Re: [Tuxnes-devel] GameGenie: Only one code is used.

[Jason D. S. <js...@an...>]

I'm not positive I understand the problem, but here goes...

Mike Mestnik wrote:
> I'm trying to fix this, but I get hung up on how to add to a pointer when parsing a string.  So if
> you can get this patch to work, much thanx.
> 
> The problem I can't overcome is the call to DecodeGameGenieCode needs ggcode[gamegenie].  It's a
> pointer withought a cast.  Giving it a cast like (char *) dose nothing.  What I need to do is add
> gamegenie to the value of (char *)ggcode to get a new pointer that points into the middle, after
> the last ',', of ggcode.  I do this in 2 places, one is unavoidable unless you rewrite the whole
> thing.

ggcode[gamegenie] is a char, not a char*.  I think you want (ggcode + 
gamegenie) or &ggcode[gamegenie] so that you have the pointer to the 
string rather than the first character of it?

> +  int gamegenie = 0;

Technically this should be a size_t.

> @@ -1373,8 +1362,9 @@
>            showheader = 1;
>            break;
>          case 'g':
> -          gamegenie = 1;
>            ggcode = optarg;
> +	  for ( gamegenie = strlen(ggcode); gamegenie <= 1; gamegenie-- )
> +	     if ( ggcode[gamegenie-1] == ',' ) break;

Shouldn't the comparison be "gamegenie >= 1"?

> @@ -2126,12 +2116,15 @@
>      }
>  
>    /* enter the Game Genie codes */
> -  if (gamegenie)
> +  while (gamegenie)
>      {
> -      ggret = DecodeGameGenieCode (ggcode, &address, &data, &compare);
> +       char * _ggcode;
> +       _ggcode = ggcode + gamegenie;
> +      ggret = DecodeGameGenieCode (_ggcode, &address, &data, &compare);

Exactly.  (But you don't need the temporary variable; you can just pass 
ggcode + gamegenie directly.)

> @@ -2167,6 +2160,9 @@
>              fprintf (stderr, "Game Genie: value at %04X = %02X\n", address,
>                       MAPTABLE[address >> 12][address]);
>          }
> +       bzero( ggcode + --gamegenie, 1 + strlen(ggcode) - gamegenie);
> +       for ( gamegenie = strlen(ggcode); gamegenie <= 1; gamegenie-- )
> +	  if ( ggcode[gamegenie-1] == ',' ) break;
>      }

I guess this is the loop part (to handle multiple codes, separated by 
commas), but I don't quite understand it.  I'm pretty sure it's not 
right, though - it doesn't corectly handle the gamegenie==0 case.  And 
again you want >= rather than <=.  I'd do something like

   while (ggcode /* Look at ggcode, not gamegenie. */) {

     /* ... */

     if (gamegenie > 0) {
       /* Find next code. */
       ggcode[--gamegenie] = '\0';
       for (gamegenie--; gamegenie >= 1; gamegenie--)
         if (ggcode[gamegenie-1] == ',') break;
     } else {
       /* End loop. */
       ggcode = NULL;
     }

Of course, it could be that I'm completely misunderstanding your code.

jason short