fltInstanceRef.cxx

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/**
 * PANDA 3D SOFTWARE
 * Copyright (c) Carnegie Mellon University.  All rights reserved.
 *
 * All use of this software is subject to the terms of the revised BSD
 * license.  You should have received a copy of this license along
 * with this source code in a file named "LICENSE."
 *
 * @file fltInstanceRef.cxx
 * @author drose
 * @date 2000-08-30
 */

#include "fltInstanceRef.h"
#include "fltRecordReader.h"
#include "fltRecordWriter.h"
#include "fltInstanceDefinition.h"
#include "fltHeader.h"

TypeHandle FltInstanceRef::_type_handle;

/**
 *
 */
FltInstanceRef::
FltInstanceRef(FltHeader *header) : FltBead(header) {
  _instance_index = 0;
}

/**
 * Returns the instance subtree referenced by this node, or NULL if the
 * reference is invalid.
 */
FltInstanceDefinition *FltInstanceRef::
get_instance() const {
  return _header->get_instance(_instance_index);
}

/**
 * Writes a multiple-line description of the record and all of its children.
 * This is a human-readable description, primarily for debugging; to write a
 * flt file, use FltHeader::write_flt().
 */
void FltInstanceRef::
write(std::ostream &out, int indent_level) const {
  indent(out, indent_level) << "instance";
  FltInstanceDefinition *def = _header->get_instance(_instance_index);
  if (def != nullptr) {
    def->write_children(out, indent_level + 2);
    indent(out, indent_level) << "}\n";
  } else {
    out << "\n";
  }
}

/**
 * Fills in the information in this bead based on the information given in the
 * indicated datagram, whose opcode has already been read.  Returns true on
 * success, false if the datagram is invalid.
 */
bool FltInstanceRef::
extract_record(FltRecordReader &reader) {
  if (!FltBead::extract_record(reader)) {
    return false;
  }

  nassertr(reader.get_opcode() == FO_instance_ref, false);
  DatagramIterator &iterator = reader.get_iterator();

  iterator.skip_bytes(2);
  _instance_index = iterator.get_be_int16();

  check_remaining_size(iterator);
  return true;
}

/**
 * Writes this record out to the flt file, along with all of its ancillary
 * records and children records.  Returns FE_ok on success, or something else
 * on error.
 */
FltError FltInstanceRef::
write_record_and_children(FltRecordWriter &writer) const {
  // First, make sure our instance definition has already been written.
  FltError result = writer.write_instance_def(_header, _instance_index);
  if (result != FE_ok) {
    return result;
  }

  // Then write out our own record.
  return FltBead::write_record_and_children(writer);
}

/**
 * Fills up the current record on the FltRecordWriter with data for this
 * record, but does not advance the writer.  Returns true on success, false if
 * there is some error.
 */
bool FltInstanceRef::
build_record(FltRecordWriter &writer) const {
  if (!FltBead::build_record(writer)) {
    return false;
  }

  writer.set_opcode(FO_instance_ref);
  Datagram &datagram = writer.update_datagram();

  datagram.pad_bytes(2);
  datagram.add_be_int16(_instance_index);

  return true;
}