minetest.git - modified minetest for gpcfs purposes

	Commit message (Expand)	Author	Age
*	updated readme a bit	Perttu Ahola	2011-05-21
*	some documentation updates	Perttu Ahola	2011-05-21
*	Added installing build-essential to build instructions and modified the main....	Perttu Ahola	2011-04-11
*	added libgl1-mesa-dev to dependencies	Perttu Ahola	2011-04-09
*	CMake working nicely on Windows, at least with MSVC. "Compiling on windows" s...	Perttu Ahola	2011-02-15
*	might work good on cmake+msvc now	Perttu Ahola	2011-02-15
*	bug-fixin'	Perttu Ahola	2011-02-08
*	tidyed README typos a bit	Perttu Ahola	2011-01-21
*	Documentation updates.	Perttu Ahola	2011-01-21
*	made old build system to work too. the cmake one doesn't make working binarie...	Perttu Ahola	2011-01-18
*	Mainly small build system fixes	Perttu Ahola	2011-01-09
*	doc updates; CMake works reasonably well now.	Perttu Ahola	2011-01-08
*	CMake stuff works now on linux and windows... and should be possible to make ...	Perttu Ahola	2011-01-08
*	Added a more flexible path system (and fixed some minor stuff)	Perttu Ahola	2011-01-07
*	slight readme update	Perttu Ahola	2010-12-24
*	before adding day/night lighting	Perttu Ahola	2010-12-18
*	settings manager: better default setting handling and updating config file an...	Perttu Ahola	2010-12-14
*	better graphics, zlib to work on vc++	Perttu Ahola	2010-12-14
*	doc update	Perttu Ahola	2010-11-29
*	Working version before block send priorization update	Perttu Ahola	2010-11-27
*	Initial files	Perttu Ahola	2010-11-27

/* * Minetest * Copyright (C) 2010-2014 celeron55, Perttu Ahola <celeron55@gmail.com> * Copyright (C) 2010-2014 kwolekr, Ryan Kwolek <kwolekr@minetest.net> * All rights reserved. * * Redistribution and use in source and binary forms, with or without modification, are * permitted provided that the following conditions are met: * 1. Redistributions of source code must retain the above copyright notice, this list of * conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright notice, this list * of conditions and the following disclaimer in the documentation and/or other materials * provided with the distribution. * * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND ANY EXPRESS OR IMPLIED * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND * FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON * ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. */ #include <cmath> #include "noise.h" #include <iostream> #include <cstring> // memset #include "debug.h" #include "util/numeric.h" #include "util/string.h" #include "exceptions.h" #define NOISE_MAGIC_X 1619 #define NOISE_MAGIC_Y 31337 #define NOISE_MAGIC_Z 52591 #define NOISE_MAGIC_SEED 1013 typedef float (*Interp2dFxn)( float v00, float v10, float v01, float v11, float x, float y); typedef float (*Interp3dFxn)( float v000, float v100, float v010, float v110, float v001, float v101, float v011, float v111, float x, float y, float z); FlagDesc flagdesc_noiseparams[] = { {"defaults", NOISE_FLAG_DEFAULTS}, {"eased", NOISE_FLAG_EASED}, {"absvalue", NOISE_FLAG_ABSVALUE}, {"pointbuffer", NOISE_FLAG_POINTBUFFER}, {"simplex", NOISE_FLAG_SIMPLEX}, {NULL, 0} }; /////////////////////////////////////////////////////////////////////////////// PcgRandom::PcgRandom(u64 state, u64 seq) { seed(state, seq); } void PcgRandom::seed(u64 state, u64 seq) { m_state = 0U; m_inc = (seq << 1u) | 1u; next(); m_state += state; next(); } u32 PcgRandom::next() { u64 oldstate = m_state; m_state = oldstate * 6364136223846793005ULL + m_inc; u32 xorshifted = ((oldstate >> 18u) ^ oldstate) >> 27u; u32 rot = oldstate >> 59u; return (xorshifted >> rot) | (xorshifted << ((-rot) & 31)); } u32 PcgRandom::range(u32 bound) { // If the bound is 0, we cover the whole RNG's range if (bound == 0) return next(); /* This is an optimization of the expression: 0x100000000ull % bound since 64-bit modulo operations typically much slower than 32. */ u32 threshold = -bound % bound; u32 r; /* If the bound is not a multiple of the RNG's range, it may cause bias, e.g. a RNG has a range from 0 to 3 and we take want a number 0 to 2. Using rand() % 3, the number 0 would be twice as likely to appear. With a very large RNG range, the effect becomes less prevalent but still present. This can be solved by modifying the range of the RNG to become a multiple of bound by dropping values above the a threshold. In our example, threshold == 4 % 3 == 1, so reject values < 1 (that is, 0), thus making the range == 3 with no bias. This loop may look dangerous, but will always terminate due to the RNG's property of uniformity. */ while ((r = next()) < threshold) ; return r % bound; } s32 PcgRandom::range(s32 min, s32 max) { if (max < min) throw PrngException("Invalid range (max < min)"); // We have to cast to s64 because otherwise this could overflow, // and signed overflow is undefined behavior. u32 bound = (s64)max - (s64)min + 1; return range(bound) + min; } void PcgRandom::bytes(void *out, size_t len) { u8 *outb = (u8 *)out; int bytes_left = 0; u32 r; while (len--) { if (bytes_left == 0) { bytes_left = sizeof(u32); r = next(); } *outb = r & 0xFF; outb++; bytes_left--; r >>= CHAR_BIT; } } s32 PcgRandom::randNormalDist(s32 min, s32 max, int num_trials) { s32 accum = 0; for (int i = 0; i != num_trials; i++) accum += range(min, max);