/* Portions Copyright (C) 2001 artofcode LLC.
   Portions Copyright (C) 1996, 2001 Artifex Software Inc.
   Portions Copyright (C) 1988, 2000 Aladdin Enterprises.
   This software is based in part on the work of the Independent JPEG Group.
   All Rights Reserved.

   This software is distributed under license and may not be copied, modified
   or distributed except as expressly authorized under the terms of that
   license.  Refer to licensing information at http://www.artifex.com/ or
   contact Artifex Software, Inc., 101 Lucas Valley Road #110,
   San Rafael, CA  94903, (415)492-9861, for further information. */

/*$RCSfile: gdevevga.c,v $ $Revision: 1.7 $ */
/* 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);
}
