Processing - Draw Square - Debug

Processin_Draw_Square_Debug.java

int MAX = 500;
int idx = 0;
RectDrawer[] rd;
int prevMouseX, prevMouseY;
color cl1 = color(255,0,0);
 
void setup() {
  rd = new RectDrawer[MAX];
  size(500, 500);
  noStroke();
  randomSeed(0);
// noLoop();
  frameRate(30);
  for (int i = 0; i < MAX; i++) {
    rd[i] = null;
  }
  prevMouseX = 0; prevMouseY = 0;
  
}
 
void draw() {
  background(128,128,128);
  if (mouseX != prevMouseX || mouseY != prevMouseY) {
    if (rd[idx] == null) {
//      println(idx + " x:" + mouseX + " y:" + mouseY);
      rd[idx] = new RectDrawer(idx, mouseX, mouseY, 15, getColor());
      idx++;
      prevMouseX = mouseX;
      prevMouseY = mouseY;
    }
  }
  if (495 < idx) idx = 0;
  
  // println("----");
  for (int i = 0; i < MAX; i++)
  {
    if (rd[i] == null) continue;
    if (rd[i].isLiving() == true) {
      rd[i].drawRect();
    }
    else {
      rd[i] = null;
    }
  }
}

color getColor()
{
  float fr = red(cl1) - 5;
  if (fr < 10) fr = 255;
  cl1 = color(fr, 0,0);
  return cl1;
}
 
class RectDrawer {
  int life = 50;
  float xpos, ypos, rectsize;
  color cl;
  color prevcl;
  int m_idx;
  
  RectDrawer(int i, float x, float y, float s, color c) {
    m_idx = i;
    xpos = x; ypos = y; rectsize = s; cl = c;
    prevcl = cl;
  }
  
  public boolean isLiving() {
    if (-20 < life) return true;
    return false;
  }
 
  void drawRect() {
    rect(xpos, ypos, rectsize, rectsize);
    fill(cl);
    //print("i:" + m_idx + "\tx:" + xpos + "\ty:" + ypos + "\tc:" + cl + "<RET>");
    onetick();
  }
  
  void onetick()
  {
    life -= 5;
  }
}