155 lines
5.1 KiB
Objective-C
155 lines
5.1 KiB
Objective-C
/****************************************************************************
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Copyright (c) 2006, Radon Labs GmbH
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Copyright (c) 2011-2013,WebJet Business Division,CYOU
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http://www.genesis-3d.com.cn
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Permission is hereby granted, free of charge, to any person obtaining a copy
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of this software and associated documentation files (the "Software"), to deal
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in the Software without restriction, including without limitation the rights
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to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
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copies of the Software, and to permit persons to whom the Software is
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furnished to do so, subject to the following conditions:
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The above copyright notice and this permission notice shall be included in
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all copies or substantial portions of the Software.
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THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
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AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
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OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
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THE SOFTWARE.
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****************************************************************************/
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#pragma once
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#ifndef MATH_NOISE_H
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#define MATH_NOISE_H
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//------------------------------------------------------------------------------
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/**
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@class Math::noise
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Perlin noise class.
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See http://mrl.nyu.edu/~perlin/noise/ for details.
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*/
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#include "core/types.h"
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//------------------------------------------------------------------------------
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namespace Math
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{
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class noise
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{
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public:
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/// generate noise value
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static float gen(float x, float y, float z);
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private:
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/// compute fade curve
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static float fade(float t);
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/// lerp between a and b
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static float lerp(float t, float a, float b);
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/// convert into gradient direction
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static float grad(int hash, float x, float y, float z);
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static int perm[512];
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};
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int noise::perm[512] = {60,137,91,90,15,
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131,13,201,95,96,53,194,233,7,225,140,36,103,30,69,142,8,99,37,240,21,10,23,
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190, 6,148,247,120,234,75,0,26,197,62,94,252,219,203,117,35,11,32,57,177,33,
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88,237,149,56,87,174,20,125,136,171,168, 68,175,74,165,71,134,139,48,27,166,
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77,146,158,231,83,111,229,122,60,211,133,230,220,105,92,41,55,46,245,40,244,
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102,143,54, 65,25,63,161, 1,216,80,73,209,76,132,187,208, 89,18,169,200,196,
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135,130,116,188,159,86,164,100,109,198,173,186, 3,64,52,217,226,250,124,123,
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5,202,38,147,118,126,255,82,85,212,207,206,59,227,47,16,58,17,182,189,28,42,
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223,183,170,213,119,248,152, 2,44,154,163, 70,221,153,101,155,167, 43,172,9,
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129,22,39,253, 19,98,108,110,79,113,224,232,178,185, 112,104,218,246,97,228,
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251,34,242,193,238,210,144,12,191,179,162,241, 81,51,145,235,249,14,239,107,
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49,192,214, 31,181,199,106,157,184, 84,204,176,115,121,50,45,127, 4,150,254,
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138,236,205,93,222,114,67,29,24,72,243,141,128,195,78,66,215,61,156,180
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};
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//------------------------------------------------------------------------------
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/**
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*/
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inline
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float
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noise::fade(float t)
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{
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return t * t * t * (t * (t * 6.0f - 15.0f) + 10.0f);
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}
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//------------------------------------------------------------------------------
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/**
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*/
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inline
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float
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noise::lerp(float t, float a, float b)
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{
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return a + t * (b - a);
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}
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//------------------------------------------------------------------------------
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/**
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*/
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inline
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float
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noise::grad(int hash, float x, float y, float z)
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{
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int h = hash & 15;
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float u = h < 8 ? x : y;
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float v = h < 4 ? y : ((h == 12) || (h==14)) ? x : z;
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return ((h & 1) == 0 ? u : -u) + ((h & 2) == 0 ? v : -v);
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}
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//------------------------------------------------------------------------------
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/**
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*/
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inline
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float
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noise::gen(float x, float y, float z)
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{
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float floorX = floorf(x);
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float floorY = floorf(y);
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float floorZ = floorf(z);
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// find unit cube that contains point
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int X = int(floorX) & 255;
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int Y = int(floorY) & 255;
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int Z = int(floorZ) & 255;
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// find relative x,y,z of point in cube
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x -= floorX;
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y -= floorY;
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z -= floorZ;
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// compute fade curves for x, y, z
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float u = fade(x);
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float v = fade(y);
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float w = fade(z);
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// hash coords of 8 cube corners
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int A = perm[X] + Y;
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int AA = perm[A] + Z;
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int AB = perm[A+1] + Z;
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int B = perm[X+1] + Y;
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int BA = perm[B] + Z;
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int BB = perm[B+1] + Z;
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// add blended results from 8 corners of cube
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return lerp(w, lerp(v, lerp(u, grad(perm[AA ], x , y , z ),
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grad(perm[BA ], x-1, y , z )),
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lerp(u, grad(perm[AB ], x , y-1, z ),
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grad(perm[BB ], x-1, y-1, z ))),
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lerp(v, lerp(u, grad(perm[AA+1], x , y , z-1 ),
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grad(perm[BA+1], x-1, y , z-1 )),
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lerp(u, grad(perm[AB+1], x , y-1, z-1 ),
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grad(perm[BB+1], x-1, y-1, z-1 ))));
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}
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} // namespace Math
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//------------------------------------------------------------------------------
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#endif |