[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 <math.h>

#include "puzzles.h"

const char *const game_name = "Sixteen";

#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 0.1F
#define FLASH_FRAME 0.1F

#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;
};

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;
}

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)
{
    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 ? rand_upto(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;
}

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;

    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;

    return ret;
}

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

game_state *make_move(game_state *from, 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++;

    /*
     * 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, float animtime, float flashtime)
{
    int i, pass, 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. We do this in two passes to make
     * animation easy.
     */

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

    for (pass = 0; pass < 2; pass++) {
        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;

                    /*
                     * On the first pass, just blank the tile.
                     */
                    if (pass == 0) {
                        x = COORD(X(state, i));
                        y = COORD(Y(state, i));
                        x2 = y2 = -1;
                        t = 0;
                    } else {
                        float c;

                        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 (abs(dx) > TILE_SIZE) {
                            dx = (dx < 0 ? dx + TILE_SIZE * state->w :
                                  dx - TILE_SIZE * state->w);
                            assert(abs(dx) == TILE_SIZE);
                        }
                        dy = (y1 - y0);
                        if (abs(dy) > TILE_SIZE) {
                            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 {
                    if (pass == 0)
                        continue;
                    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>
	11	#include <math.h>
	12
	13	#include "puzzles.h"
	14
	15	const char *const game_name = "Sixteen";
	16
	17	#define TILE_SIZE 48
	18	#define BORDER TILE_SIZE /* big border to fill with arrows */
	19	#define HIGHLIGHT_WIDTH (TILE_SIZE / 20)
	20	#define COORD(x) ( (x) * TILE_SIZE + BORDER )
	21	#define FROMCOORD(x) ( ((x) - BORDER + 2*TILE_SIZE) / TILE_SIZE - 2 )
	22
	23	#define ANIM_TIME 0.1F
	24	#define FLASH_FRAME 0.1F
	25
	26	#define X(state, i) ( (i) % (state)->w )
	27	#define Y(state, i) ( (i) / (state)->w )
	28	#define C(state, x, y) ( (y) * (state)->w + (x) )
	29
	30	enum {
	31	COL_BACKGROUND,
	32	COL_TEXT,
	33	COL_HIGHLIGHT,
	34	COL_LOWLIGHT,
	35	NCOLOURS
	36	};
	37
	38	struct game_params {
	39	int w, h;
	40	};
	41
	42	struct game_state {
	43	int w, h, n;
	44	int *tiles;
	45	int completed;
fd1a1a2b	46	int movecount;
4efb3868	47	};
	48
	49	game_params *default_params(void)
	50	{
	51	game_params *ret = snew(game_params);
	52
	53	ret->w = ret->h = 4;
	54
	55	return ret;
	56	}
	57
	58	int game_fetch_preset(int i, char name, game_params params)
	59	{
	60	game_params *ret;
	61	int w, h;
	62	char buf[80];
	63
	64	switch (i) {
	65	case 0: w = 3, h = 3; break;
	66	case 1: w = 4, h = 3; break;
	67	case 2: w = 4, h = 4; break;
	68	case 3: w = 5, h = 4; break;
	69	case 4: w = 5, h = 5; break;
	70	default: return FALSE;
	71	}
	72
	73	sprintf(buf, "%dx%d", w, h);
	74	*name = dupstr(buf);
	75	*params = ret = snew(game_params);
	76	ret->w = w;
	77	ret->h = h;
	78	return TRUE;
	79	}
	80
	81	void free_params(game_params *params)
	82	{
	83	sfree(params);
	84	}
	85
	86	game_params dup_params(game_params params)
	87	{
	88	game_params *ret = snew(game_params);
	89	ret = params; /* structure copy */
	90	return ret;
	91	}
	92
	93	int perm_parity(int *perm, int n)
	94	{
	95	int i, j, ret;
	96
	97	ret = 0;
	98
	99	for (i = 0; i < n-1; i++)
	100	for (j = i+1; j < n; j++)
	101	if (perm[i] > perm[j])
	102	ret = !ret;
	103
	104	return ret;
	105	}
	106
	107	char new_game_seed(game_params params)
	108	{
	109	int stop, n, i, x;
	110	int x1, x2, p1, p2;
111	int tiles, used;
112	char *ret;
113	int retlen;
114
115	n = params->w * params->h;
116
117	tiles = snewn(n, int);
118	used = snewn(n, int);
119
120	for (i = 0; i < n; i++) {
121	tiles[i] = -1;
122	used[i] = FALSE;
123	}
124
125	/*
126	* If both dimensions are odd, there is a parity constraint.
127	*/
128	if (params->w & params->h & 1)
129	stop = 2;
130	else
131	stop = 0;
132
133	/*
134	* Place everything except (possibly) the last two tiles.
135	*/
136	for (x = 0, i = n; i > stop; i--) {
137	int k = i > 1 ? rand_upto(i) : 0;
138	int j;
139
140	for (j = 0; j < n; j++)
141	if (!used[j] && (k-- == 0))
142	break;
143
144	assert(j < n && !used[j]);
145	used[j] = TRUE;
146
147	while (tiles[x] >= 0)
148	x++;
149	assert(x < n);
150	tiles[x] = j;
151	}
152
153	if (stop) {
154	/*
155	* Find the last two locations, and the last two pieces.
156	*/
157	while (tiles[x] >= 0)
158	x++;
159	assert(x < n);
160	x1 = x;
161	x++;
162	while (tiles[x] >= 0)
163	x++;
164	assert(x < n);
165	x2 = x;
166
167	for (i = 0; i < n; i++)
168	if (!used[i])
169	break;
170	p1 = i;
171	for (i = p1+1; i < n; i++)
172	if (!used[i])
173	break;
174	p2 = i;
175
176	/*
177	* Try the last two tiles one way round. If that fails, swap
178	* them.
179	*/
180	tiles[x1] = p1;
181	tiles[x2] = p2;
182	if (perm_parity(tiles, n) != 0) {
183	tiles[x1] = p2;
184	tiles[x2] = p1;
185	assert(perm_parity(tiles, n) == 0);
186	}
187	}
188
189	/*
190	* Now construct the game seed, by describing the tile array as
191	* a simple sequence of comma-separated integers.
192	*/
193	ret = NULL;
194	retlen = 0;
195	for (i = 0; i < n; i++) {
196	char buf[80];
197	int k;
198
199	k = sprintf(buf, "%d,", tiles[i]+1);
200
201	ret = sresize(ret, retlen + k + 1, char);
202	strcpy(ret + retlen, buf);
203	retlen += k;
204	}
205	ret[retlen-1] = '\0'; /* delete last comma */
206
207	sfree(tiles);
208	sfree(used);
209
210	return ret;
211	}
212
213	game_state new_game(game_params params, char *seed)
214	{
215	game_state *state = snew(game_state);
216	int i;
217	char *p;
218
219	state->w = params->w;
220	state->h = params->h;
221	state->n = params->w * params->h;
222	state->tiles = snewn(state->n, int);
223
224	p = seed;
225	i = 0;
226	for (i = 0; i < state->n; i++) {
227	assert(*p);
228	state->tiles[i] = atoi(p);
229	while (p && p != ',')
230	p++;
231	if (p) p++; / eat comma */
232	}
233	assert(!*p);
234
fd1a1a2b	235	state->completed = state->movecount = 0;
4efb3868	236
	237	return state;
	238	}
	239
	240	game_state dup_game(game_state state)
	241	{
	242	game_state *ret = snew(game_state);
	243
	244	ret->w = state->w;
	245	ret->h = state->h;
	246	ret->n = state->n;
	247	ret->tiles = snewn(state->w * state->h, int);
	248	memcpy(ret->tiles, state->tiles, state->w * state->h * sizeof(int));
	249	ret->completed = state->completed;
fd1a1a2b	250	ret->movecount = state->movecount;
4efb3868	251
	252	return ret;
	253	}
	254
	255	void free_game(game_state *state)
	256	{
	257	sfree(state);
	258	}
	259
	260	game_state make_move(game_state from, int x, int y, int button)
	261	{
	262	int cx, cy;
	263	int dx, dy, tx, ty, n;
	264	game_state *ret;
	265
	266	if (button != LEFT_BUTTON)
	267	return NULL;
	268
	269	cx = FROMCOORD(x);
	270	cy = FROMCOORD(y);
	271	if (cx == -1 && cy >= 0 && cy < from->h)
	272	n = from->w, dx = +1, dy = 0;
	273	else if (cx == from->w && cy >= 0 && cy < from->h)
	274	n = from->w, dx = -1, dy = 0;
	275	else if (cy == -1 && cx >= 0 && cx < from->w)
	276	n = from->h, dy = +1, dx = 0;
	277	else if (cy == from->h && cx >= 0 && cx < from->w)
	278	n = from->h, dy = -1, dx = 0;
	279	else
	280	return NULL; /* invalid click location */
	281
	282	ret = dup_game(from);
	283
	284	do {
	285	cx += dx;
	286	cy += dy;
	287	tx = (cx + dx + from->w) % from->w;
	288	ty = (cy + dy + from->h) % from->h;
	289	ret->tiles[C(ret, cx, cy)] = from->tiles[C(from, tx, ty)];
	290	} while (--n > 0);
	291
fd1a1a2b	292	ret->movecount++;
fd1a1a2b	293
4efb3868	294	/*
	295	* See if the game has been completed.
	296	*/
	297	if (!ret->completed) {
fd1a1a2b	298	ret->completed = ret->movecount;
4efb3868	299	for (n = 0; n < ret->n; n++)
	300	if (ret->tiles[n] != n+1)
	301	ret->completed = FALSE;
	302	}
	303
	304	return ret;
	305	}
	306
	307	/* ----------------------------------------------------------------------
	308	* Drawing routines.
	309	*/
	310
	311	struct game_drawstate {
	312	int started;
	313	int w, h, bgcolour;
	314	int *tiles;
	315	};
	316
	317	void game_size(game_params params, int x, int *y)
	318	{
	319	x = TILE_SIZE params->w + 2 * BORDER;
	320	y = TILE_SIZE params->h + 2 * BORDER;
	321	}
	322
	323	float game_colours(frontend fe, game_state state, int ncolours)
	324	{
	325	float ret = snewn(3 NCOLOURS, float);
	326	int i;
	327	float max;
	328
	329	frontend_default_colour(fe, &ret[COL_BACKGROUND * 3]);
	330
	331	/*
	332	* Drop the background colour so that the highlight is
	333	* noticeably brighter than it while still being under 1.
	334	*/
	335	max = ret[COL_BACKGROUND*3];
	336	for (i = 1; i < 3; i++)
	337	if (ret[COL_BACKGROUND*3+i] > max)
	338	max = ret[COL_BACKGROUND*3+i];
	339	if (max * 1.2F > 1.0F) {
	340	for (i = 0; i < 3; i++)
	341	ret[COL_BACKGROUND3+i] /= (max 1.2F);
	342	}
	343
	344	for (i = 0; i < 3; i++) {
	345	ret[COL_HIGHLIGHT * 3 + i] = ret[COL_BACKGROUND * 3 + i] * 1.2F;
	346	ret[COL_LOWLIGHT * 3 + i] = ret[COL_BACKGROUND * 3 + i] * 0.8F;
	347	ret[COL_TEXT * 3 + i] = 0.0;
	348	}
	349
	350	*ncolours = NCOLOURS;
	351	return ret;
	352	}
	353
	354	game_drawstate game_new_drawstate(game_state state)
	355	{
	356	struct game_drawstate *ds = snew(struct game_drawstate);
	357	int i;
	358
	359	ds->started = FALSE;
	360	ds->w = state->w;
	361	ds->h = state->h;
	362	ds->bgcolour = COL_BACKGROUND;
363	ds->tiles = snewn(ds->w*ds->h, int);
364	for (i = 0; i < ds->w*ds->h; i++)
365	ds->tiles[i] = -1;
366
367	return ds;
368	}
369
370	void game_free_drawstate(game_drawstate *ds)
371	{
372	sfree(ds->tiles);
373	sfree(ds);
374	}
375
376	static void draw_tile(frontend fe, game_state state, int x, int y,
377	int tile, int flash_colour)
378	{
379	if (tile == 0) {
380	draw_rect(fe, x, y, TILE_SIZE, TILE_SIZE,
381	flash_colour);
382	} else {
383	int coords[6];
384	char str[40];
385
386	coords[0] = x + TILE_SIZE - 1;
387	coords[1] = y + TILE_SIZE - 1;
388	coords[2] = x + TILE_SIZE - 1;
389	coords[3] = y;
390	coords[4] = x;
391	coords[5] = y + TILE_SIZE - 1;
392	draw_polygon(fe, coords, 3, TRUE, COL_LOWLIGHT);
393	draw_polygon(fe, coords, 3, FALSE, COL_LOWLIGHT);
394
395	coords[0] = x;
396	coords[1] = y;
397	draw_polygon(fe, coords, 3, TRUE, COL_HIGHLIGHT);
398	draw_polygon(fe, coords, 3, FALSE, COL_HIGHLIGHT);
399
400	draw_rect(fe, x + HIGHLIGHT_WIDTH, y + HIGHLIGHT_WIDTH,
401	TILE_SIZE - 2HIGHLIGHT_WIDTH, TILE_SIZE - 2HIGHLIGHT_WIDTH,
402	flash_colour);
403
404	sprintf(str, "%d", tile);
405	draw_text(fe, x + TILE_SIZE/2, y + TILE_SIZE/2,
406	FONT_VARIABLE, TILE_SIZE/3, ALIGN_VCENTRE \| ALIGN_HCENTRE,
407	COL_TEXT, str);
408	}
409	draw_update(fe, x, y, TILE_SIZE, TILE_SIZE);
410	}
411
412	static void draw_arrow(frontend *fe, int x, int y, int xdx, int xdy)
413	{
414	int coords[14];
415	int ydy = -xdx, ydx = xdy;
416
417	#define POINT(n, xx, yy) ( \
418	coords[2(n)+0] = x + (xx)xdx + (yy)*ydx, \
419	coords[2(n)+1] = y + (xx)xdy + (yy)*ydy)
420
421	POINT(0, TILE_SIZE / 2, 3 * TILE_SIZE / 4); /* top of arrow */
422	POINT(1, 3 * TILE_SIZE / 4, TILE_SIZE / 2); /* right corner */
423	POINT(2, 5 * TILE_SIZE / 8, TILE_SIZE / 2); /* right concave */
424	POINT(3, 5 * TILE_SIZE / 8, TILE_SIZE / 4); /* bottom right */
425	POINT(4, 3 * TILE_SIZE / 8, TILE_SIZE / 4); /* bottom left */
426	POINT(5, 3 * TILE_SIZE / 8, TILE_SIZE / 2); /* left concave */
427	POINT(6, TILE_SIZE / 4, TILE_SIZE / 2); /* left corner */
428
429	draw_polygon(fe, coords, 7, TRUE, COL_LOWLIGHT);
430	draw_polygon(fe, coords, 7, FALSE, COL_TEXT);
431	}
432
433	void game_redraw(frontend fe, game_drawstate ds, game_state *oldstate,
434	game_state *state, float animtime, float flashtime)
435	{
436	int i, pass, bgcolour;
437
438	if (flashtime > 0) {
439	int frame = (int)(flashtime / FLASH_FRAME);
440	bgcolour = (frame % 2 ? COL_LOWLIGHT : COL_HIGHLIGHT);
441	} else
442	bgcolour = COL_BACKGROUND;
443
444	if (!ds->started) {
445	int coords[6];
446
447	draw_rect(fe, 0, 0,
448	TILE_SIZE * state->w + 2 * BORDER,
449	TILE_SIZE * state->h + 2 * BORDER, COL_BACKGROUND);
450	draw_update(fe, 0, 0,
451	TILE_SIZE * state->w + 2 * BORDER,
452	TILE_SIZE * state->h + 2 * BORDER);
453
454	/*
455	* Recessed area containing the whole puzzle.
456	*/
457	coords[0] = COORD(state->w) + HIGHLIGHT_WIDTH - 1;
458	coords[1] = COORD(state->h) + HIGHLIGHT_WIDTH - 1;
459	coords[2] = COORD(state->w) + HIGHLIGHT_WIDTH - 1;
460	coords[3] = COORD(0) - HIGHLIGHT_WIDTH;
461	coords[4] = COORD(0) - HIGHLIGHT_WIDTH;
462	coords[5] = COORD(state->h) + HIGHLIGHT_WIDTH - 1;
463	draw_polygon(fe, coords, 3, TRUE, COL_HIGHLIGHT);
464	draw_polygon(fe, coords, 3, FALSE, COL_HIGHLIGHT);
465
466	coords[1] = COORD(0) - HIGHLIGHT_WIDTH;
467	coords[0] = COORD(0) - HIGHLIGHT_WIDTH;
468	draw_polygon(fe, coords, 3, TRUE, COL_LOWLIGHT);
469	draw_polygon(fe, coords, 3, FALSE, COL_LOWLIGHT);
470
471	/*
472	* Arrows for making moves.
473	*/
474	for (i = 0; i < state->w; i++) {
475	draw_arrow(fe, COORD(i), COORD(0), +1, 0);
476	draw_arrow(fe, COORD(i+1), COORD(state->h), -1, 0);
477	}
478	for (i = 0; i < state->h; i++) {
479	draw_arrow(fe, COORD(state->w), COORD(i), 0, +1);
480	draw_arrow(fe, COORD(0), COORD(i+1), 0, -1);
481	}
482
483	ds->started = TRUE;
484	}
485
486	/*
487	* Now draw each tile. We do this in two passes to make
488	* animation easy.
489	*/
490
491	clip(fe, COORD(0), COORD(0), TILE_SIZEstate->w, TILE_SIZEstate->h);
492
493	for (pass = 0; pass < 2; pass++) {
494	for (i = 0; i < state->n; i++) {
495	int t, t0;
496	/*
497	* Figure out what should be displayed at this
498	* location. It's either a simple tile, or it's a
499	* transition between two tiles (in which case we say
500	* -1 because it must always be drawn).
501	*/
502
503	if (oldstate && oldstate->tiles[i] != state->tiles[i])
504	t = -1;
505	else
506	t = state->tiles[i];
507
508	t0 = t;
509
510	if (ds->bgcolour != bgcolour \|\| /* always redraw when flashing */
511	ds->tiles[i] != t \|\| ds->tiles[i] == -1 \|\| t == -1) {
512	int x, y, x2, y2;
513
514	/*
515	* Figure out what to _actually_ draw, and where to
516	* draw it.
517	*/
518	if (t == -1) {
519	int x0, y0, x1, y1, dx, dy;
520	int j;
521
522	/*
523	* On the first pass, just blank the tile.
524	*/
525	if (pass == 0) {
526	x = COORD(X(state, i));
527	y = COORD(Y(state, i));
528	x2 = y2 = -1;
529	t = 0;
530	} else {
531	float c;
532
533	t = state->tiles[i];
534
535	/*
536	* FIXME: must be prepared to draw a double
537	* tile in some situations.
538	*/
539
540	/*
541	* Find the coordinates of this tile in the old and
542	* new states.
543	*/
544	x1 = COORD(X(state, i));
545	y1 = COORD(Y(state, i));
546	for (j = 0; j < oldstate->n; j++)
547	if (oldstate->tiles[j] == state->tiles[i])
548	break;
549	assert(j < oldstate->n);
550	x0 = COORD(X(state, j));
551	y0 = COORD(Y(state, j));
552
553	dx = (x1 - x0);
554	if (abs(dx) > TILE_SIZE) {
555	dx = (dx < 0 ? dx + TILE_SIZE * state->w :
556	dx - TILE_SIZE * state->w);
557	assert(abs(dx) == TILE_SIZE);
558	}
559	dy = (y1 - y0);
560	if (abs(dy) > TILE_SIZE) {
561	dy = (dy < 0 ? dy + TILE_SIZE * state->h :
562	dy - TILE_SIZE * state->h);
563	assert(abs(dy) == TILE_SIZE);
564	}
565
566	c = (animtime / ANIM_TIME);
567	if (c < 0.0F) c = 0.0F;
568	if (c > 1.0F) c = 1.0F;
569
570	x = x0 + (int)(c * dx);
571	y = y0 + (int)(c * dy);
572	x2 = x1 - dx + (int)(c * dx);
573	y2 = y1 - dy + (int)(c * dy);
574	}
575
576	} else {
577	if (pass == 0)
578	continue;
579	x = COORD(X(state, i));
580	y = COORD(Y(state, i));
581	x2 = y2 = -1;
582	}
583
584	draw_tile(fe, state, x, y, t, bgcolour);
585	if (x2 != -1 \|\| y2 != -1)
586	draw_tile(fe, state, x2, y2, t, bgcolour);
587	}
588	ds->tiles[i] = t0;
589	}
590	}
591
592	unclip(fe);
593
594	ds->bgcolour = bgcolour;
fd1a1a2b	595
	596	/*
	597	* Update the status bar.
	598	*/
	599	{
	600	char statusbuf[256];
	601
d108c342	602	/*
	603	* Don't show the new status until we're also showing the
	604	* new _state_ - after the game animation is complete.
	605	*/
	606	if (oldstate)
	607	state = oldstate;
	608
fd1a1a2b	609	sprintf(statusbuf, "%sMoves: %d",
	610	(state->completed ? "COMPLETED! " : ""),
	611	(state->completed ? state->completed : state->movecount));
	612
	613	status_bar(fe, statusbuf);
	614	}
4efb3868	615	}
	616
	617	float game_anim_length(game_state oldstate, game_state newstate)
	618	{
	619	return ANIM_TIME;
	620	}
	621
	622	float game_flash_length(game_state oldstate, game_state newstate)
	623	{
	624	if (!oldstate->completed && newstate->completed)
	625	return 2 * FLASH_FRAME;
	626	else
	627	return 0.0F;
	628	}
fd1a1a2b	629
	630	int game_wants_statusbar(void)
	631	{
	632	return TRUE;
	633	}