keys.c

知名gba模拟器vgba代码

/* Keys.c
   This file is part of the VGB-DOS project
   Copyright (C) Marcel de Kogel ([e-mail]), 1996
   You may not use this file for commercial purposes
   Please notify me if you make any changes to this file */

#include <stdio.h>
#include <sys/farptr.h>
#include <dpmi.h>
#include <go32.h>
#include <crt0.h>
#include <pc.h>

int _crt0_startup_flags = _CRT0_FLAG_NONMOVE_SBRK |
                          _CRT0_FLAG_LOCK_MEMORY  |
                          _CRT0_FLAG_DROP_EXE_SUFFIX;


static __volatile__ int key=0;
static _go32_dpmi_seginfo newirqkeyb,oldirqkeyb;

void keyb_interrupt (void)
{
 unsigned code;
 static int extkey;
 code=inportb (0x60);           /* get scancode */
 if (code<0xE0)                 /* ignore codes >0xE0 */
 {
  if (code & 0x80)              /* key is released */
   key=0;
  else                          /* key is pressed */
  {
   if (extkey)
    key=code+128;
   else
    key=code;
  }
  extkey=0;
 }
 else
  if (code==0xE0)
   extkey=1;
}

static int _getkey (char *s)
{
 printf ("Press key for %s\n",s);
 key=0;
 while (!key);
 _farpokew (_dos_ds,0x41A,_farpeekw(_dos_ds,0x41C));    /* clear buffer */
 return key;
}

int main (int argc,char *argv[])
{
 int left,right,up,down,firea,fireb,start,select;
 _go32_dpmi_get_protected_mode_interrupt_vector (9,&oldirqkeyb);
 newirqkeyb.pm_offset=(int)keyb_interrupt;
 newirqkeyb.pm_selector=_go32_my_cs();
 _go32_dpmi_chain_protected_mode_interrupt_vector (9,&newirqkeyb);
 left=_getkey ("LEFT");
 right=_getkey ("RIGHT");
 up=_getkey ("UP");
 down=_getkey ("DOWN");
 firea=_getkey ("BUTTON A");
 fireb=_getkey ("BUTTON B");
 start=_getkey ("START");
 select=_getkey ("SELECT");
 printf ("\n-keys %02X%02X%02X%02X%02X%02X%02X%02X\n",
         left,right,up,down,firea,fireb,start,select);
 _go32_dpmi_set_protected_mode_interrupt_vector (9,&oldirqkeyb);
 return 0;
}