teleprompter application- reverse text, smooth scrolling?

[Ben Rubinstein]

On 23/6/06 10:39, Sivakatirswami wrote:
 > The problem comes if you are trying to  project the type  from a
 > distance, then you have to use a really big font and text-height, and
 > then the number of words-lines visible on screen drops dramatically, and
 > you really need to crank up the scroll speed.  I couldn't find any way
 > to get the thing to scroll fast enough-smoothly. A single pixel
 > increment sent on a 1 millisecond loop, I believe is the smoothest you
 > can get and the fastest you can get.

Is the problem that the text can't render fast enough, or that you can't make 
the timer fire frequently enough?

If the first - could you pre-render the text into an image (or a series of 
images, eg one per line, to swap in and out of a group) and scroll that?

If the problem is that the timer doesn't fire enough - ie, I guess, that 
although you ask it to call you back in 1-millisecond, more time than that has 
actually elapsed before it does - does "the idleRate" effect this?  Failing 
that, can you run your own tight loop, polling "the milliseconds" until it 
changes?  (I'm guessing you don't really need to scroll at faster than 1000 
pixels/second.)

   Ben Rubinstein               |  Email: benr_mc at cogapp.com
   Cognitive Applications Ltd   |  Phone: +44 (0)1273-821600
   http://www.cogapp.com        |  Fax  : +44 (0)1273-728866