New puzzle: `Untangle', cloned (with the addition of random grid

generation) from a simple but rather fun Flash game I saw this
morning.

Small infrastructure change for this puzzle: while most game
backends find the midend's assumption that Solve moves are never
animated to be a convenience absolving them of having to handle the
special case themselves, this one actually needs Solve to be
animated. Rather than break that convenience for the other puzzles,
I've introduced a flag bit (which I've shoved in mouse_priorities
for the moment, shamefully without changing its name).

[originally from svn r6097]

Recipe

@@ -20,9 +20,10 @@ NETSLIDE = netslide tree234
 MINES    = mines tree234
 FLIP     = flip tree234
 PEGS     = pegs tree234
+UNTANGLE = untangle tree234
 
 ALL      = list NET NETSLIDE cube fifteen sixteen rect pattern solo twiddle
-         + MINES samegame FLIP guess PEGS dominosa
+         + MINES samegame FLIP guess PEGS dominosa UNTANGLE
 
 net      : [X] gtk COMMON NET
 netslide : [X] gtk COMMON NETSLIDE
@@ -39,6 +40,7 @@ flip     : [X] gtk COMMON FLIP
 guess    : [X] gtk COMMON guess
 pegs     : [X] gtk COMMON PEGS
 dominosa : [X] gtk COMMON dominosa
+untangle : [X] gtk COMMON UNTANGLE
 
 # Auxiliary command-line programs.
 solosolver :    [U] solo[STANDALONE_SOLVER] malloc
@@ -66,6 +68,7 @@ flip     : [G] WINDOWS COMMON FLIP
 guess    : [G] WINDOWS COMMON guess
 pegs     : [G] WINDOWS COMMON PEGS
 dominosa : [G] WINDOWS COMMON dominosa
+untangle : [G] WINDOWS COMMON UNTANGLE
 
 # Mac OS X unified application containing all the puzzles.
 Puzzles  : [MX] osx osx.icns osx-info.plist COMMON ALL
@@ -157,7 +160,7 @@ FORCE:
 install:
 	for i in cube net netslide fifteen sixteen twiddle \
 	         pattern rect solo mines samegame flip guess \
-		 pegs dominosa; do \
+		 pegs dominosa untangle; do \
 		$(INSTALL_PROGRAM) -m 755 $$i $(DESTDIR)$(gamesdir)/$$i; \
 	done
 !end

list.c

@@ -32,6 +32,7 @@ extern const game samegame;
 extern const game sixteen;
 extern const game solo;
 extern const game twiddle;
+extern const game untangle;
 
 const game *gamelist[] = {
     &cube,
@@ -49,6 +50,7 @@ const game *gamelist[] = {
     &sixteen,
     &solo,
     &twiddle,
+    &untangle,
 };
 
 const int gamecount = lenof(gamelist);

midend.c

@@ -432,7 +432,7 @@ static int midend_really_process_key(midend_data *me, int x, int y, int button)
 {
     game_state *oldstate =
         me->ourgame->dup_game(me->states[me->statepos - 1].state);
-    int special = FALSE, gotspecial = FALSE, ret = 1;
+    int type = MOVE, gottype = FALSE, ret = 1;
     float anim_time;
     game_state *s;
     char *movestr;
@@ -450,8 +450,8 @@ static int midend_really_process_key(midend_data *me, int x, int y, int button)
 	} else if (button == 'u' || button == 'u' ||
 		   button == '\x1A' || button == '\x1F') {
 	    midend_stop_anim(me);
-	    special = special(me->states[me->statepos-1].movetype);
-	    gotspecial = TRUE;
+	    type = me->states[me->statepos-1].movetype;
+	    gottype = TRUE;
 	    if (!midend_undo(me))
 		goto done;
 	} else if (button == 'r' || button == 'R' ||
@@ -501,13 +501,14 @@ static int midend_really_process_key(midend_data *me, int x, int y, int button)
         }
     }
 
-    if (!gotspecial)
-        special = special(me->states[me->statepos-1].movetype);
+    if (!gottype)
+        type = me->states[me->statepos-1].movetype;
 
     /*
      * See if this move requires an animation.
      */
-    if (special) {
+    if (special(type) && !(type == SOLVE &&
+			   (me->ourgame->mouse_priorities & SOLVE_ANIMATES))) {
         anim_time = 0;
     } else {
         anim_time = me->ourgame->anim_length(oldstate,
@@ -1117,8 +1118,17 @@ char *midend_solve(midend_data *me)
         me->ourgame->changed_state(me->ui,
                                    me->states[me->statepos-2].state,
                                    me->states[me->statepos-1].state);
+    me->dir = +1;
+    if (me->ourgame->mouse_priorities & SOLVE_ANIMATES) {
+	me->oldstate = me->ourgame->dup_game(me->states[me->statepos-2].state);
+        me->anim_time =
+	    me->ourgame->anim_length(me->states[me->statepos-2].state,
+				     me->states[me->statepos-1].state,
+				     +1, me->ui);
+    } else {
 	me->anim_time = 0.0;
 	midend_finish_move(me);
+    }
     midend_redraw(me);
     midend_set_timer(me);
     return NULL;

puzzles.but

@@ -1243,6 +1243,37 @@ additional challenge for an advanced player. Turning off this option
 can also speed up puzzle generation.
 
 
+\C{untangle} \i{Untangle}
+
+\cfg{winhelp-topic}{games.untangle}
+
+You are given a number of points, some of which have lines drawn
+between them. You can move the points about arbitrarily; your aim is
+to position the points so that no line crosses another.
+
+I originally saw this in the form of a Flash game called \i{Planarity}
+\k{Planarity}, written by John Tantalo.
+
+\B{Planarity} \W{http://home.cwru.edu/~jnt5/Planarity}\cw{http://home.cwru.edu/~jnt5/Planarity}
+
+\H{untangle-controls} \i{Untangle controls}
+
+\IM{Untangle controls} controls, for Untangle
+
+To move a point, click on it with the left mouse button and drag it
+into a new position.
+
+\H{untangle-parameters} \I{parameters, for Untangle}Untangle parameters
+
+There is only one parameter available from the \q{Custom...} option
+on the \q{Type} menu:
+
+\dt \e{Number of points}
+
+\dd Controls the size of the puzzle, by specifying the number of
+points in the generated graph.
+
+
 \A{licence} \I{MIT licence}\ii{Licence}
 
 This software is \i{copyright} 2004-2005 Simon Tatham.

puzzles.h

@@ -62,6 +62,10 @@ enum {
 /* Bit flags indicating mouse button priorities */
 #define BUTTON_BEATS(x,y) ( 1 << (((x)-LEFT_BUTTON)*3+(y)-LEFT_BUTTON) )
 
+/* Another random flag that goes in the mouse priorities section for want
+ * of a better place to put it */
+#define SOLVE_ANIMATES ( 1 << 9 )
+
 #define IGNOREARG(x) ( (x) = (x) )
 
 typedef struct frontend frontend;