(svn r5864) -Feature: Also allow horizontal and vertical rails on steep slopes

4 files changed, 53 insertions, 30 deletions

diff --git a/landscape.c b/landscape.c
index 8f6289888..007d653e0 100644
--- a/landscape.c
+++ b/landscape.c
@@ -51,7 +51,9 @@ const byte _tileh_to_sprite[32] = {
 };
 
 const byte _inclined_tileh[] = {
-	SLOPE_SW, SLOPE_NW, SLOPE_SW, SLOPE_SE, SLOPE_NE, SLOPE_SE, SLOPE_NE, SLOPE_NW
+	SLOPE_SW, SLOPE_NW, SLOPE_SW, SLOPE_SE, SLOPE_NE, SLOPE_SE, SLOPE_NE, SLOPE_NW,
+	SLOPE_E, SLOPE_N, SLOPE_W, SLOPE_S,
+	SLOPE_NWS, SLOPE_WSE, SLOPE_SEN, SLOPE_ENW
 };
 
 
@@ -203,31 +205,48 @@ void DrawFoundation(TileInfo *ti, uint f)
 	if (!HasFoundationNW(ti->tile, slope, z)) sprite_base += 22;
 	if (!HasFoundationNE(ti->tile, slope, z)) sprite_base += 44;
 
-	if (f < 15) {
-		// leveled foundation
-		// Use the original slope sprites if NW and NE borders should be visible
-		if (sprite_base  == SPR_SLOPES_BASE - 15) sprite_base = SPR_FOUNDATION_BASE;
+	if (IsSteepSlope(ti->tileh)) {
+		uint32 lower_base;
 
-		AddSortableSpriteToDraw(sprite_base + f, ti->x, ti->y, 16, 16, 7, ti->z);
+		// Lower part of foundation
+		lower_base = sprite_base;
+		if (lower_base == SPR_SLOPES_BASE - 15) lower_base = SPR_FOUNDATION_BASE;
+		AddSortableSpriteToDraw(
+			lower_base + (ti->tileh & ~SLOPE_STEEP), ti->x, ti->y, 16, 16, 7, ti->z
+		);
 		ti->z += TILE_HEIGHT;
-		ti->tileh = SLOPE_FLAT;
-		OffsetGroundSprite(31, 1);
+		ti->tileh = _inclined_tileh[f - 15];
+		if (f < 15 + 8) {
+			// inclined
+			AddSortableSpriteToDraw(sprite_base + f, ti->x, ti->y, 16, 16, 1, ti->z);
+			OffsetGroundSprite(31, 9);
+		} else if (f >= 15 + 8 + 4) {
+			// three corners raised
+			uint32 upper = sprite_base + 15 + (f - 15 - 8 - 4) * 2;
+
+			AddSortableSpriteToDraw(upper, ti->x, ti->y, 16, 16, 1, ti->z);
+			AddChildSpriteScreen(upper + 1, 31, 9);
+			OffsetGroundSprite(31, 9);
+		} else {
+			// one corner raised
+			OffsetGroundSprite(31, 1);
+		}
 	} else {
-		// inclined foundation
-		if (IsSteepSlope(ti->tileh)) {
-			uint32 lower_base;
-
-			// Lower part of foundation
-			lower_base = sprite_base;
-			if (lower_base == SPR_SLOPES_BASE - 15) lower_base = SPR_FOUNDATION_BASE;
-			AddSortableSpriteToDraw(
-				lower_base + (ti->tileh & ~SLOPE_STEEP), ti->x, ti->y, 16, 16, 7, ti->z
-			);
+		if (f < 15) {
+			// leveled foundation
+			// Use the original slope sprites if NW and NE borders should be visible
+			if (sprite_base  == SPR_SLOPES_BASE - 15) sprite_base = SPR_FOUNDATION_BASE;
+
+			AddSortableSpriteToDraw(sprite_base + f, ti->x, ti->y, 16, 16, 7, ti->z);
 			ti->z += TILE_HEIGHT;
+			ti->tileh = SLOPE_FLAT;
+			OffsetGroundSprite(31, 1);
+		} else {
+			// inclined foundation
+			AddSortableSpriteToDraw(sprite_base + f, ti->x, ti->y, 16, 16, 1, ti->z);
+			ti->tileh = _inclined_tileh[f - 15];
+			OffsetGroundSprite(31, 9);
 		}
-		AddSortableSpriteToDraw(sprite_base + f, ti->x, ti->y, 16, 16, 1, ti->z);
-		ti->tileh = _inclined_tileh[f - 15];
-		OffsetGroundSprite(31, 9);
 	}
 }
 
diff --git a/rail_cmd.c b/rail_cmd.c
index f94f4e2c2..4676d492b 100644
--- a/rail_cmd.c
+++ b/rail_cmd.c
@@ -160,9 +160,13 @@ uint GetRailFoundation(Slope tileh, TrackBits bits)
 	}
 
 	switch (bits) {
+		default: NOT_REACHED();
 		case TRACK_BIT_X: i = 0; break;
 		case TRACK_BIT_Y: i = 1; break;
-		default:          return 0;
+		case TRACK_BIT_LEFT:  return 15 + 8 + (tileh == SLOPE_STEEP_W ? 4 : 0);
+		case TRACK_BIT_LOWER: return 15 + 8 + (tileh == SLOPE_STEEP_S ? 5 : 1);
+		case TRACK_BIT_RIGHT: return 15 + 8 + (tileh == SLOPE_STEEP_E ? 6 : 2);
+		case TRACK_BIT_UPPER: return 15 + 8 + (tileh == SLOPE_STEEP_N ? 7 : 3);
 	}
 	switch (tileh) {
 		case SLOPE_W:
@@ -182,9 +186,9 @@ uint GetRailFoundation(Slope tileh, TrackBits bits)
 static uint32 CheckRailSlope(Slope tileh, TrackBits rail_bits, TrackBits existing, TileIndex tile)
 {
 	if (IsSteepSlope(tileh)) {
-		if (existing == 0 &&
-				(rail_bits == TRACK_BIT_X || rail_bits == TRACK_BIT_Y)) {
-			return _price.terraform;
+		if (existing == 0) {
+			TrackBits valid = TRACK_BIT_CROSS | (HASBIT(1 << SLOPE_STEEP_W | 1 << SLOPE_STEEP_E, tileh) ? TRACK_BIT_VERT : TRACK_BIT_HORZ);
+			if (valid & rail_bits) return _price.terraform;
 		}
 	} else {
 		rail_bits |= existing;
diff --git a/table/autorail.h b/table/autorail.h
index b8af0a604..bc5a9cbbd 100644
--- a/table/autorail.h
+++ b/table/autorail.h
@@ -38,14 +38,14 @@ static const int _AutorailTilehSprite[][6] = {
 	{       0,       1,       2,       3,       4,       5 }, // invalid (20)
 	{       0,       1,       2,       3,       4,       5 }, // invalid (21)
 	{       0,       1,       2,       3,       4,       5 }, // invalid (22)
-	{       6,      11, RED(17), RED(27), RED(39), RED(47) }, // tileh = 23
+	{       6,      11,      17,      27, RED(39), RED(47) }, // tileh = 23
 	{       0,       1,       2,       3,       4,       5 }, // invalid (24)
 	{       0,       1,       2,       3,       4,       5 }, // invalid (25)
 	{       0,       1,       2,       3,       4,       5 }, // invalid (26)
-	{       7,      15, RED(24), RED(33), RED(36), RED(44) }, // tileh = 27
+	{       7,      15, RED(24), RED(33),      36,      44 }, // tileh = 27
 	{       0,       1,       2,       3,       4,       5 }, // invalid (28)
-	{       3,      14, RED(18), RED(26), RED(41), RED(49) }, // tileh = 29
-	{       4,      12, RED(21), RED(30), RED(37), RED(45) }  // tileh = 30
+	{       3,      14,      18,      26, RED(41), RED(49) }, // tileh = 29
+	{       4,      12, RED(21), RED(30),      37,      45 }  // tileh = 30
 };
 #undef RED
 
diff --git a/variables.h b/variables.h
index e67b96573..b47108f36 100644
--- a/variables.h
+++ b/variables.h
@@ -405,7 +405,7 @@ StringID BindCString(const char *str);
 
 /* landscape.c */
 extern const byte _tileh_to_sprite[32];
-extern const byte _inclined_tileh[8];
+extern const byte _inclined_tileh[16];
 
 extern const TileTypeProcs * const _tile_type_procs[16];