/*
 * The functions in this file handle redisplay. There are two halves, the
 * ones that update the virtual display screen, and the ones that make the
 * physical display screen the same as the virtual display screen. These
 * functions use hints that are left in the windows by the commands.
 *
 */

#include	<stdio.h>
#include	"estruct.h"
#include	"eproto.h"
#include	"edef.h"
#include	"elang.h"

#define FARRIGHT	999		/* column beyond the right edge! */

#if     WINDOW_MSWIN
static  int     foulcursor = FALSE;     /* see vtscreen() & movecursor() */
#endif

static VIDEO   **vscreen;		       /* Virtual screen. */
#if	MEMMAP == 0
static VIDEO   **pscreen;		       /* Physical screen. */
#endif

/*	some local function declarations	*/

#if	PROTO
#if	MEMMAP
extern VOID PASCAL NEAR update_line(int row, struct VIDEO *vp1);
#else
extern VOID PASCAL NEAR update_line(int row, struct VIDEO *vp1, struct VIDEO *vp2);
#endif
extern VOID PASCAL NEAR update_hilite(void);
#else
extern VOID PASCAL NEAR update_line();
extern VOID PASCAL NEAR update_hilite();
#endif

/*
 * Initialize the data structures used by the display code. The edge vectors
 * used to access the screens are set up. The operating system's terminal I/O
 * channel is set up. All the other things get initialized at compile time.
 * The original window has "WFCHG" set, so that it will get completely
 * redrawn on the first call to "update".
 */

int PASCAL NEAR vtinit()
{
	register int i;
	register VIDEO *vp;

	TTopen();		/* open the screen */
	TTkopen();		/* open the keyboard */
	TTrev(FALSE);

	/* allocate the virtual screen pointer array */
	vscreen = (VIDEO **)room(term.t_mrow*sizeof(VIDEO *));
	
	if (vscreen == NULL)
#if     WINDOW_MSWIN
		return(FALSE);
#else
		meexit(1);
#endif


#if	MEMMAP == 0
	/* allocate the physical shadow screen array */
	pscreen = (VIDEO **)room(term.t_mrow*sizeof(VIDEO *));
	if (pscreen == NULL)
#if     WINDOW_MSWIN
		return(FALSE);
#else
		meexit(1);
#endif
#endif

	/* for every line in the display */
	for (i = 0; i < term.t_mrow; ++i) {

		/* allocate a virtual screen line */
		vp = (VIDEO *)room(sizeof(VIDEO)+term.t_mcol);
		if (vp == NULL)
#if     WINDOW_MSWIN
			return(FALSE);
#else
			meexit(1);
#endif

		vp->v_flag = 0;		/* init change flags */
		vp->v_left = FARRIGHT;	/* init requested rev video boundries */
		vp->v_right = 0;
#if	COLOR
		vp->v_rfcolor = 7;	/* init fore/background colors */
		vp->v_rbcolor = 0;
#endif
		/* connect virtual line to line array */
		vscreen[i] = vp;

#if	MEMMAP == 0
		/* allocate and initialize physical shadow screen line */
		vp = (VIDEO *)room(sizeof(VIDEO)+term.t_mcol);
		if (vp == NULL)
#if     WINDOW_MSWIN
			return(FALSE);
#else
			meexit(1);
#endif

		vp->v_flag = VFNEW;
		vp->v_left = FARRIGHT;
		vp->v_right = 0;
#if	INSDEL
		vp->v_rline = i;	/* set requested line position */
#endif
		pscreen[i] = vp;
#endif
	}
	return(TRUE);
}

#if	CLEAN || WINDOW_MSWIN
/* free up all the dynamically allocated video structures */

VOID PASCAL NEAR vtfree()
{
	int i;
	for (i = 0; i < term.t_mrow; ++i) {
		if (vscreen && vscreen[i]) free(vscreen[i]);
#if	MEMMAP == 0
		if (pscreen && pscreen[i]) free(pscreen[i]);
#endif
	}
	if (vscreen) free(vscreen);
#if	MEMMAP == 0
	if (pscreen) free(pscreen);
#endif
}
#endif

#if 	WINDOW_MSWIN
/* vtscreen:	map a screen into the Virtual Terminal system */
/* ======== 						      */

VOID PASCAL NEAR vtscreen(SCREEN *sp)
{
	TTflush();
	term.t_roworg = sp->s_roworg;
	term.t_colorg = sp->s_colorg;
	term.t_nrow = sp->s_nrow;
	term.t_ncol = sp->s_ncol;

	vscreen = sp->s_virtual;
	pscreen = sp->s_physical;
	term.t_selscr(sp);
	foulcursor = TRUE;
} /* vtscreen */

/* vtinitscr: build a virtual terminal resource for a new screen */
/* =========													 */

int PASCAL NEAR vtinitscr(SCREEN *sp, int nrow, int ncol)

/* returns TRUE if successful */
{
	int 	result;

	if (nrow < 2) nrow = 2;
	term.t_nrow = nrow;
	term.t_ncol = ncol;
	term.t_roworg = 0;
	term.t_colorg = 0;
	if ((result = vtinit()) == TRUE) {
		sp->s_virtual = vscreen;
		sp->s_physical = pscreen;
		sp->s_nrow = nrow;
		sp->s_ncol = ncol;
		sp->s_roworg = 0;
		sp->s_colorg = 0;
	}
	else {
		vtfree();
		sp->s_virtual = NULL;
		sp->s_physical = NULL;
	}
	return result;
} /* vtinitscr */

/* vtfreescr:  delete a virtual terminal resource for a dying screen */
/* =========														 */

PASCAL NEAR vtfreescr(SCREEN *sp)
{
	vtscreen(sp);
	vtfree();
	vtscreen(first_screen);	/* switch to an existing screen */
} /* vtfreescr */

/* vtsizescr:	resize the virtual terminal resources */
/* =========										  */

int PASCAL NEAR vtsizescr(SCREEN *sp, int nrow, int ncol)

/* returns TRUE if successful. Otherwise, the old VIDEO structures are
   preserved. */
{
	VIDEO	**oldvvp, **oldpvp;
	int 	oldnrow, oldncol;

	oldvvp = sp->s_virtual;
	oldpvp = sp->s_physical;
	oldnrow = sp->s_nrow;
	oldncol = sp->s_ncol;
	if (vtinitscr(sp, nrow, ncol) == TRUE) {
		/* success! let's free the old VIDEO structures */
		EWINDOW *wp;
	    
		vscreen = oldvvp;
		pscreen = oldpvp;
		term.t_nrow = oldnrow;
		term.t_ncol = oldncol;
		vtfree();		/* get rid of the old VIDEOs (kept up to now in
			   case the new allocation had failed) */
		vtscreen(sp);	/* put the new VIDEOs into active duty */
		for (wp = sp->s_first_window; wp != NULL; wp = wp->w_wndp) {
			/* the VIDEOs have been wiped clean. Let's have every window
			   marked for a complete redraw */
			wp->w_flag |= WFHARD|WFMODE;
		}
		term.t_sizscr(sp); /* resize the MDI window */
		return(TRUE);
	}
	else {
		/* failure! we still need some kind of VIDEO structures, so we
			reuse the old ones */
		term.t_nrow = oldnrow;
		term.t_ncol = oldncol;
		sp->s_virtual = vscreen = oldvvp;
		sp->s_physical = pscreen = oldpvp;
		mlabort(TEXT94);	/* "out of memory" */
		return(FALSE);
	}
} /* vtsizescr */
#endif

/*
 * Clean up the virtual terminal system, in anticipation for a return to the
 * operating system. Move down to the last line and clear it out (the next
 * system prompt will be written in the line). Shut down the channel to the
 * terminal.
 */
PASCAL NEAR vttidy()
{
    mlerase();
    movecursor(term.t_nrow, 0);
    TTflush();
    TTclose();
    TTkclose();
}

/*
 * Set the virtual cursor to the specified row and column on the virtual
 * screen. There is no checking for nonsense values; this might be a good
 * idea during the early stages.
 */
PASCAL NEAR vtmove(row, col)

int row, col;

{
    vtrow = row;
    vtcol = col;
}

/* Write a character to the virtual screen. The virtual row and
   column are updated. If we are not yet on left edge, don't print
   it yet. If the line is too long put a "$" in the last column.
   This routine only puts printing characters into the virtual
   terminal buffers. Only column overflow is checked.
*/

PASCAL NEAR vtputc(c)

int c;

{
	register VIDEO *vp;	/* ptr to line being updated */

	/* defeate automatic sign extenstion */
	c = c & 0xff;

	/* this is the line to put this character! */
	vp = vscreen[vtrow];

	if (c == '\t' && tabsize > 0) {

		/* output a hardware tab as the right number of spaces */
		do {
			vtputc(' ');
		} while (((vtcol + taboff) % (tabsize)) != 0);

	} else if (vtcol >= term.t_ncol) {

		/* we are at the right edge! */
		++vtcol;
		vp->v_text[term.t_ncol - 1] = '$';

	} else if (disphigh && c > 0x7f) {

		/* char with high bit set is displayed
		   symbolically on 7 bit screens */
		vtputc('^');
		vtputc('!');
		c -= 0x80;
		if (c == '\t') {
			vtputc('^');
			vtputc('I');
		} else
			vtputc(c);

	} else if (c < 0x20 || c == 0x7F) {

		/* control character? */
		vtputc('^');
		vtputc(c ^ 0x40);

	} else {

		/* it's normal, just put it in the screen map */
		if (vtcol >= 0)
			vp->v_text[vtcol] = c;
		++vtcol;
	}
}

/*
 * Erase from the end of the software cursor to the end of the line on which
 * the software cursor is located.
 */
PASCAL NEAR vteeol()
{
    register VIDEO	*vp;

    vp = vscreen[vtrow];
    while (vtcol < term.t_ncol) {
    	if (vtcol >= 0)
		vp->v_text[vtcol] = ' ';
	vtcol++;
    }
}

/* upscreen:	user routine to force a screen update
		always finishes complete update 	*/

int PASCAL NEAR upscreen(f, n)

int f,n;	/* prefix flag and argument */

{
	update(TRUE);
	return(TRUE);
}

/*
 * Make sure that the display is right. This is a three part process. First,
 * scan through all of the windows looking for dirty ones. Check the framing,
 * and refresh the screen. Second, make sure that "currow" and "curcol" are
 * correct for the current window. Third, make the virtual and physical
 * screens the same.
 */
VOID PASCAL NEAR update(force)

int force;	/* force update past type ahead? */

{
	register EWINDOW *wp;
#if     WINDOW_MSWIN
	SCREEN  *sp;
#endif

#if	TYPEAH
	/* if we are not forcing the update, and there are keystrokes
	   waiting to be processed, skip the update */
	if (force == FALSE && typahead())
		return;
#endif

#if	VISMAC == 0
	/* if we are replaying a keyboard macro, don't bother keeping updated */
	if (force == FALSE && kbdmode == PLAY)
		return;
#endif

#if 	WINDOW_MSWIN
	/* if we are not forcing the update, allow us to defer it */
	if (force == FALSE) {
		defferupdate = TRUE;
		return;
	}
	else
		defferupdate = FALSE;

	/* loop through all screens to update even partially hidden ones.
	   We update screens from back to front! */
	sp = first_screen;
	do {
		char scroll_flag = 0;
		int  scroll_fcol;
		static EWINDOW *scroll_wp = (EWINDOW *)NULL;
	    
		sp = sp->s_next_screen;
		if (sp == (SCREEN *)NULL) {
			sp = first_screen;
			sp->s_cur_window = curwp; /* not always up to date */
		}
		vtscreen(sp);
		wheadp = sp->s_first_window;
		scroll_fcol = sp->s_cur_window->w_fcol;
#endif
	
		/* update any windows that need refreshing */
		wp = wheadp;
		while (wp != NULL) {
			if (wp->w_flag) {
				/* if the window has changed, service it */
				reframe(wp);	/* check the framing */
				if ((wp->w_flag & ~WFMODE) == WFEDIT)
					updone(wp);	/* update EDITed line */
				else if (wp->w_flag & ~WFMOVE)
					updall(wp);	/* update all lines */
				if (wp->w_flag & WFMODE)
					modeline(wp);	/* update modeline */
#if WINDOW_MSWIN
				if (wp == sp->s_cur_window) {
					if (wp != scroll_wp) {
						/* switched to another window,
						   force scroll bar updates */
						scroll_flag = WFHARD;
						scroll_wp = wp;
					} else
						scroll_flag = wp->w_flag & WFHARD;

				}
#endif
				wp->w_flag = 0;
				wp->w_force = 0;
			}

			/* on to the next window */
			wp = wp->w_wndp;
		}

		/* recalc the current hardware cursor location */
#if 	WINDOW_MSWIN
		if (sp == first_screen) {
#endif
			updpos();

			/* update the current window if we have to move it around */
			if (curwp->w_flag & WFHARD)
				updall(curwp);
			if (curwp->w_flag & WFMODE)
				modeline(curwp);
			curwp->w_flag = 0;

			/* highlight region in the current window if needed */
			update_hilite();

#if 	WINDOW_MSWIN
		}
#endif

#if	MEMMAP
		/* update the cursor and flush the buffers */
		movecursor(currow, curcol - lbound);
#endif

		/* check for lines to de-extend */
		upddex();

		/* if screen is garbage, re-plot it */
		if (sgarbf != FALSE)
			if (gflags & GFSDRAW)
				sgarbf = FALSE;
			else
				updgar();
	
		/* update the virtual screen to the physical screen */
		updupd(force);
#if 	WINDOW_MSWIN
		if (scroll_fcol != sp->s_cur_window->w_fcol) {
			scroll_flag |= WFMOVE;
		}
		if (scroll_flag)
			updscrollbars(sp, scroll_flag);

	} while (sp != first_screen);

	sgarbf = FALSE;
#endif

	/* update the cursor and flush the buffers */
	movecursor(currow, curcol - lbound);
	TTflush();

	return;
}

/*	reframe:	check to see if the cursor is on in the window
			and re-frame it if needed or wanted		*/

VOID PASCAL NEAR reframe(wp)

EWINDOW *wp;

{
	register LINE *lp;	/* search pointer */
	register LINE *rp;	/* reverse search pointer */
	register LINE *hp;	/* ptr to header line in buffer */
	register LINE *tp;	/* temp debugging pointer */
	register int i;		/* general index/# lines to scroll */
	register int nlines;	/* number of lines in current window */

	/* figure out our window size */
	nlines = wp->w_ntrows;
	if (modeflag == FALSE)
		nlines++;

	/* if not a requested reframe, check for a needed one */
	if ((wp->w_flag & WFFORCE) == 0) {
		lp = wp->w_linep;
		for (i = 0; i < nlines; i++) {

			/* if the line is in the window, no reframe */
			if (lp == wp->w_dotp)
				return;

			/* if we are at the end of the file, reframe */
			if (lp == wp->w_bufp->b_linep)
				break;

			/* on to the next line */
			lp = lforw(lp);
		}
	}

	/* reaching here, we need a window refresh */
	i = wp->w_force;

	/* if smooth scrolling is enabled,
		first.. have we gone off the top? */
	if (sscroll && ((wp->w_flag & WFFORCE) == 0)) {
		/* search thru the buffer looking for the point */
		tp = lp = rp = wp->w_linep;
		hp = wp->w_bufp->b_linep;

		while ((lp != hp) || (rp != hp)) {

			/* did we scroll downward? */
			if (lp == wp->w_dotp) {
				i = nlines - 1;
				break;
			}

			/* did we scroll upward? */
			if (rp == wp->w_dotp) {
				i = 0;
				break;
			}

			/* advance forward and back */
			if (lp != hp)
				lp = lforw(lp);
			if (rp != hp)
				rp = lback(rp);

			/* problems????? */
			if (lp == tp || rp == tp) {
				mlforce("BUG IN SMOOTH SCROLL--GET DAN!\n");
				TTgetc();
			}
		}
	/* how far back to reframe? */
	} else if (i > 0) {	/* only one screen worth of lines max */
		if (--i >= nlines)
			i = nlines - 1;
	} else if (i < 0) {	/* negative update???? */
		i += nlines;
		if (i < 0)
			i = 0;
	} else
		i = nlines / 2;

	/* backup to new line at top of window */
	lp = wp->w_dotp;
	while (i != 0 && lback(lp) != wp->w_bufp->b_linep) {
		--i;
		if (i < 0) {
			mlforce("OTHER BUG IN DISPLAY --- GET DAN!!!\n");
			TTgetc();
		}
		lp = lback(lp);
	}

	/* and reset the current line at top of window */
	wp->w_linep = lp;
	wp->w_flag |= WFHARD;
	wp->w_flag &= ~WFFORCE;
}

/*	hilite:	in the current window, marks 10 and 11 are set and the
		area between them is on screen, hilite that area	*/

VOID PASCAL NEAR update_hilite()

{
	int first_line;		/* first screen line to highlight */
	short first_pos;	/* position in that line */
	int last_line;		/* last screen line to highlight */
	short last_pos;		/* position in that line */
	LINE *forptr, *bckptr;	/* line pointers searching in current buffer */
	int forline, bckline;	/* screen lines of for/bck ptrs */
	int nlines;		/* number of text lines in current window */
	LINE *first_mark;	/* first mark to highlighted text */
	LINE *last_mark;	/* last mark to highlighted text */
	LINE *b_linep;		/* header line of current buffer */
	int temp_line;		/* temp line # for swap */
	short temp_pos;		/*  more of the same */

	/* $hilight must be set to the first of 2 consecutive marks
	   used to define the region to highlight */
	if (hilite > NMARKS)
		return;

	/* Both marks must be set to define a highlighted region */
	first_mark = curwp->w_markp[hilite];
	last_mark = curwp->w_markp[hilite+1];
	if ((first_mark == (LINE *)NULL) ||
	    (last_mark == (LINE *)NULL))
	    	return;

	/* search for the two marks starting at the top line of this window */
	first_pos = last_pos = -1;
	forptr = curwp->w_linep;
	bckptr = curwp->w_linep;
	forline = bckline = 0;
	b_linep = curwp->w_bufp->b_linep;
	while (((first_pos == -1) || (last_pos == -1)) &&
		((forptr != (LINE *)NULL) || (bckptr != (LINE *)NULL))) {

		/* have we found either mark? */
		if (forptr == first_mark) {
			first_line = forline;
			first_pos = findcol(forptr, curwp->w_marko[hilite]);
		}
		if (forptr == last_mark) {
			last_line = forline;
			last_pos = findcol(forptr, curwp->w_marko[hilite+1]);
		}
		if (bckptr == first_mark) {
			first_line = bckline;
			first_pos = findcol(bckptr, curwp->w_marko[hilite]);
		}
		if (bckptr == last_mark) {
			last_line = bckline;
			last_pos = findcol(bckptr, curwp->w_marko[hilite+1]);
		}

		/* step outward one more line */
		if (forptr != (LINE *)NULL) {
			if (forptr != b_linep)
				forptr = lforw(forptr);
			else
				forptr = (LINE *)NULL;
			forline++;
		}
		if (bckptr != (LINE *)NULL) {
			bckptr = lback(bckptr);
			if (bckptr == b_linep)
				bckptr = (LINE *)NULL;
			bckline--;
		}
	}

	/* if both lines are before the current window */
	if ((first_line < 0) && (last_line < 0))
		return;

	/* if both lines are after the current window */
	nlines = curwp->w_ntrows;
	if (modeflag == FALSE)
		nlines++;
	if ((first_line >= nlines) && (last_line >= nlines))
		return;

	/* if we got them backwards, swap them around */
	if ((first_line > last_line) ||
	    ((first_line == last_line) && (first_pos > last_pos))) {
		temp_line = first_line;
		first_line = last_line;
		last_line = temp_line;
		temp_pos = first_pos;
		first_pos = last_pos;
		last_pos = temp_pos;
	}

	forptr = curwp->w_linep;
	forline = curwp->w_toprow;
	first_line += forline;
	last_line += forline;
	while (forline < curwp->w_toprow + nlines) {
		if ((forline >= first_line) && (forline <= last_line)) {
			vscreen[forline]->v_left = 0;
			vscreen[forline]->v_right = findcol(forptr, lused(forptr));
			if (forline == first_line)
				vscreen[forline]->v_left = first_pos;
			if (forline == last_line)
				vscreen[forline]->v_right = last_pos;

			/* adjust for shifted window */
			vscreen[forline]->v_left -= curwp->w_fcol;
			vscreen[forline]->v_right -= curwp->w_fcol;

			/* adjust for shifted line */
			if (vscreen[forline]->v_flag & VFEXT) {
				vscreen[forline]->v_left -= lbound;
				vscreen[forline]->v_right -= lbound;
			}

                } else {
                        vscreen[forline]->v_left = FARRIGHT;
                        vscreen[forline]->v_right = 0;
                }

                /* step up one more line */
                if (forptr != b_linep)
                        forptr = lforw(forptr);
                forline++;
        }

        /* we need to flag a redraw to update the hilighted region */
        curwp->w_flag |= WFHARD;
        return;
}

/*      updone: update the current line to the virtual screen           */

VOID PASCAL NEAR updone(wp)

EWINDOW *wp;     /* window to update current line in */

{
        register LINE *lp;      /* line to update */
        register int sline;     /* physical screen line to update */
        register int i;

        /* search down the line we want */
        lp = wp->w_linep;
        sline = wp->w_toprow;
        while (lp != wp->w_dotp) {
                ++sline;
                lp = lforw(lp);
        }

        /* and update the virtual line */
        vscreen[sline]->v_flag |= VFCHG;
        taboff = wp->w_fcol;
        vtmove(sline, -taboff);

        /* move each char of line to virtual screen until at end */
        for (i=0; i < lused(lp); ++i)
                vtputc(lgetc(lp, i));
#if     COLOR
        vscreen[sline]->v_rfcolor = wp->w_fcolor;
        vscreen[sline]->v_rbcolor = wp->w_bcolor;
#endif
        vteeol();
        taboff = 0;
}

/*      updall: update all the lines in a window on the virtual screen */

VOID PASCAL NEAR updall(wp)

EWINDOW *wp;     /* window to update lines in */

{
        register LINE *lp;      /* line to update */
        register int sline;     /* physical screen line to update */
        register int i;
        register int nlines;    /* number of lines in the current window */

        /* search down the lines, updating them */
        lp = wp->w_linep;
        sline = wp->w_toprow;
        nlines = wp->w_ntrows;
        if (modeflag == FALSE)
                nlines++;
        taboff = wp->w_fcol;
        while (sline < wp->w_toprow + nlines) {

                /* and update the virtual line */
                vscreen[sline]->v_flag |= VFCHG;
                vscreen[sline]->v_left = FARRIGHT;
                vscreen[sline]->v_right = 0;
                vtmove(sline, -taboff);
                if (lp != wp->w_bufp->b_linep) {
                        /* if we are not at the end */
                        for (i=0; i < lused(lp); ++i)
                                vtputc(lgetc(lp, i));
                        lp = lforw(lp);
                }

                /* make sure we are on screen */
                if (vtcol < 0)
                        vtcol = 0;

                /* on to the next one */
#if     COLOR
                vscreen[sline]->v_rfcolor = wp->w_fcolor;
                vscreen[sline]->v_rbcolor = wp->w_bcolor;
#endif
                vteeol();
                ++sline;
        }
        taboff = 0;
}

/*      updpos: update the position of the hardware cursor and handle extended
                lines. This is the only update for simple moves.        */

VOID PASCAL NEAR updpos()

{
        register LINE *lp;

        /* find the current row */
        lp = curwp->w_linep;
        currow = curwp->w_toprow;
        while (lp != curwp->w_dotp) {
                ++currow;
                lp = lforw(lp);
        }

        /* find the current column */
	curcol = getccol(FALSE);

        /* adjust by the current first column position */
        curcol -= curwp->w_fcol;

        /* make sure it is not off the left side of the screen */
        while (curcol < 0) {
                if (curwp->w_fcol >= hjump) {
                        curcol += hjump;
                        curwp->w_fcol -= hjump;
                } else {
                        curcol += curwp->w_fcol;
                        curwp->w_fcol = 0;
                }
                curwp->w_flag |= WFHARD | WFMODE;
        }

        /* if horizontall scrolling is enabled, shift if needed */
        if (hscroll) {
                while (curcol >= term.t_ncol - 1) {
                        curcol -= hjump;
                        curwp->w_fcol += hjump;
                        curwp->w_flag |= WFHARD | WFMODE;
                }
        } else {
        /* if extended, flag so and update the virtual line image */
                if (curcol >=  term.t_ncol - 1) {
                        vscreen[currow]->v_flag |= (VFEXT | VFCHG);
                        updext();
                } else
                        lbound = 0;
        }
}

/*      upddex: de-extend any line that derserves it            */

VOID PASCAL NEAR upddex()

{
        register EWINDOW *wp;
        register LINE *lp;
        register int i,j;
        register int nlines;    /* number of lines in the current window */

        wp = wheadp;

        while (wp != NULL) {
                lp = wp->w_linep;
                i = wp->w_toprow;
                nlines = wp->w_ntrows;
                if (modeflag == FALSE)
                        nlines++;

                while (i < wp->w_toprow + nlines) {
                        if (vscreen[i]->v_flag & VFEXT) {
                                if ((wp != curwp) || (lp != wp->w_dotp) ||
                                   (curcol < term.t_ncol - 1)) {
                                        taboff = wp->w_fcol;
                                        vtmove(i, -taboff);
                                        for (j = 0; j < lused(lp); ++j)
                                                vtputc(lgetc(lp, j));
                                        vteeol();
                                        taboff = 0;

                                        /* this line no longer is extended */
                                        vscreen[i]->v_flag &= ~VFEXT;
                                        vscreen[i]->v_flag |= VFCHG;
                                }
                        }
                        lp = lforw(lp);
                        ++i;
                }
                /* and onward to the next window */
                wp = wp->w_wndp;
        }
}

/*      updgar: if the screen is garbage, clear the physical screen and
                the virtual screen and force a full update              */

VOID PASCAL NEAR updgar()

{
        register int i;
#if     MEMMAP == 0
        register int j;
        register char *txt;
#endif

        for (i = 0; i < term.t_nrow; ++i) {
                vscreen[i]->v_flag |= VFCHG;
#if     COLOR
                vscreen[i]->v_fcolor = gfcolor;
                vscreen[i]->v_bcolor = gbcolor;
#endif
#if     MEMMAP == 0
                pscreen[i]->v_left = FARRIGHT;
                pscreen[i]->v_right = 0;
                txt = pscreen[i]->v_text;
                for (j = 0; j < term.t_ncol; ++j)
                        txt[j] = ' ';
                pscreen[i]->v_flag &= ~VFNEW;
#endif
        }

        movecursor(0, 0);                /* Erase the screen. */
#if     COLOR && WINDOW_MSWIN
        TTforg(gfcolor);        /* inform the driver of the colors */
        TTbacg(gbcolor);        /* to be used for erase to end of page */
#endif
#if REVSTA && WINDOW_MSWIN
        TTrev(FALSE);
#endif
        TTeeop();
#if     !WINDOW_MSWIN
        sgarbf = FALSE;                  /* Erase-page clears */
        mpresf = FALSE;                  /* the message area. */
#endif
#if     COLOR
        mlerase();                      /* needs to be cleared if colored */
#if     WINDOW_MSWIN
        mpresf = FALSE;         /* MSWIN's message area handled differently.*/
#endif
#endif
}

#if !WINDOW_MSWIN
/*      for simple screen size changes (no window re-allocation involved)
        do the following things
*/

VOID PASCAL NEAR update_size()

{
        /* if we need the size update */
        if ((first_screen->s_roworg != term.t_roworg) |
            (first_screen->s_colorg != term.t_colorg) |
            (first_screen->s_nrow != term.t_nrow) |
            (first_screen->s_ncol != term.t_ncol)) {

                /* reset the terminal drivers size concept */
                term.t_roworg = first_screen->s_roworg;
                term.t_colorg = first_screen->s_colorg;
                term.t_nrow = first_screen->s_nrow;
                term.t_ncol = first_screen->s_ncol;

                /* make sure the update routines know we need a full update */
                sgarbf = TRUE;
        }
}
#endif

/*      Display a pop up window.  Page it for the user.  Any key other
        than a space gets pushed back into the input stream to be interpeted
        later as a command.
*/

#if     PROTO
int PASCAL NEAR pop(BUFFER *popbuf)
#else
int PASCAL NEAR pop(popbuf)

BUFFER *popbuf;
#endif
{
        register int index;     /* index into the current output line */
        register int llen;      /* length of the current output line */
        register int cline;     /* current screen line number */
        LINE *lp;       /* ptr to next line to display */
        int numlines;   /* remaining number of lines to display */
        int c;          /* input character */

        /* add the barrior line to the end of the pop up buffer */
        addline(popbuf, "------------------------------------------");

        /* set up to scan pop up buffer */
        lp = lforw(popbuf->b_linep);
        numlines = term.t_nrow-2 + !modeflag;
        cline = 0;
	mmove_flag = FALSE;	/* disable mouse move events */

        while (lp != popbuf->b_linep) {

                /* update the virtual screen image for this one line */
                vtmove(cline, 0);
                llen = lused(lp);
                for (index = 0; index < llen; index++)
                        vtputc(lgetc(lp, index));
                vteeol();
#if     COLOR
                vscreen[cline]->v_rfcolor = gfcolor;
                vscreen[cline]->v_rbcolor = gbcolor;
#endif
                vscreen[cline]->v_left = FARRIGHT;
                vscreen[cline]->v_right = 0;
                vscreen[cline++]->v_flag |= VFCHG|VFCOL;

                if (numlines-- < 1) {

                        /* update the virtual screen to the physical screen */
                        updupd(FALSE);

                        /* tell the user there is more */
                        mlwrite("--- more ---");
                        TTflush();

                        /* and see if they want more */
                        if ((popwait) && ((c = tgetc()) != ' ')) {
                                cpending = TRUE;
                                charpending = c;
                                upwind();

				/* re-enable mouse move events */
				mmove_flag = TRUE;
                                return(TRUE);
                        }

                        /* reset the line counters */
                        numlines = term.t_nrow-2 + !modeflag;
                        cline = 0;

			/* if we at the end, don't requeue for more */
			if (lforw(lp) == popbuf->b_linep)
				numlines = -1;

                }

                /* on to the next line */
                lp = lforw(lp);
        }
        if (numlines >= 0) {

                /* update the virtual screen to the physical screen */
                updupd(FALSE);
                TTflush();

                if ((popwait) && ((c = tgetc()) != ' ')) {
                        cpending = TRUE;
                        charpending = c;
                }
        }
        upwind();

	/* re-enable mouse move events */
	mmove_flag = TRUE;
        return(TRUE);
}

/*      updupd: update the physical screen from the virtual screen      */

VOID PASCAL NEAR updupd(force)

int force;      /* forced update flag */

{
        register VIDEO *vp1;
        register int i;

        for (i = 0; i < term.t_nrow; ++i) {
                vp1 = vscreen[i];

                /* for each line that needs to be updated*/
                if (vp1->v_flag & VFCHG) {
#if     TYPEAH
                        if (force == FALSE && typahead())
                                return;
#endif
#if     MEMMAP
                        update_line(i, vp1);
#else
                        update_line(i, vp1, pscreen[i]);
#endif
                }
        }
        return;
}

/*      updext: update the extended line which the cursor is currently
                on at a column greater than the terminal width. The line
                will be scrolled right or left to let the user see where
                the cursor is
                                                                */
VOID PASCAL NEAR updext()

{
        register int rcursor;   /* real cursor location */
        register LINE *lp;      /* pointer to current line */
        register int j;         /* index into line */

        /* calculate what column the real cursor will end up in */
        rcursor = ((curcol - term.t_ncol) % term.t_scrsiz)
                        + term.t_margin;
        lbound = curcol - rcursor + 1;
        taboff = lbound + curwp->w_fcol;

        /* scan through the line outputing characters to the virtual screen */
        /* once we reach the left edge                                  */
        vtmove(currow, -taboff); /* start scanning offscreen */
        lp = curwp->w_dotp;             /* line to output */
        for (j=0; j<lused(lp); ++j)     /* until the end-of-line */
                vtputc(lgetc(lp, j));

        /* truncate the virtual line, restore tab offset */
        vteeol();
        taboff = 0;

        /* and put a '$' in column 1 */
        vscreen[currow]->v_text[0] = '$';
}

/*
 * Update a single line. This does not know how to use insert or delete
 * character sequences; we are using VT52 functionality. Update the physical
 * row and column variables. It does try an exploit erase to end of line.
 */
#if     MEMMAP
/*      UPDATE_LINE:    specific code for memory mapped displays */

VOID PASCAL NEAR update_line(row, vp)

int row;                /* row of screen to update */
struct VIDEO *vp;       /* virtual screen image */

{
#if     COLOR
        /* update the color request */
        vp->v_fcolor = vp->v_rfcolor;
        vp->v_bcolor = vp->v_rbcolor;

        /* write the line to the display */
        scwrite(row, vp->v_text, vp->v_fcolor, vp->v_bcolor,
                vp->v_left, vp->v_right);
#else
        /* write the line to the display */
        scwrite(row, vp->v_text, 7, 0, vp->v_left, vp->v_right);
#endif
        /* flag this line as changed */
        vp->v_flag &= ~(VFCHG | VFCOL);
}
#else
VOID PASCAL NEAR update_line(row, vp, pp)

int row;                /* row of screen to update */
struct VIDEO *vp;       /* virtual screen image */
struct VIDEO *pp;       /* physical screen image */

{

        register char *vir_left;        /* left pointer to virtual line */
        register char *phy_left;        /* left pointer to physical line */
        register char *vir_right;       /* right pointer to virtual line */
        register char *phy_right;       /* right pointer to physical line */
        int rev_left;                   /* leftmost reversed char index */
        int rev_right;                  /* rightmost reversed char index */
        char *left_blank;               /* left-most trailing blank */
        int non_blanks;                 /* non-blanks to the right flag */
        int update_column;              /* update column */
        int old_rev_state = FALSE;      /* reverse video states */
        int new_rev_state;

        /* set up pointers to virtual and physical lines */
        vir_left = &vp->v_text[0];
        vir_right = &vp->v_text[term.t_ncol];
        phy_left = &pp->v_text[0];
        phy_right = &pp->v_text[term.t_ncol];
        update_column = 0;
        rev_left = FARRIGHT;
        rev_right = 0;
	non_blanks = TRUE;

        /* if this is a legitimate line to optimize */
        if (!(pp->v_flag & VFNEW)) {

                /* advance past any common chars at the left */
                while ((vir_left != &vp->v_text[term.t_ncol])
                       && (vir_left[0] == phy_left[0])) {
                        ++vir_left;
                        ++update_column;
                        ++phy_left;
                }
        
#if     DBCS
                /* don't optimize on the left in the middle of a 2 byte char */
                if ((vir_left > &vp->v_text[0]) && is2byte(vp->v_text, vir_left - 1)) {
                        --vir_left;
                        --update_column;
                        --phy_left;
                }
#endif
                
                /* advance past any common chars at the right */
                non_blanks = FALSE;
                while ((vir_right[-1] == phy_right[-1]) &&
                       (vir_right >= vir_left)) {
                        --vir_right;
                        --phy_right;

                        /* Note if any nonblank in right match. */
                        if (vir_right[0] != ' ')
                                non_blanks = TRUE;
                }
        
#if     DBCS
                /* don't stop in the middle of a 2 byte char */
                if (is2byte(vp->v_text, vir_right-1) || is2byte(pp->v_text, phy_right-1)) {
                        ++vir_right;
                        ++phy_right;
                }
#endif
        }

#if     COLOR
        /* new line color? */
        if (((vp->v_rfcolor != vp->v_fcolor) ||
            (vp->v_rbcolor != vp->v_bcolor))) {
                vp->v_fcolor = vp->v_rfcolor;
                vp->v_bcolor = vp->v_rbcolor;
                vp->v_flag &= ~VFCOL;
                vir_left = &vp->v_text[0];
                vir_right = &vp->v_text[term.t_ncol];
                phy_left = &pp->v_text[0];
                phy_right = &pp->v_text[term.t_ncol];
                update_column = 0;
        }

        TTforg(vp->v_fcolor);
        TTbacg(vp->v_bcolor);
#endif

        /* reverse video changes? */
        if ((vp->v_left != pp->v_left) || (vp->v_right != pp->v_right)) {

                /* adjust leftmost edge */
                if (vp->v_left < pp->v_left)
                        rev_left = (vp->v_left < 0) ? 0 : vp->v_left;
                else
                        rev_left = pp->v_left;
                pp->v_left = (vp->v_left < 0) ? 0 : vp->v_left;
                if (rev_left < update_column) {
                        vir_left = &vp->v_text[rev_left];
                        phy_left = &pp->v_text[rev_left];
                        update_column = rev_left;
                }

                /* adjust rightmost edge */
                if (vp->v_right > pp->v_right)
                        rev_right = vp->v_right;
                else
                        rev_right = pp->v_right;
                pp->v_right = vp->v_right;
                if (&vp->v_text[rev_right] > vir_right) {
                        vir_right = &vp->v_text[rev_right];
                        phy_right = &pp->v_text[rev_right];
                }
        } else {
                rev_left = vp->v_left;
                rev_right = vp->v_right;
        }

        /* if both lines are the same, no update needs to be done */
        if (!(pp->v_flag & VFNEW) && (vir_left > vir_right)) {
                vp->v_flag &= ~VFCHG;   /* flag this line as changed */
                return;
        }

        left_blank = vir_right;

        /* Erase to EOL ? */
        if (non_blanks == FALSE && eolexist == TRUE) {
                while (left_blank!=vir_left && left_blank[-1]==' ')
                        --left_blank;

                if (vir_right-left_blank <= 3)          /* Use only if erase is */
                        left_blank = vir_right;         /* fewer characters. */
        }

        /* move to the beginning of the text to update */
        movecursor(row, update_column);

        while (vir_left != left_blank) {                /* Ordinary. */

                /* are we in a reverse video field? */
                if (pp->v_left <= update_column && update_column < pp->v_right)
                        new_rev_state = TRUE;
                else
                        new_rev_state = FALSE;

                /* if moving in or out of rev video, change it */
                if (new_rev_state != old_rev_state) {
                        TTrev(new_rev_state);
                        old_rev_state = new_rev_state;
		}

		/* output the next character! */
		TTputc(*vir_left);
		++ttcol;
		++update_column;
		*phy_left++ = *vir_left++;
	}

	if (left_blank != vir_right) {		/* Erase. */

                /* are we in a reverse video field? */
                if (pp->v_left <= update_column && update_column < pp->v_right)
                        new_rev_state = TRUE;
                else
                        new_rev_state = FALSE;

                /* if moving in or out of rev video, change it */
                if (new_rev_state != old_rev_state) {
                        TTrev(new_rev_state);
                        old_rev_state = new_rev_state;
                }

#if	TERMCAP
	/* TERMCAP does not tell us if the current terminal propagates
	   the current attributes to the end of the line when an erase
	   to end of line sequence is sent. Don't let TERMCAP use EEOL
	   if in a reverse video line!  (ARG...Pain....Agony....)      */
		if (new_rev_state == TRUE)
			while (update_column++ < term.t_ncol)
				TTputc(' ');
		else
			TTeeol();
#else
		TTeeol();
#endif
		while (vir_left != vir_right)
			*phy_left++ = *vir_left++;
	}

	vp->v_flag &= ~VFCHG;		/* flag this line as updated */
	vp->v_flag &= ~VFCOL;

	/* Always leave in the default state */
	if (old_rev_state == TRUE)
		TTrev(FALSE);
	return;
}
#endif

/*
 * Redisplay the mode line for the window pointed to by the "wp". This is the
 * only routine that has any idea of how the modeline is formatted. You can
 * change the modeline format by hacking at this routine. Called by "update"
 * any time there is a dirty window.
 */
VOID PASCAL NEAR modeline(wp)

EWINDOW *wp;	/* window to update modeline for */

{
	register char *cp;
	register unsigned char c;
	register int n;		/* cursor position count */
	register BUFFER *bp;
	register int i;		/* loop index */
	register int lchar; 	/* character to draw line in buffer with */
	register int firstm;	/* is this the first mode? */
	char tline[NLINE];	/* buffer for part of mode line */
	char time[6];		/* to hold current time */

	/* don't bother if there is none! */
	if (modeflag == FALSE)
		return;

	n = wp->w_toprow+wp->w_ntrows;		/* Location. */

/*
	Note that we assume that setting REVERSE will cause the terminal
	driver to draw with the inverted relationship of fcolor and
	bcolor, so that when we say to set the foreground color to "white"
	and background color to "black", the fact that "reverse" is
	enabled means that the terminal driver actually draws "black" on a
	background of "white".  Makes sense, no?  This way, devices for
	which the color controls are optional will still get the "reverse"
	signals.
*/

	vscreen[n]->v_flag |= VFCHG | VFCOL;	/* Redraw next time. */
	vscreen[n]->v_left = 0;
	vscreen[n]->v_right = term.t_ncol;
#if	COLOR
	vscreen[n]->v_rfcolor = 7;			/* black on */
	vscreen[n]->v_rbcolor = 0;			/* white.....*/
#endif
	vtmove(n, 0);				/* Seek to right line. */
	if (wp == curwp)			/* mark the current buffer */
		lchar = '=';
	else
#if	REVSTA
	if (revexist)
		lchar = ' ';
	else
#endif
		lchar = '-';

	bp = wp->w_bufp;
	if ((bp->b_flag&BFTRUNC) != 0)		/* "#" if truncated */
		vtputc('#');
	else
		vtputc(lchar);

	if ((bp->b_flag&BFCHG) != 0)		/* "*" if changed. */
		vtputc('*');
	else
		vtputc(lchar);

	if ((bp->b_flag&BFNAROW) != 0) {		/* "<>" if narrowed */
		vtputc('<');
		vtputc('>');
	} else {
		vtputc(lchar);
		vtputc(lchar);
	}

	n  = 4;
	strcpy(tline, " "); 			/* Buffer name. */
#if     !WINDOW_MSWIN
	strcat(tline, PROGNAME);
	strcat(tline, " ");
	strcat(tline, VERSION);
	strcat(tline, " ");
#endif
	/* display the time on the bottom most modeline if active */
	if (timeflag && wp->w_wndp == (EWINDOW *)NULL) {

		/* get the current time/date string */
		getdtime(time);
		if (strcmp(time, "") != 0) {

			/* append the hour/min string */
			strcat(tline, "[");
			strcat(tline, time);
			strcat(tline, "] ");
			strcpy(lasttime, time);
		}
	}

	/* display the size of the undo stack on the current modeline */
	if (dispundo && wp == curwp) {
		strcat(tline, "{");
		strcat(tline, long_asc(wp->w_bufp->undo_count));
		strcat(tline, "} ");
	}

	/* are we horizontally scrolled? */
	if (wp->w_fcol > 0) {
		strcat(tline, "[<");
		strcat(tline, int_asc(wp->w_fcol));
		strcat(tline, "]");
	}

	/* display the point position in buffer if on current modeline */
	if (posflag && wp == curwp) {

 		strcat(tline, "L:");
	 	strcat(tline, long_asc(getlinenum(bp, wp->w_dotp)));
 		strcat(tline, " C:");
	 	strcat(tline, int_asc(getccol(FALSE)));
 		strcat(tline, " ");
	}

	/* display the modes */
	strcat(tline, "(");
	firstm = TRUE;
	for (i = 0; i < NUMMODES; i++)	/* add in the mode flags */
		if (wp->w_bufp->b_mode & (1 << i)) {
			if (firstm != TRUE)
				strcat(tline, " ");
			firstm = FALSE;
			strcat(tline, modename[i]);
		}
	strcat(tline,") ");

	cp = &tline[0];
	while ((c = *cp++) != 0) {
		vtputc(c);
		++n;
	}

#if	0	/* display internal modes on modeline */
	vtputc(lchar);
	vtputc((wp->w_flag&WFCOLR) != 0  ? 'C' : lchar);
	vtputc((wp->w_flag&WFMODE) != 0  ? 'M' : lchar);
	vtputc((wp->w_flag&WFHARD) != 0  ? 'H' : lchar);
	vtputc((wp->w_flag&WFEDIT) != 0  ? 'E' : lchar);
	vtputc((wp->w_flag&WFMOVE) != 0  ? 'V' : lchar);
	vtputc((wp->w_flag&WFFORCE) != 0 ? 'F' : lchar);
	vtputc(lchar);
	n += 8;
#endif

	vtputc(lchar);
	vtputc(lchar);
	vtputc(' ');
	n += 3;
	cp = &bp->b_bname[0];

	while ((c = *cp++) != 0) {
		vtputc(c);
		++n;
	}

	vtputc(' ');
	vtputc(lchar);
	vtputc(lchar);
	n += 3;

	if (bp->b_fname[0] != 0) {	/* File name. */
		vtputc(' ');
		++n;
		cp = TEXT34;
/*                   "File: " */

		while ((c = *cp++) != 0) {
			vtputc(c);
			++n;
		}

		cp = &bp->b_fname[0];

		while ((c = *cp++) != 0) {
			vtputc(c);
			++n;
	        }

		vtputc(' ');
		++n;
	}

	while (n < term.t_ncol) {	/* Pad to full width. */
		vtputc(lchar);
		++n;
	}
}

VOID PASCAL NEAR getdtime(ts)	/* get the current display time string */

char *ts;

{
	char buf[80];

	strcpy(buf, timeset());
	if (strcmp(buf, errorm) == 0) {
		*ts = 0;
		return;
	}

	buf[16] = 0;
	strcpy(ts, &buf[11]);
	return;
}

VOID PASCAL NEAR upmode()	/* update all the mode lines */

{
	register EWINDOW *wp;
#if     WINDOW_MSWIN
    SCREEN  *sp;

    /* loop through all screens to update even partially hidden ones.
       Note that we process the "first" screen last */
    sp = first_screen;
    do {
        sp = sp->s_next_screen;
        if (sp == (SCREEN *)NULL) sp = first_screen;
        vtscreen (sp);
        wheadp = sp->s_first_window;
#endif

	wp = wheadp;
	while (wp != NULL) {
		wp->w_flag |= WFMODE;
		wp = wp->w_wndp;
	}
#if     WINDOW_MSWIN
    } while (sp != first_screen);
#endif
}

VOID PASCAL NEAR upwind()	/* force hard updates on all windows */

{
	register EWINDOW *wp;
#if     WINDOW_MSWIN
    SCREEN  *sp;

    /* loop through all screens to update even partially hidden ones.
       Note that we process the "first" screen last */
    sp = first_screen;
    do {
        sp = sp->s_next_screen;
        if (sp == (SCREEN *)NULL) sp = first_screen;
        vtscreen (sp);
        wheadp = sp->s_first_window;
#endif

	wp = wheadp;
	while (wp != NULL) {
		wp->w_flag |= WFHARD|WFMODE;
		wp = wp->w_wndp;
	}
#if     WINDOW_MSWIN
	} while (sp != first_screen);
#endif
}

/*
 * Send a command to the terminal to move the hardware cursor to row "row"
 * and column "col". The row and column arguments are origin 0. Optimize out
 * random calls. Update "ttrow" and "ttcol".
 */
VOID PASCAL NEAR movecursor(row, col)

int row, col;

{
#if     WINDOW_MSWIN
	/* emphasize move into message line to avoid confusion with
	   another, larger, screen */
	if (row >= term.t_nrow)
		row = term.t_mrow;

	/* a pending update could move the cursor somewhere else, so
	   we make sure it can't happen */
	if (defferupdate)
		update (TRUE);

	/* in MSWIN, the message line is a separate entity and a call to
	   vtscreen after a movecursor calls might actually have "stolen" the
	   cursor away from the message line! */
	if (row!=ttrow || col!=ttcol || foulcursor) {
		foulcursor = FALSE;
#else
	/* only move it if there is a difference */
	if (row != ttrow || col != ttcol) {
#endif
		ttrow = row;
		ttcol = col;
		TTmove(row, col);
	}
}

/*
 * Erase the message line. This is a special routine because the message line
 * is not considered to be part of the virtual screen. It always works
 * immediately; the terminal buffer is flushed via a call to the flusher.
 */

VOID PASCAL NEAR mlferase()

{
	register int save_discmd;

	save_discmd = discmd;
	discmd = TRUE;
	mlerase();
	discmd = save_discmd;;
}

VOID PASCAL NEAR mlerase()

{
	int i;
    
	movecursor(term.t_nrow, 0);
	if (discmd == FALSE)
		return;

#if	COLOR
	TTforg(gfcolor);
	TTbacg(gbcolor);
#endif

	if (eolexist == TRUE)
		TTeeol();
	else {
		for (i = 0; i < term.t_ncol - 1; i++)
			TTputc(' ');

		/* force the move! */
/*		movecursor(term.t_nrow, 1);*/
		movecursor(term.t_nrow, 0);
	}
	TTflush();
	mpresf = FALSE;
}

/*
 * Write a message into the message line. Keep track of the physical cursor
 * position. A small class of printf like format items is handled. Assumes the
 * stack grows down; this assumption is made by the "+=" in the argument scan
 * loop. If  STACK_GROWS_UP  is set in estruct.h, then we'll assume that the
 * stack grows up and use "-=" instead of "+=". Set the "message line"
 *  flag TRUE.  Don't write beyond the end of the current terminal width.
 */

VOID PASCAL NEAR mlout(c)

int c;	/* character to write */

{
#if WINDOW_MSWIN
	if (ttcol + 1 < NSTRING)
#else
	if (ttcol + 1 < term.t_ncol)
#endif
		TTputc(c);
	if (c != '\b')
		*lastptr++ = c;
	else if (lastptr > &lastmesg[0])
		--lastptr;
}

#if	VARARG
#if	VARG
VOID CDECL NEAR mlwrite(va_alist)

va_dcl		/* variable argument list
			arg1 = format string
			arg2+ = arguments in that string */

{
	register int c; 	/* current char in format string */
	register char *fmt;	/* ptr to format string */
	register va_list ap;	/* ptr to current data field */
	int arg_int;		/* integer argument */
	long arg_long;		/* long argument */
	char *arg_str;		/* string argument */

	/* if we are not currently echoing on the command line, abort this */
	if (discmd == FALSE)
		return;

#if	COLOR
	/* set up the proper colors for the command line */
	TTforg(gfcolor);
	TTbacg(gbcolor);
#endif

	/* point to the first argument */
	va_start(ap);
	fmt = va_arg(ap, char *);

	/* if we can not erase to end-of-line, do it manually */
	if (eolexist == FALSE) {
		mlerase();
		TTflush();
	}

	movecursor(term.t_nrow, 0);
 	lastptr = &lastmesg[0];		/* setup to record message */
	while ((c = *fmt++) != 0) {
		if (c != '%') {
			mlout(c);
			++ttcol;
		} else {
			c = *fmt++;
			switch (c) {
				case 'd':
					arg_int = va_arg(ap, int);
					mlputi(arg_int, 10);
					break;

				case 'o':
					arg_int = va_arg(ap, int);
					mlputi(arg_int, 8);
					break;

				case 'x':
					arg_int = va_arg(ap, int);
					mlputi(arg_int, 16);
					break;

				case 'D':
					arg_long = va_arg(ap, long);
					mlputli(arg_long, 10);
					break;

				case 's':
					arg_str = va_arg(ap, char *);
					mlputs(arg_str);
					break;

				case 'f':
					arg_int = va_arg(ap, int);
					mlputf(arg_int);
					break;

				default:
					mlout(c);
					++ttcol;
			}
		}
	}

	/* if we can, erase to the end of screen */
	if (eolexist == TRUE)
		TTeeol();
	TTflush();
	mpresf = TRUE;
	*lastptr = 0;	/* terminate lastmesg[] */
	va_end(ap);
}
#else
#if PROTO
VOID CDECL NEAR mlwrite(char *fmt, ...)
/* char * fmt;*/
#else
VOID CDECL NEAR mlwrite()
char *fmt;
#endif

		/* variable argument list
			arg1 = format string
			arg2+ = arguments in that string */

{
	register int c; 	/* current char in format string */
	va_list ap;		/* ptr to current data field */
	int arg_int;		/* integer argument */
	long arg_long;		/* long argument */
	char *arg_str;		/* string argument */

	/* if we are not currently echoing on the command line, abort this */
	if (discmd == FALSE)
		return;

#if	COLOR
	/* set up the proper colors for the command line */
	TTforg(gfcolor);
	TTbacg(gbcolor);
#endif

	/* point to the first argument */
	va_start(ap, fmt);

	/* if we can not erase to end-of-line, do it manually */
	if (eolexist == FALSE) {
		mlerase();
		TTflush();
	}

	movecursor(term.t_nrow, 0);
 	lastptr = &lastmesg[0];		/* setup to record message */
	while ((c = *fmt++) != 0) {
		if (c != '%') {
			mlout(c);
			++ttcol;
		} else {
			c = *fmt++;
			switch (c) {
				case 'd':
					arg_int = va_arg(ap, int);
					mlputi(arg_int, 10);
					break;

				case 'o':
					arg_int = va_arg(ap, int);
					mlputi(arg_int, 8);
					break;

				case 'x':
					arg_int = va_arg(ap, int);
					mlputi(arg_int, 16);
					break;

				case 'D':
					arg_long = va_arg(ap, long);
					mlputli(arg_long, 10);
					break;

				case 's':
					arg_str = va_arg(ap, char *);
					mlputs(arg_str);
					break;

				case 'f':
					arg_int = va_arg(ap, int);
					mlputf(arg_int);
					break;

				default:
					mlout(c);
					++ttcol;
			}
		}
	}

	/* if we can, erase to the end of screen */
	if (eolexist == TRUE)
		TTeeol();
	TTflush();
	mpresf = TRUE;
	*lastptr = 0;	/* terminate lastmesg[] */
	va_end(ap);
}
#endif
#else

#if	STACK_GROWS_UP
#define	ADJUST(ptr, dtype)	ptr -= sizeof(dtype)
#else
#define	ADJUST(ptr, dtype)	ptr += sizeof(dtype)
#endif

VOID CDECL NEAR mlwrite(fmt)

char *fmt;	/* format string for output */

{
	register int c; 	/* current char in format string */
	register char *ap;	/* ptr to current data field */

	/* if we are not currently echoing on the command line, abort this */
	if (discmd == FALSE)
		return;

#if	COLOR
	/* set up the proper colors for the command line */
	TTforg(gfcolor);
	TTbacg(gbcolor);
#endif

	/* point to the first argument */
	ap = &fmt;
	ADJUST(ap, char *);

	/* if we can not erase to end-of-line, do it manually */
	if (eolexist == FALSE) {
		mlerase();
		TTflush();
	}

	movecursor(term.t_nrow, 0);
 	lastptr = &lastmesg[0];		/* setup to record message */
	while ((c = *fmt++) != 0) {
		if (c != '%') {
			mlout(c);
			++ttcol;
		} else {
			c = *fmt++;
			switch (c) {
				case 'd':
					mlputi(*(int *)ap, 10);
			                ADJUST(ap, int);
					break;

				case 'o':
					mlputi(*(int *)ap,  8);
					ADJUST(ap, int);
					break;

				case 'x':
					mlputi(*(int *)ap, 16);
					ADJUST(ap, int);
					break;

				case 'D':
					mlputli(*(long *)ap, 10);
					ADJUST(ap, long);
					break;

				case 's':
					mlputs(*(char **)ap);
					ADJUST(ap, char *);
					break;

				case 'f':
					mlputf(*(int *)ap);
					ADJUST(ap, int);
					break;

				default:
					mlout(c);
					++ttcol;
			}
		}
	}

	/* if we can, erase to the end of screen */
	if (eolexist == TRUE)
		TTeeol();
	TTflush();
	mpresf = TRUE;
	*lastptr = 0;	/* terminate lastmesg[] */
}
#endif
/*	Force a string out to the message line regardless of the
	current $discmd setting. This is needed when $debug is TRUE
	and for the write-message and clear-message-line commands
*/

VOID PASCAL NEAR mlforce(s)

char *s;	/* string to force out */

{
	register int oldcmd;	/* original command display flag */

	oldcmd = discmd;	/* save the discmd value */
	discmd = TRUE;		/* and turn display on */
	mlwrite("%s", s);	/* write the string out */
	discmd = oldcmd;	/* and restore the original setting */
}

#if     !WINDOW_MSWIN
/* display a serious error message (like "out of memory"). This is
   replaced by a system-specific function when a multitasking system
   that does not like these kind of errors is used, so that the user can
   be offered to abort the application */

VOID PASCAL NEAR mlabort(s)
char *s;
{
    mlforce(s);
}
#endif

/*
 * Write out a string. Update the physical cursor position. This assumes that
 * the characters in the string all have width "1"; if this is not the case
 * things will get screwed up a little.
 */

VOID PASCAL NEAR mlputs(s)

char *s;

{
	register int c;

	while ((c = *s++) != 0) {
		mlout(c);
		++ttcol;
	}
}

/*
 * Write out an integer, in the specified radix. Update the physical cursor
 * position.
 */
VOID PASCAL NEAR mlputi(i, r)

int i, r;

    {
    register int q;
    static char hexdigits[] = "0123456789ABCDEF";

    if (i < 0)
	{
	i = -i;
	mlout('-');
	}

    q = i/r;

    if (q != 0)
	mlputi(q, r);

    mlout(hexdigits[i%r]);
    ++ttcol;
    }

/*
 * do the same except as a long integer.
 */
VOID PASCAL NEAR mlputli(l, r)

long l;
int r;

    {
    register long q;

    if (l < 0)
	{
	l = -l;
	mlout('-');
	}

    q = l/r;

    if (q != 0)
	mlputli(q, r);

    mlout((int)(l%r)+'0');
    ++ttcol;
    }

/*
 *	write out a scaled integer with two decimal places
 */

VOID PASCAL NEAR mlputf(s)

int s;	/* scaled integer to output */

{
	int i;	/* integer portion of number */
	int f;	/* fractional portion of number */

	/* break it up */
	i = s / 100;
	f = s % 100;

	/* send out the integer portion */
	mlputi(i, 10);
	mlout('.');
	mlout((f / 10) + '0');
	mlout((f % 10) + '0');
	ttcol += 3;
}

#if HANDLE_WINCH
winch_vtresize(rows, cols)
     int rows, cols;
{
  int i;
  register VIDEO *vp;

  for (i = 0; i < term.t_mrow; ++i) {
    free(vscreen[i]);
    free(pscreen[i]);
  }
  free(vscreen);
  free(pscreen);

  term.t_mrow=term.t_nrow=rows-1;
  term.t_mcol=term.t_ncol=cols;

  vscreen = (VIDEO **)room(term.t_mrow*sizeof(VIDEO *));
  
  if (vscreen == NULL)
    meexit(1);
  
  pscreen = (VIDEO **)room(term.t_mrow*sizeof(VIDEO *));
  
  if (pscreen == NULL)
    meexit(1);
  
  for (i = 0; i < term.t_mrow; ++i)
    {
      vp = (VIDEO *)room(sizeof(VIDEO)+term.t_mcol);
      
      if (vp == NULL)
	meexit(1);
      
      vp->v_flag = 0;
      vp->v_left = FARRIGHT;
      vp->v_right = 0;
      vp->v_flag = VFNEW;
#if	COLOR
      vp->v_rfcolor = 7;
      vp->v_rbcolor = 0;
#endif
#if	INSDEL
      vp->v_rline = i;
#endif
      vscreen[i] = vp;
      vp = (VIDEO *)room(sizeof(VIDEO)+term.t_mcol);
      
      if (vp == NULL)
	meexit(1);
      
      vp->v_flag = VFNEW;
      vp->v_left = FARRIGHT;
      vp->v_right = 0;
#if	INSDEL
      vp->v_rline = i;	/* set requested line position */
#endif
      
      pscreen[i] = vp;
    }
}
#endif

