/* Copyright (C) 1993, 1994 Aladdin Enterprises.  All rights reserved.
  
  This file is part of GNU Ghostscript.
  
  GNU Ghostscript is distributed in the hope that it will be useful, but
  WITHOUT ANY WARRANTY.  No author or distributor accepts responsibility to
  anyone for the consequences of using it or for whether it serves any
  particular purpose or works at all, unless he says so in writing.  Refer
  to the GNU Ghostscript General Public License for full details.
  
*/

/* gdevevga.c */
/* IBM PC EGA and VGA display drivers */
/* All of the real code is in gdevpcfb.c. */
#include "memory_.h"
#include "gx.h"
#include "gserrors.h"
#include "gxdevice.h"
#include "gdevpcfb.h"

/* ------ Internal routines ------ */

/* We can't catch signals.... */
void
pcfb_set_signals(gx_device *dev)
{
}

/* Read the device state */
void
pcfb_get_state(pcfb_bios_state *pbs)
{	registers regs;
	regs.h.ah = 0xf;
	int86(0x10, &regs, &regs);
	pbs->display_mode = regs.h.al;
	pbs->text_page = regs.h.bh;
	regs.h.ah = 0x3;
	int86(0x10, &regs, &regs);
	pbs->text_cursor_mode = regs.rshort.cx;
	regs.rshort.ax = 0x1130;
	regs.h.bh = 0;
	int86(0x10, &regs, &regs);
	switch ( regs.rshort.cx )
	{
	case 0x08: pbs->text_font = 0x1112; break;	/* 8 x 8 */
	case 0x10: pbs->text_font = 0x1114; break;	/* 8 x 16 */
	default:   pbs->text_font = 0x1111;		/* 8 x 14 */
	}
	regs.h.ah = 0x8;
	regs.h.bh = pbs->text_page;
	int86(0x10, &regs, &regs);
	pbs->text_attribute = regs.h.ah;
	pbs->border_color = (regs.h.ah >> 4);
	regs.rshort.ax = 0x1a00;
	int86(0x10, &regs, &regs);
	if ( regs.h.al == 0x1a && regs.h.bl == 0x8 )
	  {	regs.rshort.ax = 0x1008;
		int86(0x10, &regs, &regs);
		pbs->border_color = regs.h.bh;
	  }
	if ( pbs->display_mode != 3 )
	  {	pbs->display_mode = 3;
		pbs->text_font = 0x1112;
		pbs->text_cursor_mode = 0x0607;
		pbs->text_attribute = 7;
		pbs->text_page = 0;
	  }
}

/* Set the device mode */
void
pcfb_set_mode(int mode)
{	registers regs;
	regs.h.ah = 0;
	regs.h.al = mode;
	int86(0x10, &regs, &regs);
}

/* Restore the device state */
void
pcfb_set_state(const pcfb_bios_state *pbs)
{	registers regs;
	pcfb_set_mode(pbs->display_mode);
	regs.rshort.ax = 0x500;		/* force display of page 0 */
	int86(0x10, &regs, &regs);
	regs.rshort.ax = pbs->text_font;
	regs.h.bl = 0;
	int86(0x10, &regs, &regs);
	regs.h.ah = 0x3;
	regs.h.bh = 0;
	int86(0x10, &regs, &regs);	/* Get cursor to reset MCGA */
	regs.h.al = pbs->text_page;
	regs.h.ah = 0x5;
	int86(0x10, &regs, &regs);
	regs.rshort.cx = pbs->text_cursor_mode;
	regs.h.ah = 0x1;
	int86(0x10, &regs, &regs);
	regs.rshort.ax = 0x1001;
	regs.h.bh = pbs->border_color;
	int86(0x10, &regs, &regs);
}
