Introduce a new game backend function (there seem to have been a lot
[sgt/puzzles] / sixteen.c
index 828168e..9a347fa 100644 (file)
--- a/sixteen.c
+++ b/sixteen.c
@@ -36,13 +36,16 @@ enum {
 
 struct game_params {
     int w, h;
+    int movetarget;
 };
 
 struct game_state {
     int w, h, n;
     int *tiles;
     int completed;
-    int movecount;
+    int just_used_solve;              /* used to suppress undo animation */
+    int used_solve;                   /* used to suppress completion flash */
+    int movecount, movetarget;
     int last_movement_sense;
 };
 
@@ -51,6 +54,7 @@ static game_params *default_params(void)
     game_params *ret = snew(game_params);
 
     ret->w = ret->h = 4;
+    ret->movetarget = 0;
 
     return ret;
 }
@@ -75,6 +79,7 @@ static int game_fetch_preset(int i, char **name, game_params **params)
     *params = ret = snew(game_params);
     ret->w = w;
     ret->h = h;
+    ret->movetarget = 0;
     return TRUE;
 }
 
@@ -90,25 +95,34 @@ static game_params *dup_params(game_params *params)
     return ret;
 }
 
-static game_params *decode_params(char const *string)
+static void decode_params(game_params *ret, char const *string)
 {
-    game_params *ret = default_params();
-
     ret->w = ret->h = atoi(string);
+    ret->movetarget = 0;
     while (*string && isdigit(*string)) string++;
     if (*string == 'x') {
         string++;
         ret->h = atoi(string);
+       while (*string && isdigit((unsigned char)*string))
+           string++;
+    }
+    if (*string == 'm') {
+        string++;
+        ret->movetarget = atoi(string);
+       while (*string && isdigit((unsigned char)*string))
+           string++;
     }
-
-    return ret;
 }
 
-static char *encode_params(game_params *params)
+static char *encode_params(game_params *params, int full)
 {
     char data[256];
 
     sprintf(data, "%dx%d", params->w, params->h);
+    /* Shuffle limit is part of the limited parameters, because we have to
+     * supply the target move count. */
+    if (params->movetarget)
+        sprintf(data + strlen(data), "m%d", params->movetarget);
 
     return dupstr(data);
 }
@@ -118,7 +132,7 @@ static config_item *game_configure(game_params *params)
     config_item *ret;
     char buf[80];
 
-    ret = snewn(3, config_item);
+    ret = snewn(4, config_item);
 
     ret[0].name = "Width";
     ret[0].type = C_STRING;
@@ -132,11 +146,17 @@ static config_item *game_configure(game_params *params)
     ret[1].sval = dupstr(buf);
     ret[1].ival = 0;
 
-    ret[2].name = NULL;
-    ret[2].type = C_END;
-    ret[2].sval = NULL;
+    ret[2].name = "Number of shuffling moves";
+    ret[2].type = C_STRING;
+    sprintf(buf, "%d", params->movetarget);
+    ret[2].sval = dupstr(buf);
     ret[2].ival = 0;
 
+    ret[3].name = NULL;
+    ret[3].type = C_END;
+    ret[3].sval = NULL;
+    ret[3].ival = 0;
+
     return ret;
 }
 
@@ -146,13 +166,14 @@ static game_params *custom_params(config_item *cfg)
 
     ret->w = atoi(cfg[0].sval);
     ret->h = atoi(cfg[1].sval);
+    ret->movetarget = atoi(cfg[2].sval);
 
     return ret;
 }
 
 static char *validate_params(game_params *params)
 {
-    if (params->w < 2 && params->h < 2)
+    if (params->w < 2 || params->h < 2)
        return "Width and height must both be at least two";
 
     return NULL;
@@ -172,7 +193,8 @@ static int perm_parity(int *perm, int n)
     return ret;
 }
 
-static char *new_game_seed(game_params *params, random_state *rs)
+static char *new_game_desc(game_params *params, random_state *rs,
+                          game_aux_info **aux, int interactive)
 {
     int stop, n, i, x;
     int x1, x2, p1, p2;
@@ -183,80 +205,178 @@ static char *new_game_seed(game_params *params, random_state *rs)
     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 (params->movetarget) {
+       int prevoffset = -1;
+        int max = (params->w > params->h ? params->w : params->h);
+        int *prevmoves = snewn(max, int);
 
-    /*
-     * If both dimensions are odd, there is a parity constraint.
-     */
-    if (params->w & params->h & 1)
-        stop = 2;
-    else
-        stop = 0;
+       /*
+        * Shuffle the old-fashioned way, by making a series of
+        * single moves on the grid.
+        */
 
-    /*
-     * 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 (i = 0; i < n; i++)
+           tiles[i] = i;
 
-        for (j = 0; j < n; j++)
-            if (!used[j] && (k-- == 0))
-                break;
+       for (i = 0; i < params->movetarget; i++) {
+           int start, offset, len, direction, index;
+           int j, tmp;
 
-        assert(j < n && !used[j]);
-        used[j] = TRUE;
+           /*
+            * Choose a move to make. We can choose from any row
+            * or any column.
+            */
+           while (1) {
+               j = random_upto(rs, params->w + params->h);
+
+               if (j < params->w) {
+                   /* Column. */
+                    index = j;
+                   start = j;
+                   offset = params->w;
+                   len = params->h;
+               } else {
+                   /* Row. */
+                    index = j - params->w;
+                   start = index * params->w;
+                   offset = 1;
+                   len = params->w;
+               }
 
-        while (tiles[x] >= 0)
-            x++;
-        assert(x < n);
-        tiles[x] = j;
-    }
+               direction = -1 + 2 * random_upto(rs, 2);
 
-    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;
+               /*
+                * To at least _try_ to avoid boring cases, check
+                * that this move doesn't directly undo a previous
+                * one, or repeat it so many times as to turn it
+                * into fewer moves in the opposite direction. (For
+                * example, in a row of length 4, we're allowed to
+                * move it the same way twice, but not three
+                * times.)
+                 * 
+                 * We track this for each individual row/column,
+                 * and clear all the counters as soon as a
+                 * perpendicular move is made. This isn't perfect
+                 * (it _can't_ guaranteeably be perfect - there
+                 * will always come a move count beyond which a
+                 * shorter solution will be possible than the one
+                 * which constructed the position) but it should
+                 * sort out all the obvious cases.
+                */
+                if (offset == prevoffset) {
+                    tmp = prevmoves[index] + direction;
+                    if (abs(2*tmp) > len || abs(tmp) < abs(prevmoves[index]))
+                        continue;
+                }
+
+               /* If we didn't `continue', we've found an OK move to make. */
+                if (offset != prevoffset) {
+                    int i;
+                    for (i = 0; i < max; i++)
+                        prevmoves[i] = 0;
+                    prevoffset = offset;
+                }
+                prevmoves[index] += direction;
+               break;
+           }
 
-        /*
-         * 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);
-        }
+           /*
+            * Make the move.
+            */
+           if (direction < 0) {
+               start += (len-1) * offset;
+               offset = -offset;
+           }
+           tmp = tiles[start];
+           for (j = 0; j+1 < len; j++)
+               tiles[start + j*offset] = tiles[start + (j+1)*offset];
+           tiles[start + (len-1) * offset] = tmp;
+       }
+
+        sfree(prevmoves);
+
+    } else {
+
+       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);
+           }
+       }
+
+       sfree(used);
     }
 
     /*
-     * Now construct the game seed, by describing the tile array as
-     * a simple sequence of comma-separated integers.
+     * Now construct the game description, by describing the tile
+     * array as a simple sequence of comma-separated integers.
      */
     ret = NULL;
     retlen = 0;
@@ -273,20 +393,24 @@ static char *new_game_seed(game_params *params, random_state *rs)
     ret[retlen-1] = '\0';              /* delete last comma */
 
     sfree(tiles);
-    sfree(used);
 
     return ret;
 }
 
+static void game_free_aux_info(game_aux_info *aux)
+{
+    assert(!"Shouldn't happen");
+}
+
 
-static char *validate_seed(game_params *params, char *seed)
+static char *validate_desc(game_params *params, char *desc)
 {
     char *p, *err;
     int i, area;
     int *used;
 
     area = params->w * params->h;
-    p = seed;
+    p = desc;
     err = NULL;
 
     used = snewn(area, int);
@@ -330,7 +454,7 @@ static char *validate_seed(game_params *params, char *seed)
     return err;
 }
 
-static game_state *new_game(game_params *params, char *seed)
+static game_state *new_game(midend_data *me, game_params *params, char *desc)
 {
     game_state *state = snew(game_state);
     int i;
@@ -341,7 +465,7 @@ static game_state *new_game(game_params *params, char *seed)
     state->n = params->w * params->h;
     state->tiles = snewn(state->n, int);
 
-    p = seed;
+    p = desc;
     i = 0;
     for (i = 0; i < state->n; i++) {
         assert(*p);
@@ -353,6 +477,8 @@ static game_state *new_game(game_params *params, char *seed)
     assert(!*p);
 
     state->completed = state->movecount = 0;
+    state->movetarget = params->movetarget;
+    state->used_solve = state->just_used_solve = FALSE;
     state->last_movement_sense = 0;
 
     return state;
@@ -369,6 +495,9 @@ static game_state *dup_game(game_state *state)
     memcpy(ret->tiles, state->tiles, state->w * state->h * sizeof(int));
     ret->completed = state->completed;
     ret->movecount = state->movecount;
+    ret->movetarget = state->movetarget;
+    ret->used_solve = state->used_solve;
+    ret->just_used_solve = state->just_used_solve;
     ret->last_movement_sense = state->last_movement_sense;
 
     return ret;
@@ -376,9 +505,70 @@ static game_state *dup_game(game_state *state)
 
 static void free_game(game_state *state)
 {
+    sfree(state->tiles);
     sfree(state);
 }
 
+static game_state *solve_game(game_state *state, game_aux_info *aux,
+                             char **error)
+{
+    game_state *ret = dup_game(state);
+    int i;
+
+    /*
+     * Simply replace the grid with a solved one. For this game,
+     * this isn't a useful operation for actually telling the user
+     * what they should have done, but it is useful for
+     * conveniently being able to get hold of a clean state from
+     * which to practise manoeuvres.
+     */
+    for (i = 0; i < ret->n; i++)
+       ret->tiles[i] = i+1;
+    ret->used_solve = ret->just_used_solve = TRUE;
+    ret->completed = ret->movecount = 1;
+
+    return ret;
+}
+
+static char *game_text_format(game_state *state)
+{
+    char *ret, *p, buf[80];
+    int x, y, col, maxlen;
+
+    /*
+     * First work out how many characters we need to display each
+     * number.
+     */
+    col = sprintf(buf, "%d", state->n);
+
+    /*
+     * Now we know the exact total size of the grid we're going to
+     * produce: it's got h rows, each containing w lots of col, w-1
+     * spaces and a trailing newline.
+     */
+    maxlen = state->h * state->w * (col+1);
+
+    ret = snewn(maxlen+1, char);
+    p = ret;
+
+    for (y = 0; y < state->h; y++) {
+       for (x = 0; x < state->w; x++) {
+           int v = state->tiles[state->w*y+x];
+           sprintf(buf, "%*d", col, v);
+           memcpy(p, buf, col);
+           p += col;
+           if (x+1 == state->w)
+               *p++ = '\n';
+           else
+               *p++ = ' ';
+       }
+    }
+
+    assert(p - ret == maxlen);
+    *p = '\0';
+    return ret;
+}
+
 static game_ui *new_ui(game_state *state)
 {
     return NULL;
@@ -388,13 +578,18 @@ static void free_ui(game_ui *ui)
 {
 }
 
-static game_state *make_move(game_state *from, game_ui *ui,
-                            int x, int y, int button)
+static void game_changed_state(game_ui *ui, game_state *oldstate,
+                               game_state *newstate)
 {
+}
+
+static game_state *make_move(game_state *from, game_ui *ui, game_drawstate *ds,
+                             int x, int y, int button) {
     int cx, cy;
     int dx, dy, tx, ty, n;
     game_state *ret;
 
+    button &= ~MOD_MASK;
     if (button != LEFT_BUTTON && button != RIGHT_BUTTON)
         return NULL;
 
@@ -419,6 +614,7 @@ static game_state *make_move(game_state *from, game_ui *ui,
     }
 
     ret = dup_game(from);
+    ret->just_used_solve = FALSE;      /* zero this in a hurry */
 
     do {
         cx += dx;
@@ -584,7 +780,7 @@ static void game_redraw(frontend *fe, game_drawstate *ds, game_state *oldstate,
         bgcolour = COL_BACKGROUND;
 
     if (!ds->started) {
-        int coords[6];
+        int coords[10];
 
        draw_rect(fe, 0, 0,
                  TILE_SIZE * state->w + 2 * BORDER,
@@ -600,15 +796,19 @@ static void game_redraw(frontend *fe, game_drawstate *ds, game_state *oldstate,
         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[4] = coords[2] - TILE_SIZE;
+        coords[5] = coords[3] + TILE_SIZE;
+        coords[8] = COORD(0) - HIGHLIGHT_WIDTH;
+        coords[9] = COORD(state->h) + HIGHLIGHT_WIDTH - 1;
+        coords[6] = coords[8] + TILE_SIZE;
+        coords[7] = coords[9] - TILE_SIZE;
+        draw_polygon(fe, coords, 5, TRUE, COL_HIGHLIGHT);
+        draw_polygon(fe, coords, 5, 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);
+        draw_polygon(fe, coords, 5, TRUE, COL_LOWLIGHT);
+        draw_polygon(fe, coords, 5, FALSE, COL_LOWLIGHT);
 
         /*
          * Arrows for making moves.
@@ -741,24 +941,37 @@ static void game_redraw(frontend *fe, game_drawstate *ds, game_state *oldstate,
         if (oldstate)
             state = oldstate;
 
-       sprintf(statusbuf, "%sMoves: %d",
-               (state->completed ? "COMPLETED! " : ""),
-               (state->completed ? state->completed : state->movecount));
+       if (state->used_solve)
+           sprintf(statusbuf, "Moves since auto-solve: %d",
+                   state->movecount - state->completed);
+       else {
+           sprintf(statusbuf, "%sMoves: %d",
+                   (state->completed ? "COMPLETED! " : ""),
+                   (state->completed ? state->completed : state->movecount));
+            if (state->movetarget)
+                sprintf(statusbuf+strlen(statusbuf), " (target %d)",
+                        state->movetarget);
+       }
 
        status_bar(fe, statusbuf);
     }
 }
 
 static float game_anim_length(game_state *oldstate,
-                             game_state *newstate, int dir)
+                             game_state *newstate, int dir, game_ui *ui)
 {
-    return ANIM_TIME;
+    if ((dir > 0 && newstate->just_used_solve) ||
+       (dir < 0 && oldstate->just_used_solve))
+       return 0.0F;
+    else
+       return ANIM_TIME;
 }
 
 static float game_flash_length(game_state *oldstate,
-                              game_state *newstate, int dir)
+                              game_state *newstate, int dir, game_ui *ui)
 {
-    if (!oldstate->completed && newstate->completed)
+    if (!oldstate->completed && newstate->completed &&
+       !oldstate->used_solve && !newstate->used_solve)
         return 2 * FLASH_FRAME;
     else
         return 0.0F;
@@ -769,28 +982,36 @@ static int game_wants_statusbar(void)
     return TRUE;
 }
 
+static int game_timing_state(game_state *state)
+{
+    return TRUE;
+}
+
 #ifdef COMBINED
 #define thegame sixteen
 #endif
 
 const struct game thegame = {
-    "Sixteen", "games.sixteen", TRUE,
+    "Sixteen", "games.sixteen",
     default_params,
     game_fetch_preset,
     decode_params,
     encode_params,
     free_params,
     dup_params,
-    game_configure,
-    custom_params,
+    TRUE, game_configure, custom_params,
     validate_params,
-    new_game_seed,
-    validate_seed,
+    new_game_desc,
+    game_free_aux_info,
+    validate_desc,
     new_game,
     dup_game,
     free_game,
+    TRUE, solve_game,
+    TRUE, game_text_format,
     new_ui,
     free_ui,
+    game_changed_state,
     make_move,
     game_size,
     game_colours,
@@ -800,4 +1021,6 @@ const struct game thegame = {
     game_anim_length,
     game_flash_length,
     game_wants_statusbar,
+    FALSE, game_timing_state,
+    0,                                /* mouse_priorities */
 };