Re: A round shaped LCD screen



Steve Calfee <stevexcalfee@xxxxxxxxxxx> writes:
> Back in the early days of coin-op video games, when we first had x-y
> monitors (remember Asteroids?), we dreamed of having new display
> hardware based on r-theta displays. So you could rotate the screen
> (change theta) and then scale it by changing r.
>
> Those whining hardware guys said they could not do it (circa 1978)

Though that's exactly what early radar systems did.

They uses a round tube, with deflection on one axis, the deflection
assembly was motorized to spin around the tube. Thus the motor
position gives theta, and the electromagnetic deflection gives r.

Still, for most arcade games, having a polar coordinate display
would have caused more trouble than it solved. Even in games
where the majority of the action takes place in a polar coordinate
space, lots of things would have to be transformed since you often
need to be able to rotate objects around an origin independent of
the center of the global coordinate system. Also, displaying
the score and other text messages would have similar problems,
unless you actually wanted them displayed "wrapped around a
circle".

Eric

.