Re: A82: ash2osh secondary graph routines
[Prev][Next][Index][Thread]
Re: A82: ash2osh secondary graph routines
At 09:42 PM 11/25/97 -0600, you wrote:
>I tried other ways of implementing a backround in Avalanche and have
>concluded that the only way to do so would be to use the secondary graph
>screen routines included with ash2osh kit. So my question is what do you
>reccommend I do to display a pic (which I have) on the screen that
>appears lighter and behind the falling icicles. And how often should I
>refresh this screen? or do I just display it once and it is there?
>
>~Ilya
My secondary buffer routines were not exactly designed for greyscale
graphics. In order to produce the effect you want, you would have to
display the icicles buffer first (so that they stayed on the screen longer
and therefore were darker), then you would need to OR in the background
buffer into the icicle buffer and then display that. This should produce
the effect with minimal flicker. Remember, the 82 uses a SLOW display
controller, so you will get flicker if you attempt to do anything similar
to greyscale. Since the display controller works off of the interrupts, I
recommend using an interrupt routine instead of just copying from the
buffer to the display whenever the source code can. If you do use
greyscale, warn those who use Game Wizard v2.0 in your documentation that a
crash might occur during the loading of the game.
BTW, the secondary buffers were designed to create layers for animated 2-D
games (background, middle layer (if there is one), foreground, etc. layers)
that could scroll at different rates creating some pretty cool effects.
Thomas J. Hruska -- thruska@tir.com
Shining Light Productions -- "Meeting the needs of fellow programmers"
http://www.geocities.com/SiliconValley/Heights/8504
http://shinelight.home.ml.org
Spam-Fighter code is: 14806560 (New technique to fighting spam)
Enter "Spam-Fighter: XXXXXXXX" in the body of a personal message
to thruska@tir.com. Otherwise the message will be filtered as spam.
References: