Example #1
0
/* Set a 256 entry pallette with the values given in "palbuf". */
static void
setmany(unsigned char palbuf[256][3], int start, int count)
{
    unsigned char _far *fp;
    union REGS regs;
    struct SREGS sregs;
    unsigned i;

#if defined( __GNUC__ )
    /* This should work for most compilers - only tested with GNU C++, so
       it isn't turned on for anything else */
    for (i=start;i<start+count;i++) {
	regs.x.ax = 0x1010;
	regs.x.bx = i;
	regs.h.ch = palbuf[i][1];
	regs.h.cl = palbuf[i][2];
	regs.h.dh = palbuf[i][0];
	int86x(0x10, &regs, &regs, &sregs);
	return;
    }
#elif defined( DOS386 )
    /* Put the contents of the new palette into real memory, the only
       place I know that won't impact things is the video RAM. */
    fp = MK_FP(_x386_zero_base_selector, 0xA0000);
#else
    /* If you aren't using GNU C++ or Zortech C++ for 386 protected mode,
       then you need to use a compiler that supports access to all of the
       registers, including ES, to be able to set the pallette all at once. */
    fp = MK_FP(0xA000, 0);
#endif

    /* If you got here then you are using Zortech C++ */
    for (i=start;i<start+count;i++) {
	fp[3*(i-start)  ] = palbuf[i][0];
	fp[3*(i-start)+1] = palbuf[i][1];
	fp[3*(i-start)+2] = palbuf[i][2];
    }

    regs.x.ax = 0x1012;
    regs.x.bx = start;
    regs.x.cx = count;
    regs.x.dx = 0;
    segread(&sregs);
    sregs.es  = 0xA000;
#if defined( DOS386 )
    int86x_real(0x10, &regs, &regs, &sregs);
#else
    int86x(0x10, &regs, &regs, &sregs);
#endif
    /* Now clear off the values that got dumped into the video RAM */
    for (i=0;i<3*count; i++)
	*fp++ = 0;
}
static int
setvesamode(int mode, int clear)
{
   union REGS regs;
   struct SREGS sregs;
   struct ModeInfoBlock *VgaPtr = &VESAModeInfo;
   unsigned i;

   /* Call VESA function 1 to get mode info */
   regs.h.ah = 0x4f;
   regs.h.al = 0x01;
   regs.x.cx = mode;
#if defined( DOS386 )
   regs.x.di = real_buf[0];
   segread(&sregs);
   sregs.es  = real_buf[1];
   int86x_real(0x10, &regs, &regs, &sregs);
   if (regs.h.al != 0x4f || regs.h.ah != 0)
      return 0;
   for (i=0; i<sizeof(struct ModeInfoBlock); i++)
      ((unsigned char *)VgaPtr)[i] = real_ptr[i];
#elif defined( __GNUC__ )
   regs.x.di = real_buf[0];
   int86x(0x10, &regs, &regs, &sregs);
   if (regs.h.al != 0x4f || regs.h.ah != 0)
      return 0;
   for (i=0; i<sizeof(struct ModeInfoBlock); i++)
      ((unsigned char *)VgaPtr)[i] = real_ptr[i];
#else
   regs.x.di = FP_OFF(VgaPtr);
   sregs.es  = FP_SEG(VgaPtr);
   int86x(0x10, &regs, &regs, &sregs);
   if (regs.h.al != 0x4f || regs.h.ah != 0)
      return 0;
#endif

   /* The mode is supported - save useful information and initialize
      the graphics display */
   line_length = VgaPtr->BytesPerScanLine;
   granularity = ((unsigned long)VgaPtr->WinGranularity) << 10;
   screen_maxx = VgaPtr->XResolution;
   screen_maxy = VgaPtr->YResolution;

   if (Reset_Display_Flag) {
      /* Now go set the video adapter into the requested mode */
      regs.h.ah = 0x4f;
      regs.h.al = 0x02;
      regs.x.bx = mode;
      int86(0x10, &regs, &regs);
      return (regs.h.al == 0x4f && regs.h.ah == 0x00 ? 1 : 0);
      }
}