From 2b4dbf582ae20dccacb3641eb235ad3ed64be586 Mon Sep 17 00:00:00 2001
From: Jonathan G Rennison <j.g.rennison@gmail.com>
Date: Sat, 20 Feb 2016 21:37:45 +0000
Subject: [PATCH] Show tunnel/bridge exit signal facing correct way with
 correct colour.

---
 src/signal.cpp           | 16 ++++++++++++++++
 src/tunnelbridge_cmd.cpp | 22 ++++++++++++++++++----
 src/tunnelbridge_map.h   | 10 ++++++++++
 3 files changed, 44 insertions(+), 4 deletions(-)

diff --git a/src/signal.cpp b/src/signal.cpp
index e3c3da0e91..6893bb4ef5 100644
--- a/src/signal.cpp
+++ b/src/signal.cpp
@@ -390,11 +390,17 @@ static SigFlags ExploreSegment(Owner owner)
 							if (HasVehicleOnPos(GetOtherTunnelBridgeEnd(tile), &tile, &TrainInWormholeTileEnum)) flags |= SF_TRAIN;
 							if (!(flags & SF_TRAIN) && HasVehicleOnPos(tile, &tile, &TrainInWormholeTileEnum)) flags |= SF_TRAIN;
 						}
+						if (IsTunnelBridgeExit(tile) && !_tbuset.Add(tile, INVALID_TRACKDIR)) {
+							return flags | SF_FULL;
+						}
 						enterdir = dir;
 						exitdir = ReverseDiagDir(dir);
 						tile += TileOffsByDiagDir(exitdir); // just skip to next tile
 					} else { // NOT incoming from the wormhole!
 						if (ReverseDiagDir(enterdir) != dir) continue;
+						if (IsTunnelBridgeExit(tile) && !_tbuset.Add(tile, INVALID_TRACKDIR)) {
+							return flags | SF_FULL;
+						}
 						if (!(flags & SF_TRAIN)) {
 							if (HasVehicleOnPos(tile, &tile, &TrainInWormholeTileEnum)) flags |= SF_TRAIN;
 							if (!(flags & SF_TRAIN) && IsTunnelBridgeExit(tile)) {
@@ -443,6 +449,16 @@ static void UpdateSignalsAroundSegment(SigFlags flags)
 	Trackdir trackdir;
 
 	while (_tbuset.Get(&tile, &trackdir)) {
+		if (IsTileType(tile, MP_TUNNELBRIDGE) && IsTunnelBridgeExit(tile)) {
+			bool old_state = IsTunnelBridgeExitGreen(tile);
+			bool new_state = !(flags & SF_TRAIN);
+			if (old_state != new_state) {
+				SetTunnelBridgeExitGreen(tile, new_state);
+				MarkTileDirtyByTile(tile);
+			}
+			continue;
+		}
+
 		assert(HasSignalOnTrackdir(tile, trackdir));
 
 		SignalType sig = GetSignalType(tile, TrackdirToTrack(trackdir));
diff --git a/src/tunnelbridge_cmd.cpp b/src/tunnelbridge_cmd.cpp
index 22350db906..0149b6aaba 100644
--- a/src/tunnelbridge_cmd.cpp
+++ b/src/tunnelbridge_cmd.cpp
@@ -1164,20 +1164,34 @@ static void DrawTunnelBridgeRampSignal(const TileInfo *ti)
 		case DIAGDIR_NW: position = 3; break;
 	}
 
-	uint x = TileX(ti->tile) * TILE_SIZE + SignalPositions[side][position].x;
-	uint y = TileY(ti->tile) * TILE_SIZE + SignalPositions[side][position].y;
+	bool is_green;
+	bool show_exit;
+	if (IsTunnelBridgeExit(ti->tile) && IsBridge(ti->tile)) {
+		is_green = IsTunnelBridgeExitGreen(ti->tile);
+		show_exit = true;
+		position ^= 1;
+	} else {
+		is_green = IsTunnelBridgeWithSignGreen(ti->tile);
+		show_exit = false;
+	}
+
+	uint x = TileX(ti->tile) * TILE_SIZE + SignalPositions[side != show_exit][position ^ show_exit].x;
+	uint y = TileY(ti->tile) * TILE_SIZE + SignalPositions[side != show_exit][position ^ show_exit].y;
 	uint z = ti->z;
 
+	if (ti->tileh == SLOPE_FLAT && side == show_exit && dir == DIAGDIR_SE) z += 2;
+	if (ti->tileh == SLOPE_FLAT && side != show_exit && dir == DIAGDIR_SW) z += 2;
+
 	if (ti->tileh != SLOPE_FLAT && IsBridge(ti->tile)) z += 8; // sloped bridge head
 	SignalVariant variant = (_cur_year < _settings_client.gui.semaphore_build_before ? SIG_SEMAPHORE : SIG_ELECTRIC);
 
 	SpriteID sprite;
 	if (variant == SIG_ELECTRIC) {
 		/* Normal electric signals are picked from original sprites. */
-		sprite = SPR_ORIGINAL_SIGNALS_BASE + ((position << 1) + IsTunnelBridgeWithSignGreen(ti->tile));
+		sprite = SPR_ORIGINAL_SIGNALS_BASE + ((position << 1) + is_green);
 	} else {
 		/* All other signals are picked from add on sprites. */
-		sprite = SPR_SIGNALS_BASE + ((SIGTYPE_NORMAL - 1) * 16 + variant * 64 + (position << 1) + IsTunnelBridgeWithSignGreen(ti->tile));
+		sprite = SPR_SIGNALS_BASE + ((SIGTYPE_NORMAL - 1) * 16 + variant * 64 + (position << 1) + is_green);
 	}
 
 	AddSortableSpriteToDraw(sprite, PAL_NONE, x, y, 1, 1, TILE_HEIGHT, z, false, 0, 0, BB_Z_SEPARATOR);
diff --git a/src/tunnelbridge_map.h b/src/tunnelbridge_map.h
index 57f338b8be..43aa4f29cd 100644
--- a/src/tunnelbridge_map.h
+++ b/src/tunnelbridge_map.h
@@ -213,6 +213,16 @@ static inline bool IsTunnelBridgeExit(TileIndex t)
 	return !HasBit(_m[t].m5, 5) && HasBit(_m[t].m5, 6);
 }
 
+static inline bool IsTunnelBridgeExitGreen(TileIndex t)
+{
+	assert(IsTunnelBridgeExit(t));
+	return HasBit(_me[t].m6, 0);
+}
 
+static inline void SetTunnelBridgeExitGreen(TileIndex t, bool green)
+{
+	assert(IsTunnelBridgeExit(t));
+	SB(_me[t].m6, 0, 1, green ? 1 : 0);
+}
 
 #endif /* TUNNELBRIDGE_MAP_H */