[Freeciv-Dev] Re: buglet in normalization in init_new_game() (PR#1063)

[jdorje@xxxxxxxxxxxxxxxxxxxxx]

Raimar Falke wrote:

> IMHO it looks like a job for a new circle_iterate.

The attached patch is an adequate implementation of circle_iterate
(actually, I'm not happy with the use of sqrt() but I'm not sure how to
do without it), but doesn't quite work for this case because the current
code there adds 1 to the radius before comparing it to the maximum
radius.  So if you play with this patch the initial visible area will be
larger than it's supposed to be.

IMO it is the current implementation that is broken, but perhaps there's
some reason for that.  My solution would be to adjust
game.rgame.init_vis_radius_sq accordingly.

jason

? rc
? old
? topology
Index: common/map.h
===================================================================
RCS file: /home/freeciv/CVS/freeciv/common/map.h,v
retrieving revision 1.103
diff -u -r1.103 map.h
--- common/map.h        2001/11/11 17:46:20     1.103
+++ common/map.h        2001/11/14 20:45:01
@@ -13,7 +13,9 @@
 #ifndef FC__MAP_H
 #define FC__MAP_H
 
-#include "assert.h"
+#include <assert.h>
+#include <math.h>
+
 #include "player.h"
 #include "terrain.h"
 #include "unit.h"
@@ -429,6 +431,32 @@
     }                                                                         \
   }                                                                           \
 }
+
+/* Iterate through all tiles in a circle with given center and squared
+   radius.  Positions returned will have adjusted (x, y); those with 
+   illegal (unreal) positions will be automatically discarded. */
+#define circle_iterate(center_x, center_y, sq_radius, x_itr, y_itr)           \
+{                                                                             \
+  int _x_itr, _y_itr;                                                         \
+  int _center_x = (center_x), _center_y = (center_y);                         \
+  int _sq_radius = sq_radius, _radius = (int)sqrt(_sq_radius);                \
+  CHECK_MAP_POS(_center_x, _center_y);                                        \
+  for (_y_itr = -_radius;                                                     \
+       _y_itr <= _radius;                                                     \
+       _y_itr++)                                                              \
+    for (_x_itr = -_radius;                                                   \
+        _x_itr <= _radius;                                                   \
+        _x_itr++)                                                            \
+      if (_y_itr * _y_itr + _x_itr * _x_itr <= _sq_radius) {                  \
+        int x_itr = _center_x + _x_itr;                                       \
+        int y_itr = _center_y + _y_itr;                                       \
+        if (normalize_map_pos(&x_itr, &y_itr)) {
+
+#define circle_iterate_end                                                    \
+        }                                                                     \
+      }                                                                       \
+}
+                                                                              
 
 /* Iterate through all tiles adjacent to a tile */
 #define adjc_iterate(RI_center_x, RI_center_y, RI_x_itr, RI_y_itr)            \
Index: server/gamehand.c
===================================================================
RCS file: /home/freeciv/CVS/freeciv/server/gamehand.c,v
retrieving revision 1.98
diff -u -r1.98 gamehand.c
--- server/gamehand.c   2001/10/18 16:45:34     1.98
+++ server/gamehand.c   2001/11/14 20:45:02
@@ -35,7 +35,7 @@
 void init_new_game(void)
 {
   int i, j, x, y;
-  int vx, vy, dx, dy;
+  int dx, dy;
   Unit_Type_id utype;
   int start_pos[MAX_NUM_PLAYERS]; /* indices into map.start_positions[] */
 
@@ -130,16 +130,9 @@
                game.players[i].name);
       }
       /* Expose visible area. */
-      for (vx = 1; (vx * vx) <= game.rgame.init_vis_radius_sq; vx++) {
-       for (vy = 1; (vy * vy) <= game.rgame.init_vis_radius_sq; vy++) {
-         if (((vx *vx) + (vy *vy)) <= game.rgame.init_vis_radius_sq) {
-           show_area(&game.players[i], dx-vx+1, dy-vy+1, 1);
-           show_area(&game.players[i], dx+vx-1, dy-vy+1, 1);
-           show_area(&game.players[i], dx-vx+1, dy+vy-1, 1);
-           show_area(&game.players[i], dx+vx-1, dy+vy-1, 1);
-         }
-       }
-      }
+      circle_iterate(dx, dy, game.rgame.init_vis_radius_sq, cx, cy) {
+       show_area(&game.players[i], cx, cy, 1);
+      } circle_iterate_end;
       /* Create the unit of an appropriate type. */
       utype = get_role_unit((j < game.settlers) ? F_CITIES : L_EXPLORER, 0);
       create_unit(&game.players[i], dx, dy, utype, 0, 0, -1);