/* Copyright (C) 1993, 1994 Aladdin Enterprises.  All rights reserved.
  
  This file is part of Aladdin Ghostscript.
  
  Aladdin Ghostscript is distributed with NO WARRANTY OF ANY KIND.  No author
  or distributor accepts any responsibility for the consequences of using it,
  or for whether it serves any particular purpose or works at all, unless he
  or she says so in writing.  Refer to the Aladdin Ghostscript Free Public
  License (the "License") for full details.
  
  Every copy of Aladdin Ghostscript must include a copy of the License,
  normally in a plain ASCII text file named PUBLIC.  The License grants you
  the right to copy, modify and redistribute Aladdin Ghostscript, but only
  under certain conditions described in the License.  Among other things, the
  License requires that the copyright notice and this notice be preserved on
  all copies.
*/

/* 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);
}