[Freeciv-Dev] Re: (PR#14269) Better Control of World Size

["Benedict Adamson" <badamson@xxxxxxxxxxx>]

<URL: http://bugs.freeciv.org/Ticket/Display.html?id=14269 >

Benedict Adamson wrote:
...
> I suggest we deal with both of these problems by changing the size 
> parameter to be tiles per nation, rather than thousands of tiles.
...

And here is a patch to do it.

diff -ruN -Xvendor.freeciv.current/diff_ignore 
vendor.freeciv.current/common/map.c freeciv.PR14269/common/map.c
--- vendor.freeciv.current/common/map.c 2005-10-12 00:47:36.000000000 +0100
+++ freeciv.PR14269/common/map.c        2005-10-12 00:41:32.000000000 +0100
@@ -95,6 +95,7 @@
 {
   map.topology_id = MAP_DEFAULT_TOPO;
   map.size = MAP_DEFAULT_SIZE;
+  map.nationsize = MAP_DEFAULT_NATIONSIZE;
 
   /* The [xy]size values are set in map_init_topology.  It is initialized
    * to a non-zero value because some places erronously use these values
diff -ruN -Xvendor.freeciv.current/diff_ignore 
vendor.freeciv.current/common/map.h freeciv.PR14269/common/map.h
--- vendor.freeciv.current/common/map.h 2005-10-12 00:47:36.000000000 +0100
+++ freeciv.PR14269/common/map.h        2005-10-12 00:41:32.000000000 +0100
@@ -42,7 +42,8 @@
   int num_valid_dirs, num_cardinal_dirs;
   struct iter_index *iterate_outwards_indices;
   int num_iterate_outwards_indices;
-  int size; /* used to calculate [xy]size */
+  int size; /* number of tiles / 1000 */
+  int nationsize; /* used to calculate [xy]size: tiles per inital nation */
   int xsize, ysize; /* native dimensions */
   int seed;
   int riches;
@@ -436,6 +437,11 @@
 #define MAP_MIN_SIZE             1
 #define MAP_MAX_SIZE             29
 
+/* Size of the map in tiles per starting nation */
+#define MAP_DEFAULT_NATIONSIZE   800
+#define MAP_MIN_NATIONSIZE       100
+#define MAP_MAX_NATIONSIZE       3200
+
 /* This defines the maximum linear size in _map_ coordinates.
  * This must be smaller than 255 because of the way coordinates are sent
  * across the network. */
diff -ruN -Xvendor.freeciv.current/diff_ignore 
vendor.freeciv.current/server/generator/mapgen_topology.c 
freeciv.PR14269/server/generator/mapgen_topology.c
--- vendor.freeciv.current/server/generator/mapgen_topology.c   2005-10-12 
00:47:19.000000000 +0100
+++ freeciv.PR14269/server/generator/mapgen_topology.c  2005-10-12 
00:41:14.000000000 +0100
@@ -14,6 +14,7 @@
 #include <config.h>
 #endif
 
+#include "game.h"
 #include "map.h"
 #include "log.h"
 
@@ -182,7 +183,7 @@
 
   /* We have:
    *
-   *   1000 * size = xsize * ysize
+   *   size = xsize * ysize
    *
    * And to satisfy the ratios and other constraints we set
    *
@@ -191,31 +192,31 @@
    *
    * For any value of "i_size".  So with some substitution
    *
-   *   1000 * size = i_size * i_size * xratio * yratio * even * even * iso
-   *   i_size = sqrt(1000 * size / (xratio * yratio * even * even * iso))
+   *   size = i_size * i_size * xratio * yratio * even * even * iso
+   *   i_size = sqrt(size / (xratio * yratio * even * even * iso))
    * 
    * Make sure to round off i_size to preserve exact wanted ratios,
    * that may be importante for some topologies.
    */
   const int i_size
-    = sqrt((float)(1000 * size)
-          / (float)(Xratio * Yratio * iso * even * even)) + 0.49;
+    = sqrt(size / (float)(Xratio * Yratio * iso * even * even)) + 0.49;
 
   /* Now build xsize and ysize value as described above. */
   map.xsize = Xratio * i_size * even;
   map.ysize = Yratio * i_size * even * iso;
+  map.size = map.xsize * map.ysize / 1000;
 
   /* Now make sure the size isn't too large for this ratio.  If it is
    * then decrease the size and try again. */
   if (MAX(MAP_WIDTH, MAP_HEIGHT) > MAP_MAX_LINEAR_SIZE ) {
-    assert(size > 0.1);
-    set_sizes(size - 0.1, Xratio, Yratio);
+    assert(size > 100);
+    set_sizes(size - 100, Xratio, Yratio);
     return;
   }
 
   /* If the ratio is too big for some topology the simplest way to avoid
    * this error is to set the maximum size smaller for all topologies! */
-  if (map.size > size + 0.9) {
+  if (1000 * map.size > size + 900) {
     /* Warning when size is set uselessly big */ 
     freelog(LOG_ERROR,
            "Requested size of %d is too big for this topology.",
@@ -251,11 +252,14 @@
       {AUTO_RATIO_FLAT, AUTO_RATIO_CLASSIC,
        AUTO_RATIO_URANUS, AUTO_RATIO_TORUS};
     const int id = 0x3 & map.topology_id;
+    const double size = MIN(map.nationsize * get_num_human_and_ai_players(),
+                            1000 * MAP_MAX_SIZE);
 
     assert(TF_WRAPX == 0x1 && TF_WRAPY == 0x2);
 
-    /* Set map.xsize and map.ysize based on map.size. */
-    set_sizes(map.size, default_ratios[id][0], default_ratios[id][1]);
+    /* Set map.xsize and map.ysize based on
+     * map.nationsize and number of nations. */
+    set_sizes(size, default_ratios[id][0], default_ratios[id][1]);
   }
 
   /* initialize the ICE_BASE_LEVEL */
diff -ruN -Xvendor.freeciv.current/diff_ignore 
vendor.freeciv.current/server/generator/startpos.c 
freeciv.PR14269/server/generator/startpos.c
--- vendor.freeciv.current/server/generator/startpos.c  2005-10-12 
00:47:19.000000000 +0100
+++ freeciv.PR14269/server/generator/startpos.c 2005-10-12 00:41:14.000000000 
+0100
@@ -193,7 +193,7 @@
   int min_goodies_per_player = 2000;
   int total_goodies = 0;
   /* this is factor is used to maximize land used in extreme little maps */
-  float efactor =  game.info.nplayers / map.size / 4; 
+  float efactor =  250.0 / (float)map.nationsize;
   bool failure = FALSE;
 
   /* Unsafe terrains separate continents, otherwise small areas of green
diff -ruN -Xvendor.freeciv.current/diff_ignore 
vendor.freeciv.current/server/settings.c freeciv.PR14269/server/settings.c
--- vendor.freeciv.current/server/settings.c    2005-10-12 00:47:20.000000000 
+0100
+++ freeciv.PR14269/server/settings.c   2005-10-12 00:41:15.000000000 +0100
@@ -207,13 +207,15 @@
   /* These should be grouped by sclass */
   
   /* Map size parameters: adjustable if we don't yet have a map */  
-  GEN_INT("size", map.size, SSET_MAP_SIZE,
+  GEN_INT("nationsize", map.nationsize, SSET_MAP_SIZE,
          SSET_GEOLOGY, SSET_VITAL, SSET_TO_CLIENT,
-          N_("Map size (in thousands of tiles)"),
+          N_("Size of a typical nation (in tiles)"),
           N_("This value is used to determine the map dimensions.\n"
-             "  size = 4 is a normal map of 4,000 tiles (default)\n"
-             "  size = 20 is a huge map of 20,000 tiles"), NULL,
-          MAP_MIN_SIZE, MAP_MAX_SIZE, MAP_DEFAULT_SIZE)
+             "It is the number of map tiles per starting nation\n"
+             "(with a maximum of 29000 tiles total).\n"
+             "  nationsize = 800 is a normal map (default)\n"
+             "  nationsize = 300 is a small map"), NULL,
+          MAP_MIN_NATIONSIZE, MAP_MAX_NATIONSIZE, MAP_DEFAULT_NATIONSIZE)
   GEN_INT("topology", map.topology_id, SSET_MAP_SIZE,
          SSET_GEOLOGY, SSET_VITAL, SSET_TO_CLIENT,
          N_("Map topology index"),