Codechange: Don't store tree counter in the map array

docs/landscape.html

@@ -807,8 +807,6 @@ <h3><a name="Landscape">Landscape</a></h3>
       </table>
      </li>
      <li>m2 bits 5..4: ground density</li>
-     <li>m2 bits 3..0: update counter, incremented on every periodic processing.<br>
-          on wraparound the growth status is updated (or, if it's <tt>3</tt>, a random action is taken)</li>
      <li>m3 bits 7..0: type of trees:
       <table>
        <tr>

regression/regression/result.txt

@@ -88,22 +88,22 @@
  abs( 21): 21
 
 --AIBase--
-  Rand():       -54346916
-  Rand():       -937374575
-  Rand():       823953997
+  Rand():       -1077739811
+  Rand():       -1179776610
+  Rand():       -497449144
   RandRange(0): 0
   RandRange(0): 0
   RandRange(0): 0
   RandRange(1): 0
   RandRange(1): 0
   RandRange(1): 0
+  RandRange(2): 0
   RandRange(2): 1
   RandRange(2): 1
-  RandRange(2): 1
-  RandRange(1000000): 966676
-  RandRange(1000000): 289525
-  RandRange(1000000): 170283
-  Chance(1, 2): false
+  RandRange(1000000): 191841
+  RandRange(1000000): 925095
+  RandRange(1000000): 99057
+  Chance(1, 2): true
   Chance(1, 2): true
   Chance(1, 2): false
 
@@ -420,144 +420,144 @@
     1098 => 46116
     1099 => 46158
   Randomize ListDump:
-    1 => -200078348
-    2 => -29799264
-    1000 => 1630721656
-    1001 => 959306175
-    1002 => 1527421791
-    1003 => 1259692483
-    1004 => -1289244298
-    1005 => -1572996668
-    1006 => -2069479746
-    1007 => -1819131606
-    1008 => -1007163964
-    1009 => -1185394870
-    1010 => -1471365065
-    1011 => 364354366
-    1012 => -1478084253
-    1013 => 405281367
-    1014 => -11170062
-    1015 => 156767750
-    1016 => 1288924796
-    1017 => 1796884876
-    1018 => -1947073702
-    1019 => -1999614238
-    1020 => -231292809
-    1021 => 966621566
-    1022 => -606766557
-    1023 => -1138727825
-    1024 => -749544262
-    1025 => 2004771271
-    1026 => 686734186
-    1027 => 923274744
-    1028 => -1672035149
-    1029 => -1642064950
-    1030 => 1363389551
-    1031 => -559500928
-    1032 => 1656196991
-    1033 => 1655354425
-    1034 => -1027156689
-    1035 => 1952644328
-    1036 => 1217870217
-    1037 => 242274100
-    1038 => 201816080
-    1039 => 2127464758
-    1040 => 446043650
-    1041 => -319728455
-    1042 => 204701002
-    1043 => -571265398
-    1044 => -1422217131
-    1045 => -391208397
-    1046 => -1822628371
-    1047 => -1499755350
-    1048 => -1422137641
-    1049 => 1621693134
-    1051 => -1428728134
-    1052 => -147587573
-    1053 => 681719500
-    1054 => 1172011190
-    1055 => -1834344882
-    1056 => 1157634586
-    1057 => 1902133676
-    1058 => -1967780161
-    1059 => -1618025531
-    1060 => -810220453
-    1061 => 1582854921
-    1062 => -410004643
-    1063 => 1159917159
-    1064 => -1377804984
-    1065 => -738843914
-    1066 => -1578756103
-    1067 => -464090986
-    1068 => 1711504679
-    1069 => 545330655
-    1070 => 379462570
-    1071 => 514511099
-    1072 => -1813251176
-    1073 => 1424958266
-    1074 => -825255131
-    1075 => 539054595
-    1076 => -1764192010
-    1077 => -1243277769
-    1078 => 2017874281
-    1079 => -1972353607
-    1080 => 1879761467
-    1081 => 1638986560
-    1082 => -1832287507
-    1083 => -492411882
-    1084 => 658940812
-    1085 => -1044199400
-    1086 => 1586504918
-    1087 => -125492611
-    1088 => -1562883174
-    1089 => -1013778441
-    1090 => 1560228607
-    1091 => -550265689
-    1092 => 524767105
-    1093 => -713387661
-    1094 => 1425927738
-    1095 => 942653932
-    1096 => 1233220698
-    1097 => 1313602368
-    1098 => -140318584
-    1099 => 1199179892
+    1 => 1473447397
+    2 => -1572091528
+    1000 => -1461894323
+    1001 => -1966513355
+    1002 => -143123078
+    1003 => 1243503816
+    1004 => 731361243
+    1005 => -110249379
+    1006 => 1652302684
+    1007 => -1959331369
+    1008 => -200078348
+    1009 => -29799264
+    1010 => 1630721656
+    1011 => 959306175
+    1012 => 1527421791
+    1013 => 1259692483
+    1014 => -1289244298
+    1015 => -1572996668
+    1016 => -2069479746
+    1017 => -1819131606
+    1018 => -1007163964
+    1019 => -1185394870
+    1020 => -1471365065
+    1021 => 364354366
+    1022 => -1478084253
+    1023 => 405281367
+    1024 => -11170062
+    1025 => 156767750
+    1026 => 1288924796
+    1027 => 1796884876
+    1028 => -1947073702
+    1029 => -1999614238
+    1030 => -231292809
+    1031 => 966621566
+    1032 => -606766557
+    1033 => -1138727825
+    1034 => -749544262
+    1035 => 2004771271
+    1036 => 686734186
+    1037 => 923274744
+    1038 => -1672035149
+    1039 => -1642064950
+    1040 => 1363389551
+    1041 => -559500928
+    1042 => 1656196991
+    1043 => 1655354425
+    1044 => -1027156689
+    1045 => 1952644328
+    1046 => 1217870217
+    1047 => 242274100
+    1048 => 201816080
+    1049 => 2127464758
+    1051 => 446043650
+    1052 => -319728455
+    1053 => 204701002
+    1054 => -571265398
+    1055 => -1422217131
+    1056 => -391208397
+    1057 => -1822628371
+    1058 => -1499755350
+    1059 => -1422137641
+    1060 => 1621693134
+    1061 => -1428728134
+    1062 => -147587573
+    1063 => 681719500
+    1064 => 1172011190
+    1065 => -1834344882
+    1066 => 1157634586
+    1067 => 1902133676
+    1068 => -1967780161
+    1069 => -1618025531
+    1070 => -810220453
+    1071 => 1582854921
+    1072 => -410004643
+    1073 => 1159917159
+    1074 => -1377804984
+    1075 => -738843914
+    1076 => -1578756103
+    1077 => -464090986
+    1078 => 1711504679
+    1079 => 545330655
+    1080 => 379462570
+    1081 => 514511099
+    1082 => -1813251176
+    1083 => 1424958266
+    1084 => -825255131
+    1085 => 539054595
+    1086 => -1764192010
+    1087 => -1243277769
+    1088 => 2017874281
+    1089 => -1972353607
+    1090 => 1879761467
+    1091 => 1638986560
+    1092 => -1832287507
+    1093 => -492411882
+    1094 => 658940812
+    1095 => -1044199400
+    1096 => 1586504918
+    1097 => -125492611
+    1098 => -1562883174
+    1099 => -1013778441
   KeepTop(10):
-    1 => -200078348
-    2 => -29799264
-    1000 => 1630721656
-    1001 => 959306175
-    1002 => 1527421791
-    1003 => 1259692483
-    1004 => -1289244298
-    1005 => -1572996668
-    1006 => -2069479746
-    1007 => -1819131606
+    1 => 1473447397
+    2 => -1572091528
+    1000 => -1461894323
+    1001 => -1966513355
+    1002 => -143123078
+    1003 => 1243503816
+    1004 => 731361243
+    1005 => -110249379
+    1006 => 1652302684
+    1007 => -1959331369
   KeepBottom(8):
-    1000 => 1630721656
-    1001 => 959306175
-    1002 => 1527421791
-    1003 => 1259692483
-    1004 => -1289244298
-    1005 => -1572996668
-    1006 => -2069479746
-    1007 => -1819131606
+    1000 => -1461894323
+    1001 => -1966513355
+    1002 => -143123078
+    1003 => 1243503816
+    1004 => 731361243
+    1005 => -110249379
+    1006 => 1652302684
+    1007 => -1959331369
   RemoveBottom(2):
-    1000 => 1630721656
-    1001 => 959306175
-    1002 => 1527421791
-    1003 => 1259692483
-    1004 => -1289244298
-    1005 => -1572996668
+    1000 => -1461894323
+    1001 => -1966513355
+    1002 => -143123078
+    1003 => 1243503816
+    1004 => 731361243
+    1005 => -110249379
   RemoveTop(2):
-    1002 => 1527421791
-    1003 => 1259692483
-    1004 => -1289244298
-    1005 => -1572996668
+    1002 => -143123078
+    1003 => 1243503816
+    1004 => 731361243
+    1005 => -110249379
   RemoveList({1003, 1004}):
-    1002 => 1527421791
-    1005 => -1572996668
+    1002 => -143123078
+    1005 => -110249379
   KeepList({1003, 1004, 1005}):
-    1005 => -1572996668
+    1005 => -110249379
   AddList({1005, 4000, 4001, 4002}):
     1005 => 1005
     4000 => 8000
@@ -588,7 +588,7 @@ ERROR: IsEnd() is invalid as Begin() is never called
   SetName():            false
   GetLastErrorString(): ERR_NAME_IS_NOT_UNIQUE
   GetName():                         Regression
-  GetPresidentName():                E. McAlpine
+  GetPresidentName():                D. Watkins
   SetPresidentName():                true
   GetPresidentName():                Regression AI
   GetBankBalance():                  100000

src/tree_cmd.cpp

@@ -174,9 +174,6 @@ static void PlaceTree(TileIndex tile, uint32 r)
 		if (ground != TREE_GROUND_SNOW_DESERT && ground != TREE_GROUND_ROUGH_SNOW && ground != TREE_GROUND_SHORE) {
 			SetTreeGroundDensity(tile, (TreeGround)GB(r, 28, 1), 3);
 		}
-
-		/* Set the counter to a random start value */
-		SetTreeCounter(tile, (TreeGround)GB(r, 24, 4));
 	}
 }
 
@@ -707,10 +704,13 @@ static void TileLoop_Trees(TileIndex tile)
 
 	AmbientSoundEffect(tile);
 
-	uint treeCounter = GetTreeCounter(tile);
+	/* _tick_couter is incremented by 256 between each call, so ignore lower 8 bits.
+	 * Also, we add tile % 31 to spread the updates evenly over the map,
+	 * where 31 is just some prime number that looks ok. */
+	uint32 cycle = (uint32)tile % 31 + (_tick_counter >> 8);
 
 	/* Handle growth of grass (under trees/on MP_TREES tiles) at every 8th processings, like it's done for grass on MP_CLEAR tiles. */
-	if ((treeCounter & 7) == 7 && GetTreeGround(tile) == TREE_GROUND_GRASS) {
+	if ((cycle & 7) == 7 && GetTreeGround(tile) == TREE_GROUND_GRASS) {
 		uint density = GetTreeDensity(tile);
 		if (density < 3) {
 			SetTreeGroundDensity(tile, TREE_GROUND_GRASS, density + 1);
@@ -720,11 +720,7 @@ static void TileLoop_Trees(TileIndex tile)
 
 	if (_settings_game.construction.extra_tree_placement == ETP_NO_GROWTH_NO_SPREAD) return;
 
-	if (GetTreeCounter(tile) < 15) {
-		AddTreeCounter(tile, 1);
-		return;
-	}
-	SetTreeCounter(tile, 0);
+	if ((cycle & 15) < 15) return;
 
 	switch (GetTreeGrowth(tile)) {
 		case 3: // regular sized tree