From 8faead7e7a1f407c34b5ee3e83ba7ffd1209755b Mon Sep 17 00:00:00 2001
From: Jonathan G Rennison <j.g.rennison@gmail.com>
Date: Wed, 19 Aug 2015 21:56:22 +0100
Subject: [PATCH] Graphically indicate restricted signals by recolouring the
 signal post.

Recolour signal posts from grey to blue for restricted signals which
are not semaphores and are not custom sprites.
---
 bin/data/tracerestrict.grf | Bin 0 -> 526 bytes
 src/gfxinit.cpp            |   3 +++
 src/rail_cmd.cpp           |  15 ++++++++++++++-
 src/table/sprites.h        |   6 +++++-
 4 files changed, 22 insertions(+), 2 deletions(-)
 create mode 100644 bin/data/tracerestrict.grf

diff --git a/bin/data/tracerestrict.grf b/bin/data/tracerestrict.grf
new file mode 100644
index 0000000000000000000000000000000000000000..b71ee80c1713778d8886e3aeca4568644b075d93
GIT binary patch
literal 526
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ztEX>ZXk=_+YG!U>X=QC=YiIA^=;Z9;>gMj@>E-R?>*pU37!({58WtWA85JE98yBCD
zn3SB7nwFlCnU$TBo0nfuSX5k6T2@|BSyf$ATUXyOY4Vh*)26p~bar+3^!D{nm<SP=
zF>}`JIdkXDU$Ah|;w4L$Enl&6)#^2C*R9{Mant54TeofBv2)k%J$v`<KXCBS;Uh<n
z9Y1mM)af&4&z-+;@zUihSFc^aar4&gJ9qEhfAH|p<0ns_J%91?)$2EJ-@X6v@zduo
zU%!3-@$=X3KY#!IXM}_S)Bx;ZaPkx+3{I062FEeN-~{$CXl!b3X>DsiM$a%fg9rl#
GFaQ8SISHfy

literal 0
HcmV?d00001

diff --git a/src/gfxinit.cpp b/src/gfxinit.cpp
index 10bc0afa17..440cf5bb1a 100644
--- a/src/gfxinit.cpp
+++ b/src/gfxinit.cpp
@@ -170,6 +170,9 @@ static void LoadSpriteTables()
 	_palette_remap_grf[i] = (PAL_DOS != used_set->palette);
 	LoadGrfFile(used_set->files[GFT_BASE].filename, 0, i++);
 
+	/* Tracerestrict sprites. */
+	LoadGrfFile("tracerestrict.grf", SPR_TRACERESTRICT_BASE, i++);
+
 	/*
 	 * The second basic file always starts at the given location and does
 	 * contain a different amount of sprites depending on the "type"; DOS
diff --git a/src/rail_cmd.cpp b/src/rail_cmd.cpp
index e1b956bad9..3b706c69ea 100644
--- a/src/rail_cmd.cpp
+++ b/src/rail_cmd.cpp
@@ -1862,6 +1862,7 @@ static void DrawSingleSignal(TileIndex tile, const RailtypeInfo *rti, Track trac
 	SignalVariant variant = GetSignalVariant(tile, track);
 
 	SpriteID sprite = GetCustomSignalSprite(rti, tile, type, variant, condition);
+	bool is_custom_sprite = (sprite != 0);
 	if (sprite != 0) {
 		sprite += image;
 	} else {
@@ -1870,7 +1871,19 @@ static void DrawSingleSignal(TileIndex tile, const RailtypeInfo *rti, Track trac
 		sprite += type * 16 + variant * 64 + image * 2 + condition + (type > SIGTYPE_LAST_NOPBS ? 64 : 0);
 	}
 
-	AddSortableSpriteToDraw(sprite, PAL_NONE, x, y, 1, 1, BB_HEIGHT_UNDER_BRIDGE, GetSaveSlopeZ(x, y, track));
+	if (!is_custom_sprite && variant == SIG_ELECTRIC && IsRestrictedSignal(tile) && GetExistingTraceRestrictProgram(tile, track) != NULL) {
+		if (type == SIGTYPE_PBS || type == SIGTYPE_PBS_ONEWAY) {
+			static const SubSprite lower_part { -50, -10, 50, 50 };
+			static const SubSprite upper_part { -50, -50, 50, -11 };
+
+			AddSortableSpriteToDraw(sprite, SPR_TRACERESTRICT_BASE, x, y, 1, 1, BB_HEIGHT_UNDER_BRIDGE, GetSaveSlopeZ(x, y, track), false, 0, 0, 0, &lower_part);
+			AddSortableSpriteToDraw(sprite,               PAL_NONE, x, y, 1, 1, BB_HEIGHT_UNDER_BRIDGE, GetSaveSlopeZ(x, y, track), false, 0, 0, 0, &upper_part);
+		} else {
+			AddSortableSpriteToDraw(sprite, SPR_TRACERESTRICT_BASE + 1, x, y, 1, 1, BB_HEIGHT_UNDER_BRIDGE, GetSaveSlopeZ(x, y, track));
+		}
+	} else {
+		AddSortableSpriteToDraw(sprite, PAL_NONE, x, y, 1, 1, BB_HEIGHT_UNDER_BRIDGE, GetSaveSlopeZ(x, y, track));
+	}
 }
 
 static uint32 _drawtile_track_palette;
diff --git a/src/table/sprites.h b/src/table/sprites.h
index 81d5388f99..3bd7fdffeb 100644
--- a/src/table/sprites.h
+++ b/src/table/sprites.h
@@ -296,8 +296,12 @@ static const uint16 EMPTY_BOUNDING_BOX_SPRITE_COUNT = 1;
 static const SpriteID SPR_PALETTE_BASE = SPR_EMPTY_BOUNDING_BOX + EMPTY_BOUNDING_BOX_SPRITE_COUNT;
 static const uint16 PALETTE_SPRITE_COUNT = 1;
 
+/* Tracerestrict sprites */
+static const SpriteID SPR_TRACERESTRICT_BASE = SPR_PALETTE_BASE + PALETTE_SPRITE_COUNT;
+static const uint16 TRACERESTRICT_SPRITE_COUNT = 2;
+
 /* From where can we start putting NewGRFs? */
-static const SpriteID SPR_NEWGRFS_BASE = SPR_PALETTE_BASE + PALETTE_SPRITE_COUNT;
+static const SpriteID SPR_NEWGRFS_BASE = SPR_TRACERESTRICT_BASE + TRACERESTRICT_SPRITE_COUNT;
 
 /* Manager face sprites */
 static const SpriteID SPR_GRADIENT = 874; // background gradient behind manager face