# HG changeset patch
# User Peter Nelson <peter1138@openttd.org>
# Date 2022-12-18 12:35:08
# Node ID e6b5eb3a99022926f0a3d9982740bbbac65fbba4
# Parent  b1cb0e0a0887aed223a17d2fae12d6f7557ddbc2

Change: Separate ground sprite from foundation sprite offsets.

diff --git a/src/landscape.cpp b/src/landscape.cpp
--- a/src/landscape.cpp
+++ b/src/landscape.cpp
@@ -516,26 +516,27 @@ void DrawFoundation(TileInfo *ti, Founda
 				f == FOUNDATION_INCLINED_Y ? 16 : 1,
 				TILE_HEIGHT, ti->z
 			);
-			OffsetGroundSprite(31, 9);
+			OffsetGroundSprite(0, 0);
 		} else if (IsLeveledFoundation(f)) {
 			AddSortableSpriteToDraw(leveled_base + SlopeWithOneCornerRaised(highest_corner), PAL_NONE, ti->x, ti->y, 16, 16, 7, ti->z - TILE_HEIGHT);
-			OffsetGroundSprite(31, 1);
+			OffsetGroundSprite(0, -8);
 		} else if (f == FOUNDATION_STEEP_LOWER) {
 			/* one corner raised */
-			OffsetGroundSprite(31, 1);
+			OffsetGroundSprite(0, -8);
 		} else {
 			/* halftile foundation */
 			int x_bb = (((highest_corner == CORNER_W) || (highest_corner == CORNER_S)) ? 8 : 0);
 			int y_bb = (((highest_corner == CORNER_S) || (highest_corner == CORNER_E)) ? 8 : 0);
 
 			AddSortableSpriteToDraw(halftile_base + highest_corner, PAL_NONE, ti->x + x_bb, ti->y + y_bb, 8, 8, 7, ti->z + TILE_HEIGHT);
-			OffsetGroundSprite(31, 9);
+			Point pt = {(y_bb - x_bb) * 2, y_bb + x_bb};
+			OffsetGroundSprite(-pt.x, -pt.y);
 		}
 	} else {
 		if (IsLeveledFoundation(f)) {
 			/* leveled foundation */
 			AddSortableSpriteToDraw(leveled_base + ti->tileh, PAL_NONE, ti->x, ti->y, 16, 16, 7, ti->z);
-			OffsetGroundSprite(31, 1);
+			OffsetGroundSprite(0, -8);
 		} else if (IsNonContinuousFoundation(f)) {
 			/* halftile foundation */
 			Corner halftile_corner = GetHalftileFoundationCorner(f);
@@ -543,7 +544,8 @@ void DrawFoundation(TileInfo *ti, Founda
 			int y_bb = (((halftile_corner == CORNER_S) || (halftile_corner == CORNER_E)) ? 8 : 0);
 
 			AddSortableSpriteToDraw(halftile_base + halftile_corner, PAL_NONE, ti->x + x_bb, ti->y + y_bb, 8, 8, 7, ti->z);
-			OffsetGroundSprite(31, 9);
+			Point pt = {(y_bb - x_bb) * 2, y_bb + x_bb};
+			OffsetGroundSprite(-pt.x, -pt.y);
 		} else if (IsSpecialRailFoundation(f)) {
 			/* anti-zig-zag foundation */
 			SpriteID spr;
@@ -555,7 +557,7 @@ void DrawFoundation(TileInfo *ti, Founda
 				spr = inclined_base + 2 * GetRailFoundationCorner(f) + ((ti->tileh == SLOPE_SW || ti->tileh == SLOPE_NE) ? 1 : 0);
 			}
 			AddSortableSpriteToDraw(spr, PAL_NONE, ti->x, ti->y, 16, 16, 7, ti->z);
-			OffsetGroundSprite(31, 9);
+			OffsetGroundSprite(0, 0);
 		} else {
 			/* inclined foundation */
 			byte inclined = GetHighestSlopeCorner(ti->tileh) * 2 + (f == FOUNDATION_INCLINED_Y ? 1 : 0);
@@ -565,7 +567,7 @@ void DrawFoundation(TileInfo *ti, Founda
 				f == FOUNDATION_INCLINED_Y ? 16 : 1,
 				TILE_HEIGHT, ti->z
 			);
-			OffsetGroundSprite(31, 9);
+			OffsetGroundSprite(0, 0);
 		}
 		ti->z += ApplyPixelFoundationToSlope(f, &ti->tileh);
 	}
diff --git a/src/station_cmd.cpp b/src/station_cmd.cpp
--- a/src/station_cmd.cpp
+++ b/src/station_cmd.cpp
@@ -2921,7 +2921,7 @@ static void DrawTile_Station(TileInfo *t
 				EndSpriteCombine();
 			}
 
-			OffsetGroundSprite(31, 1);
+			OffsetGroundSprite(0, -8);
 			ti->z += ApplyPixelFoundationToSlope(FOUNDATION_LEVELED, &ti->tileh);
 		} else {
 draw_default_foundation:
diff --git a/src/viewport.cpp b/src/viewport.cpp
--- a/src/viewport.cpp
+++ b/src/viewport.cpp
@@ -538,7 +538,7 @@ static void AddChildSpriteToFoundation(S
 	int *old_child = _vd.last_child;
 	_vd.last_child = _vd.last_foundation_child[foundation_part];
 
-	AddChildSpriteScreen(image, pal, offs.x + extra_offs_x, offs.y + extra_offs_y, false, sub, false);
+	AddChildSpriteScreen(image, pal, offs.x + extra_offs_x, offs.y + extra_offs_y, false, sub, false, false);
 
 	/* Switch back to last ChildSprite list */
 	_vd.last_child = old_child;
@@ -876,16 +876,18 @@ static void AddStringToDraw(int x, int y
  * @param ti TileInfo Tile that is being drawn
  * @param z_offset Z offset relative to the groundsprite. Only used for the sprite position, not for sprite sorting.
  * @param foundation_part Foundation part the sprite belongs to.
+ * @param extra_offs_x Pixel X offset for the sprite position.
+ * @param extra_offs_y Pixel Y offset for the sprite position.
  */
-static void DrawSelectionSprite(SpriteID image, PaletteID pal, const TileInfo *ti, int z_offset, FoundationPart foundation_part)
+static void DrawSelectionSprite(SpriteID image, PaletteID pal, const TileInfo *ti, int z_offset, FoundationPart foundation_part, int extra_offs_x = 0, int extra_offs_y = 0)
 {
 	/* FIXME: This is not totally valid for some autorail highlights that extend over the edges of the tile. */
 	if (_vd.foundation[foundation_part] == -1) {
 		/* draw on real ground */
-		AddTileSpriteToDraw(image, pal, ti->x, ti->y, ti->z + z_offset);
+		AddTileSpriteToDraw(image, pal, ti->x, ti->y, ti->z + z_offset, nullptr, extra_offs_x, extra_offs_y);
 	} else {
 		/* draw on top of foundation */
-		AddChildSpriteToFoundation(image, pal, nullptr, foundation_part, 0, -z_offset * ZOOM_LVL_BASE);
+		AddChildSpriteToFoundation(image, pal, nullptr, foundation_part, extra_offs_x, extra_offs_y - z_offset * ZOOM_LVL_BASE);
 	}
 }