I've proved that a grid dimension of 2 is capable of irretrievably

[sgt/puzzles] / mines.c

diff --git a/mines.c b/mines.c
index d1ca4ff..63bfa1f 100644 (file)
--- a/mines.c
+++ b/mines.c
@@ -237,12 +237,22 @@ static game_params *custom_params(config_item *cfg)
 
 static char *validate_params(game_params *params)
 {
-    if (params->w <= 0 && params->h <= 0)
-       return "Width and height must both be greater than zero";
-    if (params->w <= 0)
-       return "Width must be greater than zero";
-    if (params->h <= 0)
-       return "Height must be greater than zero";
+    /*
+     * Lower limit on grid size: each dimension must be at least 3.
+     * 1 is theoretically workable if rather boring, but 2 is a
+     * real problem: there is often _no_ way to generate a uniquely
+     * solvable 2xn Mines grid. You either run into two mines
+     * blocking the way and no idea what's behind them, or one mine
+     * and no way to know which of the two rows it's in. If the
+     * mine count is even you can create a soluble grid by packing
+     * all the mines at one end (so what when you hit a two-mine
+     * wall there are only as many covered squares left as there
+     * are mines); but if it's odd, you are doomed, because you
+     * _have_ to have a gap somewhere which you can't determine the
+     * position of.
+     */
+    if (params->w <= 2 || params->h <= 2)
+       return "Width and height must both be greater than two";
     if (params->n > params->w * params->h - 9)
        return "Too many mines for grid size";
 
@@ -2454,10 +2464,11 @@ static game_state *make_move(game_state *from, game_ui *ui, game_drawstate *ds,
 
     cx = FROMCOORD(x);
     cy = FROMCOORD(y);
-    if (cx < 0 || cx >= from->w || cy < 0 || cy > from->h)
+    if (cx < 0 || cx >= from->w || cy < 0 || cy >= from->h)
        return NULL;
 
-    if (button == LEFT_BUTTON || button == LEFT_DRAG) {
+    if (button == LEFT_BUTTON || button == LEFT_DRAG ||
+       button == MIDDLE_BUTTON || button == MIDDLE_DRAG) {
        /*
         * Mouse-downs and mouse-drags just cause highlighting
         * updates.
@@ -2487,7 +2498,7 @@ static game_state *make_move(game_state *from, game_ui *ui, game_drawstate *ds,
        return ret;
     }
 
-    if (button == LEFT_RELEASE) {
+    if (button == LEFT_RELEASE || button == MIDDLE_RELEASE) {
        ui->hx = ui->hy = -1;
        ui->hradius = 0;
 
@@ -2501,8 +2512,9 @@ static game_state *make_move(game_state *from, game_ui *ui, game_drawstate *ds,
         * permitted if the tile is marked as a mine, for safety.
         * (Unmark it and _then_ open it.)
         */
-       if (from->grid[cy * from->w + cx] == -2 ||
-           from->grid[cy * from->w + cx] == -3) {
+       if (button == LEFT_RELEASE &&
+           (from->grid[cy * from->w + cx] == -2 ||
+            from->grid[cy * from->w + cx] == -3)) {
            ret = dup_game(from);
             ret->just_used_solve = FALSE;
            open_square(ret, cx, cy);
@@ -2512,10 +2524,10 @@ static game_state *make_move(game_state *from, game_ui *ui, game_drawstate *ds,
        }
 
        /*
-        * Left-clicking on an uncovered tile: first we check to see if
-        * the number of mine markers surrounding the tile is equal to
-        * its mine count, and if so then we open all other surrounding
-        * squares.
+        * Left-clicking or middle-clicking on an uncovered tile:
+        * first we check to see if the number of mine markers
+        * surrounding the tile is equal to its mine count, and if
+        * so then we open all other surrounding squares.
         */
        if (from->grid[cy * from->w + cx] > 0) {
            int dy, dx, n;
@@ -2857,7 +2869,7 @@ static void game_redraw(frontend *fe, game_drawstate *ds, game_state *oldstate,
        bg = COL_BACKGROUND;
 
     if (!ds->started) {
-        int coords[6];
+        int coords[10];
 
        draw_rect(fe, 0, 0,
                  TILE_SIZE * state->w + 2 * BORDER,
@@ -2873,15 +2885,19 @@ static void game_redraw(frontend *fe, game_drawstate *ds, game_state *oldstate,
         coords[1] = COORD(state->h) + OUTER_HIGHLIGHT_WIDTH - 1;
         coords[2] = COORD(state->w) + OUTER_HIGHLIGHT_WIDTH - 1;
         coords[3] = COORD(0) - OUTER_HIGHLIGHT_WIDTH;
-        coords[4] = COORD(0) - OUTER_HIGHLIGHT_WIDTH;
-        coords[5] = COORD(state->h) + OUTER_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) - OUTER_HIGHLIGHT_WIDTH;
+        coords[9] = COORD(state->h) + OUTER_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) - OUTER_HIGHLIGHT_WIDTH;
         coords[0] = COORD(0) - OUTER_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);
 
         ds->started = TRUE;
     }
@@ -3006,4 +3022,5 @@ const struct game thegame = {
     game_flash_length,
     game_wants_statusbar,
     TRUE, game_timing_state,
+    BUTTON_BEATS(LEFT_BUTTON, RIGHT_BUTTON),
 };