Towers: you can now mark clues done

html/towers.html

@@ -17,3 +17,6 @@ square and then press Backspace.
 Right-click in a square and then type a number to add or remove the
 number as a pencil mark, indicating tower heights that you think
 <em>might</em> go in that square.
+<p>
+Left-click on a clue to mark it as done (grey it out). To unmark a
+clue as done, left-click on it again.

puzzles.but

@@ -2637,6 +2637,9 @@ mode in which you can enter or remove pencil marks.
 Pressing M will fill in a full set of pencil marks in every square
 that does not have a main digit in it.
 
+Left-clicking a clue will mark it as done (grey it out), or unmark it
+if it is already marked.
+
 (All the actions described in \k{common-actions} are also available.)
 
 \H{towers-parameters} \I{parameters, for Towers}Towers parameters

towers.c

@@ -16,12 +16,6 @@
  * 	 factorial-time enumeration at a sensible rate. Easy puzzles
  * 	 higher than that would be possible, but more latin-squarey
  * 	 than skyscrapery, as it were.
- *
- *  - UI work?
- *     + Allow the user to mark a clue as 'spent' in some way once
- * 	 it's no longer interesting (typically because no
- * 	 arrangement of the remaining possibilities _can_ violate
- * 	 it)?
  */
 
 #include <stdio.h>
@@ -59,6 +53,7 @@ enum {
     COL_HIGHLIGHT,
     COL_ERROR,
     COL_PENCIL,
+    COL_DONE,
     NCOLOURS
 };
 
@@ -119,6 +114,7 @@ static const char *const cluepos[] = {
 struct game_state {
     game_params par;
     struct clues *clues;
+    int *cluesdone;
     digit *grid;
     int *pencil;		       /* bitmaps using bits 1<<1..1<<n */
     int completed, cheated;
@@ -886,6 +882,7 @@ static game_state *new_game(midend *me, const game_params *params,
     state->clues->clues = snewn(4*w, int);
     state->clues->immutable = snewn(a, digit);
     state->grid = snewn(a, digit);
+    state->cluesdone = snewn(4*w, int);
     state->pencil = snewn(a, int);
 
     for (i = 0; i < a; i++) {
@@ -894,6 +891,7 @@ static game_state *new_game(midend *me, const game_params *params,
     }
 
     memset(state->clues->immutable, 0, a);
+    memset(state->cluesdone, 0, 4*w*sizeof(int));
 
     for (i = 0; i < 4*w; i++) {
 	if (i > 0) {
@@ -947,8 +945,10 @@ static game_state *dup_game(const game_state *state)
 
     ret->grid = snewn(a, digit);
     ret->pencil = snewn(a, int);
+    ret->cluesdone = snewn(4*w, int);
     memcpy(ret->grid, state->grid, a*sizeof(digit));
     memcpy(ret->pencil, state->pencil, a*sizeof(int));
+    memcpy(ret->cluesdone, state->cluesdone, 4*w*sizeof(int));
 
     ret->completed = state->completed;
     ret->cheated = state->cheated;
@@ -960,6 +960,7 @@ static void free_game(game_state *state)
 {
     sfree(state->grid);
     sfree(state->pencil);
+    sfree(state->cluesdone);
     if (--state->clues->refcount <= 0) {
 	sfree(state->clues->immutable);
 	sfree(state->clues->clues);
@@ -1159,6 +1160,7 @@ static void game_changed_state(game_ui *ui, const game_state *oldstate,
 #define FLASH_TIME 0.4F
 
 #define DF_PENCIL_SHIFT 16
+#define DF_CLUE_DONE 0x10000
 #define DF_ERROR 0x8000
 #define DF_HIGHLIGHT 0x4000
 #define DF_HIGHLIGHT_PENCIL 0x2000
@@ -1259,6 +1261,32 @@ static int check_errors(const game_state *state, int *errors)
     return errs;
 }
 
+static int clue_index(const game_state *state, int x, int y)
+{
+    int w = state->par.w;
+
+    if (x == -1 || x == w)
+        return w * (x == -1 ? 2 : 3) + y;
+    else if (y == -1 || y == w)
+        return (y == -1 ? 0 : w) + x;
+
+    return -1;
+}
+
+static int is_clue(const game_state *state, int x, int y)
+{
+    int w = state->par.w;
+
+    if (((x == -1 || x == w) && y >= 0 && y < w) ||
+        ((y == -1 || y == w) && x >= 0 && x < w))
+    {
+        if (state->clues->clues[clue_index(state, x, y)] & DF_DIGIT_MASK)
+            return TRUE;
+    }
+
+    return FALSE;
+}
+
 static char *interpret_move(const game_state *state, game_ui *ui,
                             const game_drawstate *ds,
                             int x, int y, int button)
@@ -1341,6 +1369,11 @@ static char *interpret_move(const game_state *state, game_ui *ui,
             ui->hcursor = 0;
             return "";		       /* UI activity occurred */
         }
+    } else if (button == LEFT_BUTTON) {
+        if (is_clue(state, tx, ty)) {
+            sprintf(buf, "%c%d,%d", 'D', tx, ty);
+            return dupstr(buf);
+        }
     }
     if (IS_CURSOR_MOVE(button)) {
         move_cursor(button, &ui->hx, &ui->hy, w, w, 0);
@@ -1436,6 +1469,11 @@ static game_state *execute_move(const game_state *from, const char *move)
 		ret->pencil[i] = (1L << (w+1)) - (1L << 1);
 	}
 	return ret;
+    } else if (move[0] == 'D' && sscanf(move+1, "%d,%d", &x, &y) == 2 &&
+               is_clue(from, x, y)) {
+        int index = clue_index(from, x, y);
+        ret->cluesdone[index] = !ret->cluesdone[index];
+        return ret;
     }
 
   badmove:
@@ -1492,6 +1530,10 @@ static float *game_colours(frontend *fe, int *ncolours)
     ret[COL_PENCIL * 3 + 1] = 0.5F * ret[COL_BACKGROUND * 3 + 1];
     ret[COL_PENCIL * 3 + 2] = ret[COL_BACKGROUND * 3 + 2];
 
+    ret[COL_DONE * 3 + 0] = ret[COL_BACKGROUND * 3 + 0] / 1.5F;
+    ret[COL_DONE * 3 + 1] = ret[COL_BACKGROUND * 3 + 1] / 1.5F;
+    ret[COL_DONE * 3 + 2] = ret[COL_BACKGROUND * 3 + 2] / 1.5F;
+
     *ncolours = NCOLOURS;
     return ret;
 }
@@ -1605,6 +1647,8 @@ static void draw_tile(drawing *dr, game_drawstate *ds, struct clues *clues,
 
         if (tile & DF_ERROR)
             color = COL_ERROR;
+        else if (tile & DF_CLUE_DONE)
+            color = COL_DONE;
         else if (x < 0 || y < 0 || x >= w || y >= w)
             color = COL_GRID;
         else if (tile & DF_IMMUTABLE)
@@ -1737,6 +1781,8 @@ static void game_redraw(drawing *dr, game_drawstate *ds,
 
 	if (ds->errtmp[(y+1)*(w+2)+(x+1)])
 	    tile |= DF_ERROR;
+        else if (state->cluesdone[i])
+            tile |= DF_CLUE_DONE;
 
 	ds->tiles[(y+1)*(w+2)+(x+1)] = tile;
     }