hello,

I wrote a code that will give any pixel one after the other a random greytone. over that i would like to place a picture (.gif) with a green border and an alpha'd rectangle in the middle via a mouseclick.
both parts work when started singular, together processing returns me a "NullPointerException" i don't really get.

Can somebody tell me why it result's and how i can change that ?

Stefan



Code:

int x = 0;
int y = 0;

PImage b; 

  void setup() {
     size(512, 384);
     /* size(screen.width, screen.height); */
     background(255);
     noStroke();
     colorMode(RGB);
     /* framerate(200); */  
     PImage b = loadImage("testgruen.gif"); 
     }
     
     
  void draw() {
  
  for(int i=0; i<100; i++) { 
  
  float r = random(255);
  fill(r);		 // set Variables fill(r, r, r) for Schwarz/Weiss

  if ((x <= width) && (y <= height)) { 
  rect(x, y, 3, 3);
  x++;
  }
  
  if (x >= width) {
  y++;
  x = 0;
  x++;
  x = x - 1;
  }
  
  if (y >= height) {
  x = 0;
  y = 0;
  rect(x, y, 3, 3);
  x++;
  }
 }
  if(mousePressed) {
    image(b, 0, 0);	 
  } 

}