#include <u.h>
#include <libc.h>
#include <draw.h>
#include <event.h>
#include <cursor.h>
enum{
	DARK, LIGHT, KING, BAIZE, LSQ, HSQ, DSQ, HUE,
	Eremote = 8, SQ = 50, RAD = 20,
	MOVE = 512, MSG = 8, MSGLEN = 128,
	↖ = 0x79fbf3db, ↗ = 0x7dfdf5dd, ↙ = 0xfbfbebba, ↘ = 0xfdf9edbc,
	CROWNHEAD = 0x82041861, ∞ = 0x7fffffff
};
ulong rgb[HUE] = {
	[DARK] DRed, [LIGHT] DWhite, [KING] DBlack,
	[BAIZE] DDarkgreen, [LSQ] DPaleyellow,
	[HSQ] DPalegreygreen, [DSQ] DYellowgreen
};
char bitboard[32] = {/* dark pieces at bottom */
		11,		5,		31,		25,
	10,		4,		30,		24,
		3,		29,		23,		17,
	2,		28,		22,		16,
		27,		21,		15,		9,
	26,		20,		14,		8,
		19,		13,		7,		1,
	18,		12,		6,		0};
Rectangle sq[32], r[3];
Image *hue[HUE];
char msg[MSG][MSGLEN], p[2][64];
u32int b[3], m[MOVE], h, jump, slide;
int t, v, msgn, flip = 1;
int aislide(int, int, int, u32int*);
void drawboard(void){
	Point o; u32int i, bit;
	for(i = 0; i < 32; i++){
		bit = 1 << i;
		o = addpt(sq[i].min, Pt(SQ >> 1, SQ >> 1));
		draw(screen, sq[i], hue[HSQ + !(bit & h)], nil, ZP);
		if(bit & (b[DARK] | b[LIGHT])){
			fillellipse(screen, o, RAD, RAD, hue[!(bit & b[DARK])], ZP);
			ellipse(screen, o, RAD, RAD, 0, hue[KING], ZP);
			if(bit & b[KING]) ellipse(screen, o, RAD >> 1, RAD >> 1, 0, hue[KING], ZP);
		}
	}
}
void drawmsgs(void){
	Point o; int i;
	draw(screen, r[2], hue[LIGHT], nil, ZP);
	for(o = r[2].min, i = 0; i < MSG; o.y += font->height)
		string(screen, o, hue[KING], ZP, font, msg[msgn + i++ & MSG - 1]);
}
void drawlabel(int i){
	draw(screen, r[i], hue[BAIZE], nil, ZP);
	string(screen,
		addpt(r[i].min, Pt(Dx(r[i]) - stringwidth(font, p[i]) >> 1, 0)),
		hue[LSQ], ZP, font, p[i]);
}
void eresized(int i){
	char *n;
	if(i && getwindow(display, Refnone) < 0)
		sysfatal("can't reattach to window");
	if((!i || Dx(screen->r) != 10 * SQ + MSG * font->height)
	&& (i = open("/dev/wctl", OWRITE)) >= 0){
		fprint(i, "resize -dy %d", 10 * SQ + MSG * font->height + 2 * Borderwidth);
		close(i);
	}
	draw(screen, screen->r, hue[BAIZE], nil, ZP);
	r[0] = Rect(-4 * SQ, SQ, SQ << 2, 9 * SQ);
	r[0] = rectaddpt(r[0], Pt(screen->r.min.x + screen->r.max.x >> 1, screen->r.min.y));
	draw(screen, r[0], hue[LSQ], nil, ZP);
	r[0].max = addpt(r[0].min, Pt(SQ, SQ));
	n = bitboard + (31 & flip >> 1);
	for(i = -1; ++i < 32; n += flip)
		sq[*n] = rectaddpt(r[0], Pt(((i << 1 & 7) + !(i & 4)) * SQ, (i >> 2) * SQ));
	drawboard();
	i = flip > 0;
	r[1] = Rect(0, -SQ - font->height >> 1, 8 * SQ, font->height - SQ >> 1);
	r[i] = rectaddpt(r[1], r[0].min);
	drawlabel(i);
	r[!i] = rectaddpt(r[i], Pt(0, 9 * SQ));
	drawlabel(!i);
	r[2] = screen->r;
	r[2].min.y += 10 * SQ;
	drawmsgs();
}
void zero(void){
	b[DARK] = 0x41c71c3;
	b[LIGHT] = 0xe3820c38;
	slide = 0x4104100;
	b[KING] = jump = v = h = 0;
}
void movers(void){
	u32int nw, se, n, s, e, ∅;
	n = b[v & 1] & b[(v & 1) << 1];
	s = b[v & 1] & b[!(v & 1) + 1];
	e = b[~v & 1];
	∅ = ~(b[DARK] | b[LIGHT]);
	nw = (∅ >> 7 | ∅ << 25) & e & ↖;
	se = (∅ << 7 | ∅ >> 25) & e & ↘;
	jump = (nw >> 7 | nw << 25) & n & ↖
	| (∅ >> 1 & e & ↗) >> 1 & n & ↗
	| (∅ << 1 & e & ↙) << 1 & s & ↙
	| (se << 7 | se >> 25) & s & ↘;
	slide = jump ? 0 :
	(∅ >> 7 | ∅ << 25) & n & ↖ | ∅ >> 1 & n & ↗
	| ∅ << 1 & s & ↙ | (∅ << 7 | ∅ >> 25) & s & ↘;
}
u32int jumps(u32int from){
	u32int to, n, s, e, ∅;
	n = from & b[DARK] | from & b[LIGHT] & b[KING];
	s = from & b[LIGHT] | from & b[DARK] & b[KING];
	e = b[!(from & b[LIGHT])];
	∅ = ~(b[DARK] | b[LIGHT]);
	to = (n << 1 & e & ↙) << 1 & ∅ & ↙;
	n = (n << 7 | n >> 25) & e & ↘;
	to |= (n << 7 | n >> 25) & ∅ & ↘;
	to |= (s >> 1 & e & ↗) >> 1 & ∅ & ↗;
	s = (s >> 7 | s << 25) & e & ↖;
	return to | (s >> 7 | s << 25) & ∅ & ↖;
}
u32int slides(u32int from){
	u32int n, s, ∅;
	n = from & b[DARK] | from & b[LIGHT] & b[KING];
	s = from & b[LIGHT] | from & b[DARK] & b[KING];
	∅ = ~(b[DARK] | b[LIGHT]);
	return ∅ & ↘ & (n << 7 | n >> 25) | ∅ & ↙ & n << 1
	| ∅ & ↗ & s >> 1 | ∅ & ↖ & (s >> 7 | s << 25);
}
void move(u32int mv){
	u32int rm;
	rm = ~(mv & b[~v & 1]);
	mv &= rm;
	b[~v & 1] &= rm;
	b[KING] &= rm;
	b[v & 1] ^= mv;
	if(mv & b[KING]) b[KING] ^= mv;
	else if(mv & b[v & 1] & CROWNHEAD) b[KING] |= mv & b[v & 1];
}
void getjumps(u32int *mv, int *i, u32int from,
u32int ∅, u32int n, u32int s, u32int e, u32int rm){
	u32int x, to, j = 0;
	if((x = (n << 7 | n >> 25) & e & ↘) && (to = (x << 7 | x >> 25) & ∅ & ↘) && ++j)
		getjumps(mv, i, from, ∅ ^ to | x | n, to, s ? to : 0, e ^ x, rm | x);
	if((x = n << 1 & e & ↙) && (to = x << 1 & ∅ & ↙) && ++j)
		getjumps(mv, i, from, ∅ ^ to | x | n, to, s ? to : 0, e ^ x, rm | x);
	if((x = (s >> 7 | s << 25) & e & ↖) && (to = (x >> 7 | x << 25) & ∅ & ↖) && ++j)
		getjumps(mv, i, from, ∅ ^ to | x | s, n ? to : 0, to, e ^ x, rm | x);
	if((x = s >> 1 & e & ↗) && (to = x >> 1 & ∅ & ↗) && ++j)
		getjumps(mv, i, from, ∅ ^ to | x | s, n ? to : 0, to, e ^ x, rm | x);
	if(j == 0)
		mv[(*i)++ & 7] = from | n | s | rm;
}
int aijump(int d, int α, int β, u32int *mv){
	u32int old[3], froms, from, j[8]; int i, val;
	for(froms = jump; α < β && (from = froms & -froms); froms ^= from){
		i = 0;
		getjumps(j, &i, from, ~(b[DARK] | b[LIGHT]),
			from & (b[DARK] | b[LIGHT] & b[KING]),
			from & (b[LIGHT] | b[DARK] & b[KING]), b[~v & 1], 0);
		if(i & ~7) i = 8;
		if(mv != nil) *mv = j[nrand(i)];
		old[0] = b[0]; old[1] = b[1]; old[2] = b[2];
		while(α < β && --i >= 0){
			move(j[i]);
			v++;
			movers();
			val = jump ? -aijump(d, -β, -α, nil) : -aislide(d, -β, -α, nil);
			if(val > α){
				α = val;
				if(mv != nil) *mv = j[i];
			}
			v--;
			b[0] = old[0]; b[1] = old[1]; b[2] = old[2];
		}
	}
	return α;
}
int num(u32int bits){
	int c;
	for(c = 0; bits; c++)
		bits &= bits - 1;
	return c;
}
int aislide(int d, int α, int β, u32int *mv){
	u32int old[3], froms, from, tos, to; int val;
	if(!slide) return -∞;
	if(d < 1){	/* evaluate */
		from = b[v & 1] & ~b[KING];
		to = b[~v & 1] & ~b[KING];
		froms = b[v & 1] & b[KING];
		tos = b[~v & 1] & b[KING];
		/* material advantage */
		α = (num(b[v & 1]) << 9) + (num(froms) << 10);
		β = (num(b[~v & 1]) << 9) + (num(tos) << 10);
		if(α > β) val = (α - β) * α / (β ? β : 1);
		else val = (α - β) * β / (α ? α : 1);
		/* occupy centre, not sides */
		val += num(from & 0x10608000) - num(to & 0x10608000) << 6;
		val += num(to & 0x4020204) - num(from & 0x4020204) << 5;
		/* guard back rank */
		val += num(from & (b[DARK] & 0x41041 | b[LIGHT] & 0x82000820))
		- num(to & (b[DARK] & 0x41041 | b[LIGHT] & 0x82000820)) << 7;
		val += num(from & (b[DARK] & 0x1040 | b[LIGHT] & 0x80000020))
		- num(to & (b[DARK] & 0x1040 | b[LIGHT] & 0x80000020)) << 5;
		/* mobility */
		val += num(jump) << 7 | num(slide) << 5;
		v++;
		movers();
		val -= num(jump) << 7 | num(slide) << 5;
		v--;
		movers();
		/* advance */
		val += num(from & b[DARK] & 0x8208200 | from & b[LIGHT] & 0x10410004)
		- num(to & b[DARK] & 0x8208200 | to & b[LIGHT] & 0x10410004) << 4;
		val += num(from & b[DARK] & 0x10410004 | from & b[LIGHT] & 0x8208200)
		- num(to & b[DARK] & 0x10410004 | to & b[LIGHT] & 0x8208200) << 5;
		val += num(from & b[DARK] & 0x20820008 | from & b[LIGHT] & 0x4104100)
		- num(to & b[DARK] & 0x20820008 | to & b[LIGHT] & 0x4104100) << 6;
		val += num(from & b[DARK] & 0x41000410 | from & b[LIGHT] & 0x82082)
		- num(to & b[DARK] & 0x41000410 | to & b[LIGHT] & 0x82082) << 7;
		/* guarding the back rank and double corner is usually a good idea */
		val += num(from & b[DARK] & 0x41043 | from & b[LIGHT] & 0x82000c20)
		- num(to & b[DARK] & 0x41043 | to & b[LIGHT] & 0x82000c20) << 5;
		/* try to keep kings off the edge */
		val += num(tos & 0x82461e67) - num(froms & 0x82461e67) << 5;
		/* go in for the kill */
		if(num(b[DARK] | b[LIGHT]) < 6 && α > β){
			val -= num(b[~v & 1] & 0xc03) << 11;
			if(froms) do{
				froms |= froms >> 1 & ↗ | (froms >> 7 | froms << 25) & ↖
					| froms << 1 & ↙ | (froms << 7 | froms >> 25) & ↘;
				val -= 0x80;
			}while(!(froms & b[~v & 1]));
		}
		return val | rand() & 0xf;
	}
	old[0] = b[0]; old[1] = b[1]; old[2] = b[2];
	for(froms = slide; α < β && (from = froms & -froms); froms ^= from)
		for(tos = slides(from); α < β && (to = tos & -tos); tos ^= to){
			move(from | to);
			v++;
			movers();
			val = jump ? -aijump(d - 1, -β, -α, nil) : -aislide(d - 1, -β, -α, nil);
			if(val > α){
				α = val;
				if(mv != nil) *mv = from | to;
			}
			v--;
			b[0] = old[0]; b[1] = old[1]; b[2] = old[2];
		}
	return α;
}
void sqprint(char *s, u32int bit){
	int i;
	for(i = 0; i < 32 && !(bit & 1 << bitboard[i]); i++);
	if(i = 32 - i){
		s[0] = '0' + i / 10;
		s[1] = '0' + i % 10;
	}else s[0] = s[1] = '?';
}
void printjumps(char *str, int d, u32int ∅, u32int n, u32int s, u32int rm){
	u32int x, to, j = 0;
	if(h) return;
	sqprint(str, n | s);
	str[2] = 'x';
	str += 3;
	if((x = (n << 7 | n >> 25) & rm & ↘) && (to = (x << 7 | x >> 25) & ∅ & ↘) && ++j)
		printjumps(str, d + 1, ∅ ^ to | x | n, to, s ? to : 0, rm ^ x);
	if((x = n << 1 & rm & ↙) && (to = x << 1 & ∅ & ↙) && ++j)
		printjumps(str, d + 1, ∅ ^ to | x | n, to, s ? to : 0, rm ^ x);
	if((x = (s >> 7 | s << 25) & rm & ↖) && (to = (x >> 7 | x << 25) & ∅ & ↖) && ++j)
		printjumps(str, d + 1, ∅ ^ to | x | s, n ? to : 0, to, rm ^ x);
	if((x = s >> 1 & rm & ↗) && (to = x >> 1 & ∅ & ↗) && ++j)
		printjumps(str, d + 1, ∅ ^ to | x | s, n ? to : 0, to, rm ^ x);
	if(!j && !rm && (n | s) & m[v]) h = d;
}
u32int strtobit(char *s){
	u32int n;
	if(s == nil || *s < '0' || *s > '3') return 0;
	n = (*s++ - '0') * 10;
	return *s < '0' || *s > '9' || (n = 32 + '0' - n - *s) > 31 ? 0 : 1 << bitboard[n];
}
u32int jumped(u32int from, u32int to){
	if(to & from << 14) return to >> 7;
	if(to & from >> 18 && to & 0x3c) return to << 25;
	if(to & from >> 18) return to >> 7;
	if(to & from << 2) return to >> 1;
	if(to & from >> 14) return to << 7;
	if(to & from << 18 && from & 0x3c) return to << 7;
	if(to & from << 18) return to >> 25;
	if(to & from >> 2) return to << 1;
	return 0;
}
void domove(char *s){
	u32int from, to, mv, j[8]; int i;
	if(!(from = strtobit(s))) return;
	mv = 0;
	if(s[2] == 'x'){
		i = 0;
		getjumps(j, &i, from, ~(b[DARK] | b[LIGHT]),
			from & (b[DARK] | b[LIGHT] & b[KING]),
			from & (b[LIGHT] | b[DARK] & b[KING]), b[~v & 1], 0);
		if(i & ~7) i = 8;
		do{
			if(!(to = strtobit(s += 3))) return;
			mv ^= from | to;
			mv |= jumped(from, to);
			from = to;
		}while(s[2] == 'x');
		while(--i >= 0 && j[i] != mv);
		if(i < 0) return;
	}
	else if((mv = from | strtobit(s + 3)) == from || !(mv & slides(from))) return;
	move(mv);
	m[v] = mv;
	t = ++v;
	movers();
}
void chat(void *s, int n){
	if(n >= MSGLEN) n = MSGLEN - 1;
	memmove(msg[msgn], s, n);
	msg[msgn][n] = '\0';
	msgn = msgn + 1 & MSG - 1;
	drawmsgs();
}
void main(int argc, char **argv){
	Event e; Cursor busy = {{-1, -1},
		{0xff, 0x80, 0xff, 0x80, 0xff, 0x00, 0xfe, 0x00, 
		 0xff, 0x00, 0xff, 0x80, 0xff, 0xc0, 0xef, 0xe0, 
		 0xc7, 0xf0, 0x03, 0xf0, 0x01, 0xe0, 0x00, 0xc0, 
		 0x03, 0xff, 0x03, 0xff, 0x03, 0xff, 0x03, 0xff},
		{0x00, 0x00, 0x7f, 0x00, 0x7e, 0x00, 0x7c, 0x00, 
		 0x7e, 0x00, 0x7f, 0x00, 0x6f, 0x80, 0x47, 0xc0, 
		 0x03, 0xe0, 0x01, 0xf0, 0x00, 0xe0, 0x00, 0x40, 
		 0x00, 0x00, 0x01, 0xb6, 0x01, 0xb6, 0x00, 0x00}};
	u32int bit, king; int i, fd = -1;
	char buf[MSGLEN], *f, *u, *s;
	SET(f); ARGBEGIN{
	default:
	 	sysfatal("usage: %s [-9 file] [movetext]", argv0);
	case '9':
		f = EARGF(sysfatal("bad argument to -9"));
		if((fd = open(f, ORDWR)) < 0) sysfatal("open: %r");
	}ARGEND
	if(initdraw(nil, nil, "draughts") < 0) sysfatal("initdraw: %r");
	for(i = 0; i < HUE; i++)
		if((hue[i] = allocimage(display, Rect(0,0,1,1), screen->chan, 1, rgb[i])) == nil)
			sysfatal("allocimage: %r");
	einit(Emouse | Ekeyboard);
	srand(truerand());
	u = getuser();
	new: zero();
	for(t = i = 0; fd < 0 && i < argc; i++) domove(argv[i]);
	strcpy(p[0], u); strcpy(p[1], u);
	eresized(0);
	if(fd >= 0){
		s = strchr(f, '\0') - 3;
		if(s >= f && !strcmp(s, "ctl")){
			strcpy(buf, "light");
			do eenter("play as? [dark/light]", buf, 6, &e.mouse);
				while(strcmp(buf, "dark") && strcmp(buf, "light"));
			s = buf + 9;
			if(*buf == 'd') s = strecpy(s, buf + MSGLEN, u) + 1;
			strcpy(s, "none");
			if((i = eenter("opponent's name", s, MSGLEN + buf - s - 10, &e.mouse)) <= 0)
				sysfatal("player entry cancelled");
			s += i;
			if(*buf == 'l') s = strecpy(s + 1, buf + MSGLEN, u);
			strcpy(buf, "draughts");
			i = write(fd, buf, s - buf);
			close(fd);
			s = strecpy(buf, buf + MSGLEN, f) - 3;
			s = seprint(s, buf + MSGLEN, "%d", i);
			if((fd = open(buf, ORDWR)) < 0) sysfatal("open: %r");
			chat(buf, s - buf);
		}else chat(f, strlen(f));
		if((i = read(fd, buf, MSGLEN - 1)) < 12) sysfatal("not a draughts game?");
		buf[i] = '\0';
		if(strcmp(buf, "draughts")) sysfatal("not a draughts game!");
		strncpy(p[0], buf + 9, 63);
		for(s = buf + 9; *s++ != '\0';);
		if(s - buf >= i) sysfatal("couldn't get player 2 name");
		strncpy(p[1], s, 63);
		if(strcmp(p[0], u) && !(strcmp(p[1], u) && strcmp(p[1], "none"))) flip = -1;
		strcpy(buf + 6, buf + 9);
		strncpy(s - 4, " vs ", 4);
		while(*s++ != '\0');
		chat(buf + 6, s - buf - 7);
		if(s - buf < i) for(s = strtok(s, " "); s != nil; s = strtok(nil, " ")) domove(s);
		if(strcmp(p[t & 1], u) && strcmp(p[t & 1], "none")) esetcursor(&busy);
		estart(Eremote, fd, MSGLEN);
		eresized(0);
	}
	else chat("new game: click user name to create ai player", 45);
	for(;;){
		if(fd < 0 && !strncmp(p[t & 1], "ai level ", 9)){
			flushimage(display, 1);
			if(ecankbd() || !jump && !slide || t + 33 >= MOVE){
				chat("ai stopped", 10);
				while(ecankbd()) ekbd();	/* gulp */
				strcpy(p[t & 1], u);
				drawlabel(t & 1);
				esetcursor(nil);
				continue;
			}
			esetcursor(&busy);
			if(jump){
				aijump(p[t & 1][9] - '1', -∞, ∞, m + t);
			}else{
				for(i = nrand(num(bit = slide)); i--; bit &= bit - 1);
				m[t] = bit & -bit;
				for(i = nrand(num(bit = slides(m[t]))); i--; bit &= bit - 1);
				m[t] |= bit & -bit;
				aislide(p[t & 1][9] - '1', -∞, ∞, m + t);
			}
			move(m[t]);
			v = ++t;
			movers();
			sleep(500);
			drawboard();
			if(!jump && !slide) goto gameover;
			esetcursor(nil);
		}
		else switch(event(&e)){
		case Eremote:
			if(e.data[0] == '!' && e.n < MSGLEN){
				while(v < t){move(m[v]); v++;}
				memmove(buf, e.data, e.n);
				buf[e.n] = '\0';
				domove(buf + 1);
				drawboard();
				if(!jump && !slide) goto gameover;
				esetcursor(strcmp(p[t & 1], u) && strcmp(p[t & 1], "none") ? &busy : nil);
			}
			else chat(e.data, e.n);
			break;
		case Ekeyboard:
			h = 0;
			switch(e.kbdc){
			case 127:
				if(fd >= 0){
					close(fd);
					s = strecpy(buf, buf + MSGLEN, u);
					*s++ = '\n';
				} else s = buf;
				s = strecpy(s, buf + MSGLEN, argv0);
				zero();
				for(v = 0; v < t; v++){
					if(s + 35 >= buf + MSGLEN){
						*s = '\0';
						print(s = buf);
					}
					*s++ = ' ';
					if(~v & 1) s = seprint(s, s + 6, "%d. ", v + 2 >> 1);
					if(num(m[v]) == 2){
						sqprint(s, m[v] & b[v & 1]);
						s[2] = '-';
						move(m[v]);
						sqprint(s + 3, m[v] & b[v & 1]);
						s += 5;
					}
					else{
						printjumps(s, 0, ~(b[DARK] | b[LIGHT]),
							m[v] & b[v & 1] & (b[DARK] | b[LIGHT] & b[KING]),
							m[v] & b[v & 1] & (b[LIGHT] | b[DARK] & b[KING]),
							m[v] & b[~v & 1]);
						s += 3 * h + 2;
						move(m[v]);
						h = 0;
					}
				}
				*s++ = '\n'; *s = '\0';
				print(buf);
				exits(nil);
			case 0xf011: for(i = v - 1, zero(); v < i; v++) move(m[v]); break;
			case 0xf012: if(v < t){move(m[v]); v++;}break;
			case 0xf800: zero(); break;
			case 0xf00e: while(v < t){move(m[v]); v++;}break;
			case 0x1b: flip *= -1; eresized(0); break;
			case 'n': if(fd < 0) goto new;
			default:
				if(fd >= 0){
					buf[0] = e.kbdc; buf[1] = '\0';
					if((i = eenter("message", buf, MSGLEN, &e.mouse)) > 0)
						write(fd, buf, i);
				}
				continue;
			}
			if(fd < 0) movers();
			drawboard();
			break;
		case Emouse:
			if(!e.mouse.buttons || v + 1 >= MOVE || fd >= 0 && v != t
			|| strcmp(p[v & 1], u) && strcmp(p[v & 1], "none")) continue;
			do eread(Emouse, &e); while(e.mouse.buttons);
			if(fd < 0 && (ptinrect(e.mouse.xy, r[i = 0]) || ptinrect(e.mouse.xy, r[i = 1]))){
				*buf = '\0';
				eenter("ai level ? [0–9]", buf, 2, &e.mouse);
				if(*buf == '0') strcpy(p[i], u);
				else if(*buf >= '1' && *buf <= '9'){
					strcpy(p[i], "ai level x");
					p[i][9] = *buf;
				}
				else continue;
				drawlabel(i);
				s = strecpy(buf, buf + MSGLEN, p[0]);
				s = strecpy(s, buf + MSGLEN, " vs ");
				s = strecpy(s, buf + MSGLEN, p[1]);
				chat(buf, s - buf);
				continue;
			}
			for(i = 0; i < 32 && !ptinrect(e.mouse.xy, sq[i]); i++);
			bit = (i < 32) << i;
			if(bit & h & ~(b[DARK] | b[LIGHT])){
				if(jump){
					s = buf;
					if(fd >= 0){
						*s++ = '!';
						sqprint(s++, h & jump);
						s++;
					}
					for(m[v] = 0, king = b[KING] & h;;){
						if(fd >= 0){
							*s++ = 'x';
							sqprint(s++, bit);
							s++;
						}
						m[v] ^= h = h & jump | bit | jumped(h & jump, bit);
						move(h);
						h = jumps(bit);
						if(!h || !king && bit & b[KING]) break;
						h |= jump = bit;
						drawboard();
						do{
							do eread(Emouse, &e); while(!e.mouse.buttons);
							do eread(Emouse, &e); while(e.mouse.buttons);
							for(i = 0; i < 32 && !ptinrect(e.mouse.xy, sq[i]); i++);
							bit = (i < 32) << i;
						}while(!(bit & h & ~jump));
					}
					if(fd >= 0){
						*s++ = ' ';
						write(fd, buf, s - buf);
					}
				}
				else{
					move(m[v] = bit | h & slide);
					if(fd >= 0){
						buf[0] = '!';
						sqprint(buf + 1, h & slide);
						buf[3] = '-';
						sqprint(buf + 4, bit);
						buf[6] = ' ';
						write(fd, buf, 7);
					}
				}
				t = ++v;
				h = 0;
				movers();
				if(!jump && !slide){gameover:
					esetcursor(nil);
					if(b[DARK] | b[LIGHT]){
						s = strecpy(buf, buf + MSGLEN, p[!b[DARK]]);
						s = strecpy(s, buf + MSGLEN, " wins!");
					}
					else s = strecpy(buf, buf + MSGLEN, "it's a draw!");
					chat(buf, s - buf);
					if(fd >= 0) continue;
					strcpy(p[0], u);
					drawlabel(0);
					strcpy(p[1], u);
					drawlabel(1);
					esetcursor(nil);
				}
			}
			else if(bit & ~h & jump)
				h = bit | jumps(bit);
			else if(bit & ~h & slide)
				h = bit | slides(bit);
			else h = 0;
			drawboard();
			break;
		}
	}
}