OpenEuphoria

2. Re: get_key problem in DOS fullscreen

• Posted by DB James <larches at comcast.net> Jun 18, 2007
• 534 views

Donald wrote:
> 
> Does anyone know what the problem may be with the following?
> It may be my system but wondering if anyone else has had anything similar or
> can help.
> 
> This code works fine when run in a window but if I go to fullscreen (using
> Alt-enter
> before running) it seems to hang.
> I have to use alt-enter which minimises the window and then close the window
> 
> }}}
<eucode>
> integer c,i
> i=0
>     
>  while (1) do
> 	c = get_key()
> 	if c=' ' then
> 	    exit
> 	else if c!=-1 then
> 		i=i+1
> 	    end if
> 	end if
>  end while
> 
> ? {i,c}
> </eucode>
{{{


Hi Donald,

I moved one of your lines and it works in either a window or fullscreen:

integer c,i
i=0
    
 while (1) do
  c = get_key()
  if c=' ' then
      exit
  else if c!=-1 then
          i=i+1
          ? {i,c}
      end if
  end if
end while

To keep the window from disappearing immediately, put something like
while get_key()=-1 do end while
as the last line.

--Quark

4. Re: get_key problem in DOS fullscreen

• Posted by ChrisBurch2 <crylex at freeuk.co.uk> Jun 18, 2007
• 565 views

Donald wrote:
> 
> DB James wrote:
> > 
> > Donald wrote:
> > > 
> > > Does anyone know what the problem may be with the following?
> > > It may be my system but wondering if anyone else has had anything similar
> > > or
> > > can help.
> > > 
> > > This code works fine when run in a window but if I go to fullscreen (using
> > > Alt-enter
> > > before running) it seems to hang.
> > > I have to use alt-enter which minimises the window and then close the
> > > window
> > > 
> 
> > Hi Donald,
> > 
> > I moved one of your lines and it works in either a window or fullscreen:
> > 
> > }}}
<eucode>
> > integer c,i
> > i=0
> >     
> >  while (1) do
> >   c = get_key()
> >   if c=' ' then
> >       exit
> >   else if c!=-1 then
> >           i=i+1
> >           ? {i,c}
> >       end if
> >   end if
> > end while
> > </eucode>
{{{

> > 
> > To keep the window from disappearing immediately, put something like
> > while get_key()=-1 do end while
> > as the last line.
> > 
> > --Quark
> You code gives the same problem on my system!?
> 
> Maybe it's to do with the NVidia GEforce6150 driver or the Dell 1707 LCD
> screen.
> I don't know why they would affect the get_key routine though.
> Presumably PS2 keyboard is fine? Windows XP pro should be ok?
> 
> thanks anyway


Hi

It initially gave similar results on mine too, (incidentally I put 

? {i,c}
? 1/0

at the end, to produce the srroe, and get a readable display.

But if you repeatedly press space, or wait, then the program stops.

I think this has something to do with keyboard polling speeds in that very fast
while loop -
the loop is going to fast to read the keys - or something. Obviusly this has
something to do
with full screen dos mode, as opposed to windowed mode. Exactly what though 
is a bit of a mystery.

Try slowing the loop down a bit, using ex or exc instead of exw, and running
from the command line (cmd instead of command - I think these are slightly
different)

Chris

6. Re: get_key problem in DOS fullscreen

• Posted by Greg Haberek <ghaberek at ssoe.com> Jun 19, 2007
• 521 views

Donald,

What I would suggest here to slow down the loop, is to make use of the built-in
tasking features of Euphoria. Here is a quick example I mocked up.

procedure check_key()

    while 1 do
        if get_key() = ' ' then
            -- user pressed space bar
            exit
        end if
        task_yield()
    end while

    -- simpler version:
    --while get_key() != ' ' do
    --  task_yield()
    --end while

end procedure

integer check_key_task

    -- create the task, no parameters required
    check_key_task = task_create( routine_id("check_key"), {} )

    -- adjust timing here:
    -- (this would be one hald to a whole second)
    task_schedule( check_key_task, {0.50,1.00} )
    
    -- loop while the task is 'active'
    while task_status(check_key_task) = 1 do

        -- do important stuff here,
        -- this loop will automatically exit
        -- when the user presses the space bar
        
        task_yield()
    end while

-Greg