63 lines
2.2 KiB
C
63 lines
2.2 KiB
C
/* Copyright (C) 2010 Wildfire Games.
|
|
* This file is part of 0 A.D.
|
|
*
|
|
* 0 A.D. 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.
|
|
*
|
|
* 0 A.D. 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 0 A.D. If not, see <http://www.gnu.org/licenses/>.
|
|
*/
|
|
|
|
#ifndef INCLUDED_SIM2_ENTITY
|
|
#define INCLUDED_SIM2_ENTITY
|
|
// (can't call it INCLUDED_ENTITY because that conflicts with simulation/Entity.h)
|
|
|
|
#include "lib/types.h"
|
|
|
|
/**
|
|
* Entity ID type.
|
|
* ID numbers are never reused within a simulation run.
|
|
*/
|
|
typedef u32 entity_id_t;
|
|
|
|
/**
|
|
* Invalid entity ID. Used as an error return value by some functions.
|
|
* No valid entity will have this ID.
|
|
*/
|
|
const entity_id_t INVALID_ENTITY = 0;
|
|
|
|
/**
|
|
* Entity ID for singleton 'system' components.
|
|
* Use with QueryInterface to get the component instance.
|
|
* (This allows those systems to make convenient use of the common infrastructure
|
|
* for message-passing, scripting, serialisation, etc.)
|
|
*/
|
|
const entity_id_t SYSTEM_ENTITY = 1;
|
|
|
|
// Entities are split into two kinds:
|
|
// "Normal" (for most entities)
|
|
// "Local" (for entities that only exist on the local machine, aren't synchronised across the network,
|
|
// aren't retained in saved games, etc)
|
|
// The distinction is encoded in the entity ID, so that they're easily distinguished.
|
|
//
|
|
// We want all entity_id_ts to fit in jsval ints, i.e. 1-2^30 .. 2^30-1 (inclusive)
|
|
// We want them to be unsigned ints (actually it shouldn't matter but unsigned seems simpler)
|
|
// We want 1 tag bit
|
|
// So we have 1 JS-reserved bit, 1 unused sign bit, 1 local tag bit, 29 counter bits
|
|
// (0.5B entities should be plenty)
|
|
|
|
#define ENTITY_TAGMASK (1 << 29)
|
|
#define ENTITY_IS_NORMAL(id) (((id) & ENTITY_TAGMASK) == 0)
|
|
#define ENTITY_IS_LOCAL(id) (((id) & ENTITY_TAGMASK) == ENTITY_TAGMASK)
|
|
const entity_id_t FIRST_LOCAL_ENTITY = ENTITY_TAGMASK;
|
|
|
|
|
|
#endif // INCLUDED_SIM2_ENTITY
|