Place schematic (on vmanip): Enable use of 'place center' flags

For 'place schematic' and 'place schematic on vmanip' APIs.
Fix 'place center' code to properly centre schematics.
Fix some comments.

3 files changed, 30 insertions, 16 deletions

diff --git a/src/mapgen/mg_schematic.cpp b/src/mapgen/mg_schematic.cpp
index fc77194ac..ba619b2e0 100644
--- a/src/mapgen/mg_schematic.cpp
+++ b/src/mapgen/mg_schematic.cpp
@@ -188,15 +188,15 @@ bool Schematic::placeOnVManip(MMVManip *vm, v3s16 p, u32 flags,
 
 	//// Adjust placement position if necessary
 	if (flags & DECO_PLACE_CENTER_X)
-		p.X -= (s.X + 1) / 2;
+		p.X -= (s.X - 1) / 2;
 	if (flags & DECO_PLACE_CENTER_Y)
-		p.Y -= (s.Y + 1) / 2;
+		p.Y -= (s.Y - 1) / 2;
 	if (flags & DECO_PLACE_CENTER_Z)
-		p.Z -= (s.Z + 1) / 2;
+		p.Z -= (s.Z - 1) / 2;
 
 	blitToVManip(vm, p, rot, force_place);
 
-	return vm->m_area.contains(VoxelArea(p, p + s - v3s16(1,1,1)));
+	return vm->m_area.contains(VoxelArea(p, p + s - v3s16(1, 1, 1)));
 }
 
 void Schematic::placeOnMap(ServerMap *map, v3s16 p, u32 flags,
@@ -219,16 +219,16 @@ void Schematic::placeOnMap(ServerMap *map, v3s16 p, u32 flags,
 
 	//// Adjust placement position if necessary
 	if (flags & DECO_PLACE_CENTER_X)
-		p.X -= (s.X + 1) / 2;
+		p.X -= (s.X - 1) / 2;
 	if (flags & DECO_PLACE_CENTER_Y)
-		p.Y -= (s.Y + 1) / 2;
+		p.Y -= (s.Y - 1) / 2;
 	if (flags & DECO_PLACE_CENTER_Z)
-		p.Z -= (s.Z + 1) / 2;
+		p.Z -= (s.Z - 1) / 2;
 
 	//// Create VManip for effected area, emerge our area, modify area
 	//// inside VManip, then blit back.
 	v3s16 bp1 = getNodeBlockPos(p);
-	v3s16 bp2 = getNodeBlockPos(p + s - v3s16(1,1,1));
+	v3s16 bp2 = getNodeBlockPos(p + s - v3s16(1, 1, 1));
 
 	MMVManip vm(map);
 	vm.initialEmerge(bp1, bp2);
diff --git a/src/script/lua_api/l_mapgen.cpp b/src/script/lua_api/l_mapgen.cpp
index 775f4a76d..ccbe9a4b0 100644
--- a/src/script/lua_api/l_mapgen.cpp
+++ b/src/script/lua_api/l_mapgen.cpp
@@ -1529,7 +1529,8 @@ int ModApiMapgen::l_create_schematic(lua_State *L)
 }
 
 
-// place_schematic(p, schematic, rotation, replacement)
+// place_schematic(p, schematic, rotation,
+//     replacements, force_placement, flagstring)
 int ModApiMapgen::l_place_schematic(lua_State *L)
 {
 	MAP_LOCK_REQUIRED;
@@ -1565,12 +1566,19 @@ int ModApiMapgen::l_place_schematic(lua_State *L)
 		return 0;
 	}
 
-	schem->placeOnMap(map, p, 0, (Rotation)rot, force_placement);
+	//// Read flags
+	u32 flags = 0;
+	read_flags(L, 6, flagdesc_deco, &flags, NULL);
+
+	schem->placeOnMap(map, p, flags, (Rotation)rot, force_placement);
 
 	lua_pushboolean(L, true);
 	return 1;
 }
 
+
+// place_schematic_on_vmanip(vm, p, schematic, rotation,
+//     replacements, force_placement, flagstring)
 int ModApiMapgen::l_place_schematic_on_vmanip(lua_State *L)
 {
 	NO_MAP_LOCK_REQUIRED;
@@ -1606,13 +1614,18 @@ int ModApiMapgen::l_place_schematic_on_vmanip(lua_State *L)
 		return 0;
 	}
 
+	//// Read flags
+	u32 flags = 0;
+	read_flags(L, 7, flagdesc_deco, &flags, NULL);
+
 	bool schematic_did_fit = schem->placeOnVManip(
-		vm, p, 0, (Rotation)rot, force_placement);
+		vm, p, flags, (Rotation)rot, force_placement);
 
 	lua_pushboolean(L, schematic_did_fit);
 	return 1;
 }
 
+
 // serialize_schematic(schematic, format, options={...})
 int ModApiMapgen::l_serialize_schematic(lua_State *L)
 {
diff --git a/src/script/lua_api/l_mapgen.h b/src/script/lua_api/l_mapgen.h
index f6a821b4e..44073620b 100644
--- a/src/script/lua_api/l_mapgen.h
+++ b/src/script/lua_api/l_mapgen.h
@@ -70,10 +70,10 @@ private:
 	// get_noiseparam_defaults(name)
 	static int l_get_noiseparams(lua_State *L);
 
-	// set_gen_notify(flagstring)
+	// set_gen_notify(flags, {deco_id_table})
 	static int l_set_gen_notify(lua_State *L);
 
-	// set_gen_notify(flagstring)
+	// get_gen_notify()
 	static int l_get_gen_notify(lua_State *L);
 
 	// register_biome({lots of stuff})
@@ -109,11 +109,12 @@ private:
 	// create_schematic(p1, p2, probability_list, filename)
 	static int l_create_schematic(lua_State *L);
 
-	// place_schematic(p, schematic, rotation, replacements, force_placement)
+	// place_schematic(p, schematic, rotation,
+	//     replacements, force_placement, flagstring)
 	static int l_place_schematic(lua_State *L);
 
-	// place_schematic_on_vmanip(vm, p, schematic,
-	//     rotation, replacements, force_placement)
+	// place_schematic_on_vmanip(vm, p, schematic, rotation,
+	//     replacements, force_placement, flagstring)
 	static int l_place_schematic_on_vmanip(lua_State *L);
 
 	// serialize_schematic(schematic, format, options={...})