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- /*
- Minetest
- Copyright (C) 2013 celeron55, Perttu Ahola <celeron55@gmail.com>
- This program is free software; you can redistribute it and/or modify
- it under the terms of the GNU Lesser General Public License as published by
- the Free Software Foundation; either version 2.1 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 Lesser General Public License for more details.
- You should have received a copy of the GNU Lesser 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.
- */
- #include "database.h"
- #include "irrlichttypes.h"
- /****************
- * Black magic! *
- ****************
- * The position hashing is very messed up.
- * It's a lot more complicated than it looks.
- */
- static inline s16 unsigned_to_signed(u16 i, u16 max_positive)
- {
- if (i < max_positive) {
- return i;
- }
- return i - (max_positive * 2);
- }
- // Modulo of a negative number does not work consistently in C
- static inline s64 pythonmodulo(s64 i, s16 mod)
- {
- if (i >= 0) {
- return i % mod;
- }
- return mod - ((-i) % mod);
- }
- s64 MapDatabase::getBlockAsInteger(const v3s16 &pos)
- {
- return (u64) pos.Z * 0x1000000 +
- (u64) pos.Y * 0x1000 +
- (u64) pos.X;
- }
- v3s16 MapDatabase::getIntegerAsBlock(s64 i)
- {
- v3s16 pos;
- pos.X = unsigned_to_signed(pythonmodulo(i, 4096), 2048);
- i = (i - pos.X) / 4096;
- pos.Y = unsigned_to_signed(pythonmodulo(i, 4096), 2048);
- i = (i - pos.Y) / 4096;
- pos.Z = unsigned_to_signed(pythonmodulo(i, 4096), 2048);
- return pos;
- }
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