/* Things having to do with putting windows on the (virtual) display */

/* Copyright (c) 1983 University of Maryland Computer Science Department */

#include "win.h"
#include "display.h"
#include <stdio.h>
#include <signal.h>
#include <sys/ioctl.h>

#ifdef SIGVTALRM
/* 4.2BSD */
#define sigset(s,d)	signal(s,d)
#define sighold(s)	sigblock(1<<((s)-1))
#define sigrelse(s)	sigsetmask(sigblock(0)&~(1<<((s)-1)))
#endif SIGVTALRM

static TouchedDisp;		/* True iff DispPut has been called */

/* Return the size of the screen */
Wscreensize (rows, cols)
int *rows, *cols;
{
    *rows = ScreenLength;
    *cols = ScreenWidth;
    return 0;
}

/* Refresh the display */
Wrefresh (SkipInputCheck) {
    register Win *w;
    register i;
    static inrefresh;		/* to avoid recursive refresh, which just
				   plain does not work! */

    if (inrefresh)
	return 0;
    inrefresh++;
    if (!WindowsActive) {
	fprintf (stderr, "Bad call to Wrefresh() - windows not active\n");
	fflush (stderr);
	inrefresh = 0;
	return -1;
    }
#ifdef FIONREAD
    if (SkipInputCheck == 0
	    && ioctl (0, FIONREAD, &InputPending) == 0
	    && InputPending) {
	inrefresh = 0;
	return 0;		/* Dont bother if input is pending */
    }
#endif FIONREAD
    if (SigMagic) {
	sighold (SIGTSTP);
	sighold (SIGINT);
    }
    if (ScreenGarbaged || LastRedisplayPaused) {
	LastRedisplayPaused = 0;
	for (i = 1; i <= ScreenLength; i++)
	    WDclearline (i);
	for (w = WinList; w; w = w -> w_next) {
	    if ((w -> w_status & WHIDDEN) == 0)
		WDoDump (w);
	}
    }
    else {
	i = TouchedDisp | WSetRealCursor | WBoxActive;
	for (w = WinList; w; w = w -> w_next) {
	    if (w -> w_status & WHIDDEN) continue;
	    if (w -> w_status & WDUMP || w -> w_textbuf -> b_nmodw)
		i++, WDoDump (w);
	}
	if (i == 0)		/* Nothing changed */
	    goto out;
    }
    TouchedDisp = WBoxActive;
    if (WBoxActive)
	WBoxToggle ();
    WDUpdateScreen (MajorUpdate, SkipInputCheck);
    if (WBoxActive)
	WBoxToggle ();
out:
    MajorUpdate = 0;
    inrefresh = 0;
    if (SigMagic) {
	sigrelse (SIGTSTP);
	sigrelse (SIGINT);
    }
    fflush (stdout);
    return 0;
}

/* Write contents of window w to virtual screen */
static
WDoDump (w)
register Win *w;
{
    register Ch *wt, *ww;
    register i, j;
    register Buf *b = w -> w_textbuf;

    wt = b -> b_contents + w -> w_bstart.row * b -> b_ncols +
	 w -> w_bstart.col;
    ww = w -> w_winbuf;
    for (i = 1; i <= w -> OYE; i++) {
	WDsetpos (w -> OYO + i, w -> OXO + 1);
	for (j = 0; j < w -> OXE; j++) {
	    if (ww -> Mode & WINVIS)
		dspskip (1);
	    else if (ww -> Mode & WBUF)
		dsputc (wt -> Char, wt -> Mode ^ ww -> Mode);
	    else
		dsputc (ww -> Char, ww -> Mode);
	    wt++, ww++;
	}
	wt += b -> b_ncols - /* w -> OXE */ j;
    }
    if ((w -> w_status & WCURSOR) == 0) {/* Put up a cursor */
	i = w -> IYO + w -> w_cursor.row;
	j = w -> IXO + w -> w_cursor.col;
	if (((w -> w_winbuf + i * w -> OXE + j) -> Mode & WINVIS) == 0) {
	    WDsetpos (w -> OYO + i + 1, w -> OXO + j + 1);
	    dspxor (WBLINK|WINVERSE);
	}
    }
    w -> w_status &= ~WDUMP;
    if (b -> b_nmodw == -1)
	b -> b_nmodw = b -> b_nwins - 1;
    else if (b -> b_nmodw)
	b -> b_nmodw--;
}

/* Put up the character at position row, col, possibly with cursor */
/* row, col should already have w -> IYE, w -> IXE added if needed */
WDispPut (w, row, col, curs)
register Win *w;
register row, col, curs;
{
    register Ch *p;

    if (w -> w_status & WHIDDEN)
	return;
    p = w -> w_winbuf + row * w -> OXE + col;
    if (p -> Mode & WINVIS)
	return;
    WDsetpos (row + w -> OYO + 1, col + w -> OXO + 1);
    curs = curs ? WBLINK|WINVERSE : 0;
    if (p -> Mode & WBUF) {
	register Buf *b;
	curs ^= p -> Mode;
	b = w -> w_textbuf;
	p = b -> b_contents + (w -> w_bstart.row + row) * b -> b_ncols +
	    w -> w_bstart.col + col;
    }
    dsputc (p -> Char, p -> Mode ^ curs);
    TouchedDisp++;
}

/* THIS FUNCTION COULD BE SUBSUMED BY THE LastRedisplayPaused VARIABLE */
/* Erase visible portions of window w from display */
WErase (w)
register Win *w;
{
    register Ch *wp;
    register i, j;

    if (w -> w_status & WHIDDEN)/* No need to erase */
	return;
    wp = w -> w_winbuf;
    for (i = 1; i <= w -> OYE; i++) {
	WDsetpos (w -> OYO + i, w -> OXO + 1);
	for (j = 0; j < w -> OXE; j++) {
	    if (wp++ -> Mode & WINVIS)
		dspskip (1);
	    else
		dsputc (' ', 0);
	}
    }
    TouchedDisp++;
}

/* Toggle the box on the virtual display (write it if it's not there, remove
   it if it is). */
static
WBoxToggle () {
	register i, j;

	WDsetpos (j = WBox.yorigin + 1, WBox.xorigin + 1);
	for (i = 0; i < WBox.xextent; i++)
		dspxor (WINVERSE);
	for (i = 2; i < WBox.yextent; i++) {
		WDsetpos (++j, WBox.xorigin + 1);
		dspxor (WINVERSE);
		if (WBox.xextent > 1) {
			dspskip (WBox.xextent - 2);
			dspxor (WINVERSE);
		}
	}
	if (WBox.yextent > 1) {
		WDsetpos (++j, WBox.xorigin + 1);
		for (i = 0; i < WBox.xextent; i++)
			dspxor (WINVERSE);
	}
}