minetest_GLSLshaders/src/database.cpp

53 lines
1.5 KiB
C++

/*
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"
static s32 unsignedToSigned(s32 i, s32 max_positive)
{
if(i < max_positive)
return i;
else
return i - 2*max_positive;
}
// modulo of a negative number does not work consistently in C
static s64 pythonmodulo(s64 i, s64 mod)
{
if(i >= 0)
return i % mod;
return mod - ((-i) % mod);
}
long long Database::getBlockAsInteger(const v3s16 pos) {
return (unsigned long long)pos.Z*16777216 +
(unsigned long long)pos.Y*4096 +
(unsigned long long)pos.X;
}
v3s16 Database::getIntegerAsBlock(long long i) {
s32 x = unsignedToSigned(pythonmodulo(i, 4096), 2048);
i = (i - x) / 4096;
s32 y = unsignedToSigned(pythonmodulo(i, 4096), 2048);
i = (i - y) / 4096;
s32 z = unsignedToSigned(pythonmodulo(i, 4096), 2048);
return v3s16(x,y,z);
}