Hi, all

Thanks in advance, I am having some custom class object stored in an ArrayList. When I click any of them, it will fade away and when alpha reaches 0, it will remove itself from the ArrayList using remove(this). However, if I click them in order, the moment when it is removed causing the rendering of the next object in ArrayList to flicker a bit. It almost seems like the ArrayList lost the next object for a brief moment so it wasn't updated and drawn to the screen. How do I go around and keep that flickering from happening?

In the code below, if you click starting with the bottom-right one and go clockwise, you will see the next object flicker. I am using Processing 2.0b8 on PC, and it happens with or without P2D

*just test it this on 1.5.1, also does it.
*just test it this on a Mac, also does it.

1. ArrayList<enemy> enemies;
2. void setup() {
3.   size(300,300, P2D);
4.   enemies= new ArrayList<enemy>();
5.   float a = PI/4; //create four enemies, PI/2 away, starting bottom-right corner
   
6.   for (int i=0; i<4; i++) {
7.     enemy temp = new enemy(width/2+100*cos(a), height/2+100*sin(a));
8.     enemies.add(temp);
9.     a+=PI/2;
10.   }
11. }
12. void draw() {
13.   background(0);
14.   if (!enemies.isEmpty()) {
15.     for (int i=0; i<enemies.size(); i++) {
16.       enemy temp= enemies.get(i);
17.       temp.update();
18.     }
19.   }
20. }
21. 
    
22. class enemy {
23.   PVector pos;
24.   float size;
25.   boolean death;
26.   int alpha;//alpha for all the color in the drawing of the enemy
27.   int type;//enemy type
28.     enemy(float _x, float _y) {
29.     pos=new PVector(_x, _y);
30.     size=60;
31.     death = false;
32.     alpha = 255;
33.   }
34.   void update() {
35.     if (death) {//if dead, fade away
36.       alpha-=5;
37.       if (alpha<=0) {
38.         enemies.remove(this);
39.       }
40.     }
41.     if (mousePressed) {
42.       if (mouseX>pos.x-size/2 && mouseX<pos.x+size/2) {
43.         if (mouseY>pos.y-size/2 && mouseY<pos.y+size/2) {
44.           damage();
45.         }
46.       }
47.     }
48.     //draw the enemy
49.     pushMatrix();
50.     translate(pos.x, pos.y);
51.     fill(211, 127, 28, alpha);
52.     ellipse(0, 0, size, size);
53.     popMatrix();
54.   }
55.   void damage() {
56.     death = true;
57.   }
58. }