(svn r5070) Merged the bridge branch

-Feature: Bridges can now be placed above:
	Any railway track combination (excluding depots and waypoints)
	Any road combination (excluding depots)
	Clear tiles (duh), including fields
	Tunnel entrances
	Bridge heads

Thanks to Tron for idea and implementation, KUDr for the yapf synchronization and many others for hours of testing

There are still a number of visual problems remaining, especially when electric railways are on or under the bridge.
DO NOT REPORT THOSE BUGS FOR THE TIME BEING please.

1 files changed, 27 insertions, 10 deletions

diff --git a/bridge_map.c b/bridge_map.c
index cbb955c37..e21c5928c 100644
--- a/bridge_map.c
+++ b/bridge_map.c
@@ -3,22 +3,25 @@
 #include "stdafx.h"
 #include "openttd.h"
 #include "bridge_map.h"
+#include "variables.h"
 
 
 TileIndex GetBridgeEnd(TileIndex tile, DiagDirection dir)
 {
 	TileIndexDiff delta = TileOffsByDir(dir);
 
-	assert(DiagDirToAxis(dir) == GetBridgeAxis(tile));
-
-	do {
-		tile += delta;
-	} while (!IsBridgeRamp(tile));
+	do { tile += delta; } while (IsBridgeAbove(tile) && IsBridgeOfAxis(tile, DiagDirToAxis(dir)));
 
 	return tile;
 }
 
 
+TileIndex GetNorthernBridgeEnd(TileIndex t)
+{
+	return GetBridgeEnd(t, ReverseDiagDir(AxisToDiagDir(GetBridgeAxis(t))));
+}
+
+
 TileIndex GetSouthernBridgeEnd(TileIndex t)
 {
 	return GetBridgeEnd(t, AxisToDiagDir(GetBridgeAxis(t)));
@@ -27,11 +30,25 @@ TileIndex GetSouthernBridgeEnd(TileIndex t)
 
 TileIndex GetOtherBridgeEnd(TileIndex tile)
 {
-	TileIndexDiff delta = TileOffsByDir(GetBridgeRampDirection(tile));
+	assert(IsBridgeTile(tile));
+	return GetBridgeEnd(tile, GetBridgeRampDirection(tile));
+}
 
-	do {
-		tile += delta;
-	} while (!IsBridgeRamp(tile));
+uint GetBridgeHeight(TileIndex tile, Axis a)
+{
+	uint h, f;
+	uint tileh = GetTileSlope(tile, &h);
 
-	return tile;
+	f = GetBridgeFoundation(tileh, a);
+
+	if (f) {
+		if (f < 15) {
+			h += TILE_HEIGHT;
+			tileh = SLOPE_FLAT;
+		} else {
+			tileh = _inclined_tileh[f - 15];
+		}
+	}
+
+	return h + TILE_HEIGHT;
 }