RE: Re[2]: Pilot: Smooth auto scroll

[Richard Hartman <hartman@xxxxxxxxxxxx>]

I believe the Pilot has a "virtual screen" capability
... otherwise these graphics programs couldn't draw
pictures larger than the screen.

What would be required would be for the reader to implement
a virtual screen larger than the physical screen by at
least one line height (preferably more).  The text would
be drawn on the virtual screen, the origin of which would
be updated on a timed interval.  Once one line of text had
been scrolled, the entire bitmap image of the text would
be block-copied up the virtual screen, the origin of the
display would be reset back to the top of the virtual
screen, and the new line of text would be drawn at the
bottom of the virtual screen, at which point we could
start the scrolling timer again.

Definately doable.  I wonder how much demand there is
for this kind of reader, though.



-- 
-Richard M. Hartman
hartman@xxxxxxxxxxxx

186,000 mi./sec ... not just a good idea, it's the LAW!


> -----Original Message-----
> From: Josh Mathis [mailto:jmmathis@xxxxxxxx]
> Sent: Tuesday, September 22, 1998 2:44 PM
> To: gwilterdink@xxxxxxxx; pilot@xxxxxxxxxxxxxxxxxxxxxxxx
> Subject: Re: Re[2]: Pilot: Smooth auto scroll
> 
> 
> >        The OS may be the limiting factor and not allow 
> this, I don't know.
> I
> >     think it would be nice to see the text flowing smoothly 
> up the screen
> with
> >     the up/down buttons adjusting the speed. The jerky line 
> by line (or
> page by
> >     page) is just not very usable to me.
> 
> 
> Two options come up with this:
> 
> 1.  This would require quick drawing. Instead of flashing a 
> new line of
> TEXT, it would require the conversion of letters to a 
> bitmap-type thing.
> This would have to be DRAWN pixel-by-pixel, which (I think) 
> cannot be done
> considering the speed of the Palm processor.
> 
> 2.  If that isn't necessary,it would at least require some 
> sort of hack to
> draw out only parts of each line.  That may be the easier of the two
> options, yet probably not too feasible, either.
> 
> Josh Mathis
> jmmathis@xxxxxxxx
> 
> 
> 
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> 
> 

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