/* Copyright (c) 1990 by Sozobon, Limited.  Authors: Johann Ruegg, Don Dugger
 *
 * Permission is granted to anyone to use this software for any purpose
 * on any computer system, and to redistribute it freely, with the
 * following restrictions:
 * 1) No charge may be made other than reasonable charges for reproduction.
 * 2) Modified versions must be clearly marked as such.
 * 3) The authors are not responsible for any harmful consequences
 *    of using this software, even if they result from defects in it.
 *
 *	window.c
 */

char scrbuf[0x80ff];
char *screen;
long oscreen;
int mywindow;
int ucolor0, ucolor1;

winopen()
{
	long xbios();


	screen = scrbuf;
	screen += 0xff;
	screen = (char *)((long)screen & ~0xffL);
	
	oscreen = xbios(2);
	xbios(5, -1L, screen, -1);
	ucolor0 = xbios(7, 0, 0);
	ucolor1 = xbios(7, 1, 0x777);
	w_init();
	mywindow = 1;
}

winswtch()
{
	long xbios();

	if (mywindow) {
		xbios(5, -1L, oscreen, -1);
		xbios(7, 0, ucolor0);
		xbios(7, 1, ucolor1);
	} else {
		oscreen = xbios(2);
		xbios(5, -1L, screen, -1);
		ucolor0 = xbios(7, 0, 0);
		ucolor1 = xbios(7, 1, 0x777);
	}
	mywindow = !mywindow;
}

winclose()
{
	if (mywindow)
		winswtch();
}

puts(s)
char *s;
{
	while (*s)
		putchar(*s++);
}

putchar(c)
char c;
{
	w_curs(0);
	c &= 0x7f;
	switch (c) {
	case '\b':
		w_bs();
		break;
	case '\t':
		w_tab();
		break;
	case '\n':
		w_nl();
		break;
	default:
		w_put(c);
		break;
	}
	w_curs(1);
}

struct window {
	short cols, lines;
	short curc, curl;
	short res;
	short fontsz;
	short csz, lsz, fsz;
	char *font;
} w;

char *bw_font;
char *c_font;

w_init()
{
	int w_res;
	long fontsp, getfonts();
	long t;

	fontsp = getfonts();

	t = fontsp + 4;
	t = *(long *)t;
	t += 0x4c;
	c_font = *(char **)t;

	t = fontsp + 8;
	t = *(long *)t;
	t += 0x4c;
	bw_font = *(char **)t;

	w.curc = w.curl = 0;

	w.res = xbios(4);
	switch (w.res) {
	case 0:
		w.cols = 40;
		w.lines = 25;
		w.csz = 8;
		w.lsz = 4*40*8;
		w.fsz = 4*40;
		w.fontsz = 8;
		w.font = c_font;
		break;
	case 1:
		w.cols = 80;
		w.lines = 25;
		w.csz = 4;
		w.lsz = 2*80*8;
		w.fsz = 2*80;
		w.fontsz = 8;
		w.font = c_font;
		break;
	case 2:
		w.cols = 80;
		w.lines = 25;
		w.csz = 2;
		w.lsz = 1*80*16;
		w.fsz = 1*80;
		w.fontsz = 16;
		w.font = bw_font;
		break;
	}
	w_curs(1);
}

w_put(c)
char c;
{
	int i;
	char *fp;
	char *tp;
	int woff, horl;

	tp = screen;
	horl = w.curc & 1;
	woff = w.curc >> 1;
	tp += woff*w.csz + horl;
	tp += w.curl*w.lsz;

	fp = &w.font[c];
	for (i=0; i<w.fontsz; i++) {
		*tp = *fp;
		tp += w.fsz;
		fp += 256;
	}
	w.curc++;
	if (w.curc >= w.cols)
		w_nl();
}

w_curs(flg)
{
	int i;
	char *tp;
	int woff, horl;
	char val;

	tp = screen;
	horl = w.curc & 1;
	woff = w.curc >> 1;
	tp += woff*w.csz + horl;
	tp += w.curl*w.lsz;

	val = flg ? 0xff : 0;

	for (i=0; i<w.fontsz; i++) {
		*tp = val;
		tp += w.fsz;
	}
}

w_bs()
{
	if (w.curc)
		w.curc--;
}

optnl()
{
	if (w.curc) {
		w_curs(0);
		w_nl();
		w_curs(1);
	}
}

align(n)
{
	w_curs(0);
	if (w.curc > n)
		w_nl();
	w.curc = n;
	w_curs(1);
}

tab(n)
{
	w_curs(0);
	w.curc += n;
	w.curc -= (w.curc % n);
	if (w.curc >= w.cols)
		w_nl();
	w_curs(1);
}

w_tab()
{
	w.curc += 10;
	w.curc -= (w.curc % 10);
	if (w.curc >= w.cols)
		w_nl();
}

w_nl()
{
	w.curc = 0;
	w.curl++;
	if (w.curl >= w.lines) {
		w_scrup();
		w.curl = w.lines-1;
	}
}

w_scrup()
{
	register char *fr, *to, *clr;
	register cnt;

	clr = fr = to = screen;
	fr += w.lsz;
	cnt = w.lsz * (w.lines-1);
	clr += cnt;
	wcopy(fr, to, cnt/2);
	cnt = w.lsz;
	while (cnt--)
		*clr++ = 0;
}

char linesv[80*16];

w_help(flag)
{
	static int svcol;
	char *tp;

	if (flag == 0) {
		w_curs(0);
		tp = screen;
		tp += w.curl*w.lsz;
		wcopy(tp, linesv, w.lsz/2);
		svcol = w.curc;
		w.curc = w.cols - 40;
	} else {
		w.curl = w.lines-1;
		tp = screen;
		tp += w.curl*w.lsz;
		wcopy(linesv, tp, w.lsz/2);
		w.curc = svcol;
		w_curs(1);
	}
}

w_hline(n)
{
	w.curl = n;
	w.curc = w.cols - 40;
}

w_hchr(c)
char c;
{
	w_put(c);
}