[freeciv-ai] Re: (PR#3467) AI idles fortifying units that do not move

["Gregory Berkolaiko" <Gregory.Berkolaiko@xxxxxxxxxxxx>]

Quoting Gregory Berkolaiko <Gregory.Berkolaiko@xxxxxxxxxxxx>:

> On Wed, 19 Feb 2003, Per I. Mathisen wrote:
> 
> > And why can't you use ai_unit_goto()? And why didn't you tell my earlier
> > so I could fix it?
> 
> Sorry.  I looked up my earlier email, it's a different thing we can't use:
> ======
> Problem 2: verrrry slow.  The problem is two-fold.  First, you don't set
> activity to IDLE, so handle_unit_move_request fails and you have to
> generate warmap for _every_ move.
> ======
> And I guess we can/should use ai_unit_goto instead of 
> handle_unit_move_request.
> 
> I would prefer to fix this as a part of a bigger patch, changing EXPLORE 
> from activity to auto-mode.  If you have no objections, I will talk to 
> Cameron about it.

Talked to Cameron,he said he is too busy.  I also cannot be bothered to change
EXPLORE into an auto-mode (yeah, okay, it would be right thing to do so, but it
wouldn't influence much). So I cooked up a quick fix, together with some
cleaning up and commenting.  Essentially I moved IDLEing to where it is
immediately needed.

G.

? core.1854
? core.9656
? core.9661
Index: ai/aiunit.c
===================================================================
RCS file: /home/freeciv/CVS/freeciv/ai/aiunit.c,v
retrieving revision 1.270
diff -u -r1.270 aiunit.c
--- ai/aiunit.c 2003/03/07 05:08:41     1.270
+++ ai/aiunit.c 2003/03/22 19:04:25
@@ -498,6 +498,9 @@
 explores unknown territory, finds huts.
 
 Returns whether there is any more territory to be explored.
+
+TODO: Convert to using new Path Finding, thus unifying Parts 1 and 2 (in 
+doing so one should aim to break the PF-loop early, to avoid slow-down).
 **************************************************************************/
 bool ai_manage_explorer(struct unit *punit)
 {
@@ -505,12 +508,6 @@
   /* The position of the unit; updated inside the function */
   int x = punit->x, y = punit->y;
 
-  /* Idle unit, since otherwise handle_unit_move_request fails!
-   * TODO: Fix it and remove this idling */
-  if (punit->activity != ACTIVITY_IDLE) {
-    handle_unit_activity_request(punit, ACTIVITY_IDLE);
-  }
-
   /* 
    * PART 1: Move into unexplored territory
    * Move the unit as long as moving will unveil unknown territory
@@ -549,28 +546,40 @@
       /* We can die because easy AI may stumble on huts and so disappear 
        * in the wilderness - unit_id is used to check this */
       int unit_id = punit->id;
-      bool broken = TRUE; /* failed movement */
+      bool move_success;
 
       /* Some tile has unexplored territory adjacent, let's move there. */
       
       /* ai_unit_move for AI players, handle_unit_move_request for humans */
-      if ((pplayer->ai.control && ai_unit_move(punit, best_x, best_y))
-          || (!pplayer->ai.control 
-              && handle_unit_move_request(punit, best_x, best_y, 
-                                          FALSE, FALSE))) {
-        x = punit->x;
-        y = punit->y;
-        broken = FALSE;
+      if (pplayer->ai.control) {
+        move_success = ai_unit_move(punit, best_x, best_y);
+      } else {
+        /* Need to idle unit otherwise handle_unit_move_request fails.
+         * We can use ai_unit_goto, but it's a bit wasteful here... */
+
+        if (punit->activity != ACTIVITY_IDLE) {
+          handle_unit_activity_request(punit, ACTIVITY_IDLE);
+        }
+        move_success = handle_unit_move_request(punit, best_x, best_y, 
+                                                FALSE, FALSE);
       }
       
       if (!player_find_unit_by_id(pplayer, unit_id)) {
         /* We're dead. */
         return FALSE;
       }
+
+      if (move_success) { 
+        /* We moved, update our current position */
+        x = punit->x;
+        y = punit->y;
+      } else {
+        /* Move failed, break to avoid an endless loop */
+        break; 
+      }
 
-      if (broken) { break; } /* a move failed, so danger of endless loop */
     } else {
-      /* Everything is already explored. */
+      /* Everything immediately beside us is already explored. */
       break;
     }
   }