailLength,i*b/trailLength);
      point(trailX[i],trailY[i]);
    }
  }
}