(svn r20376) -Feature [FS#3093]: add setting for none/original/more smoke (SirkoZ)

6 files changed, 47 insertions, 8 deletions

diff --git a/src/lang/english.txt b/src/lang/english.txt
index ef6aed235..35965578a 100644
--- a/src/lang/english.txt
+++ b/src/lang/english.txt
@@ -1084,6 +1084,10 @@ STR_CONFIG_SETTING_AUTOSLOPE                                    :{LTBLUE}Allow t
 STR_CONFIG_SETTING_CATCHMENT                                    :{LTBLUE}Allow more realistically sized catchment areas: {ORANGE}{STRING1}
 STR_CONFIG_SETTING_EXTRADYNAMITE                                :{LTBLUE}Allow removal of more town-owned roads, bridges, etc: {ORANGE}{STRING1}
 STR_CONFIG_SETTING_MAMMOTHTRAINS                                :{LTBLUE}Enable building very long trains: {ORANGE}{STRING1}
+STR_CONFIG_SETTING_SMOKE_AMOUNT                                 :{LTBLUE}Amount of locomotive smoke/sparks: {ORANGE}{STRING1}
+STR_CONFIG_SETTING_SMOKE_AMOUNT_NONE                            :None
+STR_CONFIG_SETTING_SMOKE_AMOUNT_ORIGINAL                        :Original
+STR_CONFIG_SETTING_SMOKE_AMOUNT_REALISTIC                       :Realistic
 STR_CONFIG_SETTING_TRAIN_ACCELERATION_MODEL                     :{LTBLUE}Train acceleration model: {ORANGE}{STRING1}
 STR_CONFIG_SETTING_TRAIN_ACCELERATION_MODEL_ORIGINAL            :Original
 STR_CONFIG_SETTING_TRAIN_ACCELERATION_MODEL_REALISTIC           :Realistic
diff --git a/src/saveload/saveload.cpp b/src/saveload/saveload.cpp
index c57cf597b..48c07b63e 100644
--- a/src/saveload/saveload.cpp
+++ b/src/saveload/saveload.cpp
@@ -208,8 +208,9 @@
  *  142   20003
  *  143   20048
  *  144   20334
+ *  145   20376
  */
-extern const uint16 SAVEGAME_VERSION = 144; ///< current savegame version of OpenTTD
+extern const uint16 SAVEGAME_VERSION = 145; ///< current savegame version of OpenTTD
 
 SavegameType _savegame_type; ///< type of savegame we are loading
 
diff --git a/src/settings_gui.cpp b/src/settings_gui.cpp
index 5491506d7..de83a435d 100644
--- a/src/settings_gui.cpp
+++ b/src/settings_gui.cpp
@@ -1441,6 +1441,7 @@ static SettingEntry _settings_vehicles_trains[] = {
 	SettingEntry("vehicle.train_acceleration_model"),
 	SettingEntry("vehicle.train_slope_steepness"),
 	SettingEntry("vehicle.mammoth_trains"),
+	SettingEntry("vehicle.smoke_amount"),
 	SettingEntry("gui.lost_train_warn"),
 	SettingEntry("vehicle.wagon_speed_limits"),
 	SettingEntry("vehicle.disable_elrails"),
diff --git a/src/settings_type.h b/src/settings_type.h
index 8e3b61db8..f5a9a85d4 100644
--- a/src/settings_type.h
+++ b/src/settings_type.h
@@ -313,6 +313,7 @@ struct OrderSettings {
 /** Settings related to vehicles. */
 struct VehicleSettings {
 	bool   mammoth_trains;                   ///< allow very long trains
+	uint8  smoke_amount;                     ///< amount of smoke/sparks locomotives produce
 	uint8  train_acceleration_model;         ///< realistic acceleration for trains
 	uint8  roadveh_acceleration_model;       ///< realistic acceleration for road vehicles
 	uint8  train_slope_steepness;            ///< Steepness of hills for trains when using realistic acceleration
diff --git a/src/table/settings.h b/src/table/settings.h
index 8533f8f25..86ef0c23b 100644
--- a/src/table/settings.h
+++ b/src/table/settings.h
@@ -382,6 +382,7 @@ const SettingDesc _settings[] = {
 	 SDT_CONDVAR(GameSettings, vehicle.roadveh_slope_steepness,      SLE_UINT8,139, SL_MAX_VERSION, 0, 0,     7,     0,      10, 1, STR_CONFIG_SETTING_ROAD_VEHICLE_SLOPE_STEEPNESS,  RoadVehSlopeSteepnessChanged),
 	    SDT_BOOL(GameSettings, pf.forbid_90_deg,                                                    0, 0, false,                    STR_CONFIG_SETTING_FORBID_90_DEG,          NULL),
 	    SDT_BOOL(GameSettings, vehicle.mammoth_trains,                                              0,NN,  true,                    STR_CONFIG_SETTING_MAMMOTHTRAINS,          NULL),
+	 SDT_CONDVAR(GameSettings, vehicle.smoke_amount,                 SLE_UINT8,145, SL_MAX_VERSION, 0,MS,     1,     0,       2, 0, STR_CONFIG_SETTING_SMOKE_AMOUNT,           NULL),
 	    SDT_BOOL(GameSettings, order.gotodepot,                                                     0, 0,  true,                    STR_CONFIG_SETTING_GOTODEPOT,              NULL),
 	    SDT_BOOL(GameSettings, pf.roadveh_queue,                                                    0, 0,  true,                    STR_CONFIG_SETTING_ROAD_VEHICLE_QUEUEING,  NULL),
 
diff --git a/src/train_cmd.cpp b/src/train_cmd.cpp
index bac4e78d2..8d75bfcde 100644
--- a/src/train_cmd.cpp
+++ b/src/train_cmd.cpp
@@ -2034,7 +2034,17 @@ static void HandleLocomotiveSmokeCloud(const Train *v)
 {
 	bool sound = false;
 
-	if ((v->vehstatus & VS_TRAIN_SLOWING) || v->cur_speed < 2) {
+	/* Do not show any locomotive smoke/sparks when smoke_amount is set to none (0) or train is:
+	 * slowing down or stopped (by the player) or
+	 * it is ordered to reverse direction (by player) so it is slowing down to do it or
+	 * its current speed is less than 2 km-ish/h or
+	 * it is entering station with an order to stop there and its speed is equal to maximum station entering speed. */
+	if (_settings_game.vehicle.smoke_amount == 0 ||
+			v->vehstatus & (VS_TRAIN_SLOWING | VS_STOPPED) ||
+			HasBit(v->flags, VRF_REVERSING) ||
+			v->cur_speed < 2 ||
+			(IsRailStationTile(v->tile) && v->IsFrontEngine() && v->current_order.ShouldStopAtStation(v, GetStationIndex(v->tile)) &&
+			v->cur_speed >= v->Train::GetCurrentMaxSpeed())) {
 		return;
 	}
 
@@ -2076,24 +2086,45 @@ static void HandleLocomotiveSmokeCloud(const Train *v)
 
 		switch (effect_type) {
 			case 0:
-				/* steam smoke. */
-				if (GB(v->tick_counter, 0, 4) == 0) {
+				/* Steam smoke - amount is gradually falling until train reaches its maximum speed, after that it's normal.
+				 * Details: while train's current speed is gradually increasing, steam plumes' density decreases by one third each
+				 * third of its maximum speed spectrum. Steam emission finally normalises at very close to train's maximum speed.
+				 * REGULATION:
+				 * - instead of 1, 4 / 2^smoke_amount (max. 2) is used to provide sufficient regulation to steam puffs' amount. */
+				if (GB(v->tick_counter, 0, ((4 >> _settings_game.vehicle.smoke_amount) + ((u->cur_speed * 3) / u->tcache.cached_max_speed))) == 0) {
 					CreateEffectVehicleRel(v, x, y, 10, EV_STEAM_SMOKE);
 					sound = true;
 				}
 				break;
 
 			case 1:
-				/* diesel smoke */
-				if (u->cur_speed <= 40 && Chance16(15, 128)) {
+				/* Diesel smoke - thicker when train is starting, gradually subsiding till locomotive reaches its maximum speed
+				 * when it stops.
+				 * Details: Train's (max.) speed spectrum is divided into 32 parts. When max. speed is reached, chance for smoke
+				 * emission erodes by 32 (1/4). Power and train's weight come in handy too to either increase smoke emission in
+				 * 6 steps (1000HP each) if the power is low or decrease smoke emission in 6 steps (512 tonnes each) if the train
+				 * isn't overweight. Power and weight contributions are expressed in a way that neither extreme power, nor
+				 * extreme weight can ruin the balance (e.g. FreightWagonMultiplier) in the formula. When the train reaches
+				 * maximum speed no diesel_smoke is emitted as train has enough traction to keep locomotive running optimally.
+				 * REGULATION:
+				 * - up to which speed a diesel train is emitting smoke (with reduced/small setting only until 1/2 of max_speed),
+				 * - in Chance16 - the last value is 512 / 2^smoke_amount (max. smoke when 128 = smoke_amount of 2). */
+				if (u->cur_speed < (u->tcache.cached_max_speed >> (2 >> _settings_game.vehicle.smoke_amount)) &&
+						Chance16((64 - ((u->cur_speed << 5) / u->tcache.cached_max_speed) + (32 >> (u->acc_cache.cached_power >> 10)) - (32 >> (u->acc_cache.cached_weight >> 9))), (512 >> _settings_game.vehicle.smoke_amount))) {
 					CreateEffectVehicleRel(v, 0, 0, 10, EV_DIESEL_SMOKE);
 					sound = true;
 				}
 				break;
 
 			case 2:
-				/* blue spark */
-				if (GB(v->tick_counter, 0, 2) == 0 && Chance16(1, 45)) {
+				/* Electric train's spark - more often occurs when train is departing (more load)
+				 * Details: Electric locomotives are usually at least twice as powerful as their diesel counterparts, so spark
+				 * emissions are kept simple. Only when starting, creating huge force are sparks more likely to happen, but when
+				 * reaching its max. speed, quarter by quarter of it, chance decreases untill the usuall 2,22% at train's top speed.
+				 * REGULATION:
+				 * - in Chance16 the last value is 360 / 2^smoke_amount (max. sparks when 90 = smoke_amount of 2). */
+				if (GB(v->tick_counter, 0, 2) == 0 &&
+						Chance16((6 - ((u->cur_speed << 2) / u->tcache.cached_max_speed)), (360 >> _settings_game.vehicle.smoke_amount))) {
 					CreateEffectVehicleRel(v, 0, 0, 10, EV_ELECTRIC_SPARK);
 					sound = true;
 				}