Re: A83: an idea for greyscale
[Prev][Next][Index][Thread]
Re: A83: an idea for greyscale
A while ago when Hideaki (crashman) and I were discussing/writing eight way
scrolling tile engines, I gave him the crazy idea (probably inspired by
something I'd seen/done on the PC years ago, or something Kirk mentioned) to
interleave the tile map drawing with the copy to the display controller. He
took the idea seriously and managed to write code to draw an arbitrary row
from a tilemap faster than the delay necessary for the display controller.
The result was an almost unbelievably fast scrolling engine (somewhere
around 120 frames per second if I remember correctly). This technique is
not applicable to most types of games, but it shows that if you think
sometimes you can make things work to your advantage (think, the delay
waiting for the display controller normally just goes to waste...so use it
to draw your tilemap). I doubt you could get a raycaster close to that, but
something similiar might be possible there. Just some ideas...
> When coding for the VGA (or DirectX), you create a backbuffer and draw to
> that, when finished drawing, you copy the whole stuff to the display, to
> prefend the screen to flicker.... THAT's the same thing we do for the
calc:
> draw to an offscreen-buffer, and when finished copy the whole stuff to the
> display (using fastcopy)...
>
> if we would write directly to the display it would flicker... (and besides
> that, it's vary usefull to have a buffer with the current screendata, IE
for
> plotting masked sprites; it would be much slower to constantly read our
data
> from the display)
References: