Path: chuka.playstation.co.uk!scea!peter_alau@playstation.sony.com
From: Elliott Lee <tenchi@jps.net>
Newsgroups: scea.yaroze.programming.2d_graphics,scee.yaroze.freetalk.english
Subject: Re: Controlling the PAD...
Date: Thu, 20 Aug 1998 15:35:35 -0700
Organization: Cisco Systems
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Message-ID: <35DCA4B7.23251261@jps.net>
References: <6rgb76$g19@scea> <6rgmt1$l2e20@chuka.playstation.co.uk>
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That would work, although you need to have a flag to note that the
down direction was released.  The reason is that it would appear you
are using the PadStatus buffer and masking it for the PADdown bit.
Thus, your code will initiate the timer on the first frame that Down
is pressed and then the next frame the down direction will still be
pressed so it will fall through to the else condition.

It may be more efficient to set up a general queue of events which
tracks the last 16 or so pad direction presses.  That way you could
know when the down was first pressed then released and check to see
if a second down/release occurred so many frames afterward.  This
could also extend to fighting games where you would want to track
the combos of your character.

For instance, the following (without regard to timing) could provide
you with the history of pad directional presses for the past 16
pad events.  To check to see if the down was pressed twice, then you
could check to see if currently the down direction bit is set and that
somewhere in the history the down was released once and pressed at
least once before that.  If you wanted to check to see if someone did
a fireball motion (down, down-right, right), you could walk back up
the queue checking the down and right bits to see if they were set
in that order.  Etc. etc...

============================================================

#define PAD_EVENT_LEN 16
#define PAD_EVENT_MASK (PADdown|PADup|PADleft|PADright)
u_long	PadStatusQ[PAD_EVENT_LEN],PadStatusLast;

#...........................................
# Call when you need to init
void InitPadQ( void )
{
int	p;
for( p=0; p<PAD_EVENT_LEN; p++ )
  { PadStatusQ[p]=0; }
PadStatusLast=0;
}

#...........................................
# Support function for PadPoll()
sub PadAddEvent( u_long padstat )
{
int	p;

# push all events down
for( p=0; p<(PAD_EVENT_LEN-1); p++ )
  PadStatusQ[p]=PadStatusQ[p+1];

PadStatusQ[PAD_EVENT_LEN-1] = padstat;
}

#...........................................
# Call each video frame after reading the pad
void PadPoll( u_long current_pad_stat )
{
# Mask out all bits except the directions....
current_pad_stat &= PAD_EVENT_MASK

# Any change?
if( current_pad_stat == PadStatusLast )
  return;

# Record the new changes...
PadAddEvent(current_pad_stat);
PadStatusLast=current_pad_stat; 
}

- e!

David Smethurst wrote:
> 
> Steve Tolin wrote in message <6rgb76$g19@scea>...
> >I don't know if anyone has asked this yet....
> >
> >How would you register a double tap on the d-pad???
> >
> >Let's say holding down on pad makes character duck
> >        if (PadStatus&PADdown)
> >                {
> >//              printf("You just pressed the D-PAD: DOWN\n");
> >                AnimateDucking();
> >               }
> >
> >
> >What would have to go in here???
> >
> >        if (PadStatus&*******************)
> >                {
> >//              printf("You just pressed the D-PAD: DOWN\n");
> >                AnimateCrouch();
> >                }
> 
> I think the only way you would be able to do this is by having a
> timer -
> i.e.
> 
> static short iTimer=0;
> static short iLast=-1;
> 
> if( PadStatus&PADdown)
> {
>     printf("You just pressed the D-PAD: DOWN\n");
>     if( iLast == -1 )
>     {
>          iLast   = iTimer;
>         printf("First press\n");
>     }
>     else
>     {
>         // take it that we want it to be pressed twice within 5 updates
>         // you will have to alter this according to how fast you need to do
>         // the double press
>         if( iTimer - iLast < 5 )
>         {
>             AnimateCrouch();
>             iTimer = 0;
>             iLast = -1;
>         }
>     }
> }
> 
> if( iLast != -1 ) iTimer++;
> 
> This should help. If not just drop me an email
> 
> D.
> --
> dave@ulthwe.demon.co.uk
> ICQ: 244386

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