dupli_persistent_id.cc

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/* SPDX-FileCopyrightText: 2020 Blender Authors
 *
 * SPDX-License-Identifier: GPL-2.0-or-later */
 
#include "dupli_parent_finder.hh"
 
#include <climits>
 
#include <fmt/format.h>
 
namespace blender::io {
 
PersistentID::PersistentID()
{
  persistent_id_[0] = INT_MAX;
}
 
PersistentID::PersistentID(const DupliObject *dupli_ob)
{
  for (int index = 0; index < array_length_; ++index) {
    persistent_id_[index] = dupli_ob->persistent_id[index];
  }
}
 
PersistentID::PersistentID(const PIDArray &persistent_id_values)
{
  persistent_id_ = persistent_id_values;
}
 
bool PersistentID::is_from_same_instancer_as(const PersistentID &other) const
{
  if (persistent_id_[0] == INT_MAX || other.persistent_id_[0] == INT_MAX) {
    /* Either one or the other is not instanced at all, so definitely not from the same instancer.
     */
    return false;
  }
 
  /* Start at index 1 to skip the first digit. */
  for (int index = 1; index < array_length_; ++index) {
    const int pid_digit_a = persistent_id_[index];
    const int pid_digit_b = other.persistent_id_[index];
 
    if (pid_digit_a != pid_digit_b) {
      return false;
    }
 
    if (pid_digit_a == INT_MAX) {
      /* Both persistent IDs were identical so far, and this marks the end of the useful data. */
      break;
    }
  }
  return true;
}
 
PersistentID PersistentID::instancer_pid() const
{
  if (persistent_id_[0] == INT_MAX) {
    return PersistentID();
  }
 
  /* Left-shift the entire PID by 1. */
  PIDArray new_pid_values;
  int index;
  for (index = 0; index < array_length_ - 1; ++index) {
    new_pid_values[index] = persistent_id_[index + 1];
  }
  new_pid_values[index] = INT_MAX;
 
  return PersistentID(new_pid_values);
}
 
std::string PersistentID::as_object_name_suffix() const
{
  fmt::basic_memory_buffer<char, 64> buf;
 
  /* Find one past the last index. */
  int index;
  for (index = 0; index < array_length_ && persistent_id_[index] < INT_MAX; ++index) {
    ;
  }
 
  /* Iterate backward to construct the string. */
  --index;
  for (; index >= 0; --index) {
    fmt::format_to(fmt::appender(buf), "{}", persistent_id_[index]);
    if (index > 0) {
      fmt::format_to(fmt::appender(buf), "-");
    }
  }
 
  return fmt::to_string(buf);
}
 
uint64_t PersistentID::hash() const
{
  uint64_t hash = 5381;
  for (const int value : persistent_id_) {
    if (value == INT_MAX) {
      break;
    }
    hash = hash * 33 ^ uint64_t(value);
  }
  return hash;
}
 
bool operator==(const PersistentID &persistent_id_a, const PersistentID &persistent_id_b)
{
  const PersistentID::PIDArray &pid_a = persistent_id_a.persistent_id_;
  const PersistentID::PIDArray &pid_b = persistent_id_b.persistent_id_;
 
  for (int index = 0; index < PersistentID::array_length_; ++index) {
    const int pid_digit_a = pid_a[index];
    const int pid_digit_b = pid_b[index];
 
    if (pid_digit_a != pid_digit_b) {
      return false;
    }
 
    if (pid_a[index] == INT_MAX) {
      break;
    }
  }
  return true;
}
 
}  // namespace blender::io