[sgt/puzzles] / sixteen.c

/*
 * sixteen.c: `16-puzzle', a sliding-tiles jigsaw which differs
 * from the 15-puzzle in that you toroidally rotate a row or column
 * at a time.
 */

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <assert.h>
#include <ctype.h>
#include <math.h>

#include "puzzles.h"

const char *const game_name = "Sixteen";
const char *const game_winhelp_topic = "games.sixteen";
const int game_can_configure = TRUE;

#define TILE_SIZE 48
#define BORDER    TILE_SIZE            /* big border to fill with arrows */
#define HIGHLIGHT_WIDTH (TILE_SIZE / 20)
#define COORD(x)  ( (x) * TILE_SIZE + BORDER )
#define FROMCOORD(x)  ( ((x) - BORDER + 2*TILE_SIZE) / TILE_SIZE - 2 )

#define ANIM_TIME 0.13F
#define FLASH_FRAME 0.13F

#define X(state, i) ( (i) % (state)->w )
#define Y(state, i) ( (i) / (state)->w )
#define C(state, x, y) ( (y) * (state)->w + (x) )

enum {
    COL_BACKGROUND,
    COL_TEXT,
    COL_HIGHLIGHT,
    COL_LOWLIGHT,
    NCOLOURS
};

struct game_params {
    int w, h;
};

struct game_state {
    int w, h, n;
    int *tiles;
    int completed;
    int movecount;
    int last_movement_sense;
};

game_params *default_params(void)
{
    game_params *ret = snew(game_params);

    ret->w = ret->h = 4;

    return ret;
}

int game_fetch_preset(int i, char **name, game_params **params)
{
    game_params *ret;
    int w, h;
    char buf[80];

    switch (i) {
      case 0: w = 3, h = 3; break;
      case 1: w = 4, h = 3; break;
      case 2: w = 4, h = 4; break;
      case 3: w = 5, h = 4; break;
      case 4: w = 5, h = 5; break;
      default: return FALSE;
    }

    sprintf(buf, "%dx%d", w, h);
    *name = dupstr(buf);
    *params = ret = snew(game_params);
    ret->w = w;
    ret->h = h;
    return TRUE;
}

void free_params(game_params *params)
{
    sfree(params);
}

game_params *dup_params(game_params *params)
{
    game_params *ret = snew(game_params);
    *ret = *params;		       /* structure copy */
    return ret;
}

game_params *decode_params(char const *string)
{
    game_params *ret = default_params();

    ret->w = ret->h = atoi(string);
    while (*string && isdigit(*string)) string++;
    if (*string == 'x') {
        string++;
        ret->h = atoi(string);
    }

    return ret;
}

char *encode_params(game_params *params)
{
    char data[256];

    sprintf(data, "%dx%d", params->w, params->h);

    return dupstr(data);
}

config_item *game_configure(game_params *params)
{
    config_item *ret;
    char buf[80];

    ret = snewn(3, config_item);

    ret[0].name = "Width";
    ret[0].type = C_STRING;
    sprintf(buf, "%d", params->w);
    ret[0].sval = dupstr(buf);
    ret[0].ival = 0;

    ret[1].name = "Height";
    ret[1].type = C_STRING;
    sprintf(buf, "%d", params->h);
    ret[1].sval = dupstr(buf);
    ret[1].ival = 0;

    ret[2].name = NULL;
    ret[2].type = C_END;
    ret[2].sval = NULL;
    ret[2].ival = 0;

    return ret;
}

game_params *custom_params(config_item *cfg)
{
    game_params *ret = snew(game_params);

    ret->w = atoi(cfg[0].sval);
    ret->h = atoi(cfg[1].sval);

    return ret;
}

char *validate_params(game_params *params)
{
    if (params->w < 2 && params->h < 2)
	return "Width and height must both be at least two";

    return NULL;
}

int perm_parity(int *perm, int n)
{
    int i, j, ret;

    ret = 0;

    for (i = 0; i < n-1; i++)
        for (j = i+1; j < n; j++)
            if (perm[i] > perm[j])
                ret = !ret;

    return ret;
}

char *new_game_seed(game_params *params, random_state *rs)
{
    int stop, n, i, x;
    int x1, x2, p1, p2;
    int *tiles, *used;
    char *ret;
    int retlen;

    n = params->w * params->h;

    tiles = snewn(n, int);
    used = snewn(n, int);

    for (i = 0; i < n; i++) {
        tiles[i] = -1;
        used[i] = FALSE;
    }

    /*
     * If both dimensions are odd, there is a parity constraint.
     */
    if (params->w & params->h & 1)
        stop = 2;
    else
        stop = 0;

    /*
     * Place everything except (possibly) the last two tiles.
     */
    for (x = 0, i = n; i > stop; i--) {
        int k = i > 1 ? random_upto(rs, i) : 0;
        int j;

        for (j = 0; j < n; j++)
            if (!used[j] && (k-- == 0))
                break;

        assert(j < n && !used[j]);
        used[j] = TRUE;

        while (tiles[x] >= 0)
            x++;
        assert(x < n);
        tiles[x] = j;
    }

    if (stop) {
        /*
         * Find the last two locations, and the last two pieces.
         */
        while (tiles[x] >= 0)
            x++;
        assert(x < n);
        x1 = x;
        x++;
        while (tiles[x] >= 0)
            x++;
        assert(x < n);
        x2 = x;

        for (i = 0; i < n; i++)
            if (!used[i])
                break;
        p1 = i;
        for (i = p1+1; i < n; i++)
            if (!used[i])
                break;
        p2 = i;

        /*
         * Try the last two tiles one way round. If that fails, swap
         * them.
         */
        tiles[x1] = p1;
        tiles[x2] = p2;
        if (perm_parity(tiles, n) != 0) {
            tiles[x1] = p2;
            tiles[x2] = p1;
            assert(perm_parity(tiles, n) == 0);
        }
    }

    /*
     * Now construct the game seed, by describing the tile array as
     * a simple sequence of comma-separated integers.
     */
    ret = NULL;
    retlen = 0;
    for (i = 0; i < n; i++) {
        char buf[80];
        int k;

        k = sprintf(buf, "%d,", tiles[i]+1);

        ret = sresize(ret, retlen + k + 1, char);
        strcpy(ret + retlen, buf);
        retlen += k;
    }
    ret[retlen-1] = '\0';              /* delete last comma */

    sfree(tiles);
    sfree(used);

    return ret;
}


char *validate_seed(game_params *params, char *seed)
{
    char *p, *err;
    int i, area;
    int *used;

    area = params->w * params->h;
    p = seed;
    err = NULL;

    used = snewn(area, int);
    for (i = 0; i < area; i++)
	used[i] = FALSE;

    for (i = 0; i < area; i++) {
	char *q = p;
	int n;

	if (*p < '0' || *p > '9') {
	    err = "Not enough numbers in string";
	    goto leave;
	}
	while (*p >= '0' && *p <= '9')
	    p++;
	if (i < area-1 && *p != ',') {
	    err = "Expected comma after number";
	    goto leave;
	}
	else if (i == area-1 && *p) {
	    err = "Excess junk at end of string";
	    goto leave;
	}
	n = atoi(q);
	if (n < 1 || n > area) {
	    err = "Number out of range";
	    goto leave;
	}
	if (used[n-1]) {
	    err = "Number used twice";
	    goto leave;
	}
	used[n-1] = TRUE;

	if (*p) p++;		       /* eat comma */
    }

    leave:
    sfree(used);
    return err;
}

game_state *new_game(game_params *params, char *seed)
{
    game_state *state = snew(game_state);
    int i;
    char *p;

    state->w = params->w;
    state->h = params->h;
    state->n = params->w * params->h;
    state->tiles = snewn(state->n, int);

    p = seed;
    i = 0;
    for (i = 0; i < state->n; i++) {
        assert(*p);
        state->tiles[i] = atoi(p);
        while (*p && *p != ',')
            p++;
        if (*p) p++;                   /* eat comma */
    }
    assert(!*p);

    state->completed = state->movecount = 0;
    state->last_movement_sense = 0;

    return state;
}

game_state *dup_game(game_state *state)
{
    game_state *ret = snew(game_state);

    ret->w = state->w;
    ret->h = state->h;
    ret->n = state->n;
    ret->tiles = snewn(state->w * state->h, int);
    memcpy(ret->tiles, state->tiles, state->w * state->h * sizeof(int));
    ret->completed = state->completed;
    ret->movecount = state->movecount;
    ret->last_movement_sense = state->last_movement_sense;

    return ret;
}

void free_game(game_state *state)
{
    sfree(state);
}

game_ui *new_ui(game_state *state)
{
    return NULL;
}

void free_ui(game_ui *ui)
{
}

game_state *make_move(game_state *from, game_ui *ui, int x, int y, int button)
{
    int cx, cy;
    int dx, dy, tx, ty, n;
    game_state *ret;

    if (button != LEFT_BUTTON && button != RIGHT_BUTTON)
        return NULL;

    cx = FROMCOORD(x);
    cy = FROMCOORD(y);
    if (cx == -1 && cy >= 0 && cy < from->h)
        n = from->w, dx = +1, dy = 0;
    else if (cx == from->w && cy >= 0 && cy < from->h)
        n = from->w, dx = -1, dy = 0;
    else if (cy == -1 && cx >= 0 && cx < from->w)
        n = from->h, dy = +1, dx = 0;
    else if (cy == from->h && cx >= 0 && cx < from->w)
        n = from->h, dy = -1, dx = 0;
    else
        return NULL;                   /* invalid click location */

    /* reverse direction if right hand button is pressed */
    if (button == RIGHT_BUTTON)
    {
        dx = -dx; if (dx) cx = from->w - 1 - cx;
        dy = -dy; if (dy) cy = from->h - 1 - cy;
    }

    ret = dup_game(from);

    do {
        cx += dx;
        cy += dy;
        tx = (cx + dx + from->w) % from->w;
        ty = (cy + dy + from->h) % from->h;
        ret->tiles[C(ret, cx, cy)] = from->tiles[C(from, tx, ty)];
    } while (--n > 0);

    ret->movecount++;

    ret->last_movement_sense = -(dx+dy);

    /*
     * See if the game has been completed.
     */
    if (!ret->completed) {
        ret->completed = ret->movecount;
        for (n = 0; n < ret->n; n++)
            if (ret->tiles[n] != n+1)
                ret->completed = FALSE;
    }

    return ret;
}

/* ----------------------------------------------------------------------
 * Drawing routines.
 */

struct game_drawstate {
    int started;
    int w, h, bgcolour;
    int *tiles;
};

void game_size(game_params *params, int *x, int *y)
{
    *x = TILE_SIZE * params->w + 2 * BORDER;
    *y = TILE_SIZE * params->h + 2 * BORDER;
}

float *game_colours(frontend *fe, game_state *state, int *ncolours)
{
    float *ret = snewn(3 * NCOLOURS, float);
    int i;
    float max;

    frontend_default_colour(fe, &ret[COL_BACKGROUND * 3]);

    /*
     * Drop the background colour so that the highlight is
     * noticeably brighter than it while still being under 1.
     */
    max = ret[COL_BACKGROUND*3];
    for (i = 1; i < 3; i++)
        if (ret[COL_BACKGROUND*3+i] > max)
            max = ret[COL_BACKGROUND*3+i];
    if (max * 1.2F > 1.0F) {
        for (i = 0; i < 3; i++)
            ret[COL_BACKGROUND*3+i] /= (max * 1.2F);
    }

    for (i = 0; i < 3; i++) {
        ret[COL_HIGHLIGHT * 3 + i] = ret[COL_BACKGROUND * 3 + i] * 1.2F;
        ret[COL_LOWLIGHT * 3 + i] = ret[COL_BACKGROUND * 3 + i] * 0.8F;
        ret[COL_TEXT * 3 + i] = 0.0;
    }

    *ncolours = NCOLOURS;
    return ret;
}

game_drawstate *game_new_drawstate(game_state *state)
{
    struct game_drawstate *ds = snew(struct game_drawstate);
    int i;

    ds->started = FALSE;
    ds->w = state->w;
    ds->h = state->h;
    ds->bgcolour = COL_BACKGROUND;
    ds->tiles = snewn(ds->w*ds->h, int);
    for (i = 0; i < ds->w*ds->h; i++)
        ds->tiles[i] = -1;

    return ds;
}

void game_free_drawstate(game_drawstate *ds)
{
    sfree(ds->tiles);
    sfree(ds);
}

static void draw_tile(frontend *fe, game_state *state, int x, int y,
                      int tile, int flash_colour)
{
    if (tile == 0) {
        draw_rect(fe, x, y, TILE_SIZE, TILE_SIZE,
                  flash_colour);
    } else {
        int coords[6];
        char str[40];

        coords[0] = x + TILE_SIZE - 1;
        coords[1] = y + TILE_SIZE - 1;
        coords[2] = x + TILE_SIZE - 1;
        coords[3] = y;
        coords[4] = x;
        coords[5] = y + TILE_SIZE - 1;
        draw_polygon(fe, coords, 3, TRUE, COL_LOWLIGHT);
        draw_polygon(fe, coords, 3, FALSE, COL_LOWLIGHT);

        coords[0] = x;
        coords[1] = y;
        draw_polygon(fe, coords, 3, TRUE, COL_HIGHLIGHT);
        draw_polygon(fe, coords, 3, FALSE, COL_HIGHLIGHT);

        draw_rect(fe, x + HIGHLIGHT_WIDTH, y + HIGHLIGHT_WIDTH,
                  TILE_SIZE - 2*HIGHLIGHT_WIDTH, TILE_SIZE - 2*HIGHLIGHT_WIDTH,
                  flash_colour);

        sprintf(str, "%d", tile);
        draw_text(fe, x + TILE_SIZE/2, y + TILE_SIZE/2,
                  FONT_VARIABLE, TILE_SIZE/3, ALIGN_VCENTRE | ALIGN_HCENTRE,
                  COL_TEXT, str);
    }
    draw_update(fe, x, y, TILE_SIZE, TILE_SIZE);
}

static void draw_arrow(frontend *fe, int x, int y, int xdx, int xdy)
{
    int coords[14];
    int ydy = -xdx, ydx = xdy;

#define POINT(n, xx, yy) ( \
    coords[2*(n)+0] = x + (xx)*xdx + (yy)*ydx, \
    coords[2*(n)+1] = y + (xx)*xdy + (yy)*ydy)

    POINT(0, TILE_SIZE / 2, 3 * TILE_SIZE / 4);   /* top of arrow */
    POINT(1, 3 * TILE_SIZE / 4, TILE_SIZE / 2);   /* right corner */
    POINT(2, 5 * TILE_SIZE / 8, TILE_SIZE / 2);   /* right concave */
    POINT(3, 5 * TILE_SIZE / 8, TILE_SIZE / 4);   /* bottom right */
    POINT(4, 3 * TILE_SIZE / 8, TILE_SIZE / 4);   /* bottom left */
    POINT(5, 3 * TILE_SIZE / 8, TILE_SIZE / 2);   /* left concave */
    POINT(6,     TILE_SIZE / 4, TILE_SIZE / 2);   /* left corner */

    draw_polygon(fe, coords, 7, TRUE, COL_LOWLIGHT);
    draw_polygon(fe, coords, 7, FALSE, COL_TEXT);
}

void game_redraw(frontend *fe, game_drawstate *ds, game_state *oldstate,
                 game_state *state, int dir, game_ui *ui,
                 float animtime, float flashtime)
{
    int i, bgcolour;

    if (flashtime > 0) {
        int frame = (int)(flashtime / FLASH_FRAME);
        bgcolour = (frame % 2 ? COL_LOWLIGHT : COL_HIGHLIGHT);
    } else
        bgcolour = COL_BACKGROUND;

    if (!ds->started) {
        int coords[6];

	draw_rect(fe, 0, 0,
		  TILE_SIZE * state->w + 2 * BORDER,
		  TILE_SIZE * state->h + 2 * BORDER, COL_BACKGROUND);
	draw_update(fe, 0, 0,
		    TILE_SIZE * state->w + 2 * BORDER,
		    TILE_SIZE * state->h + 2 * BORDER);

        /*
         * Recessed area containing the whole puzzle.
         */
        coords[0] = COORD(state->w) + HIGHLIGHT_WIDTH - 1;
        coords[1] = COORD(state->h) + HIGHLIGHT_WIDTH - 1;
        coords[2] = COORD(state->w) + HIGHLIGHT_WIDTH - 1;
        coords[3] = COORD(0) - HIGHLIGHT_WIDTH;
        coords[4] = COORD(0) - HIGHLIGHT_WIDTH;
        coords[5] = COORD(state->h) + HIGHLIGHT_WIDTH - 1;
        draw_polygon(fe, coords, 3, TRUE, COL_HIGHLIGHT);
        draw_polygon(fe, coords, 3, FALSE, COL_HIGHLIGHT);

        coords[1] = COORD(0) - HIGHLIGHT_WIDTH;
        coords[0] = COORD(0) - HIGHLIGHT_WIDTH;
        draw_polygon(fe, coords, 3, TRUE, COL_LOWLIGHT);
        draw_polygon(fe, coords, 3, FALSE, COL_LOWLIGHT);

        /*
         * Arrows for making moves.
         */
        for (i = 0; i < state->w; i++) {
            draw_arrow(fe, COORD(i), COORD(0), +1, 0);
            draw_arrow(fe, COORD(i+1), COORD(state->h), -1, 0);
        }
        for (i = 0; i < state->h; i++) {
            draw_arrow(fe, COORD(state->w), COORD(i), 0, +1);
            draw_arrow(fe, COORD(0), COORD(i+1), 0, -1);
        }

        ds->started = TRUE;
    }

    /*
     * Now draw each tile.
     */

    clip(fe, COORD(0), COORD(0), TILE_SIZE*state->w, TILE_SIZE*state->h);

    for (i = 0; i < state->n; i++) {
	int t, t0;
	/*
	 * Figure out what should be displayed at this
	 * location. It's either a simple tile, or it's a
	 * transition between two tiles (in which case we say
	 * -1 because it must always be drawn).
	 */

	if (oldstate && oldstate->tiles[i] != state->tiles[i])
	    t = -1;
	else
	    t = state->tiles[i];

	t0 = t;

	if (ds->bgcolour != bgcolour ||   /* always redraw when flashing */
	    ds->tiles[i] != t || ds->tiles[i] == -1 || t == -1) {
	    int x, y, x2, y2;

	    /*
	     * Figure out what to _actually_ draw, and where to
	     * draw it.
	     */
	    if (t == -1) {
		int x0, y0, x1, y1, dx, dy;
		int j;
		float c;
		int sense;

		if (dir < 0) {
		    assert(oldstate);
		    sense = -oldstate->last_movement_sense;
		} else {
		    sense = state->last_movement_sense;
		}

		t = state->tiles[i];

		/*
		 * FIXME: must be prepared to draw a double
		 * tile in some situations.
		 */

		/*
		 * Find the coordinates of this tile in the old and
		 * new states.
		 */
		x1 = COORD(X(state, i));
		y1 = COORD(Y(state, i));
		for (j = 0; j < oldstate->n; j++)
		    if (oldstate->tiles[j] == state->tiles[i])
			break;
		assert(j < oldstate->n);
		x0 = COORD(X(state, j));
		y0 = COORD(Y(state, j));

		dx = (x1 - x0);
		if (dx != 0 &&
		    dx != TILE_SIZE * sense) {
		    dx = (dx < 0 ? dx + TILE_SIZE * state->w :
			  dx - TILE_SIZE * state->w);
		    assert(abs(dx) == TILE_SIZE);
		}
		dy = (y1 - y0);
		if (dy != 0 &&
		    dy != TILE_SIZE * sense) {
		    dy = (dy < 0 ? dy + TILE_SIZE * state->h :
			  dy - TILE_SIZE * state->h);
		    assert(abs(dy) == TILE_SIZE);
		}

		c = (animtime / ANIM_TIME);
		if (c < 0.0F) c = 0.0F;
		if (c > 1.0F) c = 1.0F;

		x = x0 + (int)(c * dx);
		y = y0 + (int)(c * dy);
		x2 = x1 - dx + (int)(c * dx);
		y2 = y1 - dy + (int)(c * dy);
	    } else {
		x = COORD(X(state, i));
		y = COORD(Y(state, i));
		x2 = y2 = -1;
	    }

	    draw_tile(fe, state, x, y, t, bgcolour);
	    if (x2 != -1 || y2 != -1)
		draw_tile(fe, state, x2, y2, t, bgcolour);
	}
	ds->tiles[i] = t0;
    }

    unclip(fe);

    ds->bgcolour = bgcolour;

    /*
     * Update the status bar.
     */
    {
	char statusbuf[256];

        /*
         * Don't show the new status until we're also showing the
         * new _state_ - after the game animation is complete.
         */
        if (oldstate)
            state = oldstate;

	sprintf(statusbuf, "%sMoves: %d",
		(state->completed ? "COMPLETED! " : ""),
		(state->completed ? state->completed : state->movecount));

	status_bar(fe, statusbuf);
    }
}

float game_anim_length(game_state *oldstate, game_state *newstate, int dir)
{
    return ANIM_TIME;
}

float game_flash_length(game_state *oldstate, game_state *newstate, int dir)
{
    if (!oldstate->completed && newstate->completed)
        return 2 * FLASH_FRAME;
    else
        return 0.0F;
}

int game_wants_statusbar(void)
{
    return TRUE;
}
Commit	Line	Data
4efb3868	1	/*
	2	* sixteen.c: `16-puzzle', a sliding-tiles jigsaw which differs
	3	* from the 15-puzzle in that you toroidally rotate a row or column
	4	* at a time.
	5	*/
	6
	7	#include <stdio.h>
	8	#include <stdlib.h>
	9	#include <string.h>
	10	#include <assert.h>
b0e26073	11	#include <ctype.h>
4efb3868	12	#include <math.h>
	13
	14	#include "puzzles.h"
	15
	16	const char *const game_name = "Sixteen";
e91825f8	17	const char *const game_winhelp_topic = "games.sixteen";
c8230524	18	const int game_can_configure = TRUE;
4efb3868	19
	20	#define TILE_SIZE 48
	21	#define BORDER TILE_SIZE /* big border to fill with arrows */
	22	#define HIGHLIGHT_WIDTH (TILE_SIZE / 20)
	23	#define COORD(x) ( (x) * TILE_SIZE + BORDER )
	24	#define FROMCOORD(x) ( ((x) - BORDER + 2*TILE_SIZE) / TILE_SIZE - 2 )
	25
8c1fd974	26	#define ANIM_TIME 0.13F
8c1fd974	27	#define FLASH_FRAME 0.13F
4efb3868	28
	29	#define X(state, i) ( (i) % (state)->w )
	30	#define Y(state, i) ( (i) / (state)->w )
	31	#define C(state, x, y) ( (y) * (state)->w + (x) )
	32
	33	enum {
	34	COL_BACKGROUND,
	35	COL_TEXT,
	36	COL_HIGHLIGHT,
	37	COL_LOWLIGHT,
	38	NCOLOURS
	39	};
	40
	41	struct game_params {
	42	int w, h;
	43	};
	44
	45	struct game_state {
	46	int w, h, n;
	47	int *tiles;
	48	int completed;
fd1a1a2b	49	int movecount;
c8230524	50	int last_movement_sense;
4efb3868	51	};
	52
	53	game_params *default_params(void)
	54	{
	55	game_params *ret = snew(game_params);
	56
	57	ret->w = ret->h = 4;
	58
	59	return ret;
	60	}
	61
	62	int game_fetch_preset(int i, char name, game_params params)
	63	{
	64	game_params *ret;
	65	int w, h;
	66	char buf[80];
	67
	68	switch (i) {
	69	case 0: w = 3, h = 3; break;
	70	case 1: w = 4, h = 3; break;
	71	case 2: w = 4, h = 4; break;
	72	case 3: w = 5, h = 4; break;
	73	case 4: w = 5, h = 5; break;
	74	default: return FALSE;
	75	}
	76
	77	sprintf(buf, "%dx%d", w, h);
	78	*name = dupstr(buf);
	79	*params = ret = snew(game_params);
	80	ret->w = w;
	81	ret->h = h;
	82	return TRUE;
	83	}
	84
	85	void free_params(game_params *params)
	86	{
	87	sfree(params);
	88	}
	89
	90	game_params dup_params(game_params params)
	91	{
	92	game_params *ret = snew(game_params);
	93	ret = params; /* structure copy */
	94	return ret;
	95	}
	96
b0e26073	97	game_params decode_params(char const string)
	98	{
	99	game_params *ret = default_params();
	100
	101	ret->w = ret->h = atoi(string);
	102	while (string && isdigit(string)) string++;
	103	if (*string == 'x') {
	104	string++;
	105	ret->h = atoi(string);
	106	}
	107
	108	return ret;
	109	}
	110
	111	char encode_params(game_params params)
	112	{
	113	char data[256];
	114
	115	sprintf(data, "%dx%d", params->w, params->h);
	116
	117	return dupstr(data);
	118	}
	119
c8230524	120	config_item game_configure(game_params params)
	121	{
	122	config_item *ret;
	123	char buf[80];
	124
	125	ret = snewn(3, config_item);
	126
	127	ret[0].name = "Width";
95709966	128	ret[0].type = C_STRING;
c8230524	129	sprintf(buf, "%d", params->w);
	130	ret[0].sval = dupstr(buf);
	131	ret[0].ival = 0;
	132
	133	ret[1].name = "Height";
95709966	134	ret[1].type = C_STRING;
c8230524	135	sprintf(buf, "%d", params->h);
	136	ret[1].sval = dupstr(buf);
	137	ret[1].ival = 0;
	138
	139	ret[2].name = NULL;
95709966	140	ret[2].type = C_END;
c8230524	141	ret[2].sval = NULL;
	142	ret[2].ival = 0;
	143
	144	return ret;
	145	}
	146
	147	game_params custom_params(config_item cfg)
	148	{
	149	game_params *ret = snew(game_params);
	150
	151	ret->w = atoi(cfg[0].sval);
	152	ret->h = atoi(cfg[1].sval);
	153
	154	return ret;
	155	}
	156
	157	char validate_params(game_params params)
	158	{
	159	if (params->w < 2 && params->h < 2)
	160	return "Width and height must both be at least two";
	161
	162	return NULL;
	163	}
	164
4efb3868	165	int perm_parity(int *perm, int n)
	166	{
	167	int i, j, ret;
	168
	169	ret = 0;
	170
	171	for (i = 0; i < n-1; i++)
	172	for (j = i+1; j < n; j++)
	173	if (perm[i] > perm[j])
	174	ret = !ret;
	175
	176	return ret;
	177	}
	178
48d70ca9	179	char new_game_seed(game_params params, random_state *rs)
4efb3868	180	{
	181	int stop, n, i, x;
	182	int x1, x2, p1, p2;
	183	int tiles, used;
	184	char *ret;
	185	int retlen;
	186
	187	n = params->w * params->h;
	188
	189	tiles = snewn(n, int);
	190	used = snewn(n, int);
	191
	192	for (i = 0; i < n; i++) {
	193	tiles[i] = -1;
	194	used[i] = FALSE;
	195	}
	196
	197	/*
	198	* If both dimensions are odd, there is a parity constraint.
	199	*/
	200	if (params->w & params->h & 1)
	201	stop = 2;
	202	else
	203	stop = 0;
	204
	205	/*
	206	* Place everything except (possibly) the last two tiles.
	207	*/
	208	for (x = 0, i = n; i > stop; i--) {
48d70ca9	209	int k = i > 1 ? random_upto(rs, i) : 0;
4efb3868	210	int j;
	211
	212	for (j = 0; j < n; j++)
	213	if (!used[j] && (k-- == 0))
	214	break;
	215
	216	assert(j < n && !used[j]);
	217	used[j] = TRUE;
	218
	219	while (tiles[x] >= 0)
	220	x++;
	221	assert(x < n);
	222	tiles[x] = j;
	223	}
	224
	225	if (stop) {
	226	/*
	227	* Find the last two locations, and the last two pieces.
	228	*/
	229	while (tiles[x] >= 0)
	230	x++;
	231	assert(x < n);
	232	x1 = x;
	233	x++;
	234	while (tiles[x] >= 0)
	235	x++;
	236	assert(x < n);
	237	x2 = x;
	238
	239	for (i = 0; i < n; i++)
	240	if (!used[i])
	241	break;
	242	p1 = i;
	243	for (i = p1+1; i < n; i++)
	244	if (!used[i])
	245	break;
	246	p2 = i;
	247
	248	/*
	249	* Try the last two tiles one way round. If that fails, swap
	250	* them.
	251	*/
	252	tiles[x1] = p1;
	253	tiles[x2] = p2;
	254	if (perm_parity(tiles, n) != 0) {
	255	tiles[x1] = p2;
	256	tiles[x2] = p1;
	257	assert(perm_parity(tiles, n) == 0);
	258	}
	259	}
	260
	261	/*
	262	* Now construct the game seed, by describing the tile array as
	263	* a simple sequence of comma-separated integers.
	264	*/
	265	ret = NULL;
	266	retlen = 0;
	267	for (i = 0; i < n; i++) {
	268	char buf[80];
	269	int k;
	270
	271	k = sprintf(buf, "%d,", tiles[i]+1);
	272
	273	ret = sresize(ret, retlen + k + 1, char);
274	strcpy(ret + retlen, buf);
275	retlen += k;
276	}
277	ret[retlen-1] = '\0'; /* delete last comma */
278
279	sfree(tiles);
280	sfree(used);
281
282	return ret;
283	}
284
5928817c	285
	286	char validate_seed(game_params params, char *seed)
	287	{
	288	char p, err;
	289	int i, area;
	290	int *used;
	291
	292	area = params->w * params->h;
	293	p = seed;
	294	err = NULL;
	295
	296	used = snewn(area, int);
	297	for (i = 0; i < area; i++)
	298	used[i] = FALSE;
	299
	300	for (i = 0; i < area; i++) {
	301	char *q = p;
	302	int n;
	303
	304	if (p < '0' \|\| p > '9') {
	305	err = "Not enough numbers in string";
	306	goto leave;
	307	}
	308	while (p >= '0' && p <= '9')
	309	p++;
	310	if (i < area-1 && *p != ',') {
	311	err = "Expected comma after number";
	312	goto leave;
	313	}
	314	else if (i == area-1 && *p) {
	315	err = "Excess junk at end of string";
	316	goto leave;
	317	}
	318	n = atoi(q);
	319	if (n < 1 \|\| n > area) {
	320	err = "Number out of range";
	321	goto leave;
	322	}
	323	if (used[n-1]) {
	324	err = "Number used twice";
	325	goto leave;
	326	}
	327	used[n-1] = TRUE;
	328
	329	if (p) p++; / eat comma */
	330	}
	331
	332	leave:
	333	sfree(used);
	334	return err;
	335	}
	336
4efb3868	337	game_state new_game(game_params params, char *seed)
	338	{
	339	game_state *state = snew(game_state);
	340	int i;
	341	char *p;
	342
	343	state->w = params->w;
	344	state->h = params->h;
	345	state->n = params->w * params->h;
	346	state->tiles = snewn(state->n, int);
	347
	348	p = seed;
	349	i = 0;
	350	for (i = 0; i < state->n; i++) {
	351	assert(*p);
	352	state->tiles[i] = atoi(p);
	353	while (p && p != ',')
	354	p++;
	355	if (p) p++; / eat comma */
	356	}
	357	assert(!*p);
	358
fd1a1a2b	359	state->completed = state->movecount = 0;
c8230524	360	state->last_movement_sense = 0;
4efb3868	361
	362	return state;
	363	}
	364
	365	game_state dup_game(game_state state)
	366	{
	367	game_state *ret = snew(game_state);
	368
	369	ret->w = state->w;
	370	ret->h = state->h;
	371	ret->n = state->n;
	372	ret->tiles = snewn(state->w * state->h, int);
	373	memcpy(ret->tiles, state->tiles, state->w * state->h * sizeof(int));
	374	ret->completed = state->completed;
fd1a1a2b	375	ret->movecount = state->movecount;
c8230524	376	ret->last_movement_sense = state->last_movement_sense;
4efb3868	377
	378	return ret;
	379	}
	380
	381	void free_game(game_state *state)
	382	{
	383	sfree(state);
	384	}
	385
74a4e547	386	game_ui new_ui(game_state state)
	387	{
	388	return NULL;
	389	}
	390
	391	void free_ui(game_ui *ui)
	392	{
	393	}
	394
	395	game_state make_move(game_state from, game_ui *ui, int x, int y, int button)
4efb3868	396	{
	397	int cx, cy;
	398	int dx, dy, tx, ty, n;
	399	game_state *ret;
	400
e91825f8	401	if (button != LEFT_BUTTON && button != RIGHT_BUTTON)
4efb3868	402	return NULL;
	403
	404	cx = FROMCOORD(x);
	405	cy = FROMCOORD(y);
	406	if (cx == -1 && cy >= 0 && cy < from->h)
	407	n = from->w, dx = +1, dy = 0;
	408	else if (cx == from->w && cy >= 0 && cy < from->h)
	409	n = from->w, dx = -1, dy = 0;
	410	else if (cy == -1 && cx >= 0 && cx < from->w)
	411	n = from->h, dy = +1, dx = 0;
	412	else if (cy == from->h && cx >= 0 && cx < from->w)
	413	n = from->h, dy = -1, dx = 0;
	414	else
	415	return NULL; /* invalid click location */
	416
e91825f8	417	/* reverse direction if right hand button is pressed */
	418	if (button == RIGHT_BUTTON)
	419	{
	420	dx = -dx; if (dx) cx = from->w - 1 - cx;
	421	dy = -dy; if (dy) cy = from->h - 1 - cy;
	422	}
	423
4efb3868	424	ret = dup_game(from);
	425
	426	do {
	427	cx += dx;
	428	cy += dy;
	429	tx = (cx + dx + from->w) % from->w;
	430	ty = (cy + dy + from->h) % from->h;
	431	ret->tiles[C(ret, cx, cy)] = from->tiles[C(from, tx, ty)];
	432	} while (--n > 0);
	433
fd1a1a2b	434	ret->movecount++;
fd1a1a2b	435
c8230524	436	ret->last_movement_sense = -(dx+dy);
c8230524	437
4efb3868	438	/*
	439	* See if the game has been completed.
	440	*/
	441	if (!ret->completed) {
fd1a1a2b	442	ret->completed = ret->movecount;
4efb3868	443	for (n = 0; n < ret->n; n++)
	444	if (ret->tiles[n] != n+1)
	445	ret->completed = FALSE;
	446	}
	447
	448	return ret;
	449	}
	450
	451	/* ----------------------------------------------------------------------
	452	* Drawing routines.
	453	*/
	454
	455	struct game_drawstate {
	456	int started;
	457	int w, h, bgcolour;
	458	int *tiles;
	459	};
	460
	461	void game_size(game_params params, int x, int *y)
	462	{
	463	x = TILE_SIZE params->w + 2 * BORDER;
	464	y = TILE_SIZE params->h + 2 * BORDER;
	465	}
	466
	467	float game_colours(frontend fe, game_state state, int ncolours)
	468	{
	469	float ret = snewn(3 NCOLOURS, float);
	470	int i;
	471	float max;
	472
	473	frontend_default_colour(fe, &ret[COL_BACKGROUND * 3]);
	474
	475	/*
	476	* Drop the background colour so that the highlight is
	477	* noticeably brighter than it while still being under 1.
	478	*/
	479	max = ret[COL_BACKGROUND*3];
	480	for (i = 1; i < 3; i++)
	481	if (ret[COL_BACKGROUND*3+i] > max)
	482	max = ret[COL_BACKGROUND*3+i];
	483	if (max * 1.2F > 1.0F) {
	484	for (i = 0; i < 3; i++)
	485	ret[COL_BACKGROUND3+i] /= (max 1.2F);
	486	}
	487
	488	for (i = 0; i < 3; i++) {
	489	ret[COL_HIGHLIGHT * 3 + i] = ret[COL_BACKGROUND * 3 + i] * 1.2F;
	490	ret[COL_LOWLIGHT * 3 + i] = ret[COL_BACKGROUND * 3 + i] * 0.8F;
	491	ret[COL_TEXT * 3 + i] = 0.0;
	492	}
	493
	494	*ncolours = NCOLOURS;
	495	return ret;
	496	}
	497
	498	game_drawstate game_new_drawstate(game_state state)
	499	{
	500	struct game_drawstate *ds = snew(struct game_drawstate);
	501	int i;
	502
	503	ds->started = FALSE;
	504	ds->w = state->w;
	505	ds->h = state->h;
	506	ds->bgcolour = COL_BACKGROUND;
507	ds->tiles = snewn(ds->w*ds->h, int);
508	for (i = 0; i < ds->w*ds->h; i++)
509	ds->tiles[i] = -1;
510
511	return ds;
512	}
513
514	void game_free_drawstate(game_drawstate *ds)
515	{
516	sfree(ds->tiles);
517	sfree(ds);
518	}
519
520	static void draw_tile(frontend fe, game_state state, int x, int y,
521	int tile, int flash_colour)
522	{
523	if (tile == 0) {
524	draw_rect(fe, x, y, TILE_SIZE, TILE_SIZE,
525	flash_colour);
526	} else {
527	int coords[6];
528	char str[40];
529
530	coords[0] = x + TILE_SIZE - 1;
531	coords[1] = y + TILE_SIZE - 1;
532	coords[2] = x + TILE_SIZE - 1;
533	coords[3] = y;
534	coords[4] = x;
535	coords[5] = y + TILE_SIZE - 1;
536	draw_polygon(fe, coords, 3, TRUE, COL_LOWLIGHT);
537	draw_polygon(fe, coords, 3, FALSE, COL_LOWLIGHT);
538
539	coords[0] = x;
540	coords[1] = y;
541	draw_polygon(fe, coords, 3, TRUE, COL_HIGHLIGHT);
542	draw_polygon(fe, coords, 3, FALSE, COL_HIGHLIGHT);
543
544	draw_rect(fe, x + HIGHLIGHT_WIDTH, y + HIGHLIGHT_WIDTH,
545	TILE_SIZE - 2HIGHLIGHT_WIDTH, TILE_SIZE - 2HIGHLIGHT_WIDTH,
546	flash_colour);
547
548	sprintf(str, "%d", tile);
549	draw_text(fe, x + TILE_SIZE/2, y + TILE_SIZE/2,
550	FONT_VARIABLE, TILE_SIZE/3, ALIGN_VCENTRE \| ALIGN_HCENTRE,
551	COL_TEXT, str);
552	}
553	draw_update(fe, x, y, TILE_SIZE, TILE_SIZE);
554	}
555
556	static void draw_arrow(frontend *fe, int x, int y, int xdx, int xdy)
557	{
558	int coords[14];
559	int ydy = -xdx, ydx = xdy;
560
561	#define POINT(n, xx, yy) ( \
562	coords[2(n)+0] = x + (xx)xdx + (yy)*ydx, \
563	coords[2(n)+1] = y + (xx)xdy + (yy)*ydy)
564
565	POINT(0, TILE_SIZE / 2, 3 * TILE_SIZE / 4); /* top of arrow */
566	POINT(1, 3 * TILE_SIZE / 4, TILE_SIZE / 2); /* right corner */
567	POINT(2, 5 * TILE_SIZE / 8, TILE_SIZE / 2); /* right concave */
568	POINT(3, 5 * TILE_SIZE / 8, TILE_SIZE / 4); /* bottom right */
569	POINT(4, 3 * TILE_SIZE / 8, TILE_SIZE / 4); /* bottom left */
570	POINT(5, 3 * TILE_SIZE / 8, TILE_SIZE / 2); /* left concave */
571	POINT(6, TILE_SIZE / 4, TILE_SIZE / 2); /* left corner */
572
573	draw_polygon(fe, coords, 7, TRUE, COL_LOWLIGHT);
574	draw_polygon(fe, coords, 7, FALSE, COL_TEXT);
575	}
576
577	void game_redraw(frontend fe, game_drawstate ds, game_state *oldstate,
c822de4a	578	game_state state, int dir, game_ui ui,
74a4e547	579	float animtime, float flashtime)
4efb3868	580	{
b443c381	581	int i, bgcolour;
4efb3868	582
	583	if (flashtime > 0) {
	584	int frame = (int)(flashtime / FLASH_FRAME);
	585	bgcolour = (frame % 2 ? COL_LOWLIGHT : COL_HIGHLIGHT);
	586	} else
	587	bgcolour = COL_BACKGROUND;
	588
	589	if (!ds->started) {
	590	int coords[6];
	591
	592	draw_rect(fe, 0, 0,
	593	TILE_SIZE * state->w + 2 * BORDER,
	594	TILE_SIZE * state->h + 2 * BORDER, COL_BACKGROUND);
	595	draw_update(fe, 0, 0,
	596	TILE_SIZE * state->w + 2 * BORDER,
	597	TILE_SIZE * state->h + 2 * BORDER);
	598
	599	/*
	600	* Recessed area containing the whole puzzle.
	601	*/
	602	coords[0] = COORD(state->w) + HIGHLIGHT_WIDTH - 1;
	603	coords[1] = COORD(state->h) + HIGHLIGHT_WIDTH - 1;
	604	coords[2] = COORD(state->w) + HIGHLIGHT_WIDTH - 1;
	605	coords[3] = COORD(0) - HIGHLIGHT_WIDTH;
	606	coords[4] = COORD(0) - HIGHLIGHT_WIDTH;
	607	coords[5] = COORD(state->h) + HIGHLIGHT_WIDTH - 1;
	608	draw_polygon(fe, coords, 3, TRUE, COL_HIGHLIGHT);
	609	draw_polygon(fe, coords, 3, FALSE, COL_HIGHLIGHT);
	610
	611	coords[1] = COORD(0) - HIGHLIGHT_WIDTH;
	612	coords[0] = COORD(0) - HIGHLIGHT_WIDTH;
	613	draw_polygon(fe, coords, 3, TRUE, COL_LOWLIGHT);
	614	draw_polygon(fe, coords, 3, FALSE, COL_LOWLIGHT);
	615
	616	/*
	617	* Arrows for making moves.
	618	*/
	619	for (i = 0; i < state->w; i++) {
	620	draw_arrow(fe, COORD(i), COORD(0), +1, 0);
	621	draw_arrow(fe, COORD(i+1), COORD(state->h), -1, 0);
	622	}
	623	for (i = 0; i < state->h; i++) {
	624	draw_arrow(fe, COORD(state->w), COORD(i), 0, +1);
	625	draw_arrow(fe, COORD(0), COORD(i+1), 0, -1);
	626	}
	627
	628	ds->started = TRUE;
	629	}
	630
	631	/*
b443c381	632	* Now draw each tile.
4efb3868	633	*/
	634
	635	clip(fe, COORD(0), COORD(0), TILE_SIZEstate->w, TILE_SIZEstate->h);
	636
b443c381	637	for (i = 0; i < state->n; i++) {
	638	int t, t0;
	639	/*
	640	* Figure out what should be displayed at this
	641	* location. It's either a simple tile, or it's a
	642	* transition between two tiles (in which case we say
	643	* -1 because it must always be drawn).
	644	*/
	645
	646	if (oldstate && oldstate->tiles[i] != state->tiles[i])
	647	t = -1;
	648	else
	649	t = state->tiles[i];
	650
	651	t0 = t;
	652
	653	if (ds->bgcolour != bgcolour \|\| /* always redraw when flashing */
	654	ds->tiles[i] != t \|\| ds->tiles[i] == -1 \|\| t == -1) {
	655	int x, y, x2, y2;
	656
	657	/*
	658	* Figure out what to _actually_ draw, and where to
	659	* draw it.
	660	*/
	661	if (t == -1) {
	662	int x0, y0, x1, y1, dx, dy;
	663	int j;
	664	float c;
	665	int sense;
	666
5b5c6b12	667	if (dir < 0) {
5b5c6b12	668	assert(oldstate);
b443c381	669	sense = -oldstate->last_movement_sense;
5b5c6b12	670	} else {
b443c381	671	sense = state->last_movement_sense;
5b5c6b12	672	}
b443c381	673
	674	t = state->tiles[i];
	675
	676	/*
	677	* FIXME: must be prepared to draw a double
	678	* tile in some situations.
	679	*/
	680
	681	/*
	682	* Find the coordinates of this tile in the old and
	683	* new states.
	684	*/
	685	x1 = COORD(X(state, i));
	686	y1 = COORD(Y(state, i));
	687	for (j = 0; j < oldstate->n; j++)
	688	if (oldstate->tiles[j] == state->tiles[i])
	689	break;
	690	assert(j < oldstate->n);
	691	x0 = COORD(X(state, j));
	692	y0 = COORD(Y(state, j));
	693
	694	dx = (x1 - x0);
	695	if (dx != 0 &&
	696	dx != TILE_SIZE * sense) {
	697	dx = (dx < 0 ? dx + TILE_SIZE * state->w :
	698	dx - TILE_SIZE * state->w);
	699	assert(abs(dx) == TILE_SIZE);
	700	}
	701	dy = (y1 - y0);
	702	if (dy != 0 &&
	703	dy != TILE_SIZE * sense) {
	704	dy = (dy < 0 ? dy + TILE_SIZE * state->h :
	705	dy - TILE_SIZE * state->h);
	706	assert(abs(dy) == TILE_SIZE);
	707	}
	708
	709	c = (animtime / ANIM_TIME);
	710	if (c < 0.0F) c = 0.0F;
	711	if (c > 1.0F) c = 1.0F;
	712
	713	x = x0 + (int)(c * dx);
	714	y = y0 + (int)(c * dy);
	715	x2 = x1 - dx + (int)(c * dx);
	716	y2 = y1 - dy + (int)(c * dy);
	717	} else {
	718	x = COORD(X(state, i));
	719	y = COORD(Y(state, i));
	720	x2 = y2 = -1;
	721	}
	722
	723	draw_tile(fe, state, x, y, t, bgcolour);
	724	if (x2 != -1 \|\| y2 != -1)
	725	draw_tile(fe, state, x2, y2, t, bgcolour);
	726	}
	727	ds->tiles[i] = t0;
4efb3868	728	}
	729
	730	unclip(fe);
	731
	732	ds->bgcolour = bgcolour;
fd1a1a2b	733
	734	/*
	735	* Update the status bar.
	736	*/
	737	{
	738	char statusbuf[256];
	739
d108c342	740	/*
	741	* Don't show the new status until we're also showing the
	742	* new _state_ - after the game animation is complete.
	743	*/
	744	if (oldstate)
	745	state = oldstate;
	746
fd1a1a2b	747	sprintf(statusbuf, "%sMoves: %d",
	748	(state->completed ? "COMPLETED! " : ""),
	749	(state->completed ? state->completed : state->movecount));
	750
	751	status_bar(fe, statusbuf);
	752	}
4efb3868	753	}
4efb3868	754
c822de4a	755	float game_anim_length(game_state oldstate, game_state newstate, int dir)
4efb3868	756	{
	757	return ANIM_TIME;
	758	}
	759
c822de4a	760	float game_flash_length(game_state oldstate, game_state newstate, int dir)
4efb3868	761	{
	762	if (!oldstate->completed && newstate->completed)
	763	return 2 * FLASH_FRAME;
	764	else
	765	return 0.0F;
	766	}
fd1a1a2b	767
	768	int game_wants_statusbar(void)
	769	{
	770	return TRUE;
	771	}