CityBufFeature.fbs

include "CityBufHeader.fbs";

namespace CityBuf_;

enum CityObjectType:ubyte { 
  Bridge,
  BridgePart,
  BridgeInstallation,
  BridgeConstructiveElement,
  BridgeRoom,
  BridgeFurniture,
  
  Building,
  BuildingPart,
  BuildingInstallation,
  BuildingConstructiveElement,
  BuildingFurniture,
  BuildingStorey,
  BuildingRoom,
  BuildingUnit,

  CityFurniture,
  CityObjectGroup,
  GenericCityObject,
  LandUse,
  OtherConstruction,
  PlantCover,
  SolitaryVegetationObject,
  TINRelief,
  
  // Transportation objects
  Road,
  Railway,
  Waterway,
  TransportSquare,

  Tunnel,
  TunnelPart,
  TunnelInstallation,
  TunnelConstructiveElement,
  TunnelHollowSpace,
  TunnelFurniture,
  
  WaterBody
}

enum SemanticSurfaceType:ubyte {
  // Building
  RoofSurface, 
  GroundSurface, 
  WallSurface, 
  ClosureSurface, 
  OuterCeilingSurface, 
  OuterFloorSurface, 
  Window, 
  Door, 
  InteriorWallSurface, 
  CeilingSurface, 
  FloorSurface,
  // WaterBody
  WaterSurface,
  WaterGroundSurface,
  WaterClosureSurface,
  // Transportation ("Road", "Railway", "TransportSquare")
  TrafficArea,
  AuxiliaryTrafficArea,
  TransportationMarking,
  TransportationHole
}

enum GeometryType:ubyte { 
  MultiPoint,
  MultiLineString,
  MultiSurface,
  CompositeSurface,
  Solid,
  MultiSolid,
  CompositeSolid
}

struct Vertex {
  x:int;
  y:int;
  z:int;
}

table CityFeature {
  id:string (key, required);
  objects:[CityObject];
  vertices:[Vertex];
}

table CityObject {
  type:CityObjectType;
  id:string (key, required);
  geographical_extent:GeographicalExtent;
  geometry:[Geometry];
  attributes:[ubyte];
  columns:[Column];         // Attribute columns schema (optional, if set it should be used instead of the header columns)
  children:[string];
  children_roles:[string];  // for CityObjectGroup only
  parents:[string];
}

table Geometry {
  type:GeometryType;
  lod:string;
  
  // these are lengths in the 
  // depending on the geometry_type, different fields are used
  solids:[uint];
  shells:[uint];
  surfaces:[uint];
  strings:[uint];           // Rings or LineStrings

  boundaries:[uint];        // flat list of vertex indices
  semantics:[uint];         // flat list of semantic object indices

  semantics_objects:[SemanticObject];
}

table SemanticObject {
  type:SemanticSurfaceType;
  attributes:[ubyte];
  children:[uint];
  parent:uint = null;       // default is null, important to be able to check if this field is set
}

root_type CityFeature;