(svn r20996) -Change: [NewGRF] the X and Y offsets in the parameter for industry vars 60,61,62,63 are unsigned instead of signed

5 files changed, 12 insertions, 11 deletions

diff --git a/src/newgrf_commons.cpp b/src/newgrf_commons.cpp
index 6521a39f7..4bf5b6e9f 100644
--- a/src/newgrf_commons.cpp
+++ b/src/newgrf_commons.cpp
@@ -395,13 +395,13 @@ uint32 GetTerrainType(TileIndex tile, TileContext context)
 	}
 }
 
-TileIndex GetNearbyTile(byte parameter, TileIndex tile)
+TileIndex GetNearbyTile(byte parameter, TileIndex tile, bool signed_offsets)
 {
 	int8 x = GB(parameter, 0, 4);
 	int8 y = GB(parameter, 4, 4);
 
-	if (x >= 8) x -= 16;
-	if (y >= 8) y -= 16;
+	if (signed_offsets && x >= 8) x -= 16;
+	if (signed_offsets && y >= 8) y -= 16;
 
 	/* Swap width and height depending on axis for railway stations */
 	if (HasStationTileRail(tile) && GetRailStationAxis(tile) == AXIS_Y) Swap(x, y);
diff --git a/src/newgrf_commons.h b/src/newgrf_commons.h
index 172641743..171ccf759 100644
--- a/src/newgrf_commons.h
+++ b/src/newgrf_commons.h
@@ -144,7 +144,7 @@ extern AirportTileOverrideManager _airporttile_mngr;
 extern ObjectOverrideManager _object_mngr;
 
 uint32 GetTerrainType(TileIndex tile, TileContext context = TCX_NORMAL);
-TileIndex GetNearbyTile(byte parameter, TileIndex tile);
+TileIndex GetNearbyTile(byte parameter, TileIndex tile, bool signed_offsets = true);
 uint32 GetNearbyTileInformation(TileIndex tile);
 
 /**
diff --git a/src/newgrf_industries.cpp b/src/newgrf_industries.cpp
index a88a2d0a0..76b6af876 100644
--- a/src/newgrf_industries.cpp
+++ b/src/newgrf_industries.cpp
@@ -236,19 +236,19 @@ uint32 IndustryGetVariable(const ResolverObject *object, byte variable, byte par
 		case 0x46: return industry->construction_date; // Date when built - long format - (in days)
 
 		/* Get industry ID at offset param */
-		case 0x60: return GetIndustryIDAtOffset(GetNearbyTile(parameter, industry->location.tile), industry, object->grffile->grfid);
+		case 0x60: return GetIndustryIDAtOffset(GetNearbyTile(parameter, industry->location.tile, false), industry, object->grffile->grfid);
 
 		/* Get random tile bits at offset param */
 		case 0x61:
-			tile = GetNearbyTile(parameter, tile);
+			tile = GetNearbyTile(parameter, tile, false);
 			return (IsTileType(tile, MP_INDUSTRY) && Industry::GetByTile(tile) == industry) ? GetIndustryRandomBits(tile) : 0;
 
 		/* Land info of nearby tiles */
-		case 0x62: return GetNearbyIndustryTileInformation(parameter, tile, INVALID_INDUSTRY);
+		case 0x62: return GetNearbyIndustryTileInformation(parameter, tile, INVALID_INDUSTRY, false);
 
 		/* Animation stage of nearby tiles */
 		case 0x63:
-			tile = GetNearbyTile(parameter, tile);
+			tile = GetNearbyTile(parameter, tile, false);
 			if (IsTileType(tile, MP_INDUSTRY) && Industry::GetByTile(tile) == industry) {
 				return GetAnimationFrame(tile);
 			}
diff --git a/src/newgrf_industries.h b/src/newgrf_industries.h
index c05cd1246..af12a390e 100644
--- a/src/newgrf_industries.h
+++ b/src/newgrf_industries.h
@@ -46,6 +46,6 @@ bool IndustryTemporarilyRefusesCargo(Industry *ind, CargoID cargo_type);
 IndustryType MapNewGRFIndustryType(IndustryType grf_type, uint32 grf_id);
 
 /* in newgrf_industrytiles.cpp*/
-uint32 GetNearbyIndustryTileInformation(byte parameter, TileIndex tile, IndustryID index);
+uint32 GetNearbyIndustryTileInformation(byte parameter, TileIndex tile, IndustryID index, bool signed_offsets = true);
 
 #endif /* NEWGRF_INDUSTRIES_H */
diff --git a/src/newgrf_industrytiles.cpp b/src/newgrf_industrytiles.cpp
index fa1606b39..db6378702 100644
--- a/src/newgrf_industrytiles.cpp
+++ b/src/newgrf_industrytiles.cpp
@@ -32,11 +32,12 @@
  * @param parameter from callback.  It's in fact a pair of coordinates
  * @param tile TileIndex from which the callback was initiated
  * @param index of the industry been queried for
+ * @param signed_offsets Are the x and y offset encoded in parameter signed?
  * @return a construction of bits obeying the newgrf format
  */
-uint32 GetNearbyIndustryTileInformation(byte parameter, TileIndex tile, IndustryID index)
+uint32 GetNearbyIndustryTileInformation(byte parameter, TileIndex tile, IndustryID index, bool signed_offsets)
 {
-	if (parameter != 0) tile = GetNearbyTile(parameter, tile); // only perform if it is required
+	if (parameter != 0) tile = GetNearbyTile(parameter, tile, signed_offsets); // only perform if it is required
 	bool is_same_industry = (IsTileType(tile, MP_INDUSTRY) && GetIndustryIndex(tile) == index);
 
 	return GetNearbyTileInformation(tile) | (is_same_industry ? 1 : 0) << 8;