vg_perlin.c

   1 #include "vg_m.h"
   2 #include "vg_perlin.h"
   3
   4 static int perlin_hash[] = {
   5 0x46,0xD5,0xB8,0xD3,0xF2,0xE5,0xCC,0x07,0xD0,0xB3,0x7A,0xA2,0xC3,0xDA,0xDC,0x7F,
   6 0xE0,0xB7,0x42,0xA0,0xBF,0x41,0x92,0x32,0x6F,0x0D,0x45,0xC7,0x54,0xDB,0x30,0xC2,
   7 0xD5,0xDA,0x55,0x09,0xDE,0x74,0x48,0x20,0xE1,0x24,0x5C,0x4D,0x6F,0x36,0xD8,0xE9,
   8 0x8D,0x8F,0x54,0x99,0x98,0x51,0xFE,0xDB,0x26,0x04,0x65,0x57,0x56,0xF3,0x53,0x30,
   9 0x3D,0x16,0xC0,0xB6,0xF2,0x47,0xCF,0x62,0xB0,0x6C,0x8F,0x4F,0x8C,0x4C,0x17,0xF0,
  10 0x19,0x7E,0x2D,0x81,0x8D,0xFB,0x10,0xD3,0x49,0x50,0x60,0xFD,0x38,0x15,0x3B,0xEE,
  11 0x05,0xC1,0xCF,0x62,0x97,0x75,0xDF,0x4E,0x4D,0x89,0x5E,0x88,0x5C,0x30,0x8C,0x54,
  12 0x1D,0x39,0x41,0xEA,0xA2,0x63,0x12,0x1B,0x8E,0x35,0x22,0x9B,0x98,0xA3,0x7F,0x80,
  13 0xD6,0x27,0x94,0x66,0xB5,0x1D,0x7E,0xDF,0x96,0x28,0x38,0x3A,0xA0,0xE8,0x71,0x09,
  14 0x62,0x5E,0x9D,0x53,0x58,0x1B,0x7D,0x0D,0x2D,0x99,0x77,0x83,0xC3,0x89,0xC2,0xA2,
  15 0xA7,0x1D,0x78,0x80,0x37,0xC1,0x87,0xFF,0x65,0xBF,0x2C,0xF1,0xE5,0xB3,0x09,0xE0,
  16 0x25,0x92,0x83,0x0F,0x8A,0x57,0x3C,0x0B,0xC6,0xBC,0x44,0x16,0xE3,0xCE,0xC3,0x0D,
  17 0x69,0xD3,0xC6,0x99,0xB8,0x46,0x44,0xC4,0xF3,0x1E,0xBF,0xF5,0xB4,0xDB,0xFB,0x93,
  18 0xA1,0x7B,0xC9,0x08,0x77,0x22,0xE5,0x02,0xEF,0x9E,0x90,0x94,0x8A,0xA6,0x3D,0x7E,
  19 0xA2,0xA0,0x10,0x82,0x47,0x5C,0xAA,0xF8,0x2F,0x0D,0x9F,0x76,0xDA,0x99,0x0F,0xCB,
  20 0xE2,0x02,0x0C,0x75,0xCA,0x35,0x29,0xA6,0x49,0x83,0x6D,0x91,0xB4,0xEC,0x31,0x69,
  21 0xBA,0x13,0xF3,0xC7,0x21,0x06,0xC8,0x79,0xEF,0xB1,0x9C,0x6A,0xEE,0x64,0x9A,0xDC,
  22 0x1E,0xC6,0x18,0x93,0xA9,0x7E,0x89,0x7D,0x96,0xE5,0x44,0xB8,0x00,0x15,0xAF,0x8C,
  23 0x78,0x8F,0xA8,0x05,0xA7,0x07,0x25,0x9A,0xC8,0x5D,0x90,0x1A,0x41,0x53,0x30,0xD3,
  24 0x24,0x33,0x71,0xB4,0x50,0x6E,0xE4,0xEA,0x0D,0x2B,0x6D,0xF5,0x17,0x08,0x74,0x49,
  25 0x71,0xC2,0xAC,0xF7,0xDC,0xB2,0x7E,0xCC,0xB6,0x1B,0xB8,0xA9,0x52,0xCF,0x6B,0x51,
  26 0xD2,0x4E,0xC9,0x43,0xEE,0x2E,0x92,0x24,0xBB,0x47,0x4D,0x0C,0x3E,0x21,0x53,0x19,
  27 0xD4,0x82,0xE2,0xC6,0x93,0x85,0x0A,0xF8,0xFA,0x04,0x07,0xD3,0x1D,0xEC,0x03,0x66,
  28 0xFD,0xB1,0xFB,0x8F,0xC5,0xDE,0xE8,0x29,0xDF,0x23,0x09,0x9D,0x7C,0x43,0x3D,0x4D,
  29 0x89,0xB9,0x6F,0xB4,0x6B,0x4A,0x51,0xC3,0x94,0xF4,0x7C,0x5E,0x19,0x87,0x79,0xC1,
  30 0x80,0x0C,0x45,0x12,0xEC,0x95,0xF3,0x31,0x68,0x42,0xE1,0x06,0x57,0x0E,0xA7,0xFB,
  31 0x78,0x96,0x87,0x23,0xA5,0x20,0x7A,0x09,0x3A,0x45,0xE6,0xD9,0x5E,0x6A,0xD6,0xAA,
  32 0x29,0x50,0x92,0x4E,0xD0,0xB5,0x91,0xC2,0x9A,0xCF,0x07,0xFE,0xB2,0x15,0xEB,0xE4,
  33 0x84,0x40,0x14,0x47,0xFA,0x93,0xB9,0x06,0x69,0xDB,0xBD,0x4E,0xEA,0x52,0x9B,0xDE,
  34 0x5B,0x50,0x36,0xAB,0xB3,0x1F,0xD2,0xCD,0x9C,0x13,0x07,0x7E,0x8B,0xED,0x72,0x62,
  35 0x74,0x77,0x3B,0x88,0xAC,0x5B,0x6A,0xBC,0xDA,0x99,0xE8,0x24,0x90,0x5A,0xCA,0x8D,
  36 0x5C,0x2B,0xF8,0xF1,0xE1,0x1D,0x94,0x11,0xEA,0xCC,0x02,0x09,0x1E,0xA2,0x48,0x67,
  37 0x87,0x5A,0x7E,0xC6,0xCC,0xA3,0xFB,0xC5,0x36,0xEB,0x5C,0xE1,0xAF,0x1E,0xBE,0xE7,
  38 0xD8,0x8F,0x70,0xAE,0x42,0x05,0xF5,0xCD,0x2D,0xA2,0xB0,0xFD,0xEF,0x65,0x2C,0x22,
  39 0xCB,0x8C,0x8B,0xAA,0x3D,0x86,0xE2,0xCD,0xBE,0xC3,0x42,0x38,0xE3,0x9C,0x08,0xB5,
  40 0xAE,0xBD,0x54,0x73,0x83,0x70,0x24,0x47,0xCA,0x4C,0x04,0xC4,0xE0,0x1D,0x40,0xED,
  41 0xF4,0x2B,0x50,0x8E,0x97,0xB3,0xF0,0xA6,0x76,0xDB,0x49,0x30,0xE5,0xD9,0x71,0x07,
  42 0xB2,0xF1,0x0F,0xD6,0x77,0xAA,0x72,0xC0,0xAF,0x66,0xD8,0x40,0xC6,0x08,0x19,0x8C,
  43 0xD9,0x8F,0x5A,0x75,0xAC,0xBE,0xC2,0x40,0x5B,0xBD,0x0D,0x1D,0x00,0xAF,0x26,0x5E,
  44 0x78,0x43,0xAA,0xC6,0x4F,0xF3,0xD8,0xE2,0x7F,0x0C,0x1E,0x77,0x4D,0x35,0x96,0x23,
  45 0x32,0x44,0x03,0x8D,0x92,0xE7,0xFD,0x48,0x07,0xD0,0x58,0xFC,0x6D,0xC9,0x91,0x33,
  46 0xF0,0x23,0x45,0xA4,0x29,0xB9,0xF5,0xB0,0x68,0x8F,0x7B,0x59,0x15,0x8E,0xA6,0x66,
  47 0x15,0xA0,0x76,0x9B,0x69,0xCB,0x38,0xA5,0xF4,0xB4,0x6B,0xDC,0x1F,0xAB,0xAE,0x12,
  48 0x77,0xC0,0x8C,0x4A,0x03,0xB9,0x73,0xD3,0x6D,0x52,0xC5,0xF5,0x6E,0x4E,0x4B,0xA3,
  49 0x24,0x02,0x58,0xEE,0x5F,0xF9,0xD6,0xD0,0x1D,0xBC,0xF4,0xB8,0x4F,0xFD,0x4B,0x2D,
  50 0x34,0x77,0x46,0xE5,0xD4,0x33,0x7B,0x9C,0x35,0xCD,0xB0,0x5D,0x06,0x39,0x99,0xEB,
  51 0x0C,0xD0,0x0F,0xF7,0x92,0xB5,0x58,0x5B,0x5E,0x79,0x12,0xF4,0x05,0xF6,0x21,0x07,
  52 0x0B,0x49,0x1A,0xFB,0xD4,0x98,0xC4,0xEF,0x7A,0xD6,0xCA,0xA1,0xDA,0xB3,0x51,0x00,
  53 0x76,0xEC,0x08,0x48,0x40,0x35,0xD7,0x94,0xBE,0xF5,0x7B,0xA4,0x20,0x81,0x5F,0x82,
  54 0xF3,0x6F,0x96,0x24,0x98,0xB6,0x49,0x18,0xC8,0xC5,0x8C,0xD2,0x38,0x7F,0xC4,0xF6,
  55 0xAA,0x87,0xDC,0x73,0x5B,0xA1,0xAF,0xE5,0x3D,0x37,0x6B,0x85,0xED,0x38,0x62,0x7D,
  56 0x57,0xBD,0xCF,0xB5,0x1B,0xA8,0xBB,0x32,0x33,0xD3,0x34,0x5A,0xC1,0x5D,0xFB,0x28,
  57 0x6E,0xE1,0x67,0x51,0xBB,0x31,0x92,0x83,0xAC,0xAA,0x72,0x52,0xFD,0x13,0x4F,0x73,
  58 0xD3,0xF0,0x5E,0xFC,0xBA,0xB1,0x3C,0x7B,0x08,0x76,0x03,0x38,0x1E,0xD1,0xCC,0x33,
  59 0xA3,0x1E,0xFC,0xE0,0x82,0x30,0x27,0x93,0x71,0x35,0x75,0x77,0xBA,0x78,0x10,0x33,
  60 0xCD,0xAB,0xCF,0x8E,0xAD,0xF9,0x32,0xC9,0x15,0x9F,0xD6,0x6D,0xA8,0xAE,0xB1,0x3F,
  61 0x90,0xEB,0xD4,0xF9,0x31,0x81,0xA3,0x53,0x99,0x4B,0x3C,0x93,0x3B,0xFE,0x55,0xFF,
  62 0x25,0x9F,0xCC,0x07,0xC5,0x2C,0x14,0xA7,0xA4,0x1E,0x6C,0xB6,0x91,0x2A,0xE0,0x3E,
  63 0x7F,0x39,0x0A,0xD9,0x24,0x3C,0x01,0xA0,0x30,0x99,0x8E,0xB8,0x1D,0xF9,0xA7,0x78,
  64 0x86,0x95,0x35,0x0E,0x21,0xDA,0x7A,0x7B,0xAD,0x9F,0x4E,0xF6,0x63,0x5B,0x96,0xBB,
  65 0x87,0x36,0x3F,0xA7,0x1A,0x66,0x91,0xCD,0xB0,0x3B,0xC0,0x4F,0x54,0xD2,0x5F,0xBB,
  66 0x38,0x89,0x1C,0x79,0x7E,0xA2,0x02,0xE4,0x80,0x84,0x1E,0x33,0xAB,0x74,0xFA,0xBE,
  67 0x31,0x46,0x2E,0xC5,0x15,0xB9,0x12,0xE9,0xD3,0x73,0x43,0xEA,0x74,0x11,0xA7,0xC0,
  68 0xD5,0xD8,0x39,0x08,0x9F,0x4F,0xC7,0x71,0x25,0x09,0x51,0x65,0xD6,0xA8,0x02,0x1F
  69 };
  70
  71 // Note: Hash must be power of 2!
  72 #define PERLIN_HASH_LENGTH 1024
  73 #define PERLIN_HASH_MASK (PERLIN_HASH_LENGTH-1)
  74
  75 static int perlin_noise2( int x, int y, int seed )
  76 {
  77         return perlin_hash[ (perlin_hash[(y+seed) & PERLIN_HASH_MASK] + x)
  78             & PERLIN_HASH_MASK ];
  79 }
  80
  81 static int perlin_noise1( int i, int seed )
  82 {
  83         return perlin_hash[ (seed + i) & PERLIN_HASH_MASK ];
  84 }
  85
  86 static f32 perlin_smooth( f32 x, f32 y, f32 t )
  87 {
  88         return vg_lerpf( x, y, t*t*(3.0f-2.0f*t) );
  89 }
  90
  91 f32 vg_perlin_noise_2d( f32 x, f32 y, int seed )
  92 {
  93         int ix = x, iy = y;
  94         f32 x_frac = x - ix,
  95               y_frac = y - iy;
  96
  97         int s = perlin_noise2( ix,   iy,   seed ),
  98             t = perlin_noise2( ix+1, iy,   seed ),
  99             u = perlin_noise2( ix,   iy+1, seed ),
 100             v = perlin_noise2( ix+1, iy+1, seed );
 101
 102         f32 low  = perlin_smooth( s,t,x_frac ),
 103               high = perlin_smooth( u,v,x_frac );
 104
 105         return perlin_smooth( low, high, y_frac );
 106 }
 107
 108 f32 vg_perlin_noise_1d( f32 v, int seed )
 109 {
 110         int iv = v;
 111         f32 frac = v-iv;
 112         int s = perlin_noise1( iv,   seed ),
 113             t = perlin_noise1( iv+1, seed );
 114
 115         return perlin_smooth( s, t, frac );
 116 }
 117
 118 f32 vg_perlin_fract_1d( f32 v, f32 freq, int octaves, int seed )
 119 {
 120         f32 xa  = v*freq,
 121               amp = 1.0f,
 122               fin = 0.f,
 123               div = 0.f;
 124
 125         for( int i=0; i<octaves; i++ ){
 126                 div += 256 * amp;
 127                 fin += vg_perlin_noise_1d( xa, seed ) * amp;
 128                 amp /= 2.f;
 129                 xa *= 2.f;
 130         }
 131
 132         return fin/div;
 133 }
 134
 135 f32 vg_perlin_fract_2d( f32 x, f32 y, f32 freq, int octaves, int seed )
 136 {
 137         f32 xa  = x*freq,
 138             ya  = y*freq,
 139             amp = 1.0f,
 140             fin = 0.f,
 141             div = 0.f;
 142
 143         for( int i=0; i<octaves; i++ ){
 144                 div += 256 * amp;
 145                 fin += vg_perlin_noise_2d( xa, ya, seed ) * amp;
 146                 amp /= 2;
 147                 xa *= 2;
 148                 ya *= 2;
 149         }
 150
 151         return fin/div;
 152 }