tornavis/source/blender/blenkernel/BKE_persistent_data_handle.hh

130 lines
3.1 KiB
C++

/*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version 2
* of the License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software Foundation,
* Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
*/
#pragma once
/** \file
* \ingroup bke
*
* A PersistentDataHandle is a weak reference to some data in a Blender file. The handle itself is
* just a number. A PersistentDataHandleMap is used to convert between handles and the actual data.
*/
#include "BLI_map.hh"
#include "DNA_ID.h"
struct Object;
namespace blender::bke {
class PersistentDataHandleMap;
class PersistentDataHandle {
private:
/* Negative values indicate that the handle is "empty". */
int32_t handle_;
friend PersistentDataHandleMap;
protected:
PersistentDataHandle(int handle) : handle_(handle)
{
}
public:
PersistentDataHandle() : handle_(-1)
{
}
friend bool operator==(const PersistentDataHandle &a, const PersistentDataHandle &b)
{
return a.handle_ == b.handle_;
}
friend bool operator!=(const PersistentDataHandle &a, const PersistentDataHandle &b)
{
return !(a == b);
}
friend std::ostream &operator<<(std::ostream &stream, const PersistentDataHandle &a)
{
stream << a.handle_;
return stream;
}
uint64_t hash() const
{
return static_cast<uint64_t>(handle_);
}
};
class PersistentIDHandle : public PersistentDataHandle {
friend PersistentDataHandleMap;
using PersistentDataHandle::PersistentDataHandle;
};
class PersistentObjectHandle : public PersistentIDHandle {
friend PersistentDataHandleMap;
using PersistentIDHandle::PersistentIDHandle;
};
class PersistentDataHandleMap {
private:
Map<int32_t, ID *> id_by_handle_;
Map<ID *, int32_t> handle_by_id_;
public:
void add(int32_t handle, ID &id)
{
BLI_assert(handle >= 0);
handle_by_id_.add(&id, handle);
id_by_handle_.add(handle, &id);
}
PersistentIDHandle lookup(ID *id) const
{
const int handle = handle_by_id_.lookup_default(id, -1);
return PersistentIDHandle(handle);
}
PersistentObjectHandle lookup(Object *object) const
{
const int handle = handle_by_id_.lookup_default((ID *)object, -1);
return PersistentObjectHandle(handle);
}
ID *lookup(const PersistentIDHandle &handle) const
{
ID *id = id_by_handle_.lookup_default(handle.handle_, nullptr);
return id;
}
Object *lookup(const PersistentObjectHandle &handle) const
{
ID *id = this->lookup((const PersistentIDHandle &)handle);
if (id == nullptr) {
return nullptr;
}
if (GS(id->name) != ID_OB) {
return nullptr;
}
return (Object *)id;
}
};
} // namespace blender::bke