3 Copyright (C) 2010-2015 kwolekr, Ryan Kwolek <kwolekr@minetest.net>
5 This program is free software; you can redistribute it and/or modify
6 it under the terms of the GNU Lesser General Public License as published by
7 the Free Software Foundation; either version 2.1 of the License, or
8 (at your option) any later version.
10 This program is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 GNU Lesser General Public License for more details.
15 You should have received a copy of the GNU Lesser General Public License along
16 with this program; if not, write to the Free Software Foundation, Inc.,
17 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
21 #include "util/numeric.h"
25 ObjDefManager::ObjDefManager(IGameDef *gamedef, ObjDefType type)
28 m_ndef = gamedef ? gamedef->getNodeDefManager() : NULL;
32 ObjDefManager::~ObjDefManager()
34 for (size_t i = 0; i != m_objects.size(); i++)
39 ObjDefHandle ObjDefManager::add(ObjDef *obj)
43 if (obj->name.length() && getByName(obj->name))
44 return OBJDEF_INVALID_HANDLE;
46 u32 index = addRaw(obj);
47 if (index == OBJDEF_INVALID_INDEX)
48 return OBJDEF_INVALID_HANDLE;
50 obj->handle = createHandle(index, m_objtype, obj->uid);
55 ObjDef *ObjDefManager::get(ObjDefHandle handle) const
57 u32 index = validateHandle(handle);
58 return (index != OBJDEF_INVALID_INDEX) ? getRaw(index) : NULL;
62 ObjDef *ObjDefManager::set(ObjDefHandle handle, ObjDef *obj)
64 u32 index = validateHandle(handle);
65 if (index == OBJDEF_INVALID_INDEX)
68 ObjDef *oldobj = setRaw(index, obj);
70 obj->uid = oldobj->uid;
71 obj->index = oldobj->index;
72 obj->handle = oldobj->handle;
78 u32 ObjDefManager::addRaw(ObjDef *obj)
80 size_t nobjects = m_objects.size();
81 if (nobjects >= OBJDEF_MAX_ITEMS)
84 obj->index = nobjects;
86 // Ensure UID is nonzero so that a valid handle == OBJDEF_INVALID_HANDLE
87 // is not possible. The slight randomness bias isn't very significant.
88 obj->uid = myrand() & OBJDEF_UID_MASK;
92 m_objects.push_back(obj);
94 infostream << "ObjDefManager: added " << getObjectTitle()
95 << ": name=\"" << obj->name
96 << "\" index=" << obj->index
97 << " uid=" << obj->uid
104 ObjDef *ObjDefManager::getRaw(u32 index) const
106 return m_objects[index];
110 ObjDef *ObjDefManager::setRaw(u32 index, ObjDef *obj)
112 ObjDef *old_obj = m_objects[index];
113 m_objects[index] = obj;
118 ObjDef *ObjDefManager::getByName(const std::string &name) const
120 for (size_t i = 0; i != m_objects.size(); i++) {
121 ObjDef *obj = m_objects[i];
122 if (obj && !strcasecmp(name.c_str(), obj->name.c_str()))
130 void ObjDefManager::clear()
132 for (size_t i = 0; i != m_objects.size(); i++)
139 u32 ObjDefManager::validateHandle(ObjDefHandle handle) const
146 (handle != OBJDEF_INVALID_HANDLE) &&
147 decodeHandle(handle, &index, &type, &uid) &&
148 (type == m_objtype) &&
149 (index < m_objects.size()) &&
150 (m_objects[index]->uid == uid);
152 return is_valid ? index : -1;
156 ObjDefHandle ObjDefManager::createHandle(u32 index, ObjDefType type, u32 uid)
158 ObjDefHandle handle = 0;
159 set_bits(&handle, 0, 18, index);
160 set_bits(&handle, 18, 6, type);
161 set_bits(&handle, 24, 7, uid);
163 u32 parity = calc_parity(handle);
164 set_bits(&handle, 31, 1, parity);
166 return handle ^ OBJDEF_HANDLE_SALT;
170 bool ObjDefManager::decodeHandle(ObjDefHandle handle, u32 *index,
171 ObjDefType *type, u32 *uid)
173 handle ^= OBJDEF_HANDLE_SALT;
175 u32 parity = get_bits(handle, 31, 1);
176 set_bits(&handle, 31, 1, 0);
177 if (parity != calc_parity(handle))
180 *index = get_bits(handle, 0, 18);
181 *type = (ObjDefType)get_bits(handle, 18, 6);
182 *uid = get_bits(handle, 24, 7);