[Freeciv-Dev] (PR#9959) Re: [freeciv-ai] Re: Inprovements in settler.c

["Per I. Mathisen" <per@xxxxxxxxxxx>]

<URL: http://rt.freeciv.org/Ticket/Display.html?id=9959 >

On Wed, 1 Sep 2004, Jordi Negrevernis i Font wrote:
>   Updated to current CVS. I did not test fuly because the cvs-Aug-29
> crashed a lot - cma specialy.

Here is another updated patch. I changed the if-logic a little to waste
fewer CPU-cycles and made it return when failing to build cities.

TODO:
 - the borders check should also check if we are using borders in the
server (iirc game.borders)
 - we should use the movemap code instead of enemies_at(), because
enemies_at() is really insufficient here

So I wish to delay this patch until we have the movemap in cvs, and
movemap is currently waiting for Greg's new pf patch.

  - Per

Index: ai/aitools.c
===================================================================
RCS file: /home/freeciv/CVS/freeciv/ai/aitools.c,v
retrieving revision 1.122
diff -u -r1.122 aitools.c
--- ai/aitools.c        2 Sep 2004 14:58:23 -0000       1.122
+++ ai/aitools.c        5 Sep 2004 20:25:20 -0000
@@ -425,7 +425,7 @@
   bodyguard has not. This is an ai_unit_* auxiliary function, do not use 
   elsewhere.
 **************************************************************************/
-static void ai_unit_bodyguard_move(int unitid, int x, int y)
+void ai_unit_bodyguard_move(int unitid, int x, int y)
 {
   struct unit *bodyguard = find_unit_by_id(unitid);
   struct unit *punit;
@@ -459,7 +459,7 @@
   Repair incompletely referenced bodyguards. When the rest of the bodyguard
   mess is cleaned up, this repairing should be replaced with an assert.
 **************************************************************************/
-static bool has_bodyguard(struct unit *punit)
+bool has_bodyguard(struct unit *punit)
 {
   struct unit *guard;
   if (punit->ai.bodyguard > BODYGUARD_NONE) {
Index: ai/aitools.h
===================================================================
RCS file: /home/freeciv/CVS/freeciv/ai/aitools.h,v
retrieving revision 1.46
diff -u -r1.46 aitools.h
--- ai/aitools.h        3 Sep 2004 04:22:36 -0000       1.46
+++ ai/aitools.h        5 Sep 2004 20:25:20 -0000
@@ -51,6 +51,7 @@
 bool ai_unit_make_homecity(struct unit *punit, struct city *pcity);
 bool ai_unit_attack(struct unit *punit, int x, int y);
 bool ai_unit_move(struct unit *punit, int x, int y);
+void ai_unit_bodyguard_move(int unitid, int x, int y);
 
 struct city *dist_nearest_city(struct player *pplayer, int x, int y,
                                bool everywhere, bool enemy);
@@ -69,4 +70,7 @@
 
 bool is_player_dangerous(struct player *pplayer, struct player *aplayer);
 
+bool has_bodyguard(struct unit *punit);
+
+
 #endif  /* FC__AITOOLS_H */
Index: ai/aiunit.c
===================================================================
RCS file: /home/freeciv/CVS/freeciv/ai/aiunit.c,v
retrieving revision 1.334
diff -u -r1.334 aiunit.c
--- ai/aiunit.c 1 Sep 2004 11:47:25 -0000       1.334
+++ ai/aiunit.c 5 Sep 2004 20:25:20 -0000
@@ -903,6 +903,34 @@
 }
 
 /*************************************************************************
+  Tries to find a land tile adjacent to a unit to defend from an attack
+  (dest_x, dest_y).  Prefers tiles which are more defensible.
+**************************************************************************/
+bool find_defending_spot(struct unit *punit, int *x, int *y)
+{
+  int ok, best = 0;
+  enum tile_terrain_type t;
+
+  CHECK_UNIT(punit);
+
+  adjc_iterate(punit->x, punit->y, x1, y1) {
+    ok = 0;
+    t = map_get_terrain(x1, y1);
+    if (!is_ocean(t) && is_my_zoc(unit_owner(punit), x1, y1)) {
+      /* accessible tile nearby */
+      ok = get_tile_type(t)->defense_bonus;
+      if (ok > best) {
+        best = ok;
+        *x = x1;
+        *y = y1;
+      }
+    }
+  } adjc_iterate_end;
+
+  return (best > 0);
+}
+
+/*************************************************************************
   Does the unit with the id given have the flag L_DEFEND_GOOD?
 **************************************************************************/
 static bool unit_role_defender(Unit_Type_id type)
Index: ai/aiunit.h
===================================================================
RCS file: /home/freeciv/CVS/freeciv/ai/aiunit.h,v
retrieving revision 1.54
diff -u -r1.54 aiunit.h
--- ai/aiunit.h 3 Sep 2004 04:22:36 -0000       1.54
+++ ai/aiunit.h 5 Sep 2004 20:25:21 -0000
@@ -64,6 +64,7 @@
                             int *x, int *y);
 bool find_beachhead(struct unit *punit, int dest_x, int dest_y, 
                     int *x, int *y);
+bool find_defending_spot(struct unit *punit, int *x, int *y);
 
 int build_cost_balanced(Unit_Type_id type);
 int unittype_att_rating(Unit_Type_id type, int veteran,
Index: server/settlers.c
===================================================================
RCS file: /home/freeciv/CVS/freeciv/server/settlers.c,v
retrieving revision 1.199
diff -u -r1.199 settlers.c
--- server/settlers.c   31 Aug 2004 04:40:51 -0000      1.199
+++ server/settlers.c   5 Sep 2004 20:25:22 -0000
@@ -63,6 +63,8 @@
 {
   int x = punit->x, y = punit->y;
   struct city *pcity;
+  int bodyguard = punit->ai.bodyguard;
+  struct unit *pbody = find_unit_by_id(bodyguard);
 
   assert(pplayer == unit_owner(punit));
   handle_unit_activity_request(punit, ACTIVITY_IDLE);
@@ -79,6 +81,14 @@
     return FALSE;
   }
 
+  /* If we carried a bodyguard just use it!.
+   *  Its the new defender of the city */
+  if (pbody) {
+    if (ai_unit_make_homecity(pbody, pcity)) {
+      ai_unit_new_role(pbody, AIUNIT_ESCORT, -1, -1);
+    }
+  }
+
   /* We have to rebuild at least the cache for this city.  This event is
    * rare enough we might as well build the whole thing.  Who knows what
    * else might be cached in the future? */
@@ -145,11 +155,34 @@
 **************************************************************************/
 void ai_manage_settler(struct player *pplayer, struct unit *punit)
 {
+  bool pos_dangerous = 0;
+
   punit->ai.control = TRUE;
   /* if BUILD_CITY must remain BUILD_CITY, otherwise turn into autosettler */
   if (punit->ai.ai_role == AIUNIT_NONE) {
     ai_unit_new_role(punit, AIUNIT_AUTO_SETTLER, -1, -1);
   }
+
+  /* If goto is set and we do not have a bodyguard, check if we are in or
+   * are headed for a dangerous position. */
+  if (!has_bodyguard(punit)) {
+    if (is_goto_dest_set(punit)) {
+      pos_dangerous = enemies_at(punit, goto_dest_x(punit), goto_dest_y(punit))
+                      || map_get_owner(goto_dest_x(punit), goto_dest_y(punit))
+                         != pplayer;
+    } else {
+      /* otherwise we check for the current location */
+      pos_dangerous = enemies_at(punit, punit->x, punit->y);
+    }
+
+    if (pos_dangerous > 0) {
+      punit->ai.bodyguard = BODYGUARD_WANTED;
+    }
+  } else {
+    UNIT_LOG(LOG_DEBUG, punit, "with a bodyguard!");
+    ai_unit_bodyguard_move(punit->ai.bodyguard, punit->x, punit->y);
+  }
+
   return;
 }
 
@@ -1096,23 +1129,39 @@
       ai_unit_new_role(punit, AIUNIT_NONE, -1, -1);
       return; /* avoid recursion at all cost */
     } else {
-      /* Go there */
-      if ((!ai_gothere(pplayer, punit, x, y) && !find_unit_by_id(sanity))
-          || punit->moves_left <= 0) {
+      if (enemies_at(punit, punit->x, punit->y) && !has_bodyguard(punit)) {
+        /* there are enemies at current location! so scatter and hide */
+        UNIT_LOG(LOG_SETTLER, punit, "enemies side by side settler!");
+        if (find_defending_spot(punit, &gx, &gy)) {
+         ai_unit_goto(punit, gx, gy);
+       }
         return;
-      }
-      if (same_pos(punit->x, punit->y, x, y)) {
-        if (!ai_do_build_city(pplayer, punit)) {
-          UNIT_LOG(LOG_ERROR, punit, "could not make city on %s",
-                   map_get_tile_info_text(punit->x, punit->y));
-          ai_unit_new_role(punit, AIUNIT_NONE, -1, -1);
-        } else {
-          return; /* We came, we saw, we built... */
-        }
       } else {
-        UNIT_LOG(LOG_SETTLER, punit, "could not go to target");
-        /* ai_unit_new_role(punit, AIUNIT_NONE, -1, -1); */
-        return;
+        if (enemies_at(punit, x, y) && !has_bodyguard(punit)) {
+          /* there are enemies at destination! */
+          UNIT_LOG(LOG_SETTLER, punit, "enemies at city founding location!");
+          return;
+       } else {
+          /* Go there */
+          if ((!ai_gothere(pplayer, punit, x, y) && !find_unit_by_id(sanity))
+              || punit->moves_left <= 0) {
+            return;
+          }
+          if (same_pos(punit->x, punit->y, x, y)) {
+            if (!ai_do_build_city(pplayer, punit)) {
+              UNIT_LOG(LOG_ERROR, punit, "could not make city on %s",
+                       map_get_tile_info_text(punit->x, punit->y));
+              ai_unit_new_role(punit, AIUNIT_NONE, -1, -1);
+              return;
+            } else {
+              return; /* We came, we saw, we built... */
+            }
+          } else {
+            UNIT_LOG(LOG_SETTLER, punit, "we are en route");
+            /* ai_unit_new_role(punit, AIUNIT_NONE, -1, -1); */
+            return;
+          }
+        }
       }
     }
   }