Add GUI settings and setting/help texts.

Move tree-related functions into their own GUI sub-category.

src/lang/english.txt

@@ -1568,6 +1568,11 @@ STR_CONFIG_SETTING_EXTRA_TREE_PLACEMENT_NONE                    :None {RED}(brea
 STR_CONFIG_SETTING_EXTRA_TREE_PLACEMENT_RAINFOREST              :Only in rain forests
 STR_CONFIG_SETTING_EXTRA_TREE_PLACEMENT_ALL                     :Everywhere
 
+STR_CONFIG_SETTING_TREES_AROUND_SNOWLINE                        :Adjusted arctic tree placement: {STRING2}
+STR_CONFIG_SETTING_TREES_AROUND_SNOWLINE_HELPTEXT               :Adjust placement of trees around snow line in artic climate. Trees thin out above snowline. Trees are a mix of arctic and temperate just below snowline. Below that trees are temperate.
+STR_CONFIG_SETTING_TREES_AROUND_SNOWLINE_RANGE                  :Arctic tree range: {STRING2}
+STR_CONFIG_SETTING_TREES_AROUND_SNOWLINE_RANGE_HELPTEXT         :Approximate range of arctic trees around snow line
+
 STR_CONFIG_SETTING_TOOLBAR_POS                                  :Position of main toolbar: {STRING2}
 STR_CONFIG_SETTING_TOOLBAR_POS_HELPTEXT                         :Horizontal position of the main toolbar at the top of the screen
 STR_CONFIG_SETTING_STATUSBAR_POS                                :Position of status bar: {STRING2}
@@ -1685,6 +1690,7 @@ STR_CONFIG_SETTING_ENVIRONMENT_AUTHORITIES                      :{ORANGE}Authori
 STR_CONFIG_SETTING_ENVIRONMENT_TOWNS                            :{ORANGE}Towns
 STR_CONFIG_SETTING_ENVIRONMENT_INDUSTRIES                       :{ORANGE}Industries
 STR_CONFIG_SETTING_ENVIRONMENT_CARGODIST                        :{ORANGE}Cargo distribution
+STR_CONFIG_SETTING_ENVIRONMENT_TREES                            :{ORANGE}Trees
 STR_CONFIG_SETTING_AI                                           :{ORANGE}Competitors
 STR_CONFIG_SETTING_AI_NPC                                       :{ORANGE}Computer players
 

src/settings_gui.cpp

@@ -1719,9 +1719,14 @@ static SettingsContainer &GetSettingsTree()
 				cdist->Add(new SettingEntry("linkgraph.demand_size"));
 				cdist->Add(new SettingEntry("linkgraph.short_path_saturation"));
 			}
+			SettingsPage *treedist = environment->Add(new SettingsPage(STR_CONFIG_SETTING_ENVIRONMENT_TREES));
+			{
+				treedist->Add(new SettingEntry("construction.extra_tree_placement"));
+				treedist->Add(new SettingEntry("construction.trees_around_snow_line_enabled"));
+				treedist->Add(new SettingEntry("construction.trees_around_snow_line_range"));
+			}
 
 			environment->Add(new SettingEntry("station.modified_catchment"));
-			environment->Add(new SettingEntry("construction.extra_tree_placement"));
 		}
 
 		SettingsPage *ai = main->Add(new SettingsPage(STR_CONFIG_SETTING_AI));

src/table/settings.ini

@@ -2314,6 +2314,8 @@ cat      = SC_BASIC
 base     = GameSettings
 var      = construction.trees_around_snow_line_enabled
 def      = true
+str      = STR_CONFIG_SETTING_TREES_AROUND_SNOWLINE
+strhelp  = STR_CONFIG_SETTING_TREES_AROUND_SNOWLINE_HELPTEXT
 cat      = SC_BASIC
 patxname = ""everest_treeline.construction.trees_around_snow_line_enabled""
 
@@ -2324,6 +2326,9 @@ type     = SLE_UINT8
 def      = 8
 min      = 1
 max      = 20
+str      = STR_CONFIG_SETTING_TREES_AROUND_SNOWLINE_RANGE
+strhelp  = STR_CONFIG_SETTING_TREES_AROUND_SNOWLINE_RANGE_HELPTEXT
+strval   = STR_JUST_COMMA
 cat      = SC_BASIC
 patxname = ""everest_treeline.construction.trees_around_snow_line_range""