CityBufHeader.fbs

namespace CityBuf_;

enum ColumnType: ubyte {
  Byte,                         // Signed 8-bit integer
  UByte,                        // Unsigned 8-bit integer
  Bool,                         // Boolean
  Short,                        // Signed 16-bit integer
  UShort,                       // Unsigned 16-bit integer
  Int,                          // Signed 32-bit integer
  UInt,                         // Unsigned 32-bit integer
  Long,                         // Signed 64-bit integer
  ULong,                        // Unsigned 64-bit integer
  Float,                        // Single precision floating point number
  Double,                       // Double precision floating point number
  String,                       // UTF8 string
  Json,                         // General JSON type intended to be application specific
  DateTime,                     // ISO 8601 date time
  Binary                        // General binary type intended to be application specific
}

table Column {
  name: string (required);      // Column name
  type: ColumnType;             // Column type
  title: string;                // Column title
  description: string;          // Column description (intended for free form long text)
  precision: int = -1;          // Column values expected precision (-1 = unknown) as defined by SQL
  scale: int = -1;              // Column values expected scale (-1 = unknown) as defined by SQL
  nullable: bool = true;        // Column values expected nullability
  unique: bool = false;         // Column values expected uniqueness
  primary_key: bool = false;    // Indicates this column has been (part of) a primary key
  metadata: string;             // Column metadata (intended to be application specific and suggested to be structured fx. JSON)
}

table ReferenceSystem {
  authority: string;            // Case-insensitive name of the defining organization e.g. EPSG or epsg (NULL = EPSG)
  version: int;                 // Version of the Spatial Reference System assigned by the organization (0 = not defined)
  code: int;                    // Numeric ID of the Spatial Reference System assigned by the organization (0 = unknown)
  code_string: string;          // Text ID of the Spatial Reference System assigned by the organization in the (rare) case when it is not an integer and thus cannot be set into code
}

struct Vector {
  x:double;
  y:double;
  z:double;
}

struct Transform {
  scale: Vector;
  translate: Vector;
}

struct GeographicalExtent {
  min: Vector;
  max: Vector;
}

table Header {
  transform: Transform;                     // Transformation vectors
  columns: [Column];                        // Attribute columns schema (can be omitted if per feature schema)
  features_count: ulong;                    // Number of features in the dataset (0 = unknown)
  // index_node_size: ushort = 16;          // Index node size (0 = no index)

  // metadata
  geographical_extent: GeographicalExtent;  // Bounds
  reference_system: ReferenceSystem;        // Spatial Reference System
  identifier: string;                       // Dataset identifier
  reference_date: string;                   // Reference date
  title: string;                            // Dataset title
  poc_contact_name: string;                 // Point of contact name
  poc_contact_type: string;                 // Point of contact type
  poc_role: string;                         // Point of contact role
  poc_phone: string;                        // Point of contact phone
  poc_email: string;                        // Point of contact email
  poc_website: string;                      // Point of contact website
  poc_address_thoroughfare_number: string;  // Point of contact address thoroughfare number
  poc_address_thoroughfare_name: string;    // Point of contact address thoroughfare name
  poc_address_locality: string;             // Point of contact address locality
  poc_address_postcode: string;             // Point of contact address postcode
  poc_address_country: string;              // Point of contact address country
  
  attributes: [ubyte];                      // Other attributes that are stored in root CityJSON object
}

root_type Header;