/* Copyright (c) 1983 University of Maryland Computer Science Department */
/* terminal control module for DEC VT100's */

/* Modified version of Gosling's C100 driver -- jpershing@bbn */

/* This is a somewhat primitive driver for the DEC VT100 terminal.  The
   terminal is driven in so-called "ansi" mode, using jump scroll.  It is
   assumed to have the Control-S misfeature disabled (although this
   shouldn't get in the way -- it does anyway).  Specific optimization left
   to be done are (1) deferral of setting the window until necessary (as
   the escape sequence to do this is expensive) and (2) being more clever
   about optimizing motion (as the direct-cursor-motion sequence is also
   quite verbose).  Also, something needs to be done about putting the
   terminal back into slow-scroll mode if that's the luser's preference (or
   perhaps having EMACS itself use slow-scroll mode [lose, lose]).
*/

#include <stdio.h>
#include "Trm.h"

static
int	curX, curY;
static
int	WindowSize;

static curmodes, CurGraph;
static
modes (m) register m; {
    static char *mds[16] = { "0", "0;1", "0;4", "0;1;4", "0;5",
	"0;1;5", "0;4;5", "0;1;4;5", "0;7", "0;1;7", "0;4;7",
	"0;1;4;7", "0;5;7", "0;1;5;7", "0;4;5;7", "1;4;5;7" };

    if (curmodes == m)
	return;
    printf ("\033[%sm", mds[m]);
    curmodes = m;
}

static
inslines (n) register n; {
    printf ("\033[%d;%dr\033[%dH", curY, WindowSize, curY);
    curX = 1;
    while (--n >= 0) {
	printf ("\033M");
	pad (1, 20.);		/* DEC sez pad=30, but what do they know? */
    }
    printf ("\033[r");
    pad (1, 2.);		/* ACT */
    curX = curY = 1;
};

static
dellines (n) register n; {
    printf ("\033[%d;%dr\033[%dH", curY, WindowSize, WindowSize);
    curX = 1;
    curY = WindowSize;
    while (--n >= 0) {
	printf ("\033E");
	pad (1, 20.);		/* [see above comment] */
    }
    printf ("\033[r");
    pad (1, 2.);		/* ACT */
    curX = curY = 1;
};

static	Baud;

static
writechars (start, end)
register char	*start,
		*end; {
    register count = 0;
    while (start <= end) {
	if (*start & 0x80) {
	    if (CurGraph == 0) {
		printf ("\033(0");
		CurGraph++;
	    }
	    putchar (*start++ & 0x7f);
	}
	else {
	    if (CurGraph && *start != ' ') {
		printf ("\033(B");
		CurGraph = 0;
	    }
	    putchar (*start++);
	}
	curX++;
	if (count++ > 15 && Baud > 9600) count = 0, pad (1, 2.5);/* ACT */
    }
};

static
blanks (n) register n; {
    while (--n >= 0) {
	putchar (' ');
	curX++;
    }
};

static float BaudFactor;

static pad(n,f)
register n;
register float f; {
    register    k = n * f * BaudFactor;
    while (--k >= 0)
 	putchar (0);
};

static				/* This routine needs lots of work */
topos (row, column) register row, column; {
    register k;
    if (curY == row) {
	k = curX - column;
	if (k) {
	    if (k > 0 && k < 4) {
		while (k--) putchar(010);
		goto done;
	    }
	}
	else return;
    }
    if (curY + 1 == row && (column == 1 || column==curX)) {
	if(column!=curX) putchar (015);
	putchar (012);
	goto done;
    }
    if (row == 1 && column == 1) {
	printf ("\033[H");
	pad (1, 5.);		/* ACT */
	goto done;
    }
    printf ("\033[%d;%dH", row, column );
    pad (1, 5.);		/* ACT */
done:
    curX = column;
    curY = row;
};

static
init (BaudRate) {
    static inited = 0;
    if (!inited) {
	char *getenv();
	static char tbuf[1024];		/* ACT Try for termcap's co# */
	register char *t = getenv ("COL");
	W_tt.t_width = t ? atoi (t)
	: ((t = getenv ("TERM")) && tgetent (tbuf,t)>0) ? tgetnum ("co") : 80;
    }
    Baud = BaudRate;
    BaudFactor = BaudRate/10000.;
    W_tt.t_ILmf = 0.0;
    W_tt.t_ILov = 15 + 2+BaudFactor*20.;
    return 0;
};

static
reset () {
    printf ("\033<\033[r\033[m\033[?4;6l\033[2J\033(B\017");/* Whew! */
    if (InverseVideo) printf ("\033[?5h");/* Use inverse video */
    pad (1, 55.);
    WindowSize = 24;
    curmodes = 0;
    CurGraph = 0;
    curX = curY = 1;
};

static
cleanup () {
    modes (0);
    if (CurGraph) {
	printf ("\033(B");
	CurGraph = 0;
    }
    window (0);
    topos (WindowSize, 1);
    wipeline ();
};

static
wipeline () {
    printf("\033[K");
    pad (1, 2.);
};

static
wipescreen () {
    printf("\033[2J");
    pad (1, 60.);		/* ACT was 45. */
};

static
window (n) register n; {
    if (n <= 0 || n > 24)
	n = 24;
    WindowSize = n;
}

/* Visible Bell for DT80/1 -ACT */
static
flash () {
    printf (InverseVideo ? "\033[?5l" : "\033[?5h");
    pad (1, 40.);
    printf (InverseVideo ? "\033[?5h" : "\033[?5l");
}

/* Turn off graphics mode */
static donerefresh () {
    if (CurGraph) {
	printf ("\033(B");
	CurGraph = 0;
    }
}

TrmVT100 () {
	W_tt.t_INSmode = NoOperation;
	W_tt.t_modes = modes;
	W_tt.t_inslines = inslines;
	W_tt.t_dellines = dellines;
	W_tt.t_blanks = blanks;
	W_tt.t_init = init;
	W_tt.t_cleanup = cleanup;
	W_tt.t_wipeline = wipeline;
	W_tt.t_wipescreen = wipescreen;
	W_tt.t_topos = topos;
	W_tt.t_reset = reset;
	W_tt.t_delchars = 0;
	W_tt.t_writechars = writechars;
	W_tt.t_window = window;
	W_tt.t_flash = flash;
	W_tt.t_donerefresh = donerefresh;
	W_tt.t_ILmf = 0;
	W_tt.t_ILov = 0;
	W_tt.t_ICmf = MissingFeature;
	W_tt.t_ICov = MissingFeature;
	W_tt.t_DCmf = MissingFeature;
	W_tt.t_DCov = MissingFeature;
	W_tt.t_length = 24;
	W_tt.t_width = 80;
	W_tt.t_frames[0] = 'l' | 0x80;	/* ulc */
	W_tt.t_frames[1] =
	W_tt.t_frames[6] = 'q' | 0x80;	/* top, bottom */
	W_tt.t_frames[2] = 'k' | 0x80;	/* urc */
	W_tt.t_frames[3] =
	W_tt.t_frames[4] = 'x' | 0x80;	/* left, right sides */
	W_tt.t_frames[5] = 'm' | 0x80;	/* llc */
	W_tt.t_frames[7] = 'j' | 0x80;	/* lrc */
	return 0;
};