From 261018fc8c0d8a1d366de834d71865bce55bfde3 Mon Sep 17 00:00:00 2001
From: peter1138 <peter1138@openttd.org>
Date: Thu, 5 Jun 2008 12:08:20 +0000
Subject: [PATCH] (svn r13388) -Codechange: Remove "my invented flag for
 something that is a wagon"

---
 src/engine.cpp      | 19 +++++++++----------
 src/engine_type.h   |  2 +-
 src/newgrf.cpp      | 24 ++++++++++--------------
 src/table/engines.h | 10 +++++-----
 4 files changed, 25 insertions(+), 30 deletions(-)

diff --git a/src/engine.cpp b/src/engine.cpp
index d2a0f2bb64..71e09773b0 100644
--- a/src/engine.cpp
+++ b/src/engine.cpp
@@ -184,6 +184,13 @@ void LoadCustomEngineNames()
 	DEBUG(misc, 1, "LoadCustomEngineNames: not done");
 }
 
+/* Determine if an engine type is a wagon (and not a loco) */
+static bool IsWagon(EngineID index)
+{
+	const Engine *e = GetEngine(index);
+	return e->type == VEH_TRAIN && e->u.rail.railveh_type == RAILVEH_WAGON;
+}
+
 static void CalcEngineReliability(Engine *e)
 {
 	uint age = e->age;
@@ -256,10 +263,9 @@ void StartupEngines()
 		e->duration_phase_2 = GB(r, 5, 4) + ei->base_life * 12 - 96;
 		e->duration_phase_3 = GB(r, 9, 7) + 120;
 
-		e->reliability_spd_dec = (ei->unk2&0x7F) << 2;
+		e->reliability_spd_dec = ei->decay_speed << 2;
 
-		/* my invented flag for something that is a wagon */
-		if (ei->unk2 & 0x80) {
+		if (IsWagon(e->index)) {
 			e->age = 0xFFFF;
 		} else {
 			CalcEngineReliability(e);
@@ -377,13 +383,6 @@ CommandCost CmdWantEnginePreview(TileIndex tile, uint32 flags, uint32 p1, uint32
 	return CommandCost();
 }
 
-/* Determine if an engine type is a wagon (and not a loco) */
-static bool IsWagon(EngineID index)
-{
-	const Engine *e = GetEngine(index);
-	return e->type == VEH_TRAIN && e->u.rail.railveh_type == RAILVEH_WAGON;
-}
-
 StringID GetEngineCategoryName(EngineID engine);
 
 static void NewVehicleAvailable(Engine *e)
diff --git a/src/engine_type.h b/src/engine_type.h
index 66a4956075..db923d8b98 100644
--- a/src/engine_type.h
+++ b/src/engine_type.h
@@ -109,7 +109,7 @@ struct EngineInfo {
 	Date base_intro;
 	Year lifelength;
 	Year base_life;
-	byte unk2;         ///< flag for carriage(bit 7) and decay speed(bits0..6)
+	byte decay_speed;
 	byte load_amount;
 	byte climates;
 	uint32 refit_mask;
diff --git a/src/newgrf.cpp b/src/newgrf.cpp
index 1101821699..aa7496b927 100644
--- a/src/newgrf.cpp
+++ b/src/newgrf.cpp
@@ -417,18 +417,6 @@ static void MapSpriteMappingRecolour(PalSpriteID *grf_sprite)
 
 typedef bool (*VCI_Handler)(uint engine, int numinfo, int prop, byte **buf, int len);
 
-static void dewagonize(int condition, Engine *e)
-{
-	if (condition != 0) {
-		e->info.unk2 &= ~0x80;
-		if (e->u.rail.railveh_type == RAILVEH_WAGON)
-			e->u.rail.railveh_type = RAILVEH_SINGLEHEAD;
-	} else {
-		e->info.unk2 |= 0x80;
-		e->u.rail.railveh_type = RAILVEH_WAGON;
-	}
-}
-
 static bool RailVehicleChangeInfo(uint engine, int numinfo, int prop, byte **bufp, int len)
 {
 	byte *buf = *bufp;
@@ -468,7 +456,15 @@ static bool RailVehicleChangeInfo(uint engine, int numinfo, int prop, byte **buf
 
 			case 0x0B: // Power
 				rvi->power = grf_load_word(&buf);
-				dewagonize(rvi->power, e);
+
+				/* Set engine / wagon state based on power */
+				if (rvi->power != 0) {
+					if (rvi->railveh_type == RAILVEH_WAGON) {
+						rvi->railveh_type = RAILVEH_SINGLEHEAD;
+					}
+				} else {
+					rvi->railveh_type = RAILVEH_WAGON;
+				}
 				break;
 
 			case 0x0D: // Running cost factor
@@ -2300,7 +2296,7 @@ static void FeatureChangeInfo(byte *buf, size_t len)
 							break;
 
 						case 0x02: // Decay speed
-							SB(ei->unk2, 0, 7, grf_load_byte(&buf) & 0x7F);
+							ei->decay_speed = grf_load_byte(&buf);
 							break;
 
 						case 0x03: // Vehicle life
diff --git a/src/table/engines.h b/src/table/engines.h
index 3ca03afbad..3e8bc30576 100644
--- a/src/table/engines.h
+++ b/src/table/engines.h
@@ -18,7 +18,7 @@ enum {
 /** Writes the properties of a train or road vehicle into the EngineInfo struct.
  * @see EngineInfo
  * @param a Introduction date
- * @param b unk2, flag for carriage(bit 7) and decay speed(bits0..6)
+ * @param b decay speed
  * @param c life length
  * @param d base life
  * @param e Bitmask of the climates
@@ -29,18 +29,18 @@ enum {
 
 /** Writes the properties of a train carriage into the EngineInfo struct.
  * @param a Introduction date
- * @param b unk2, flag for carriage(bit 7) and decay speed(bits0..6)
+ * @param b decay speed
  * @param c life length
  * @param d base life
  * @param e Bitmask of the climates
  * @see MK
  * @note the 5 between d and e is the load amount
  */
-#define MW(a, b, c, d, e) { DAYS_TILL_ORIGINAL_BASE_YEAR + a, c, d, b | 0x80, 5, e, 0, 8, 0, 0, 0, STR_EMPTY }
+#define MW(a, b, c, d, e) { DAYS_TILL_ORIGINAL_BASE_YEAR + a, c, d, b, 5, e, 0, 8, 0, 0, 0, STR_EMPTY }
 
 /** Writes the properties of a ship into the EngineInfo struct.
  * @param a Introduction date
- * @param b unk2, flag for carriage(bit 7) and decay speed(bits0..6)
+ * @param b decay speed
  * @param c life length
  * @param d base life
  * @param e Bitmask of the climates
@@ -51,7 +51,7 @@ enum {
 
 /** Writes the properties of an aeroplane into the EngineInfo struct.
  * @param a Introduction date
- * @param b unk2, flag for carriage(bit 7) and decay speed(bits0..6)
+ * @param b decay speed
  * @param c life length
  * @param d base life
  * @param e Bitmask of the climates