I've noticed something odd. I have a sketch which uses noise() that I then map to the width and height of the display window. On Java Mode this works fine, and the co-ordinates move around the whole display.

However, when I switch to JavaScript mode, the values seem to constrain themselves to near the centre of the screen (or near the starting point) They don't drift near as much as in the Java mode.

Any ideas why this is happening?

2. float x,y,x2,y2,px,py;
3. float nx,ny;
4. color c;
5. 
   
6. void setup(){
7.   size(800,600);
8.   colorMode(HSB);
9.   background(0);
10.   c = 255;
11.   stroke(c,20);
12.   nx = 0;
13.   ny = 20000;
14.   x = map(noise(nx),0,1,0,width); 
15.   y = map(noise(ny),0,1,0,height);
16.   px = x;
17.   py = y;
18. }
19. 
    
20. void draw(){
21.   x = map(noise(nx),0,1,0,width); 
22.   y = map(noise(ny),0,1,0,height);
23.     for(int i = 0;i<int(random(25,50));i++){
24.     float d = random(360);
25.     float r = radians(d);
26.     float x2 = x + sin(r) * random(50);
27.     float y2 = y + cos(r) * random(50);
28.       stroke(c,20);
29.       line(x,y,x2,y2);
30.     }
31.     stroke(c,200);
32.     line(x,y,px,py);
33.   nx+=0.01;
34.   ny+=0.01;
35.   px = x;
36.   py = y;
37. }