forked from Mirrorlandia_minetest/minetest
368 lines
8.1 KiB
C++
368 lines
8.1 KiB
C++
/*
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Minetest
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Copyright (C) 2010-2013 celeron55, Perttu Ahola <celeron55@gmail.com>
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This program is free software; you can redistribute it and/or modify
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it under the terms of the GNU Lesser General Public License as published by
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the Free Software Foundation; either version 2.1 of the License, or
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(at your option) any later version.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU Lesser General Public License for more details.
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You should have received a copy of the GNU Lesser General Public License along
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with this program; if not, write to the Free Software Foundation, Inc.,
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51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
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*/
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#ifndef UTIL_NUMERIC_HEADER
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#define UTIL_NUMERIC_HEADER
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#include "basic_macros.h"
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#include "../irrlichttypes.h"
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#include "../irr_v2d.h"
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#include "../irr_v3d.h"
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#include "../irr_aabb3d.h"
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#define rangelim(d, min, max) ((d) < (min) ? (min) : ((d) > (max) ? (max) : (d)))
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#define myfloor(x) ((x) < 0.0 ? (int)(x) - 1 : (int)(x))
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// The naive swap performs better than the xor version
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#define SWAP(t, x, y) do { \
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t temp = x; \
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x = y; \
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y = temp; \
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} while (0)
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inline s16 getContainerPos(s16 p, s16 d)
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{
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return (p >= 0 ? p : p - d + 1) / d;
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}
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inline v2s16 getContainerPos(v2s16 p, s16 d)
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{
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return v2s16(
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getContainerPos(p.X, d),
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getContainerPos(p.Y, d)
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);
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}
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inline v3s16 getContainerPos(v3s16 p, s16 d)
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{
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return v3s16(
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getContainerPos(p.X, d),
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getContainerPos(p.Y, d),
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getContainerPos(p.Z, d)
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);
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}
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inline v2s16 getContainerPos(v2s16 p, v2s16 d)
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{
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return v2s16(
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getContainerPos(p.X, d.X),
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getContainerPos(p.Y, d.Y)
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);
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}
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inline v3s16 getContainerPos(v3s16 p, v3s16 d)
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{
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return v3s16(
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getContainerPos(p.X, d.X),
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getContainerPos(p.Y, d.Y),
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getContainerPos(p.Z, d.Z)
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);
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}
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inline void getContainerPosWithOffset(s16 p, s16 d, s16 &container, s16 &offset)
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{
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container = (p >= 0 ? p : p - d + 1) / d;
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offset = p & (d - 1);
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}
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inline void getContainerPosWithOffset(const v2s16 &p, s16 d, v2s16 &container, v2s16 &offset)
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{
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getContainerPosWithOffset(p.X, d, container.X, offset.X);
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getContainerPosWithOffset(p.Y, d, container.Y, offset.Y);
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}
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inline void getContainerPosWithOffset(const v3s16 &p, s16 d, v3s16 &container, v3s16 &offset)
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{
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getContainerPosWithOffset(p.X, d, container.X, offset.X);
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getContainerPosWithOffset(p.Y, d, container.Y, offset.Y);
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getContainerPosWithOffset(p.Z, d, container.Z, offset.Z);
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}
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inline bool isInArea(v3s16 p, s16 d)
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{
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return (
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p.X >= 0 && p.X < d &&
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p.Y >= 0 && p.Y < d &&
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p.Z >= 0 && p.Z < d
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);
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}
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inline bool isInArea(v2s16 p, s16 d)
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{
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return (
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p.X >= 0 && p.X < d &&
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p.Y >= 0 && p.Y < d
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);
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}
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inline bool isInArea(v3s16 p, v3s16 d)
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{
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return (
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p.X >= 0 && p.X < d.X &&
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p.Y >= 0 && p.Y < d.Y &&
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p.Z >= 0 && p.Z < d.Z
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);
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}
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inline void sortBoxVerticies(v3s16 &p1, v3s16 &p2) {
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if (p1.X > p2.X)
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SWAP(s16, p1.X, p2.X);
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if (p1.Y > p2.Y)
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SWAP(s16, p1.Y, p2.Y);
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if (p1.Z > p2.Z)
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SWAP(s16, p1.Z, p2.Z);
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}
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inline v3s16 componentwise_min(const v3s16 &a, const v3s16 &b)
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{
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return v3s16(MYMIN(a.X, b.X), MYMIN(a.Y, b.Y), MYMIN(a.Z, b.Z));
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}
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inline v3s16 componentwise_max(const v3s16 &a, const v3s16 &b)
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{
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return v3s16(MYMAX(a.X, b.X), MYMAX(a.Y, b.Y), MYMAX(a.Z, b.Z));
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}
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/** Returns \p f wrapped to the range [-360, 360]
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*
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* See test.cpp for example cases.
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*
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* \note This is also used in cases where degrees wrapped to the range [0, 360]
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* is innapropriate (e.g. pitch needs negative values)
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*
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* \internal functionally equivalent -- although precision may vary slightly --
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* to fmodf((f), 360.0f) however empirical tests indicate that this approach is
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* faster.
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*/
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inline float modulo360f(float f)
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{
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int sign;
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int whole;
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float fraction;
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if (f < 0) {
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f = -f;
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sign = -1;
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} else {
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sign = 1;
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}
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whole = f;
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fraction = f - whole;
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whole %= 360;
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return sign * (whole + fraction);
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}
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/** Returns \p f wrapped to the range [0, 360]
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*/
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inline float wrapDegrees_0_360(float f)
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{
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float value = modulo360f(f);
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return value < 0 ? value + 360 : value;
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}
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/** Returns \p f wrapped to the range [-180, 180]
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*/
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inline float wrapDegrees_180(float f)
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{
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float value = modulo360f(f + 180);
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if (value < 0)
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value += 360;
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return value - 180;
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}
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/*
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Pseudo-random (VC++ rand() sucks)
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*/
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#define MYRAND_RANGE 0xffffffff
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u32 myrand();
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void mysrand(unsigned int seed);
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void myrand_bytes(void *out, size_t len);
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int myrand_range(int min, int max);
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/*
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Miscellaneous functions
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*/
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inline u32 get_bits(u32 x, u32 pos, u32 len)
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{
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u32 mask = (1 << len) - 1;
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return (x >> pos) & mask;
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}
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inline void set_bits(u32 *x, u32 pos, u32 len, u32 val)
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{
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u32 mask = (1 << len) - 1;
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*x &= ~(mask << pos);
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*x |= (val & mask) << pos;
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}
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inline u32 calc_parity(u32 v)
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{
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v ^= v >> 16;
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v ^= v >> 8;
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v ^= v >> 4;
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v &= 0xf;
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return (0x6996 >> v) & 1;
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}
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u64 murmur_hash_64_ua(const void *key, int len, unsigned int seed);
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bool isBlockInSight(v3s16 blockpos_b, v3f camera_pos, v3f camera_dir,
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f32 camera_fov, f32 range, f32 *distance_ptr=NULL);
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/*
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Returns nearest 32-bit integer for given floating point number.
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<cmath> and <math.h> in VC++ don't provide round().
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*/
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inline s32 myround(f32 f)
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{
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return (s32)(f < 0.f ? (f - 0.5f) : (f + 0.5f));
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}
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/*
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Returns integer position of node in given floating point position
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*/
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inline v3s16 floatToInt(v3f p, f32 d)
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{
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return v3s16(
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(p.X + (p.X > 0 ? d / 2 : -d / 2)) / d,
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(p.Y + (p.Y > 0 ? d / 2 : -d / 2)) / d,
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(p.Z + (p.Z > 0 ? d / 2 : -d / 2)) / d);
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}
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/*
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Returns floating point position of node in given integer position
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*/
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inline v3f intToFloat(v3s16 p, f32 d)
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{
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return v3f(
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(f32)p.X * d,
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(f32)p.Y * d,
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(f32)p.Z * d
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);
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}
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// Random helper. Usually d=BS
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inline aabb3f getNodeBox(v3s16 p, float d)
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{
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return aabb3f(
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(float)p.X * d - 0.5 * d,
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(float)p.Y * d - 0.5 * d,
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(float)p.Z * d - 0.5 * d,
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(float)p.X * d + 0.5 * d,
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(float)p.Y * d + 0.5 * d,
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(float)p.Z * d + 0.5 * d
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);
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}
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class IntervalLimiter
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{
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public:
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IntervalLimiter() {}
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/*
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dtime: time from last call to this method
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wanted_interval: interval wanted
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return value:
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true: action should be skipped
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false: action should be done
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*/
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bool step(float dtime, float wanted_interval)
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{
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m_accumulator += dtime;
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if (m_accumulator < wanted_interval)
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return false;
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m_accumulator -= wanted_interval;
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return true;
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}
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private:
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float m_accumulator = 0.0f;
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};
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/*
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Splits a list into "pages". For example, the list [1,2,3,4,5] split
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into two pages would be [1,2,3],[4,5]. This function computes the
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minimum and maximum indices of a single page.
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length: Length of the list that should be split
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page: Page number, 1 <= page <= pagecount
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pagecount: The number of pages, >= 1
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minindex: Receives the minimum index (inclusive).
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maxindex: Receives the maximum index (exclusive).
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Ensures 0 <= minindex <= maxindex <= length.
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*/
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inline void paging(u32 length, u32 page, u32 pagecount, u32 &minindex, u32 &maxindex)
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{
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if (length < 1 || pagecount < 1 || page < 1 || page > pagecount) {
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// Special cases or invalid parameters
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minindex = maxindex = 0;
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} else if(pagecount <= length) {
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// Less pages than entries in the list:
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// Each page contains at least one entry
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minindex = (length * (page-1) + (pagecount-1)) / pagecount;
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maxindex = (length * page + (pagecount-1)) / pagecount;
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} else {
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// More pages than entries in the list:
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// Make sure the empty pages are at the end
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if (page < length) {
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minindex = page-1;
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maxindex = page;
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} else {
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minindex = 0;
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maxindex = 0;
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}
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}
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}
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inline float cycle_shift(float value, float by = 0, float max = 1)
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{
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if (value + by < 0) return value + by + max;
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if (value + by > max) return value + by - max;
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return value + by;
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}
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inline bool is_power_of_two(u32 n)
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{
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return n != 0 && (n & (n - 1)) == 0;
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}
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// Compute next-higher power of 2 efficiently, e.g. for power-of-2 texture sizes.
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// Public Domain: https://graphics.stanford.edu/~seander/bithacks.html#RoundUpPowerOf2
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inline u32 npot2(u32 orig) {
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orig--;
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orig |= orig >> 1;
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orig |= orig >> 2;
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orig |= orig >> 4;
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orig |= orig >> 8;
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orig |= orig >> 16;
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return orig + 1;
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}
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#endif
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