Add NewGRF object property for new edge foundation mode

src/newgrf.cpp

@@ -4301,6 +4301,14 @@ static ChangeInfoResult ObjectChangeInfo(uint id, int numinfo, int prop, const G
 				SB(spec->ctrl_flags, OBJECT_CTRL_FLAG_USE_LAND_GROUND, 1, (buf->ReadByte() != 0 ? 1 : 0));
 				break;
 
+			case A0RPI_OBJECT_EDGE_FOUNDATION_MODE:
+				if (MappedPropertyLengthMismatch(buf, 4, mapping_entry)) break;
+				SetBit(spec->ctrl_flags, OBJECT_CTRL_FLAG_EDGE_FOUNDATION);
+				for (int i = 0; i < 4; i++) {
+					spec->edge_foundation[i] = buf->ReadByte();
+				}
+				break;
+
 			default:
 				ret = HandleAction0PropertyDefault(buf, prop);
 				break;

src/newgrf_extension.cpp

@@ -68,6 +68,7 @@ extern const GRFPropertyMapDefinition _grf_action0_remappable_properties[] = {
 	GRFPropertyMapDefinition(GSF_SIGNALS, A0RPI_SIGNALS_ENABLE_SIGNAL_RECOLOUR, "signals_enable_signal_recolour"),
 	GRFPropertyMapDefinition(GSF_SIGNALS, A0RPI_SIGNALS_EXTRA_ASPECTS, "signals_extra_aspects"),
 	GRFPropertyMapDefinition(GSF_OBJECTS, A0RPI_OBJECT_USE_LAND_GROUND, "object_use_land_ground"),
+	GRFPropertyMapDefinition(GSF_OBJECTS, A0RPI_OBJECT_EDGE_FOUNDATION_MODE, "object_edge_foundation_mode"),
 	GRFPropertyMapDefinition(),
 };
 

src/newgrf_extension.h

@@ -33,6 +33,7 @@ enum Action0RemapPropertyIds {
 	A0RPI_SIGNALS_ENABLE_SIGNAL_RECOLOUR,
 	A0RPI_SIGNALS_EXTRA_ASPECTS,
 	A0RPI_OBJECT_USE_LAND_GROUND,
+	A0RPI_OBJECT_EDGE_FOUNDATION_MODE,
 };
 
 

src/newgrf_object.cpp

@@ -418,7 +418,7 @@ uint16 GetObjectCallback(CallbackID callback, uint32 param1, uint32 param2, cons
  * @param group The group of sprites to draw.
  * @param spec  Object spec to draw.
  */
-static void DrawTileLayout(const TileInfo *ti, const TileLayoutSpriteGroup *group, const ObjectSpec *spec)
+static void DrawTileLayout(TileInfo *ti, const TileLayoutSpriteGroup *group, const ObjectSpec *spec, int building_z_offset)
 {
 	const DrawTileSprites *dts = group->ProcessRegisters(nullptr);
 	PaletteID palette = ((spec->flags & OBJECT_FLAG_2CC_COLOUR) ? SPR_2CCMAP_BASE : PALETTE_RECOLOUR_START) + Object::GetByTile(ti->tile)->colour;
@@ -455,7 +455,9 @@ static void DrawTileLayout(const TileInfo *ti, const TileLayoutSpriteGroup *grou
 		}
 	}
 
+	if (building_z_offset) ti->z += building_z_offset;
 	DrawNewGRFTileSeq(ti, dts, TO_STRUCTURES, 0, palette);
+	if (building_z_offset) ti->z -= building_z_offset;
 }
 
 /**
@@ -463,7 +465,7 @@ static void DrawTileLayout(const TileInfo *ti, const TileLayoutSpriteGroup *grou
  * @param ti   Information about the tile to draw on.
  * @param spec Object spec to draw.
  */
-void DrawNewObjectTile(TileInfo *ti, const ObjectSpec *spec)
+void DrawNewObjectTile(TileInfo *ti, const ObjectSpec *spec, int building_z_offset)
 {
 	Object *o = Object::GetByTile(ti->tile);
 	ObjectResolverObject object(spec, o, ti->tile);
@@ -471,7 +473,7 @@ void DrawNewObjectTile(TileInfo *ti, const ObjectSpec *spec)
 	const SpriteGroup *group = object.Resolve();
 	if (group == nullptr || group->type != SGT_TILELAYOUT) return;
 
-	DrawTileLayout(ti, (const TileLayoutSpriteGroup *)group, spec);
+	DrawTileLayout(ti, (const TileLayoutSpriteGroup *)group, spec, building_z_offset);
 }
 
 /**

src/newgrf_object.h

@@ -43,9 +43,17 @@ DECLARE_ENUM_AS_BIT_SET(ObjectFlags)
 enum ObjectCtrlFlags {
 	OBJECT_CTRL_FLAG_NONE               =       0, ///< Just nothing.
 	OBJECT_CTRL_FLAG_USE_LAND_GROUND    = 1 <<  0, ///< Use land for ground sprite.
+	OBJECT_CTRL_FLAG_EDGE_FOUNDATION    = 1 <<  2, ///< Use edge foundation mode.
 };
 DECLARE_ENUM_AS_BIT_SET(ObjectCtrlFlags)
 
+enum ObjectEdgeFoundationFlags {
+	/* Bits 0 and 1 use for edge DiagDirection */
+	OBJECT_EF_FLAG_ADJUST_Z             = 1 <<  2, ///< Adjust sprite z position to z at edge.
+	OBJECT_EF_FLAG_FOUNDATION_LOWER     = 1 <<  3, ///< If edge is lower than tile max z, add foundation.
+};
+DECLARE_ENUM_AS_BIT_SET(ObjectEdgeFoundationFlags)
+
 void ResetObjects();
 
 /** Class IDs for objects. */
@@ -75,6 +83,7 @@ struct ObjectSpec {
 	Date end_of_life_date;        ///< When can't this object be built anymore.
 	ObjectFlags flags;            ///< Flags/settings related to the object.
 	ObjectCtrlFlags ctrl_flags;   ///< Extra control flags.
+	uint8 edge_foundation[4];     ///< Edge foundation flags
 	AnimationInfo animation;      ///< Information about the animation.
 	uint16 callback_mask;         ///< Bitmask of requested/allowed callbacks.
 	uint8 height;                 ///< The height of this structure, in heightlevels; max MAX_TILE_HEIGHT.
@@ -167,7 +176,7 @@ static const CargoID CT_PURCHASE_OBJECT = 1;
 
 uint16 GetObjectCallback(CallbackID callback, uint32 param1, uint32 param2, const ObjectSpec *spec, Object *o, TileIndex tile, uint8 view = 0);
 
-void DrawNewObjectTile(TileInfo *ti, const ObjectSpec *spec);
+void DrawNewObjectTile(TileInfo *ti, const ObjectSpec *spec, int building_z_offset);
 void DrawNewObjectTileInGUI(int x, int y, const ObjectSpec *spec, uint8 view);
 void AnimateNewObjectTile(TileIndex tile);
 uint8 GetNewObjectTileAnimationSpeed(TileIndex tile);

src/object_cmd.cpp

@@ -517,13 +517,34 @@ static Foundation GetFoundation_Object(TileIndex tile, Slope tileh);
 
 static void DrawTile_Object(TileInfo *ti, DrawTileProcParams params)
 {
-	ObjectType type = GetObjectType(ti->tile);
+	const Object *obj = Object::GetByTile(ti->tile);
+	ObjectType type = obj->type;
 	const ObjectSpec *spec = ObjectSpec::Get(type);
 
-	/* Fall back for when the object doesn't exist anymore. */
+	int building_z_offset = 0;
-	if (!spec->enabled) type = OBJECT_TRANSMITTER;
 
-	if ((spec->flags & OBJECT_FLAG_HAS_NO_FOUNDATION) == 0) DrawFoundation(ti, GetFoundation_Object(ti->tile, ti->tileh));
+	/* Fall back for when the object doesn't exist anymore. */
+	if (!spec->enabled) {
+		type = OBJECT_TRANSMITTER;
+	} else if ((spec->flags & OBJECT_FLAG_HAS_NO_FOUNDATION) == 0) {
+		if (spec->ctrl_flags & OBJECT_CTRL_FLAG_EDGE_FOUNDATION) {
+			uint8 flags = spec->edge_foundation[obj->view];
+			DiagDirection edge = (DiagDirection)GB(flags, 0, 2);
+			Slope incline = InclinedSlope(edge);
+			if (IsSteepSlope(ti->tileh) || IsOddParity(incline & ti->tileh)) {
+				/* Steep slope, or odd number of matching bits indicating that edge is not level */
+				DrawFoundation(ti, GetFoundation_Object(ti->tile, ti->tileh));
+			} else if (flags & OBJECT_EF_FLAG_FOUNDATION_LOWER && !(ti->tileh & incline)) {
+				/* The edge is the lower edge of an inclined slope */
+				DrawFoundation(ti, GetFoundation_Object(ti->tile, ti->tileh));
+			} else if (flags & OBJECT_EF_FLAG_ADJUST_Z && ti->tileh & incline) {
+				/* The edge is elevated relative to the lowest tile height, adjust z */
+				building_z_offset = TILE_HEIGHT;
+			}
+		} else {
+			DrawFoundation(ti, GetFoundation_Object(ti->tile, ti->tileh));
+		}
+	}
 
 	if (type < NEW_OBJECT_OFFSET) {
 		const DrawTileSprites *dts = nullptr;
@@ -564,7 +585,7 @@ static void DrawTile_Object(TileInfo *ti, DrawTileProcParams params)
 			}
 		}
 	} else {
-		DrawNewObjectTile(ti, spec);
+		DrawNewObjectTile(ti, spec, building_z_offset);
 	}
 
 	DrawBridgeMiddle(ti);
@@ -1065,6 +1086,16 @@ static void ChangeTileOwner_Object(TileIndex tile, Owner old_owner, Owner new_ow
 	}
 }
 
+static int GetObjectEffectiveZ(TileIndex tile, const ObjectSpec *spec, int z, Slope tileh)
+{
+	if ((spec->ctrl_flags & OBJECT_CTRL_FLAG_EDGE_FOUNDATION) && !(spec->flags & OBJECT_FLAG_HAS_NO_FOUNDATION)) {
+		uint8 flags = spec->edge_foundation[Object::GetByTile(tile)->view];
+		DiagDirection edge = (DiagDirection)GB(flags, 0, 2);
+		if (!(flags & OBJECT_EF_FLAG_FOUNDATION_LOWER) && !(tileh & InclinedSlope(edge))) return z;
+	}
+	return z + GetSlopeMaxZ(tileh);
+}
+
 static CommandCost TerraformTile_Object(TileIndex tile, DoCommandFlag flags, int z_new, Slope tileh_new)
 {
 	ObjectType type = GetObjectType(tile);
@@ -1080,10 +1111,11 @@ static CommandCost TerraformTile_Object(TileIndex tile, DoCommandFlag flags, int
 		 *  - Allow autoslope by default.
 		 *  - Disallow autoslope if callback succeeds and returns non-zero.
 		 */
-		Slope tileh_old = GetTileSlope(tile);
+		int z_old;
-		/* TileMaxZ must not be changed. Slopes must not be steep. */
+		Slope tileh_old = GetTileSlope(tile, &z_old);
-		if (!IsSteepSlope(tileh_old) && !IsSteepSlope(tileh_new) && (GetTileMaxZ(tile) == z_new + GetSlopeMaxZ(tileh_new))) {
 		const ObjectSpec *spec = ObjectSpec::Get(type);
+		/* Object height must not be changed. Slopes must not be steep. */
+		if (!IsSteepSlope(tileh_old) && !IsSteepSlope(tileh_new) && (GetObjectEffectiveZ(tile, spec, z_old, tileh_old) == GetObjectEffectiveZ(tile, spec, z_new, tileh_new))) {
 
 			/* Call callback 'disable autosloping for objects'. */
 			if (HasBit(spec->callback_mask, CBM_OBJ_AUTOSLOPE)) {

src/table/newgrf_debug_data.h

@@ -897,6 +897,7 @@ class NIHObject : public NIHelper {
 				check_flag(OBJECT_FLAG_ANIM_RANDOM_BITS,   "OBJECT_FLAG_ANIM_RANDOM_BITS");
 				check_flag(OBJECT_FLAG_SCALE_BY_WATER,     "OBJECT_FLAG_SCALE_BY_WATER");
 				check_ctrl_flag(OBJECT_CTRL_FLAG_USE_LAND_GROUND, "OBJECT_CTRL_FLAG_USE_LAND_GROUND");
+				check_ctrl_flag(OBJECT_CTRL_FLAG_EDGE_FOUNDATION, "OBJECT_CTRL_FLAG_EDGE_FOUNDATION");
 			}
 		}
 	}

src/table/object_land.h

@@ -121,7 +121,7 @@ static const DrawTileSprites _object_hq[] = {
 
 #undef TILE_SPRITE_LINE
 
-#define M(name, size, build_cost_multiplier, clear_cost_multiplier, height, climate, gen_amount, flags) { GRFFilePropsBase<2>(), INVALID_OBJECT_CLASS, name, climate, size, build_cost_multiplier, clear_cost_multiplier, 0, MAX_DAY + 1, flags, OBJECT_CTRL_FLAG_NONE, {0, 0, 0, 0}, 0, height, 1, gen_amount, true }
+#define M(name, size, build_cost_multiplier, clear_cost_multiplier, height, climate, gen_amount, flags) { GRFFilePropsBase<2>(), INVALID_OBJECT_CLASS, name, climate, size, build_cost_multiplier, clear_cost_multiplier, 0, MAX_DAY + 1, flags, OBJECT_CTRL_FLAG_NONE, {0, 0, 0, 0}, {0, 0, 0, 0}, 0, height, 1, gen_amount, true }
 
 /* Climates
  * T = Temperate