(svn r5363) Revert 5312, 5288, 5248, 3992, 3249, 3228

They were all aimed at fixing the terraform-into-tunnel problem, but introduced new sideeffects while doing so

1 files changed, 15 insertions, 27 deletions

diff --git a/tile.c b/tile.c
index 98fb5f0bd..ba6900a36 100644
--- a/tile.c
+++ b/tile.c
@@ -3,37 +3,14 @@
 #include "stdafx.h"
 #include "tile.h"
 
-/** Converts the heights of 4 corners into a tileh, and returns the minimum height of the tile
-  * @param n,w,e,s the four corners
-  * @param h uint pointer to write the height to
-  * @return the tileh
-*/
-Slope GetTileh(uint n, uint w, uint e, uint s, uint *h)
-{
-	uint min = n;
-	Slope r;
-
-	if (min >= w) min = w;
-	if (min >= e) min = e;
-	if (min >= s) min = s;
-
-	r = SLOPE_FLAT;
-	if ((n -= min) != 0) r += (--n << 4) + SLOPE_N;
-	if ((e -= min) != 0) r += (--e << 4) + SLOPE_E;
-	if ((s -= min) != 0) r += (--s << 4) + SLOPE_S;
-	if ((w -= min) != 0) r += (--w << 4) + SLOPE_W;
-
-	if (h != NULL) *h = min * TILE_HEIGHT;
-
-	return r;
-}
-
 Slope GetTileSlope(TileIndex tile, uint *h)
 {
 	uint a;
 	uint b;
 	uint c;
 	uint d;
+	uint min;
+	uint r;
 
 	assert(tile < MapSize());
 
@@ -42,12 +19,23 @@ Slope GetTileSlope(TileIndex tile, uint *h)
 		return 0;
 	}
 
-	a = TileHeight(tile);
+	min = a = TileHeight(tile);
 	b = TileHeight(tile + TileDiffXY(1, 0));
+	if (min >= b) min = b;
 	c = TileHeight(tile + TileDiffXY(0, 1));
+	if (min >= c) min = c;
 	d = TileHeight(tile + TileDiffXY(1, 1));
+	if (min >= d) min = d;
+
+	r = SLOPE_FLAT;
+	if ((a -= min) != 0) r += (--a << 4) + SLOPE_N;
+	if ((c -= min) != 0) r += (--c << 4) + SLOPE_E;
+	if ((d -= min) != 0) r += (--d << 4) + SLOPE_S;
+	if ((b -= min) != 0) r += (--b << 4) + SLOPE_W;
 
-	return GetTileh(a, b, c, d, h);
+	if (h != NULL) *h = min * TILE_HEIGHT;
+
+	return r;
 }
 
 uint GetTileZ(TileIndex tile)