shithub: puzzles

Download patch

ref: 980880be1f2801b2a69fcc67abc0f5827fd106f2
parent: 8c6c8df8f4bd07602931485956fce524925dc2bb
author: Simon Tatham <anakin@pobox.com>
date: Sat Apr 2 12:19:12 EDT 2011

Add a function to every game backend which indicates whether a game
state is in a solved position, and a midend function wrapping it.

(Or, at least, a situation in which further play is pointless. The
point is, given that game state, would it be a good idea for a front
end that does that sort of thing to proactively provide the option to
start a fresh game?)

[originally from svn r9140]

--- a/blackbox.c
+++ b/blackbox.c
@@ -1462,6 +1462,15 @@
         return 0.0F;
 }
 
+static int game_is_solved(game_state *state)
+{
+    /*
+     * We return true whenever the solution has been revealed, even
+     * (on spoiler grounds) if it wasn't guessed correctly.
+     */
+    return state->reveal;
+}
+
 static int game_timing_state(game_state *state, game_ui *ui)
 {
     return TRUE;
@@ -1510,6 +1519,7 @@
     game_redraw,
     game_anim_length,
     game_flash_length,
+    game_is_solved,
     FALSE, FALSE, game_print_size, game_print,
     TRUE,			       /* wants_statusbar */
     FALSE, game_timing_state,
--- a/bridges.c
+++ b/bridges.c
@@ -2715,6 +2715,11 @@
     return 0.0F;
 }
 
+static int game_is_solved(game_state *state)
+{
+    return state->completed;
+}
+
 static int game_timing_state(game_state *state, game_ui *ui)
 {
     return TRUE;
@@ -2818,6 +2823,7 @@
     game_redraw,
     game_anim_length,
     game_flash_length,
+    game_is_solved,
     TRUE, FALSE, game_print_size, game_print,
     FALSE,			       /* wants_statusbar */
     FALSE, game_timing_state,
--- a/cube.c
+++ b/cube.c
@@ -1710,6 +1710,11 @@
     return 0.0F;
 }
 
+static int game_is_solved(game_state *state)
+{
+    return state->completed;
+}
+
 static int game_timing_state(game_state *state, game_ui *ui)
 {
     return TRUE;
@@ -1758,6 +1763,7 @@
     game_redraw,
     game_anim_length,
     game_flash_length,
+    game_is_solved,
     FALSE, FALSE, game_print_size, game_print,
     TRUE,			       /* wants_statusbar */
     FALSE, game_timing_state,
--- a/devel.but
+++ b/devel.but
@@ -1224,6 +1224,28 @@
 to achieve this, its \cw{flash_length()} function has to store a
 flag in the \c{game_ui} to indicate which flash type is required.)
 
+\S{backend-is-solved} \cw{is_solved()}
+
+\c int (*is_solved)(game_state *state);
+
+This function returns \cw{TRUE} if the game represented by \cw{state}
+is currently in a solved state. The mid-end uses this to implement
+\cw{midend_is_solved()} (\k{midend-is-solved}).
+
+Front ends may wish to use this as a cue to proactively offer the
+option of starting a new game. Therefore, back ends should consider
+returning TRUE in situations where the game is \e{lost} as well as
+won, if losing makes it unlikely that the player would play on.
+
+(For instance, games with hidden information such as Guess or Mines
+might well set this flag whenever they reveal the solution, whether or
+not the player guessed it correctly, on the grounds that a player
+would be unlikely to hide the solution and continue playing after the
+answer was spoiled. On the other hand, games where you can merely get
+into a dead end such as Same Game or Inertia might choose not to, on
+the grounds that the player would quite likely press Undo and carry on
+playing.)
+
 \S{backend-redraw} \cw{redraw()}
 
 \c void (*redraw)(drawing *dr, game_drawstate *ds,
@@ -3095,6 +3117,19 @@
 The front end can expect its drawing API and/or
 \cw{activate_timer()} to be called from within a call to this
 function.
+
+\S{midend-is-solved} \cw{midend_is_solved()}
+
+\c int midend_is_solved(midend *me);
+
+This function returns \cw{TRUE} if the midend is currently displaying
+a game in a solved state, according to the back end's \cw{is_solved()}
+function. Front ends may wish to use this as a cue to proactively
+offer the option of starting a new game.
+
+(See \k{backend-is-solved} for more detail about the back end's
+\cw{is_solved()} function and discussion of what should count as
+\q{solved} anyway).
 
 \H{midend-can-undo} \cw{midend_can_undo()}
 
--- a/dominosa.c
+++ b/dominosa.c
@@ -1535,6 +1535,11 @@
     return 0.0F;
 }
 
+static int game_is_solved(game_state *state)
+{
+    return state->completed;
+}
+
 static int game_timing_state(game_state *state, game_ui *ui)
 {
     return TRUE;
@@ -1623,6 +1628,7 @@
     game_redraw,
     game_anim_length,
     game_flash_length,
+    game_is_solved,
     TRUE, FALSE, game_print_size, game_print,
     FALSE,			       /* wants_statusbar */
     FALSE, game_timing_state,
--- a/fifteen.c
+++ b/fifteen.c
@@ -830,6 +830,11 @@
         return 0.0F;
 }
 
+static int game_is_solved(game_state *state)
+{
+    return state->completed;
+}
+
 static int game_timing_state(game_state *state, game_ui *ui)
 {
     return TRUE;
@@ -878,6 +883,7 @@
     game_redraw,
     game_anim_length,
     game_flash_length,
+    game_is_solved,
     FALSE, FALSE, game_print_size, game_print,
     TRUE,			       /* wants_statusbar */
     FALSE, game_timing_state,
--- a/filling.c
+++ b/filling.c
@@ -1617,6 +1617,11 @@
     return 0.0F;
 }
 
+static int game_is_solved(game_state *state)
+{
+    return state->completed;
+}
+
 static int game_timing_state(game_state *state, game_ui *ui)
 {
     return TRUE;
@@ -1715,6 +1720,7 @@
     game_redraw,
     game_anim_length,
     game_flash_length,
+    game_is_solved,
     TRUE, FALSE, game_print_size, game_print,
     FALSE,				   /* wants_statusbar */
     FALSE, game_timing_state,
--- a/flip.c
+++ b/flip.c
@@ -1251,6 +1251,11 @@
     return 0.0F;
 }
 
+static int game_is_solved(game_state *state)
+{
+    return state->completed;
+}
+
 static int game_timing_state(game_state *state, game_ui *ui)
 {
     return TRUE;
@@ -1299,6 +1304,7 @@
     game_redraw,
     game_anim_length,
     game_flash_length,
+    game_is_solved,
     FALSE, FALSE, game_print_size, game_print,
     TRUE,			       /* wants_statusbar */
     FALSE, game_timing_state,
--- a/galaxies.c
+++ b/galaxies.c
@@ -3348,6 +3348,11 @@
         return 0.0F;
 }
 
+static int game_is_solved(game_state *state)
+{
+    return state->completed;
+}
+
 static int game_timing_state(game_state *state, game_ui *ui)
 {
     return TRUE;
@@ -3568,6 +3573,7 @@
     game_redraw,
     game_anim_length,
     game_flash_length,
+    game_is_solved,
 #ifdef EDITOR
     FALSE, FALSE, NULL, NULL,
     TRUE,                              /* wants_statusbar */
--- a/guess.c
+++ b/guess.c
@@ -1314,6 +1314,18 @@
     return 0.0F;
 }
 
+static int game_is_solved(game_state *state)
+{
+    /*
+     * We return true whenever the solution has been revealed, even
+     * (on spoiler grounds) if it wasn't guessed correctly.
+     *
+     * However, in that situation, 'solved' is still true, so we don't
+     * have to make any effort to arrange this.
+     */
+    return state->solved;
+}
+
 static int game_timing_state(game_state *state, game_ui *ui)
 {
     return TRUE;
@@ -1362,6 +1374,7 @@
     game_redraw,
     game_anim_length,
     game_flash_length,
+    game_is_solved,
     FALSE, FALSE, game_print_size, game_print,
     FALSE,			       /* wants_statusbar */
     FALSE, game_timing_state,
--- a/inertia.c
+++ b/inertia.c
@@ -2135,6 +2135,16 @@
     return 0.0F;
 }
 
+static int game_is_solved(game_state *state)
+{
+    /*
+     * If the player has died, we don't list the game as solved,
+     * because they're more likely to undo and carry on than to give
+     * up and start a new game.
+     */
+    return !state->gems;
+}
+
 static int game_timing_state(game_state *state, game_ui *ui)
 {
     return TRUE;
@@ -2183,6 +2193,7 @@
     game_redraw,
     game_anim_length,
     game_flash_length,
+    game_is_solved,
     FALSE, FALSE, game_print_size, game_print,
     TRUE,			       /* wants_statusbar */
     FALSE, game_timing_state,
--- a/keen.c
+++ b/keen.c
@@ -2013,6 +2013,11 @@
     return 0.0F;
 }
 
+static int game_is_solved(game_state *state)
+{
+    return state->completed;
+}
+
 static int game_timing_state(game_state *state, game_ui *ui)
 {
     if (state->completed)
@@ -2289,6 +2294,7 @@
     game_redraw,
     game_anim_length,
     game_flash_length,
+    game_is_solved,
     TRUE, FALSE, game_print_size, game_print,
     FALSE,			       /* wants_statusbar */
     FALSE, game_timing_state,
--- a/lightup.c
+++ b/lightup.c
@@ -2160,6 +2160,11 @@
     return 0.0F;
 }
 
+static int game_is_solved(game_state *state)
+{
+    return state->completed;
+}
+
 static int game_timing_state(game_state *state, game_ui *ui)
 {
     return TRUE;
@@ -2262,6 +2267,7 @@
     game_redraw,
     game_anim_length,
     game_flash_length,
+    game_is_solved,
     TRUE, FALSE, game_print_size, game_print,
     FALSE,			       /* wants_statusbar */
     FALSE, game_timing_state,
--- a/loopy.c
+++ b/loopy.c
@@ -3834,6 +3834,11 @@
     return 0.0F;
 }
 
+static int game_is_solved(game_state *state)
+{
+    return state->solved;
+}
+
 static void game_print_size(game_params *params, float *x, float *y)
 {
     int pw, ph;
@@ -3960,6 +3965,7 @@
     game_redraw,
     game_anim_length,
     game_flash_length,
+    game_is_solved,
     TRUE, FALSE, game_print_size, game_print,
     FALSE /* wants_statusbar */,
     FALSE, game_timing_state,
--- a/magnets.c
+++ b/magnets.c
@@ -2235,6 +2235,11 @@
     return 0.0F;
 }
 
+static int game_is_solved(game_state *state)
+{
+    return state->completed;
+}
+
 static int game_timing_state(game_state *state, game_ui *ui)
 {
     return TRUE;
@@ -2374,6 +2379,7 @@
     game_redraw,
     game_anim_length,
     game_flash_length,
+    game_is_solved,
     TRUE, FALSE, game_print_size, game_print,
     FALSE,			       /* wants_statusbar */
     FALSE, game_timing_state,
--- a/map.c
+++ b/map.c
@@ -3025,6 +3025,11 @@
 	return 0.0F;
 }
 
+static int game_is_solved(game_state *state)
+{
+    return state->completed;
+}
+
 static int game_timing_state(game_state *state, game_ui *ui)
 {
     return TRUE;
@@ -3218,6 +3223,7 @@
     game_redraw,
     game_anim_length,
     game_flash_length,
+    game_is_solved,
     TRUE, TRUE, game_print_size, game_print,
     FALSE,			       /* wants_statusbar */
     FALSE, game_timing_state,
--- a/midend.c
+++ b/midend.c
@@ -1336,6 +1336,21 @@
     return NULL;
 }
 
+int midend_is_solved(midend *me)
+{
+    /*
+     * We should probably never be called when the state stack has no
+     * states on it at all - ideally, midends should never be left in
+     * that state for long enough to get put down and forgotten about.
+     * But if we are, I think we return _true_ - pedantically speaking
+     * a midend in that state is 'vacuously solved', and more
+     * practically, a user whose midend has been left in that state
+     * probably _does_ want the 'new game' option to be prominent.
+     */
+    return (me->statepos == 0 ||
+            me->ourgame->is_solved(me->states[me->statepos-1].state));
+}
+
 char *midend_rewrite_statusbar(midend *me, char *text)
 {
     /*
--- a/mines.c
+++ b/mines.c
@@ -3084,6 +3084,11 @@
     return 0.0F;
 }
 
+static int game_is_solved(game_state *state)
+{
+    return state->won;
+}
+
 static int game_timing_state(game_state *state, game_ui *ui)
 {
     if (state->dead || state->won || ui->completed || !state->layout->mines)
@@ -3134,6 +3139,7 @@
     game_redraw,
     game_anim_length,
     game_flash_length,
+    game_is_solved,
     FALSE, FALSE, game_print_size, game_print,
     TRUE,			       /* wants_statusbar */
     TRUE, game_timing_state,
--- a/net.c
+++ b/net.c
@@ -2864,6 +2864,11 @@
     return 0.0F;
 }
 
+static int game_is_solved(game_state *state)
+{
+    return state->completed;
+}
+
 static int game_timing_state(game_state *state, game_ui *ui)
 {
     return TRUE;
@@ -3039,6 +3044,7 @@
     game_redraw,
     game_anim_length,
     game_flash_length,
+    game_is_solved,
     TRUE, FALSE, game_print_size, game_print,
     TRUE,			       /* wants_statusbar */
     FALSE, game_timing_state,
--- a/netslide.c
+++ b/netslide.c
@@ -1829,6 +1829,11 @@
     return 0.0F;
 }
 
+static int game_is_solved(game_state *state)
+{
+    return state->completed;
+}
+
 static int game_timing_state(game_state *state, game_ui *ui)
 {
     return FALSE;
@@ -1877,6 +1882,7 @@
     game_redraw,
     game_anim_length,
     game_flash_length,
+    game_is_solved,
     FALSE, FALSE, game_print_size, game_print,
     TRUE,			       /* wants_statusbar */
     FALSE, game_timing_state,
--- a/nullgame.c
+++ b/nullgame.c
@@ -238,6 +238,11 @@
     return 0.0F;
 }
 
+static int game_is_solved(game_state *state)
+{
+    return FALSE;
+}
+
 static int game_timing_state(game_state *state, game_ui *ui)
 {
     return TRUE;
@@ -286,6 +291,7 @@
     game_redraw,
     game_anim_length,
     game_flash_length,
+    game_is_solved,
     FALSE, FALSE, game_print_size, game_print,
     FALSE,			       /* wants_statusbar */
     FALSE, game_timing_state,
--- a/pattern.c
+++ b/pattern.c
@@ -1282,6 +1282,11 @@
     return 0.0F;
 }
 
+static int game_is_solved(game_state *state)
+{
+    return state->completed;
+}
+
 static int game_timing_state(game_state *state, game_ui *ui)
 {
     return TRUE;
@@ -1386,6 +1391,7 @@
     game_redraw,
     game_anim_length,
     game_flash_length,
+    game_is_solved,
     TRUE, FALSE, game_print_size, game_print,
     FALSE,			       /* wants_statusbar */
     FALSE, game_timing_state,
--- a/pegs.c
+++ b/pegs.c
@@ -1269,6 +1269,11 @@
         return 0.0F;
 }
 
+static int game_is_solved(game_state *state)
+{
+    return state->completed;
+}
+
 static int game_timing_state(game_state *state, game_ui *ui)
 {
     return TRUE;
@@ -1317,6 +1322,7 @@
     game_redraw,
     game_anim_length,
     game_flash_length,
+    game_is_solved,
     FALSE, FALSE, game_print_size, game_print,
     FALSE,			       /* wants_statusbar */
     FALSE, game_timing_state,
--- a/puzzles.h
+++ b/puzzles.h
@@ -253,6 +253,7 @@
 int midend_can_format_as_text_now(midend *me);
 char *midend_text_format(midend *me);
 char *midend_solve(midend *me);
+int midend_is_solved(midend *me);
 int midend_can_undo(midend *me);
 int midend_can_redo(midend *me);
 void midend_supersede_game_desc(midend *me, char *desc, char *privdesc);
@@ -478,6 +479,7 @@
 			 game_ui *ui);
     float (*flash_length)(game_state *oldstate, game_state *newstate, int dir,
 			  game_ui *ui);
+    int (*is_solved)(game_state *state);
     int can_print, can_print_in_colour;
     void (*print_size)(game_params *params, float *x, float *y);
     void (*print)(drawing *dr, game_state *state, int tilesize);
--- a/range.c
+++ b/range.c
@@ -1480,6 +1480,11 @@
     return 0.0F;
 }
 
+static int game_is_solved(game_state *state)
+{
+    return state->was_solved;
+}
+
 /* ----------------------------------------------------------------------
  * Drawing routines.
  */
@@ -1727,6 +1732,7 @@
     game_redraw,
     game_anim_length,
     game_flash_length,
+    game_is_solved,
     TRUE, FALSE, game_print_size, game_print,
     FALSE, /* wants_statusbar */
     FALSE, game_timing_state,
--- a/rect.c
+++ b/rect.c
@@ -2855,6 +2855,11 @@
     return 0.0F;
 }
 
+static int game_is_solved(game_state *state)
+{
+    return state->completed;
+}
+
 static int game_timing_state(game_state *state, game_ui *ui)
 {
     return TRUE;
@@ -2960,6 +2965,7 @@
     game_redraw,
     game_anim_length,
     game_flash_length,
+    game_is_solved,
     TRUE, FALSE, game_print_size, game_print,
     TRUE,			       /* wants_statusbar */
     FALSE, game_timing_state,
--- a/samegame.c
+++ b/samegame.c
@@ -1611,6 +1611,16 @@
 	return 0.0F;
 }
 
+static int game_is_solved(game_state *state)
+{
+    /*
+     * If the player has run out of moves without winning, we don't
+     * list the game as solved, because they're more likely to undo
+     * and carry on than to give up and start a new game.
+     */
+    return state->complete;
+}
+
 static int game_timing_state(game_state *state, game_ui *ui)
 {
     return TRUE;
@@ -1659,6 +1669,7 @@
     game_redraw,
     game_anim_length,
     game_flash_length,
+    game_is_solved,
     FALSE, FALSE, game_print_size, game_print,
     TRUE,			       /* wants_statusbar */
     FALSE, game_timing_state,
--- a/signpost.c
+++ b/signpost.c
@@ -2122,6 +2122,11 @@
         return 0.0F;
 }
 
+static int game_is_solved(game_state *state)
+{
+    return state->completed;
+}
+
 static int game_timing_state(game_state *state, game_ui *ui)
 {
     return TRUE;
@@ -2203,6 +2208,7 @@
     game_redraw,
     game_anim_length,
     game_flash_length,
+    game_is_solved,
     TRUE, FALSE, game_print_size, game_print,
     FALSE,			       /* wants_statusbar */
     FALSE, game_timing_state,
--- a/singles.c
+++ b/singles.c
@@ -1735,6 +1735,11 @@
     return 0.0F;
 }
 
+static int game_is_solved(game_state *state)
+{
+    return state->completed;
+}
+
 static int game_timing_state(game_state *state, game_ui *ui)
 {
     return TRUE;
@@ -1821,6 +1826,7 @@
     game_redraw,
     game_anim_length,
     game_flash_length,
+    game_is_solved,
     TRUE, FALSE, game_print_size, game_print,
     FALSE,			       /* wants_statusbar */
     FALSE, game_timing_state,
--- a/sixteen.c
+++ b/sixteen.c
@@ -1073,6 +1073,11 @@
         return 0.0F;
 }
 
+static int game_is_solved(game_state *state)
+{
+    return state->completed;
+}
+
 static int game_timing_state(game_state *state, game_ui *ui)
 {
     return TRUE;
@@ -1121,6 +1126,7 @@
     game_redraw,
     game_anim_length,
     game_flash_length,
+    game_is_solved,
     FALSE, FALSE, game_print_size, game_print,
     TRUE,			       /* wants_statusbar */
     FALSE, game_timing_state,
--- a/slant.c
+++ b/slant.c
@@ -2079,6 +2079,11 @@
     return 0.0F;
 }
 
+static int game_is_solved(game_state *state)
+{
+    return state->completed;
+}
+
 static int game_timing_state(game_state *state, game_ui *ui)
 {
     return TRUE;
@@ -2190,6 +2195,7 @@
     game_redraw,
     game_anim_length,
     game_flash_length,
+    game_is_solved,
     TRUE, FALSE, game_print_size, game_print,
     FALSE,			       /* wants_statusbar */
     FALSE, game_timing_state,
--- a/solo.c
+++ b/solo.c
@@ -5169,6 +5169,11 @@
     return 0.0F;
 }
 
+static int game_is_solved(game_state *state)
+{
+    return state->completed;
+}
+
 static int game_timing_state(game_state *state, game_ui *ui)
 {
     if (state->completed)
@@ -5488,6 +5493,7 @@
     game_redraw,
     game_anim_length,
     game_flash_length,
+    game_is_solved,
     TRUE, FALSE, game_print_size, game_print,
     FALSE,			       /* wants_statusbar */
     FALSE, game_timing_state,
--- a/tents.c
+++ b/tents.c
@@ -2524,6 +2524,11 @@
     return 0.0F;
 }
 
+static int game_is_solved(game_state *state)
+{
+    return state->completed;
+}
+
 static int game_timing_state(game_state *state, game_ui *ui)
 {
     return TRUE;
@@ -2594,6 +2599,7 @@
     game_redraw,
     game_anim_length,
     game_flash_length,
+    game_is_solved,
     TRUE, FALSE, game_print_size, game_print,
     FALSE,			       /* wants_statusbar */
     FALSE, game_timing_state,
--- a/towers.c
+++ b/towers.c
@@ -1809,6 +1809,11 @@
     return 0.0F;
 }
 
+static int game_is_solved(game_state *state)
+{
+    return state->completed;
+}
+
 static int game_timing_state(game_state *state, game_ui *ui)
 {
     if (state->completed)
@@ -1928,6 +1933,7 @@
     game_redraw,
     game_anim_length,
     game_flash_length,
+    game_is_solved,
     TRUE, FALSE, game_print_size, game_print,
     FALSE,			       /* wants_statusbar */
     FALSE, game_timing_state,
--- a/twiddle.c
+++ b/twiddle.c
@@ -1070,6 +1070,11 @@
         return 0.0F;
 }
 
+static int game_is_solved(game_state *state)
+{
+    return state->completed;
+}
+
 static void game_redraw(drawing *dr, game_drawstate *ds, game_state *oldstate,
 			game_state *state, int dir, game_ui *ui,
 			float animtime, float flashtime)
@@ -1287,6 +1292,7 @@
     game_redraw,
     game_anim_length,
     game_flash_length,
+    game_is_solved,
     FALSE, FALSE, game_print_size, game_print,
     TRUE,			       /* wants_statusbar */
     FALSE, game_timing_state,
--- a/unequal.c
+++ b/unequal.c
@@ -1864,6 +1864,11 @@
     return 0.0F;
 }
 
+static int game_is_solved(game_state *state)
+{
+    return state->completed;
+}
+
 static int game_timing_state(game_state *state, game_ui *ui)
 {
     return TRUE;
@@ -1952,6 +1957,7 @@
     game_redraw,
     game_anim_length,
     game_flash_length,
+    game_is_solved,
     TRUE, FALSE, game_print_size, game_print,
     FALSE,			       /* wants_statusbar */
     FALSE, game_timing_state,
--- a/unfinished/group.c
+++ b/unfinished/group.c
@@ -1813,6 +1813,11 @@
     return 0.0F;
 }
 
+static int game_is_solved(game_state *state)
+{
+    return state->completed;
+}
+
 static int game_timing_state(game_state *state, game_ui *ui)
 {
     if (state->completed)
@@ -1931,6 +1936,7 @@
     game_redraw,
     game_anim_length,
     game_flash_length,
+    game_is_solved,
     TRUE, FALSE, game_print_size, game_print,
     FALSE,			       /* wants_statusbar */
     FALSE, game_timing_state,
--- a/unfinished/pearl.c
+++ b/unfinished/pearl.c
@@ -1349,6 +1349,11 @@
     return 0.0F;
 }
 
+static int game_is_solved(game_state *state)
+{
+    return FALSE;
+}
+
 static int game_timing_state(game_state *state, game_ui *ui)
 {
     return TRUE;
@@ -1397,6 +1402,7 @@
     game_redraw,
     game_anim_length,
     game_flash_length,
+    game_is_solved,
     FALSE, FALSE, game_print_size, game_print,
     FALSE,			       /* wants_statusbar */
     FALSE, game_timing_state,
--- a/unfinished/separate.c
+++ b/unfinished/separate.c
@@ -795,6 +795,11 @@
     return 0.0F;
 }
 
+static int game_is_solved(game_state *state)
+{
+    return FALSE;
+}
+
 static int game_timing_state(game_state *state, game_ui *ui)
 {
     return TRUE;
@@ -843,6 +848,7 @@
     game_redraw,
     game_anim_length,
     game_flash_length,
+    game_is_solved,
     FALSE, FALSE, game_print_size, game_print,
     FALSE,			       /* wants_statusbar */
     FALSE, game_timing_state,
--- a/unfinished/slide.c
+++ b/unfinished/slide.c
@@ -2293,6 +2293,11 @@
     return 0.0F;
 }
 
+static int game_is_solved(game_state *state)
+{
+    return state->completed;
+}
+
 static int game_timing_state(game_state *state, game_ui *ui)
 {
     return TRUE;
@@ -2341,6 +2346,7 @@
     game_redraw,
     game_anim_length,
     game_flash_length,
+    game_is_solved,
     FALSE, FALSE, game_print_size, game_print,
     TRUE,			       /* wants_statusbar */
     FALSE, game_timing_state,
--- a/unfinished/sokoban.c
+++ b/unfinished/sokoban.c
@@ -1415,6 +1415,11 @@
         return 0.0F;
 }
 
+static int game_is_solved(game_state *state)
+{
+    return state->completed;
+}
+
 static int game_timing_state(game_state *state, game_ui *ui)
 {
     return TRUE;
@@ -1463,6 +1468,7 @@
     game_redraw,
     game_anim_length,
     game_flash_length,
+    game_is_solved,
     FALSE, FALSE, game_print_size, game_print,
     FALSE,			       /* wants_statusbar */
     FALSE, game_timing_state,
--- a/untangle.c
+++ b/untangle.c
@@ -1412,6 +1412,11 @@
     return 0.0F;
 }
 
+static int game_is_solved(game_state *state)
+{
+    return state->completed;
+}
+
 static int game_timing_state(game_state *state, game_ui *ui)
 {
     return TRUE;
@@ -1460,6 +1465,7 @@
     game_redraw,
     game_anim_length,
     game_flash_length,
+    game_is_solved,
     FALSE, FALSE, game_print_size, game_print,
     FALSE,			       /* wants_statusbar */
     FALSE, game_timing_state,