[gnugo-devel] Bug fix

[Daniel Bump]

Earlier today I posted a game in which a colossal blunder occurs at move 56. 

http://mail.gnu.org/pipermail/gnugo-devel/2001-October/000272.html

It turns out that the reason is a familiar one.  At move 56 there
are two moves that defend the worm at H6.  One, at J7 only produces
ko. Unfortunately estimate_territorial_value doesn't know the difference. 

Luckily one that recent changes of Gunnar's makes easy to fix.
Since all move reasons are now cached in the struct worm_data
array, it is easy to go through and deprecate attack and
defend move reasons that produce KO_A or KO_B.

I won't put this in the CVS until I've run the regressions and
given Gunnar (and anyone else) a chance to comment.

For 1D debugging I recommend adding this to your .gdbinit file:

define pascii
set gprintf("%o%m\n",($arg0)/20 -1, ($arg0)%20 -1)
end

Then

(gdb) pascii pos

will tell you where pos is on the board.

Dan



===================================================================
RCS file: /cvsroot/gnugo/gnugo/ChangeLog,v
retrieving revision 1.62
diff -u -r1.62 ChangeLog
--- ChangeLog   2001/10/25 02:46:23     1.62
+++ ChangeLog   2001/10/25 03:15:10
@@ -2,6 +2,7 @@
 -- ChangeLog
 -------------------------------------------------------------------------
 
+- estimate_territorial_value deprecates attack/defend reasons which only get ko
 - new reorientation test suites
 - remove rot* subdirs from EXTRA_DIST
 - bugfix in score.c (typo from 1D conversion)
Index: engine/liberty.h
===================================================================
RCS file: /cvsroot/gnugo/gnugo/engine/liberty.h,v
retrieving revision 1.37
diff -u -r1.37 liberty.h
--- engine/liberty.h    2001/10/18 19:17:19     1.37
+++ engine/liberty.h    2001/10/25 03:15:24
@@ -559,7 +559,8 @@
                      /* worm which can be captured easily. */
   int cutstone;      /* 1=potential cutting stone; 2=cutting stone */
   int cutstone2;     /* Number of potential cuts involving the worm. */
-  int genus;         /* number of connected components of the complement, less 
one */
+  int genus;         /* number of connected components of the complement, */
+                     /* less one */
   int inessential;   /* 1=inessential worm */
   int invincible;    /* 1=strongly unconditionally non-capturable */
   int unconditional_status; /* ALIVE, DEAD, WHITE_BORDER, BLACK_BORDER, 
UNKNOWN */
Index: engine/move_reasons.c
===================================================================
RCS file: /cvsroot/gnugo/gnugo/engine/move_reasons.c,v
retrieving revision 1.30
diff -u -r1.30 move_reasons.c
--- engine/move_reasons.c       2001/10/18 19:17:19     1.30
+++ engine/move_reasons.c       2001/10/25 03:15:53
@@ -2082,6 +2082,19 @@
 
       this_value = 2 * worm[aa].effective_size;
 
+      /* Reduce the value if it only works with ko */
+      {
+       int u;
+       for (u = 0; u < MAX_TACTICAL_POINTS; u++)
+         if (worm[aa].attack_points[u] == pos) {
+           if (worm[aa].attack_codes[u] == KO_A)
+             this_value *= .9;
+           else if (worm[aa].attack_codes[u] == KO_B)
+             this_value *= .8;
+           break;
+         }
+      }
+
       /* If the stones are dead, there is only a secondary value in
        * capturing them tactically as well.
        */
@@ -2126,6 +2139,19 @@
       }        
 
       this_value = 2 * worm[aa].effective_size;
+
+      /* Reduce the value if it only works with ko */
+      {
+       int u;
+       for (u = 0; u < MAX_TACTICAL_POINTS; u++)
+         if (worm[aa].defense_points[u] == pos) {
+           if (worm[aa].defend_codes[u] == KO_A)
+             this_value *= .9;
+           else if (worm[aa].defend_codes[u] == KO_B)
+             this_value *= .8;
+           break;
+         }
+      }
 
       /* If the stones are dead, we use the convention that
        * defending them has a strategical value rather than
Index: engine/worm.c
===================================================================
RCS file: /cvsroot/gnugo/gnugo/engine/worm.c,v
retrieving revision 1.19
diff -u -r1.19 worm.c
--- engine/worm.c       2001/10/18 19:17:19     1.19
+++ engine/worm.c       2001/10/25 03:16:15
@@ -1947,6 +1947,7 @@
 void
 report_worm(int m, int n)
 {
+  int k;
   int pos = POS(m, n);
   if (board[pos] == EMPTY) {
     gprintf("There is no worm at %1m\n", pos);
@@ -1964,34 +1965,37 @@
          worm[pos].liberties3, 
          worm[pos].liberties4);
 
-  /* FIXME: List all attack points. */
-  if (worm[pos].attack_points[0] != NO_MOVE)
-    gprintf("attack point %1m, ", worm[pos].attack_points[0]);
-  else
-    gprintf("no attack point, ");
-
-  if (worm[pos].attack_codes[0] == WIN)
-    gprintf("attack code WIN\n");
-  else if (worm[pos].attack_codes[0] == KO_A)
-    gprintf("attack code KO_A\n");
-  else if (worm[pos].attack_codes[0] == KO_B)
-    gprintf("attack code KO_B\n");
-
-  /* FIXME: List all defense points. */
-  if (worm[pos].defense_points[0] != NO_MOVE)
-    gprintf("defense point %1m, ", worm[pos].defense_points[0]);
-  else
-    gprintf("no defense point, ");
+  for (k = 0; k < MAX_TACTICAL_POINTS; k++) {
+    if (worm[pos].attack_points[k] == NO_MOVE) {
+      if (k == 0)
+       gprintf("no attack point, ");
+      break;
+    }
+    gprintf("attack point %1m, ", worm[pos].attack_points[k]);
+    if (worm[pos].attack_codes[k] == WIN)
+      gprintf("attack code WIN\n");
+    else if (worm[pos].attack_codes[k] == KO_A)
+      gprintf("attack code KO_A\n");
+    else if (worm[pos].attack_codes[k] == KO_B)
+      gprintf("attack code KO_B\n");
+  }
 
-  if (worm[pos].defend_codes[0] == WIN)
-    gprintf("defend code WIN\n");
-  else if (worm[pos].defend_codes[0] == KO_A)
-    gprintf("defend code KO_A\n");
-  else if (worm[pos].defend_codes[0] == KO_B)
-    gprintf("defend code KO_B\n");
+  for (k = 0; k < MAX_TACTICAL_POINTS; k++) {
+    if (worm[pos].defense_points[k] == NO_MOVE) {
+      if (k == 0)
+       gprintf("no defense point, ");
+      break;
+    }
+    gprintf("defense point %1m, ", worm[pos].defense_points[k]);
+    if (worm[pos].defend_codes[k] == WIN)
+      gprintf("defend code WIN\n");
+    else if (worm[pos].defend_codes[k] == KO_A)
+      gprintf("defend code KO_A\n");
+    else if (worm[pos].defend_codes[k] == KO_B)
+      gprintf("defend code KO_B\n");
+  }
 
   /* FIXME: List all attack and defense threat points. */
-
 
   if (worm[pos].lunch != NO_MOVE)
     gprintf("lunch at %1m\n", worm[pos].lunch);