[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 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)
        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 */

    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, 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 (oldstate && state->movecount < oldstate->movecount)
		    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)
{
    return ANIM_TIME;
}

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