(svn r3992) -Fix: Rewrote the code to determine whether a rail-tile can be terraformed.

Fixes a bug where you could terraform a tunnel (fixed by r3228, but reverted that one)
Fixes a bug introduced by r3228 which allowed steep rail tiles resulting in ... unwanted effects such as display artifacts.
That means the terraform feature should not work as intended; it also uses _valid_tileh_slopes to determine valid configurations instead of hand-brewn stuff.
TODO: _terraform_err_tile and similar TileIndices should have INVALID_TILE as "unused", not 0. (0 is a valid tile).

1 files changed, 1 insertions, 0 deletions

diff --git a/tile.h b/tile.h
index af6c0e1f1..e3a0d45d6 100644
--- a/tile.h
+++ b/tile.h
@@ -24,6 +24,7 @@ typedef enum TileTypes {
 void SetMapExtraBits(TileIndex tile, byte flags);
 uint GetMapExtraBits(TileIndex tile);
 
+uint GetTileh(uint n, uint w, uint e, uint s, uint *h);
 uint GetTileSlope(TileIndex tile, uint *h);
 uint GetTileZ(TileIndex tile);