addintermediatepnt(midpnt, 1);				return(1);			}			if (computerboard[midpnt] <= 0) {				useroll(dice[0]);				useroll(dice[1]);				addintermediatepnt(midpnt, 0);				return(1);			}			message(ERR, "You cannot touch down on a blocked point!");			return(0);		}		message(ERR, "You didn't roll that  move!");		return(0);	}}useroll(num)int num;{	if (num == (humandieroll[0] & NUMMASK)) {		if ((humandieroll[0] & ROLLUSED) == 0) {			humandieroll[0] |= ROLLUSED;			rollstack[rollcntr++] = humandieroll[0] & NUMMASK;		} else if ((humandieroll[0] & SECONDROLLUSED) == 0) { /* must be dbles */			humandieroll[0] |= SECONDROLLUSED;			rollstack[rollcntr++] = humandieroll[0] & NUMMASK;		} else if ((humandieroll[1] & ROLLUSED) == 0) {			humandieroll[1] |= ROLLUSED;			rollstack[rollcntr++] = humandieroll[1] & NUMMASK;		} else {			humandieroll[1] |= SECONDROLLUSED;			rollstack[rollcntr++] = humandieroll[1] & NUMMASK;		}	} else {		humandieroll[1] |= ROLLUSED;		rollstack[rollcntr++] = humandieroll[1] & NUMMASK;	}}domove(from, to)int from, to;{	int ind = 0;	humanmoves[movesmade][FROM] = from;	if (intcntr) {		for (ind = 0; ind < intcntr; ind++) {			humanmoves[movesmade][TO] = intpnts[ind][0];			if (intpnts[ind][1]) {				movepiece(intpnts[ind][0], BAR, COMPUTER);				humanmoves[movesmade][HITBLOT] = 1;			} else {				humanmoves[movesmade][HITBLOT] = 0;			}			humanmoves[movesmade][DIEUSED] = rollstack[ind] | INTERMED;			humanmoves[++movesmade][FROM] = intpnts[ind][0];		}	}	if (computerboard[to] == 1 && to != HOME) {		movepiece(to, BAR, COMPUTER);		humanmoves[movesmade][HITBLOT] = 1;	} else {		humanmoves[movesmade][HITBLOT] = 0;	}	humanmoves[movesmade][TO] = to;	humanmoves[movesmade][DIEUSED] = rollstack[ind];	movepiece(from, to, HUMAN);	if (++movesmade == maxmoves || humanboard[HOME] == 15)		endhumanturn();}int rollsleft, dicecopy[4], boardcopy[26], numdice;starthumanturn(){	int index;	/* find the maximum number of moves the human can make */	boardcopy[BAR] = humanboard[BAR];	for (index = 1; index < 25; index++) {		boardcopy[25 - index] = humanboard[index];		if (computerboard[index] > 1)			boardcopy[25 - index] = BLOCKED;	}	dicecopy[0] = humandieroll[0];	dicecopy[1] = humandieroll[1];	if (humandieroll[0] == humandieroll[1]) {		dicecopy[2] = dicecopy[3] = dicecopy[0];		numdice = 4;		rollsleft = 4;	} else {		numdice = 2;		rollsleft = 2;	}	maxmoves = 0;	findmaxrolls(0);	if (!diddouble)		sendtogammon(NODOUBLE);	diddouble = 0;	if (maxmoves > 0) {		state = MOVE;		setcursor(MOVE_CUR);		movesmade = 0;		humannomove = 0;		sendtogammon(CANMOVE);		sendtogammon(DIEROLL);		sendtogammon((humandieroll[0] & NUMMASK) + '0');		sendtogammon((humandieroll[1] & NUMMASK) + '0');		lastmoved = HUMAN;	} else {		message(MSG, "You can't move...");		humannomove = 1;		setcursor(THINKING_CUR);		sleep(2);		message(MSG, "Thinking...");		sendtogammon(CANTMOVE);		state = THINKING;		if (logfp != NULL)			fprintf(logfp, "Human: (%d, %d) Can't move.\n", humandieroll[0], humandieroll[1]);	}}findmaxrolls(movesdone)int movesdone;{	int point, roll;	if (boardcopy[BAR] > 0) {		for (roll = 0; roll < numdice; roll++) {			if (dicecopy[roll] & ROLLUSED)				continue;			if (boardcopy[dicecopy[roll]] != BLOCKED) {				boardcopy[dicecopy[roll]]++;				boardcopy[BAR]--;				dicecopy[roll] |= ROLLUSED;				if (++movesdone > maxmoves)					maxmoves = movesdone;				if (--rollsleft == 0)					return(1);				if (findmaxrolls(movesdone))					return(1);				dicecopy[roll] &= ~ROLLUSED;				boardcopy[dicecopy[roll]]--;				boardcopy[BAR]++;				rollsleft++;				movesdone--;			}		}		if (boardcopy[BAR] > 0)			return(0);	}	for (point = 1; point <= 24; point++) {		if (boardcopy[point] <= 0)			continue;		for (roll = 0; roll < numdice; roll++) {			if (dicecopy[roll] & ROLLUSED)				continue;			if (dicecopy[roll] + point >= 25) {				int c;				for (c = 1; c < 24; c++)					if (boardcopy[c] > 0)						break;				if (c < 19)					continue;				if (dicecopy[roll] + point > 25 && point != c)					continue;				boardcopy[HOME]++;			} else if (boardcopy[dicecopy[roll] + point] != BLOCKED) {				boardcopy[dicecopy[roll] + point]++;			} else {				continue;			}			boardcopy[point]--;			dicecopy[roll] |= ROLLUSED;			if (++movesdone > maxmoves)				maxmoves = movesdone;			if (--rollsleft == 0)				return(1);			if (findmaxrolls(movesdone))				return(1);			dicecopy[roll] &= ~ROLLUSED;			if (dicecopy[roll] + point >= 25)				boardcopy[HOME]--;			else				boardcopy[dicecopy[roll] + point]--;			boardcopy[point]++;			rollsleft++;			movesdone--;		}	}	return(0);}endhumanturn(){	int c;	if (humanboard[HOME] == 15) {		if (computerboard[BAR] > 0) {			win(HUMAN, BACKGAMMON);		} else {			for (c = 1; c < 25; c++)				if (computerboard[c] > 0)					break;			if (c <= 6)				win(HUMAN, BACKGAMMON);			else if (computerboard[HOME] == 0)				win(HUMAN, GAMMON);			else				win(HUMAN, STRAIGHT);		}	} else {		sendhumanmove();		message(MSG, "Thinking...");		state = THINKING;		setcursor(THINKING_CUR);	}}undoonemove(){	if (movesmade == 0)		return;	movesmade--;	movepiece(humanmoves[movesmade][TO], humanmoves[movesmade][FROM], HUMAN);	if (humanmoves[movesmade][HITBLOT])		movepiece(BAR, humanmoves[movesmade][TO], COMPUTER);	/* painstakingly find which roll was used and reclaim it */	if ((humandieroll[0] & NUMMASK) == (humandieroll[1] & NUMMASK)) {		if (humandieroll[1] & SECONDROLLUSED) {			humandieroll[1] &= ~SECONDROLLUSED;		} else if (humandieroll[1] & ROLLUSED) {			humandieroll[1] &= ~ROLLUSED;		} else if (humandieroll[0] & SECONDROLLUSED) {			humandieroll[0] &= ~SECONDROLLUSED;		} else {			humandieroll[0] &= ~ROLLUSED;		}	} else {		if ((humandieroll[0] & NUMMASK) == (humanmoves[movesmade][DIEUSED] & ~INTERMED)) {			humandieroll[0] &= ~ROLLUSED;		} else {			humandieroll[1] &= ~ROLLUSED;		}	}	if (movesmade && (humanmoves[movesmade-1][DIEUSED] & INTERMED))		undoonemove();}undowholemove(){	while (movesmade)		undoonemove();}sendhumanmove(){	int c;	for (c = 0; c < movesmade; c++) {		if (c > 0)			sendtogammon(',');		if (humanmoves[c][FROM] == BAR) {			sendtogammon('B');		} else {			if (humanmoves[c][FROM] > 9)				sendtogammon(humanmoves[c][FROM] / 10 + '0');			sendtogammon(humanmoves[c][FROM] % 10 + '0');		}		sendtogammon('-');		if (humanmoves[c][TO] == HOME) {			sendtogammon('H');		} else {			if (humanmoves[c][TO] > 9)				sendtogammon(humanmoves[c][TO] / 10 + '0');			sendtogammon(humanmoves[c][TO] % 10 + '0');		}	}	sendtogammon('\n');	if (logfp != NULL) {		fprintf(logfp, "Human: (%d, %d) ", humandieroll[0] & NUMMASK, humandieroll[1] & NUMMASK);		for (c = 0; c < movesmade; c++) {			if (c > 0)				fprintf(logfp, ", ");			fprintf(logfp, "%d%c%d", humanmoves[c][FROM],				humanmoves[c][HITBLOT] ? 'x' : '-',				humanmoves[c][TO]);		}		putc('\n', logfp);	}}showlasthumanmove(){	int index;	if (movesmade == 0) {		message(ERR, "Nobody has moved yet!");		return;	}	if (!humannomove) {		for (index = 0; index < movesmade; index++) {			movepiece(humanmoves[index][TO], humanmoves[index][FROM], HUMAN);			if (humanmoves[index][HITBLOT])				movepiece(BAR, humanmoves[index][TO], COMPUTER);		}	}	if (dicedisplayed == COMPUTER)		showlastdice();	sleep(2);	if (!humannomove) {		for (index--; index >= 0; index--) {			if (humanmoves[index][HITBLOT])				movepiece(humanmoves[index][TO], BAR, COMPUTER);			movepiece(humanmoves[index][FROM], humanmoves[index][TO], HUMAN);		}	}	if (dicedisplayed == COMPUTER)		showlastdice();}clearintermediatepnts(){	int i;	for (i = 0; i < 3; i++)		intpnts[i][0] = intpnts[i][1] = 0;	intcntr = 0;	rollcntr = 0;}addintermediatepnt(point, hitblot)int point, hitblot;{	intpnts[intcntr][0] = point;	intpnts[intcntr][1] = hitblot;	intcntr++;}