D.M.Johnson@newcastle.ac.uk (Dave Johnson) (05/23/91)
I was messing around with the aline routines in the 'COMPUTE! volume 3 - DOS' and can across this problem: I was ploting sprite to the screen (using either the Blitbit or Sprite routine, I can not a present remember which) in assembler. I was waiting until the VVsync to prevent flicker: no problem here. the sprite moved around the screen. flickering slightly (this was do with the code - I fixed it so there was no flicker) but when the sprite moved around the screen. There was a region in which the sprite disappeared as it moved through it, (it got worse when I removed the wait for the Vsync). Could anyone explain what is happening and if so whats the cause and the cure. Machine used 2.5meg STFM mono Monitor 1.2 OS Dave P.S. If the above does make sense I will try and dig up the program and post it so some one could help me.
warwick@cs.uq.oz.au (Warwick Allison) (05/24/91)
>When the sprite moved around the screen, there was a region in >which the sprite disappeared as it moved through it, (it got worse when I >removed the wait for the Vsync). >mono Monitor The trouble is, you are drawing of the screen as it is being displayed. Possible solutions: 1. Write faster wipe/draw procedures 2. Use double buffering 3. Write a wipe/draw that interlaces wipes with redraws Also, try move the Vsync() around. Try Vsync()ing after you erase, but before you redraw. Warwick. -- _-_|\ warwick@cs.uq.oz.au / * <-- Computer Science Department, \_.-._/ University of Queensland, v Brisbane, AUSTRALIA.
bart@bluemoon.uucp (Bart Jaszcz) (05/25/91)
> flicker) but when the sprite moved around the screen. There was a region in > which the sprite disappeared as it moved through it, (it got worse when I > removed the wait for the Vsync). The same thing happens to gfa basic sprites. The only solution I see is to try using two virtual screens... l8er Bart This is from bart@bluemoon.uucp bart%bluemoon@nstar.rn.com who doesn't have their own obnoxious signature yet