OpenEuphoria

Re: sprites

• Posted by "Cuny, David" <ATB.DCUNY at HW1.CAHWNET.GOV> Mar 31, 1997
• 1035 views

It's nice to see a Euphoria graphics demo that doesn't require a Pentium. :)

I did notice that there is flickering when the screen refreshes, so I dug up
this snippet of code in the VGA Trainer portion of the PC Game Programmer's
Encyclopedia. Since I'm no good at coding assembly, I thought I'd post it
here and see if anyone else is interested in it. It's written for Turbo
Pascal.

 -- David Cuny


 -- SNIP --------------------------------------------------------------------
procedure WaitRetrace; assembler;
  { This waits until you are in a Verticle Retrace ... this means that all
    screen manipulation you do only appears on screen in the next verticle
    retrace ... this removes most of the "fuzz" that you see on the screen
    when changing the pallette. It unfortunately slows down your program
    by "synching" your program with your monitor card ... it does mean
    that the program will run at almost the same speed on different
    speeds of computers which have similar monitors. In our SilkyDemo,
    we used a WaitRetrace, and it therefore runs at the same (fairly
    fast) speed when Turbo is on or off. }

label
  l1, l2;
asm
    mov dx,3DAh
l1:
    in al,dx
    and al,08h
    jnz l1
l2:
    in al,dx
    and al,08h
    jz  l2
end;

 -- SNIP
 ---------------------------------------------------------------------