From 39247b012078b60cd1f17397e4e7baf269fe32dd Mon Sep 17 00:00:00 2001
From: Jonathan G Rennison <j.g.rennison@gmail.com>
Date: Sun, 15 Oct 2023 22:27:28 +0100
Subject: [PATCH] Road stops: Add tile slope to varact2 variable 0x42

---
 docs/newgrf-roadstops.html | 8 ++++++--
 src/newgrf_extension.cpp   | 2 +-
 src/newgrf_roadstop.cpp    | 2 +-
 3 files changed, 8 insertions(+), 4 deletions(-)

diff --git a/docs/newgrf-roadstops.html b/docs/newgrf-roadstops.html
index 872651a513..1c6da7de97 100644
--- a/docs/newgrf-roadstops.html
+++ b/docs/newgrf-roadstops.html
@@ -261,13 +261,17 @@
 	</p>
 
 	<h4 id="roadstop_terrain_type">Road stop tile terrain type (42, or mappable variable: roadstop_terrain_type)</h4>
-	<p>This has the same value as bits 0 - 7 of <a href="https://newgrf-specs.tt-wiki.net/wiki/VariationalAction2/Objects#Tile_information_.2841.29">object (feature F) variable 41</a>.
+	<p>This has the same value as bits 0 - 15 of <a href="https://newgrf-specs.tt-wiki.net/wiki/VariationalAction2/Objects#Tile_information_.2841.29">object (feature F) variable 41</a>.
 		<table>
-		<tr><th>Value</th><th>Meaning</th></tr>
+		<tr><th>Bit</th><th>Meaning</th></tr>
 		<tr><td>0</td><td>Normal</td></tr>
 		<tr><td>1</td><td>Desert</td></tr>
 		<tr><td>2</td><td>Rainforest</td></tr>
 		<tr><td>4</td><td>On or above snowline</td></tr>
+		<tr><td>8 - 15</td><td>
+			Tile slope<br />
+			This requires <font face="monospace">road_stops</font>, version 10.
+		</td></tr>
 		</table>
 	</p>
 
diff --git a/src/newgrf_extension.cpp b/src/newgrf_extension.cpp
index 518f0dd65b..f8d9ba72c9 100644
--- a/src/newgrf_extension.cpp
+++ b/src/newgrf_extension.cpp
@@ -62,7 +62,7 @@ extern const GRFFeatureInfo _grf_feature_list[] = {
 	GRFFeatureInfo("action0_object_flood_resistant", 1),
 	GRFFeatureInfo("action0_object_viewport_map_tile_type", 1),
 	GRFFeatureInfo("varaction2_airporttiles_airport_info", 1),
-	GRFFeatureInfo("road_stops", 9, GFTOF_ROAD_STOPS),
+	GRFFeatureInfo("road_stops", 10, GFTOF_ROAD_STOPS),
 	GRFFeatureInfo("new_landscape", 2),
 	GRFFeatureInfo("more_objects_per_grf", 1),
 	GRFFeatureInfo("more_action2_ids", 1, GFTOF_MORE_ACTION2_IDS),
diff --git a/src/newgrf_roadstop.cpp b/src/newgrf_roadstop.cpp
index 2faf2bce6d..aa8f9d498b 100644
--- a/src/newgrf_roadstop.cpp
+++ b/src/newgrf_roadstop.cpp
@@ -130,7 +130,7 @@ uint32 RoadStopScopeResolver::GetVariable(uint16 variable, uint32 parameter, Get
 			return 2;
 
 		/* Terrain type */
-		case 0x42: return this->tile == INVALID_TILE ? 0 : GetTerrainType(this->tile, TCX_NORMAL); // terrain_type
+		case 0x42: return this->tile == INVALID_TILE ? 0 : (GetTileSlope(this->tile) << 8 | GetTerrainType(this->tile, TCX_NORMAL));
 
 		/* Road type */
 		case 0x43: return get_road_type_variable(RTT_ROAD);