[freeciv-ai] (PR#12453) Great Library and AI

["Mateusz Stefek" <mstefek@xxxxxxxxx>]

<URL: http://bugs.freeciv.org/Ticket/Display.html?id=12453 >

I think that the AI should do the same as most players do after building
Great Library - set maximum tax rates, no science.

AI doesn't need any research if there are still techs which can be given
to it for free. I implemented it through the ai_wants_no_science()
function. The calculations are done only once per turn, so the patch
doesn't make AI slower.

See attached patch
--
mateusz

Index: ai/aidata.c
===================================================================
RCS file: /home/freeciv/CVS/freeciv/ai/aidata.c,v
retrieving revision 1.53
diff -u -r1.53 aidata.c
--- ai/aidata.c 5 Mar 2005 13:37:04 -0000       1.53
+++ ai/aidata.c 6 Mar 2005 13:31:13 -0000
@@ -116,6 +116,46 @@
 }
 
 /**************************************************************************
+  Check if the player still takes advantage of EFT_TECH_PARASITE.
+  Research is useless if there are still techs which may be given to the
+  player for free.
+**************************************************************************/
+static bool player_has_really_useful_tech_parasite(struct player* pplayer)
+{
+  int players_needed = get_player_bonus(pplayer, EFT_TECH_PARASITE);
+
+  if (players_needed == 0) {
+    return FALSE;
+  }
+  
+  tech_type_iterate(tech) {
+    int players_having;
+
+    if (get_invention(pplayer, tech) == TECH_KNOWN
+        || !tech_is_available(pplayer, tech)) {
+      continue;
+    }
+
+    players_having = 0;
+
+    players_iterate(aplayer) {
+      if (aplayer == pplayer || !aplayer->is_alive) {
+        continue;
+      }
+
+      if (get_invention(aplayer, tech) == TECH_KNOWN ||
+          aplayer->research.researching == tech) {
+       players_having++;
+       if (players_having >= players_needed) {
+         return TRUE;
+       }
+      }
+    } players_iterate_end;
+  } tech_type_iterate_end;
+  return FALSE;
+}
+
+/**************************************************************************
   Analyze rulesets. Must be run after rulesets after loaded, unlike
   _init, which must be run before savegames are loaded, which is usually
   before rulesets.
@@ -409,6 +449,14 @@
       *punit->ai.cur_pos = punit->tile;
     } unit_list_iterate_end;
   } players_iterate_end;
+  
+  /* Research want */
+  if (is_future_tech(pplayer->research.researching) || 
+      player_has_really_useful_tech_parasite(pplayer)) {
+    ai->wants_no_science = TRUE;
+  } else {
+    ai->wants_no_science = FALSE;
+  }
 }
 
 /**************************************************************************
@@ -494,4 +542,5 @@
     ai->diplomacy.player_intel[i].asked_about_ceasefire = 0;
     ai->diplomacy.player_intel[i].warned_about_space = 0;
   }
+  ai->wants_no_science = FALSE;
 }
Index: ai/aidata.h
===================================================================
RCS file: /home/freeciv/CVS/freeciv/ai/aidata.h,v
retrieving revision 1.23
diff -u -r1.23 aidata.h
--- ai/aidata.h 2 Mar 2005 10:43:57 -0000       1.23
+++ ai/aidata.h 6 Mar 2005 13:31:25 -0000
@@ -142,6 +142,9 @@
     } govt;
     int revolution;   /* The best gov of the now available */
   } goal;
+  
+  /* If the ai doesn't want/need any research */
+  bool wants_no_science;
 };
 
 void ai_data_init(struct player *pplayer);
Index: ai/aitools.c
===================================================================
RCS file: /home/freeciv/CVS/freeciv/ai/aitools.c,v
retrieving revision 1.137
diff -u -r1.137 aitools.c
--- ai/aitools.c        2 Mar 2005 10:43:57 -0000       1.137
+++ ai/aitools.c        6 Mar 2005 13:31:25 -0000
@@ -792,5 +792,5 @@
 **************************************************************************/
 bool ai_wants_no_science(struct player *pplayer)
 {
-  return is_future_tech(pplayer->research.researching);
+  return ai_data_get(pplayer)->wants_no_science;
 }