Huh. Seems like that sweet answer disappeared. Anyway, if you want to display a loading percentage that goes up 5% at a time, and takes between 5 and 10 seconds, you can do this:

1. 
   
2. int totalTime;
3. PFont myFont = createFont( "Ariel", 12 );
4. 
   
5. void setup() {
6.   size(200,200);
7.   fill(0);
8.   totalTime = 5 + int(random(6));
9.   textFont( myFont );
10. }
11. 
    
12. void draw() {
13.   background(255);
14.   text( str(totalTime) + " seconds", 20, 20 );
15.   text( str(5 * int(map(constrain(millis(),0,1000*totalTime), 0, 1000 * totalTime, 0, 20)) ) + "%", width/2-15, height/2+5);
16. }