http://ftp.x.org/contrib/applications/xscreensaver-3.24.tar.gz

[xscreensaver] / hacks / maze.c

diff --git a/hacks/maze.c b/hacks/maze.c
index 40edf41b58bf9e8dfdc310585680c9b963d037a2..9d22778fb87ac6d5c4d300bc186ad416ab5a8a79 100644 (file)
--- a/hacks/maze.c
+++ b/hacks/maze.c
@@ -1,6 +1,10 @@
 /******************************************************************************
  * [ maze ] ...
  *
+ * modified:  [ 1-04-00 ]  Johannes Keukelaar <johannes@nada.kth.se>
+ *              Added -ignorant option (not the default) to remove knowlege
+ *              of the direction in which the exit lies.
+ *
  * modified:  [ 6-28-98 ]  Zack Weinberg <zack@rabi.phys.columbia.edu>
  *
  *              Made the maze-solver somewhat more intelligent.  There are
@@ -159,7 +163,7 @@ static GC   gc, cgc, tgc, sgc, ugc, logo_gc, erase_gc;
 static Pixmap  logo_map;
 
 static int     x = 0, y = 0, restart = 0, stop = 1, state = 1, max_length;
-static int      sync_p, bridge_p;
+static int      sync_p, bridge_p, ignorant_p;
 
 static int
 check_events (void)                        /* X event handler [ rhess ] */
@@ -1434,44 +1438,60 @@ solve_maze (void)                     /* solve it with graphical feedback */
        
        if(!ways)
            goto backtrack;
-      
-       x = path[i].x - start_x;
-       y = path[i].y - start_y;
-       /* choice one */
-       if(abs(y) <= abs(x))
-           dir = (x > 0) ? WALL_LEFT : WALL_RIGHT;
-       else
-           dir = (y > 0) ? WALL_TOP : WALL_BOTTOM;
-       
-       if(dir & ways)
-           goto found;
-       
-       /* choice two */
-       switch(dir)
-       {
-       case WALL_LEFT:
-       case WALL_RIGHT:
-           dir = (y > 0) ? WALL_TOP : WALL_BOTTOM; break;
-       case WALL_TOP:
-       case WALL_BOTTOM:
-           dir = (x > 0) ? WALL_LEFT : WALL_RIGHT;
-       }
-       
-       if(dir & ways)
-           goto found;
-       
-       /* choice three */
-       
-       dir = (dir << 2 & WALL_ANY) | (dir >> 2 & WALL_ANY);
-       if(dir & ways)
-           goto found;
-       
-       /* choice four */
-       dir = ways;
-       if(!dir)
-           goto backtrack;
 
-    found:
+       if (!ignorant_p)
+         {
+           x = path[i].x - start_x;
+           y = path[i].y - start_y;
+           /* choice one */
+           if(abs(y) <= abs(x))
+             dir = (x > 0) ? WALL_LEFT : WALL_RIGHT;
+           else
+             dir = (y > 0) ? WALL_TOP : WALL_BOTTOM;
+           
+           if(dir & ways)
+             goto found;
+           
+           /* choice two */
+           switch(dir)
+             {
+             case WALL_LEFT:
+             case WALL_RIGHT:
+               dir = (y > 0) ? WALL_TOP : WALL_BOTTOM; break;
+             case WALL_TOP:
+             case WALL_BOTTOM:
+               dir = (x > 0) ? WALL_LEFT : WALL_RIGHT;
+             }
+           
+           if(dir & ways)
+             goto found;
+           
+           /* choice three */
+           
+           dir = (dir << 2 & WALL_ANY) | (dir >> 2 & WALL_ANY);
+           if(dir & ways)
+             goto found;
+           
+           /* choice four */
+           dir = ways;
+           if(!dir)
+             goto backtrack;
+           
+         found:
+         }
+       else
+         {
+           if(ways&WALL_TOP)
+             dir = WALL_TOP;
+           else if(ways&WALL_LEFT)
+             dir = WALL_LEFT;
+           else if(ways&WALL_BOTTOM)
+             dir = WALL_BOTTOM;
+           else if(ways&WALL_RIGHT)
+             dir = WALL_RIGHT;
+           else
+             goto backtrack;
+         }
        bt = 0;
        ways &= ~dir;  /* tried this one */
        
@@ -1498,7 +1518,7 @@ solve_maze (void)                     /* solve it with graphical feedback */
            return;
        }
 
-       if(!bt)
+       if(!bt && !ignorant_p)
            find_dead_regions();
        bt = 1;
        from = path[i-1].dir;
@@ -1565,6 +1585,8 @@ char *defaults[] = {
 };
 
 XrmOptionDescRec options[] = {
+  { "-ignorant",        ".ignorant",    XrmoptionNoArg, "True" },
+  { "-no-ignorant",     ".ignorant",    XrmoptionNoArg, "False" },
   { "-grid-size",      ".gridSize",    XrmoptionSepArg, 0 },
   { "-solve-delay",    ".solveDelay",  XrmoptionSepArg, 0 },
   { "-pre-delay",      ".preDelay",    XrmoptionSepArg, 0 },
@@ -1600,6 +1622,7 @@ screenhack(Display *display, Window window)
   generator = get_integer_resource("generator", "Integer");
   max_length = get_integer_resource("maxLength", "Integer");
   bridge_p = get_boolean_resource("bridge", "Boolean");
+  ignorant_p = get_boolean_resource("ignorant", "Boolean");
 
   if (size < 2) size = 7 + (random () % 30);
   grid_width = grid_height = size;