khet/src/game.c

/* -*- c-basic-offset: 4 -*- */

#include <assert.h>
#include <stdlib.h>

#include "net.h"
#include "game.h"

pieceinfo_t pieceinfo[] = {
    { // NONE
	.num = 0,
	.name = "" },
    { 
	.num = 1,
        .name = "pharao" },
    { // DJHED
	.num = 2,
        .name = "djhed" },
    { // PYRAMID
	.num = 7,
	.name = "pyramid" },
    { // OBELISK
	.num = 4,
	.name = "obelisk" },
    { // OBELISK2
	.num = 0,
	.name = "stacked obelisk" },
};

sideinfo_t sideinfo[] = {
    { .ch = '.', .name = "silver" },
    { .ch = '=', .name = "red" }
};

char classic_setup[] =
    "H40" // PHARAO
    "E40E51" // DJHED
    "H22G73E22D21E91D92C32" // PYRAMID
    "H30H30H50H50" // OBELISK
    ;

int
laser_at(game_t *game, int x, int y)
{
    return game->laser_pos[0] == x && game->laser_pos[1] == y;
}

int
laser(game_t *game, int side) {
#define lreturn(v) do { retval=(v); goto ret; } while (0);
    int x, y, dir;
    int ddir;
    int retval;

    /*
      dir:
        0
      3 X 1
        2
     */

    net_all_printf("LASER (%s)\n", sideinfo[side].name);

    assert(side == 0 || side == 1);
    switch (side) {
    case 0:
	x=9; y=7; dir=0;
	break;
    case 1:
	x=0; y=0; dir=2;
	break;
    }
  
    for (;;) {
	net_all_printf("pos: (%d,%d)\n", y, x);
	switch (game->board[x][y].piece) {
	case NONE:
	    break;
	case PHARAO:
            game->last_hit = game->board[x][y];
	    lreturn(SILVER_WINS + 1-game->board[x][y].side); /* GAME OVER */
	case OBELISK2:
            game->last_hit = game->board[x][y];
	    game->board[x][y].piece = OBELISK;
	    lreturn(L_PIECE);
	case OBELISK:
            game->last_hit = game->board[x][y];
	    game->board[x][y].piece = NONE;
	    lreturn(L_PIECE);
	case DJHED:
	    ddir = (game->board[x][y].dir - dir) & 3;
	    dir=(dir + 1 - 2*(ddir & 1)) & 3;
	    break;
	case PYRAMID:
	    ddir = (game->board[x][y].dir - dir) & 3;
	    if (ddir & 2) {
		game->last_hit = game->board[x][y];
		game->board[x][y].piece = NONE;
		lreturn(L_PIECE);
	    }
	    dir=(dir + 1 - 2*(ddir & 1)) & 3;
	    break;
	}
	switch (dir & 3) {
	case 0: y--;
	    if (y<0) lreturn(L_WALL);
	    break;
	case 1: x++;
	    if (x>BOARD_WIDTH-1) lreturn(L_WALL);
	    break;
	case 2: y++;
	    if (y>BOARD_HEIGHT-1) lreturn(L_WALL);
	    break;
	case 3: x--;
	    if (x<0) lreturn(L_WALL);
break;
	}
    }

ret:
    game->laser_pos[0] = x;
    game->laser_pos[1] = y;
    return retval;
}

int
movable(game_t *game, int row, int col, int side)
{
    return
	row>=0 && row<BOARD_HEIGHT &&
	col>=0 && col<BOARD_WIDTH &&
	game->board[col][row].piece != NONE &&
	game->board[col][row].side == side;
}

int
rotate(game_t *game, int side, int row, int col, rot_t dir)
{
    int incr;
    
    if (!movable(game, row, col, side))
	return E_ILLEGAL_MOVE;

    assert(dir==R_CW || dir==R_CCW);

    incr = dir==R_CW ? 1 : -1;
    game->board[col][row].dir = (game->board[col][row].dir + incr) & 3;
    return HUGE_SUCCESS;
}

int
move(game_t *game, int side, int row, int col, int dir, int flags) {
    if (!movable(game, row, col, side))
	return E_ILLEGAL_MOVE;

    /* dir =
       0 1 2
       7 X 3
       6 5 4
    */

    assert((dir>=0) || (dir<=7));
    int nrow = row - (dir<3) + ((dir>3) && (dir<7));
    int ncol = col + ((dir>1) && (dir<5)) - ((dir<1) || (dir>5));
    if ((ncol<0) || (ncol>9) || (nrow<0) || (nrow>7))
	return E_ILLEGAL_MOVE;
  
    if (flags & F_SPLIT) {
	if (game->board[ncol][nrow].piece || (game->board[col][row].piece != OBELISK2))
	    return E_ILLEGAL_MOVE;
	game->board[col][row].piece = OBELISK;
	game->board[ncol][nrow].piece = OBELISK;
	game->board[ncol][nrow].side = game->board[col][row].side;
	return HUGE_SUCCESS;
    }
  
    if (game->board[ncol][nrow].piece &&
	!((game->board[col][row].piece == DJHED) &&
	  ((game->board[ncol][nrow].piece != DJHED) &&
	   (game->board[ncol][nrow].piece != PHARAO))))
	return E_ILLEGAL_MOVE;

    struct square tmp;
    tmp = game->board[ncol][nrow];
    game->board[ncol][nrow] = game->board[col][row];
    game->board[col][row] = tmp;
  
    return HUGE_SUCCESS;
}

void
place(game_t *game, int row, int col, int piece, int side, int dir)
{
    if (game->board[col][row].piece == OBELISK &&
	game->board[col][row].side == side &&
	piece == OBELISK) {
	piece = OBELISK2;
    } else if (game->board[col][row].piece != NONE &&
	       piece != NONE) {
	fprintf(stderr, "error: trying to place a piece on a non-empty square\n");
	exit(EXIT_FAILURE);
    }

    game->board[col][row].piece = piece;
    game->board[col][row].side = side;
    game->board[col][row].dir = dir;
}

void
clear_board(game_t *game)
{
    int i, j;
    for (i = 0; i < BOARD_HEIGHT; i++)
	for (j = 0; j < BOARD_WIDTH; j++)
	    place(game, i, j, 0, 0, 0);
}

void
setup_board_place_piece(game_t *game, int piece, int side, char *place_desc)
{
    int row, col, dir;

    row = place_desc[0]-'A';
    col = place_desc[1]-'0';
    dir = place_desc[2]-'0';

    if (side == 1) {
	row = BOARD_HEIGHT-row-1;
	col = BOARD_WIDTH-col-1;
	dir = (dir+2)&3;
    }

    place(game, row, col, piece, side, dir);
}

void
setup_board(game_t *game, char *desc)
{
    int side, piece, num, i;

    clear_board(game);

    for (side = 0; side < 2; side++) {
	i = 0;
	for (piece = 0; piece < N_PIECE_TYPES; piece++) {
	    for (num = 0; num < pieceinfo[piece].num; num++) {
		setup_board_place_piece(game, piece, side,
					&desc[i*3]);
		i++;
	    }
	}
    }
}

void
init_game(game_t *game)
{
    game->move = 0;
    game->winner = -1;
    game->laser_pos[0] = game->laser_pos[1] = -1;
    clear_board(game);
}