Merge branch 'peasantgrowth_acceleration' of https://github.com/stm2/server into stm2-peasantgrowth_acceleration

res/core/messages.xml

@@ -3658,6 +3658,13 @@
     <text locale="fr">"$unit($unit): '$order($command)' - The unit already uses $resource($using,0)."</text>
     <text locale="en">"$unit($unit): '$order($command)' - The unit already uses $resource($using,0)."</text>
   </message>
+  <message name="peasantluck_success" section="events">
+    <type>
+      <arg name="births" type="int"/>
+    </type>
+    <text locale="de">"$if($eq($births,1),"Einen Bauern","$int($births) Bauern") besucht unverhofft der Storch."</text>
+    <text locale="en">"The stork paid an unexpected visit to $if($eq($births,1),"a peasant","$int($births) peasants")."</text>
+  </message>
   <message name="shipsink" section="events">
     <type>
       <arg name="ship" type="ship"/>

src/laws.c

@@ -258,7 +258,61 @@ static void calculate_emigration(region * r)
     }
 }
 
-/** Bauern vermehren sich */
+
+static float peasant_growth_factor(void)
+{
+  return get_param_flt(global.parameters, "rules.peasants.growth.factor",
+    0.0001F * PEASANTGROWTH);
+}
+
+#ifndef SLOWLUCK
+static float peasant_luck_factor(void)
+{
+  return get_param_int(global.parameters, "rules.peasants.peasantluck.factor",
+    PEASANTLUCK);
+}
+
+static
+int peasant_luck_effect(int peasants, int luck, int maxp, float variance)
+{
+  int births = 0;
+  double mean = _min(luck, peasants) * peasant_luck_factor()
+    * peasant_growth_factor() * ((peasants / (float)maxp < .9) ? 1 :
+      PEASANTFORCE);
+
+  births = RAND_ROUND(normalvariate(mean, variance * mean));
+  if (births <= 0)
+    births = 1;
+  if (births > peasants / 2)
+    births = peasants / 2 + 1;
+  return (int)births;
+}
+
+#else
+int peasant_luck_effect(int peasants, int luck, int maxp, float variance) {
+  int n, births=0;
+  float factor = peasant_growth_factor();
+  for (n = peasants; n && luck; --n) {
+    int chances = 0;
+
+    if (luck > 0) {
+      --luck;
+      chances += PEASANTLUCK;
+    }
+
+    while (chances--) {
+      if (rng_double() < factor) {
+        /* Only raise with 75% chance if peasants have
+         * reached 90% of maxpopulation */
+        if (peasants / (float)maxp < 0.9 || chance(PEASANTFORCE)) {
+          ++births;
+        }
+      }
+    }
+  }
+  return births;
+}
+#endif
 
 static void peasants(region * r)
 {
@@ -268,42 +322,20 @@ static void peasants(region * r)
     int n, satiated;
     int dead = 0;
 
-    /* Bis zu 1000 Bauern können Zwillinge bekommen oder 1000 Bauern
-     * wollen nicht! */
-
     if (peasants > 0 && get_param_int(global.parameters, "rules.peasants.growth", 1)) {
-        int glueck = 0;
-        double fraction = peasants * 0.0001F * PEASANTGROWTH;
-        int births = (int)fraction;
+        int luck = 0;
+        double fraction = peasants * peasant_growth_factor();
+        int births = RAND_ROUND(fraction);
         attrib *a = a_find(r->attribs, &at_peasantluck);
 
-        if (rng_double() < (fraction - births)) {
-            /* because we don't want regions that never grow pga. rounding. */
-            ++births;
-        }
         if (a != NULL) {
-            glueck = a->data.i * 1000;
+            luck = a->data.i * 1000;
         }
 
-        for (n = peasants; n; --n) {
-            int chances = 0;
+        luck = peasant_luck_effect(peasants, luck, maxp, .5);
+        ADDMSG(&r->msgs, msg_message("peasantluck_success", "births", luck));
 
-            if (glueck > 0) {
-                --glueck;
-                chances += PEASANTLUCK;
-            }
-
-            while (chances--) {
-                if (rng_int() % 10000 < PEASANTGROWTH) {
-                    /* Only raise with 75% chance if peasants have
-                     * reached 90% of maxpopulation */
-                    if (peasants / (float)maxp < 0.9 || chance(PEASANTFORCE)) {
-                        ++births;
-                    }
-                }
-            }
-        }
-        peasants += births;
+        peasants += births + luck;
     }
 
     /* Alle werden satt, oder halt soviele für die es auch Geld gibt */

src/laws.test.c

@@ -1,5 +1,5 @@
 #include <platform.h>
-#include "laws.h"
+#include "laws.c"
 
 #include <kernel/ally.h>
 #include <kernel/config.h>
@@ -16,6 +16,7 @@
 #include <util/base36.h>
 #include <util/language.h>
 #include <util/message.h>
+#include <util/rand.h>
 
 #include <CuTest.h>
 #include <tests.h>
@@ -691,6 +692,32 @@ static void test_reserve_self(CuTest *tc) {
     test_cleanup();
 }
 
+static void statistic_test(CuTest *tc, int peasants, int luck, int maxp,
+  float variance, int min_value, int max_value)
+{
+  int effect, i;
+  for (i = 0; i < 1000; ++i) {
+    effect = peasant_luck_effect(peasants, luck, maxp, variance);
+    CuAssertTrue(tc, min_value <= effect);
+    CuAssertTrue(tc, max_value >= effect);
+  }
+}
+
+static void test_peasant_luck_effect(CuTest *tc)
+{
+
+  set_param(&global.parameters, "rules.peasants.peasantluck.factor", "10");
+  set_param(&global.parameters, "rules.peasants.growth.factor", "0.001");
+
+  statistic_test(tc, 100, 2, 1000, 0, 1, 1);
+  statistic_test(tc, 1000, 400, 1000, 0, 400 * 10 * 0.001 * .75,
+    400 * 10 * 0.001 * .75);
+  statistic_test(tc, 1000, 1000, 2000, .5, 1, 501);
+
+  set_param(&global.parameters, "rules.peasants.growth.factor", "1");
+  statistic_test(tc, 1000, 1000, 1000, 0, 501, 501);
+}
+
 CuSuite *get_laws_suite(void)
 {
     CuSuite *suite = CuSuiteNew();
@@ -721,6 +748,7 @@ CuSuite *get_laws_suite(void)
     SUITE_ADD_TEST(suite, test_force_leave_buildings);
     SUITE_ADD_TEST(suite, test_force_leave_ships);
     SUITE_ADD_TEST(suite, test_force_leave_ships_on_ocean);
+    SUITE_ADD_TEST(suite, test_peasant_luck_effect);
 
     return suite;
 }

src/test_eressea.c

@@ -53,6 +53,7 @@ int RunAllTests(void)
   RUN_TESTS(suite, umlaut);
   RUN_TESTS(suite, unicode);
   RUN_TESTS(suite, strings);
+  RUN_TESTS(suite, rng);
   /* kernel */
   RUN_TESTS(suite, alliance);
   RUN_TESTS(suite, unit);

src/util/CMakeLists.txt

@@ -9,6 +9,7 @@ bsdstring.test.c
 functions.test.c
 umlaut.test.c
 unicode.test.c
+rng.test.c
 )
 
 SET(_FILES

src/util/rng.h

@@ -39,6 +39,7 @@ extern "C" {
 # define rng_double ((rand()%RAND_MAX)/(double)RAND_MAX)
 # define RNG_RAND_MAX RAND_MAX
 #endif
+#define RAND_ROUND(fractional) ((rng_double() < fractional-(int)fractional)?((int)fractional+1):((int)fractional))
 #ifdef __cplusplus
 }
 #endif

src/util/rng.test.c

@@ -0,0 +1,26 @@
+#include <CuTest.h>
+#include <ctype.h>
+
+#include "rng.h"
+
+static void test_rng_round(CuTest * tc)
+{
+  double f;
+  int i, r;
+  for (i = 0; i < 1000; ++i) {
+    f = rng_double();
+    r = RAND_ROUND(f);
+    CuAssertTrue(tc, f >= 0);
+    CuAssertTrue(tc, r <= (int ) f + 1);
+    CuAssertTrue(tc, r >= (int ) f);
+    CuAssertTrue(tc, r == (int ) r);
+    CuAssertTrue(tc, r == RAND_ROUND(r));
+  }
+}
+
+CuSuite *get_rng_suite(void)
+{
+  CuSuite *suite = CuSuiteNew();
+  SUITE_ADD_TEST(suite, test_rng_round);
+  return suite;
+}