13a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org/* 23a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org * Mesa 3-D graphics library 33a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org * Version: 6.5 43a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org * 53a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org * Copyright (C) 2006 Brian Paul All Rights Reserved. 63a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org * 73a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org * Permission is hereby granted, free of charge, to any person obtaining a 83a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org * copy of this software and associated documentation files (the "Software"), 93a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org * to deal in the Software without restriction, including without limitation 103a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org * the rights to use, copy, modify, merge, publish, distribute, sublicense, 113a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org * and/or sell copies of the Software, and to permit persons to whom the 123a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org * Software is furnished to do so, subject to the following conditions: 133a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org * 143a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org * The above copyright notice and this permission notice shall be included 153a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org * in all copies or substantial portions of the Software. 163a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org * 173a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS 183a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 193a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL 203a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org * BRIAN PAUL BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN 213a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org * AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN 223a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. 233a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org */ 243a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org 253a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org/* 263a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org * SimplexNoise1234 273a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org * Copyright (c) 2003-2005, Stefan Gustavson 283a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org * 293a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org * Contact: stegu@itn.liu.se 303a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org */ 313a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org 323a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org/** 333a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org * \file 343a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org * \brief C implementation of Perlin Simplex Noise over 1, 2, 3 and 4 dims. 353a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org * \author Stefan Gustavson (stegu@itn.liu.se) 363a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org * 373a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org * 383a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org * This implementation is "Simplex Noise" as presented by 393a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org * Ken Perlin at a relatively obscure and not often cited course 403a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org * session "Real-Time Shading" at Siggraph 2001 (before real 413a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org * time shading actually took on), under the title "hardware noise". 423a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org * The 3D function is numerically equivalent to his Java reference 433a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org * code available in the PDF course notes, although I re-implemented 443a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org * it from scratch to get more readable code. The 1D, 2D and 4D cases 453a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org * were implemented from scratch by me from Ken Perlin's text. 463a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org * 473a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org * This file has no dependencies on any other file, not even its own 483a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org * header file. The header file is made for use by external code only. 493a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org */ 503a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org 513a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org 523a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org#include "main/imports.h" 533a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org#include "prog_noise.h" 543a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org 553a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org#define FASTFLOOR(x) ( ((x)>0) ? ((int)x) : (((int)x)-1) ) 563a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org 573a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org/* 583a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org * --------------------------------------------------------------------- 593a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org * Static data 603a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org */ 613a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org 623a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org/** 633a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org * Permutation table. This is just a random jumble of all numbers 0-255, 643a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org * repeated twice to avoid wrapping the index at 255 for each lookup. 653a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org * This needs to be exactly the same for all instances on all platforms, 663a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org * so it's easiest to just keep it as static explicit data. 673a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org * This also removes the need for any initialisation of this class. 683a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org * 693a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org * Note that making this an int[] instead of a char[] might make the 703a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org * code run faster on platforms with a high penalty for unaligned single 713a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org * byte addressing. Intel x86 is generally single-byte-friendly, but 723a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org * some other CPUs are faster with 4-aligned reads. 733a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org * However, a char[] is smaller, which avoids cache trashing, and that 743a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org * is probably the most important aspect on most architectures. 753a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org * This array is accessed a *lot* by the noise functions. 763a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org * A vector-valued noise over 3D accesses it 96 times, and a 773a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org * float-valued 4D noise 64 times. We want this to fit in the cache! 783a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org */ 793a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.orgunsigned char perm[512] = { 151, 160, 137, 91, 90, 15, 803a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org 131, 13, 201, 95, 96, 53, 194, 233, 7, 225, 140, 36, 103, 30, 69, 142, 8, 813a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org 99, 37, 240, 21, 10, 23, 823a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org 190, 6, 148, 247, 120, 234, 75, 0, 26, 197, 62, 94, 252, 219, 203, 117, 35, 833a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org 11, 32, 57, 177, 33, 843a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org 88, 237, 149, 56, 87, 174, 20, 125, 136, 171, 168, 68, 175, 74, 165, 71, 853a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org 134, 139, 48, 27, 166, 863a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org 77, 146, 158, 231, 83, 111, 229, 122, 60, 211, 133, 230, 220, 105, 92, 41, 873a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org 55, 46, 245, 40, 244, 883a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org 102, 143, 54, 65, 25, 63, 161, 1, 216, 80, 73, 209, 76, 132, 187, 208, 89, 893a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org 18, 169, 200, 196, 903a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org 135, 130, 116, 188, 159, 86, 164, 100, 109, 198, 173, 186, 3, 64, 52, 217, 913a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org 226, 250, 124, 123, 923a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org 5, 202, 38, 147, 118, 126, 255, 82, 85, 212, 207, 206, 59, 227, 47, 16, 58, 933a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org 17, 182, 189, 28, 42, 943a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org 223, 183, 170, 213, 119, 248, 152, 2, 44, 154, 163, 70, 221, 153, 101, 155, 953a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org 167, 43, 172, 9, 963a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org 129, 22, 39, 253, 19, 98, 108, 110, 79, 113, 224, 232, 178, 185, 112, 104, 973a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org 218, 246, 97, 228, 983a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org 251, 34, 242, 193, 238, 210, 144, 12, 191, 179, 162, 241, 81, 51, 145, 235, 993a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org 249, 14, 239, 107, 1003a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org 49, 192, 214, 31, 181, 199, 106, 157, 184, 84, 204, 176, 115, 121, 50, 45, 1013a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org 127, 4, 150, 254, 1023a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org 138, 236, 205, 93, 222, 114, 67, 29, 24, 72, 243, 141, 128, 195, 78, 66, 1033a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org 215, 61, 156, 180, 1043a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org 151, 160, 137, 91, 90, 15, 1053a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org 131, 13, 201, 95, 96, 53, 194, 233, 7, 225, 140, 36, 103, 30, 69, 142, 8, 1063a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org 99, 37, 240, 21, 10, 23, 1073a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org 190, 6, 148, 247, 120, 234, 75, 0, 26, 197, 62, 94, 252, 219, 203, 117, 35, 1083a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org 11, 32, 57, 177, 33, 1093a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org 88, 237, 149, 56, 87, 174, 20, 125, 136, 171, 168, 68, 175, 74, 165, 71, 1103a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org 134, 139, 48, 27, 166, 1113a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org 77, 146, 158, 231, 83, 111, 229, 122, 60, 211, 133, 230, 220, 105, 92, 41, 1123a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org 55, 46, 245, 40, 244, 1133a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org 102, 143, 54, 65, 25, 63, 161, 1, 216, 80, 73, 209, 76, 132, 187, 208, 89, 1143a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org 18, 169, 200, 196, 1153a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org 135, 130, 116, 188, 159, 86, 164, 100, 109, 198, 173, 186, 3, 64, 52, 217, 1163a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org 226, 250, 124, 123, 1173a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org 5, 202, 38, 147, 118, 126, 255, 82, 85, 212, 207, 206, 59, 227, 47, 16, 58, 1183a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org 17, 182, 189, 28, 42, 1193a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org 223, 183, 170, 213, 119, 248, 152, 2, 44, 154, 163, 70, 221, 153, 101, 155, 1203a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org 167, 43, 172, 9, 1213a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org 129, 22, 39, 253, 19, 98, 108, 110, 79, 113, 224, 232, 178, 185, 112, 104, 1223a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org 218, 246, 97, 228, 1233a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org 251, 34, 242, 193, 238, 210, 144, 12, 191, 179, 162, 241, 81, 51, 145, 235, 1243a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org 249, 14, 239, 107, 1253a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org 49, 192, 214, 31, 181, 199, 106, 157, 184, 84, 204, 176, 115, 121, 50, 45, 1263a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org 127, 4, 150, 254, 1273a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org 138, 236, 205, 93, 222, 114, 67, 29, 24, 72, 243, 141, 128, 195, 78, 66, 1283a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org 215, 61, 156, 180 1293a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org}; 1303a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org 1313a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org/* 1323a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org * --------------------------------------------------------------------- 1333a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org */ 1343a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org 1353a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org/* 1363a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org * Helper functions to compute gradients-dot-residualvectors (1D to 4D) 1373a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org * Note that these generate gradients of more than unit length. To make 1383a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org * a close match with the value range of classic Perlin noise, the final 1393a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org * noise values need to be rescaled to fit nicely within [-1,1]. 1403a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org * (The simplex noise functions as such also have different scaling.) 1413a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org * Note also that these noise functions are the most practical and useful 1423a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org * signed version of Perlin noise. To return values according to the 1433a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org * RenderMan specification from the SL noise() and pnoise() functions, 1443a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org * the noise values need to be scaled and offset to [0,1], like this: 1453a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org * float SLnoise = (SimplexNoise1234::noise(x,y,z) + 1.0) * 0.5; 1463a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org */ 1473a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org 1483a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.orgstatic float 1493a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.orggrad1(int hash, float x) 1503a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org{ 1513a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org int h = hash & 15; 1523a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org float grad = 1.0f + (h & 7); /* Gradient value 1.0, 2.0, ..., 8.0 */ 1533a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org if (h & 8) 1543a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org grad = -grad; /* Set a random sign for the gradient */ 1553a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org return (grad * x); /* Multiply the gradient with the distance */ 1563a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org} 1573a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org 1583a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.orgstatic float 1593a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.orggrad2(int hash, float x, float y) 1603a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org{ 1613a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org int h = hash & 7; /* Convert low 3 bits of hash code */ 1623a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org float u = h < 4 ? x : y; /* into 8 simple gradient directions, */ 1633a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org float v = h < 4 ? y : x; /* and compute the dot product with (x,y). */ 1643a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org return ((h & 1) ? -u : u) + ((h & 2) ? -2.0f * v : 2.0f * v); 1653a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org} 1663a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org 1673a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.orgstatic float 1683a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.orggrad3(int hash, float x, float y, float z) 1693a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org{ 1703a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org int h = hash & 15; /* Convert low 4 bits of hash code into 12 simple */ 1713a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org float u = h < 8 ? x : y; /* gradient directions, and compute dot product. */ 1723a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org float v = h < 4 ? y : h == 12 || h == 14 ? x : z; /* Fix repeats at h = 12 to 15 */ 1733a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org return ((h & 1) ? -u : u) + ((h & 2) ? -v : v); 1743a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org} 1753a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org 1763a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.orgstatic float 1773a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.orggrad4(int hash, float x, float y, float z, float t) 1783a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org{ 1793a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org int h = hash & 31; /* Convert low 5 bits of hash code into 32 simple */ 1803a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org float u = h < 24 ? x : y; /* gradient directions, and compute dot product. */ 1813a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org float v = h < 16 ? y : z; 1823a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org float w = h < 8 ? z : t; 1833a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org return ((h & 1) ? -u : u) + ((h & 2) ? -v : v) + ((h & 4) ? -w : w); 1843a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org} 1853a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org 1863a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org/** 1873a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org * A lookup table to traverse the simplex around a given point in 4D. 1883a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org * Details can be found where this table is used, in the 4D noise method. 1893a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org * TODO: This should not be required, backport it from Bill's GLSL code! 1903a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org */ 1913a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.orgstatic unsigned char simplex[64][4] = { 1923a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org {0, 1, 2, 3}, {0, 1, 3, 2}, {0, 0, 0, 0}, {0, 2, 3, 1}, 1933a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org {0, 0, 0, 0}, {0, 0, 0, 0}, {0, 0, 0, 0}, {1, 2, 3, 0}, 1943a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org {0, 2, 1, 3}, {0, 0, 0, 0}, {0, 3, 1, 2}, {0, 3, 2, 1}, 1953a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org {0, 0, 0, 0}, {0, 0, 0, 0}, {0, 0, 0, 0}, {1, 3, 2, 0}, 1963a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org {0, 0, 0, 0}, {0, 0, 0, 0}, {0, 0, 0, 0}, {0, 0, 0, 0}, 1973a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org {0, 0, 0, 0}, {0, 0, 0, 0}, {0, 0, 0, 0}, {0, 0, 0, 0}, 1983a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org {1, 2, 0, 3}, {0, 0, 0, 0}, {1, 3, 0, 2}, {0, 0, 0, 0}, 1993a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org {0, 0, 0, 0}, {0, 0, 0, 0}, {2, 3, 0, 1}, {2, 3, 1, 0}, 2003a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org {1, 0, 2, 3}, {1, 0, 3, 2}, {0, 0, 0, 0}, {0, 0, 0, 0}, 2013a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org {0, 0, 0, 0}, {2, 0, 3, 1}, {0, 0, 0, 0}, {2, 1, 3, 0}, 2023a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org {0, 0, 0, 0}, {0, 0, 0, 0}, {0, 0, 0, 0}, {0, 0, 0, 0}, 2033a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org {0, 0, 0, 0}, {0, 0, 0, 0}, {0, 0, 0, 0}, {0, 0, 0, 0}, 2043a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org {2, 0, 1, 3}, {0, 0, 0, 0}, {0, 0, 0, 0}, {0, 0, 0, 0}, 2053a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org {3, 0, 1, 2}, {3, 0, 2, 1}, {0, 0, 0, 0}, {3, 1, 2, 0}, 2063a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org {2, 1, 0, 3}, {0, 0, 0, 0}, {0, 0, 0, 0}, {0, 0, 0, 0}, 2073a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org {3, 1, 0, 2}, {0, 0, 0, 0}, {3, 2, 0, 1}, {3, 2, 1, 0} 2083a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org}; 2093a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org 2103a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org 2113a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org/** 1D simplex noise */ 2123a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.orgGLfloat 2133a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org_mesa_noise1(GLfloat x) 2143a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org{ 2153a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org int i0 = FASTFLOOR(x); 2163a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org int i1 = i0 + 1; 2173a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org float x0 = x - i0; 2183a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org float x1 = x0 - 1.0f; 2193a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org float t1 = 1.0f - x1 * x1; 2203a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org float n0, n1; 2213a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org 2223a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org float t0 = 1.0f - x0 * x0; 2233a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org/* if(t0 < 0.0f) t0 = 0.0f; // this never happens for the 1D case */ 2243a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org t0 *= t0; 2253a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org n0 = t0 * t0 * grad1(perm[i0 & 0xff], x0); 2263a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org 2273a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org/* if(t1 < 0.0f) t1 = 0.0f; // this never happens for the 1D case */ 2283a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org t1 *= t1; 2293a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org n1 = t1 * t1 * grad1(perm[i1 & 0xff], x1); 2303a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org /* The maximum value of this noise is 8*(3/4)^4 = 2.53125 */ 2313a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org /* A factor of 0.395 would scale to fit exactly within [-1,1], but */ 2323a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org /* we want to match PRMan's 1D noise, so we scale it down some more. */ 2333a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org return 0.25f * (n0 + n1); 2343a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org} 2353a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org 2363a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org 2373a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org/** 2D simplex noise */ 2383a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.orgGLfloat 2393a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org_mesa_noise2(GLfloat x, GLfloat y) 2403a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org{ 2413a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org#define F2 0.366025403f /* F2 = 0.5*(sqrt(3.0)-1.0) */ 2423a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org#define G2 0.211324865f /* G2 = (3.0-Math.sqrt(3.0))/6.0 */ 2433a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org 2443a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org float n0, n1, n2; /* Noise contributions from the three corners */ 2453a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org 2463a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org /* Skew the input space to determine which simplex cell we're in */ 2473a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org float s = (x + y) * F2; /* Hairy factor for 2D */ 2483a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org float xs = x + s; 2493a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org float ys = y + s; 2503a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org int i = FASTFLOOR(xs); 2513a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org int j = FASTFLOOR(ys); 2523a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org 2533a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org float t = (float) (i + j) * G2; 2543a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org float X0 = i - t; /* Unskew the cell origin back to (x,y) space */ 2553a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org float Y0 = j - t; 2563a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org float x0 = x - X0; /* The x,y distances from the cell origin */ 2573a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org float y0 = y - Y0; 2583a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org 2593a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org float x1, y1, x2, y2; 2603a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org int ii, jj; 2613a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org float t0, t1, t2; 2623a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org 2633a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org /* For the 2D case, the simplex shape is an equilateral triangle. */ 2643a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org /* Determine which simplex we are in. */ 2653a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org int i1, j1; /* Offsets for second (middle) corner of simplex in (i,j) coords */ 2663a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org if (x0 > y0) { 2673a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org i1 = 1; 2683a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org j1 = 0; 2693a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org } /* lower triangle, XY order: (0,0)->(1,0)->(1,1) */ 2703a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org else { 2713a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org i1 = 0; 2723a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org j1 = 1; 2733a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org } /* upper triangle, YX order: (0,0)->(0,1)->(1,1) */ 2743a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org 2753a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org /* A step of (1,0) in (i,j) means a step of (1-c,-c) in (x,y), and */ 2763a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org /* a step of (0,1) in (i,j) means a step of (-c,1-c) in (x,y), where */ 2773a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org /* c = (3-sqrt(3))/6 */ 2783a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org 2793a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org x1 = x0 - i1 + G2; /* Offsets for middle corner in (x,y) unskewed coords */ 2803a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org y1 = y0 - j1 + G2; 2813a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org x2 = x0 - 1.0f + 2.0f * G2; /* Offsets for last corner in (x,y) unskewed coords */ 2823a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org y2 = y0 - 1.0f + 2.0f * G2; 2833a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org 2843a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org /* Wrap the integer indices at 256, to avoid indexing perm[] out of bounds */ 2853a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org ii = i % 256; 2863a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org jj = j % 256; 2873a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org 2883a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org /* Calculate the contribution from the three corners */ 2893a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org t0 = 0.5f - x0 * x0 - y0 * y0; 2903a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org if (t0 < 0.0f) 2913a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org n0 = 0.0f; 2923a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org else { 2933a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org t0 *= t0; 2943a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org n0 = t0 * t0 * grad2(perm[ii + perm[jj]], x0, y0); 2953a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org } 2963a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org 2973a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org t1 = 0.5f - x1 * x1 - y1 * y1; 2983a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org if (t1 < 0.0f) 2993a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org n1 = 0.0f; 3003a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org else { 3013a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org t1 *= t1; 3023a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org n1 = t1 * t1 * grad2(perm[ii + i1 + perm[jj + j1]], x1, y1); 3033a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org } 3043a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org 3053a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org t2 = 0.5f - x2 * x2 - y2 * y2; 3063a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org if (t2 < 0.0f) 3073a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org n2 = 0.0f; 3083a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org else { 3093a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org t2 *= t2; 3103a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org n2 = t2 * t2 * grad2(perm[ii + 1 + perm[jj + 1]], x2, y2); 3113a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org } 3123a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org 3133a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org /* Add contributions from each corner to get the final noise value. */ 3143a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org /* The result is scaled to return values in the interval [-1,1]. */ 3153a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org return 40.0f * (n0 + n1 + n2); /* TODO: The scale factor is preliminary! */ 3163a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org} 3173a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org 3183a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org 3193a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org/** 3D simplex noise */ 3203a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.orgGLfloat 3213a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org_mesa_noise3(GLfloat x, GLfloat y, GLfloat z) 3223a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org{ 3233a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org/* Simple skewing factors for the 3D case */ 3243a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org#define F3 0.333333333f 3253a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org#define G3 0.166666667f 3263a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org 3273a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org float n0, n1, n2, n3; /* Noise contributions from the four corners */ 3283a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org 3293a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org /* Skew the input space to determine which simplex cell we're in */ 3303a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org float s = (x + y + z) * F3; /* Very nice and simple skew factor for 3D */ 3313a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org float xs = x + s; 3323a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org float ys = y + s; 3333a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org float zs = z + s; 3343a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org int i = FASTFLOOR(xs); 3353a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org int j = FASTFLOOR(ys); 3363a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org int k = FASTFLOOR(zs); 3373a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org 3383a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org float t = (float) (i + j + k) * G3; 3393a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org float X0 = i - t; /* Unskew the cell origin back to (x,y,z) space */ 3403a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org float Y0 = j - t; 3413a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org float Z0 = k - t; 3423a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org float x0 = x - X0; /* The x,y,z distances from the cell origin */ 3433a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org float y0 = y - Y0; 3443a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org float z0 = z - Z0; 3453a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org 3463a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org float x1, y1, z1, x2, y2, z2, x3, y3, z3; 3473a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org int ii, jj, kk; 3483a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org float t0, t1, t2, t3; 3493a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org 3503a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org /* For the 3D case, the simplex shape is a slightly irregular tetrahedron. */ 3513a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org /* Determine which simplex we are in. */ 3523a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org int i1, j1, k1; /* Offsets for second corner of simplex in (i,j,k) coords */ 3533a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org int i2, j2, k2; /* Offsets for third corner of simplex in (i,j,k) coords */ 3543a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org 3553a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org/* This code would benefit from a backport from the GLSL version! */ 3563a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org if (x0 >= y0) { 3573a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org if (y0 >= z0) { 3583a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org i1 = 1; 3593a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org j1 = 0; 3603a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org k1 = 0; 3613a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org i2 = 1; 3623a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org j2 = 1; 3633a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org k2 = 0; 3643a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org } /* X Y Z order */ 3653a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org else if (x0 >= z0) { 3663a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org i1 = 1; 3673a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org j1 = 0; 3683a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org k1 = 0; 3693a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org i2 = 1; 3703a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org j2 = 0; 3713a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org k2 = 1; 3723a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org } /* X Z Y order */ 3733a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org else { 3743a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org i1 = 0; 3753a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org j1 = 0; 3763a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org k1 = 1; 3773a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org i2 = 1; 3783a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org j2 = 0; 3793a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org k2 = 1; 3803a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org } /* Z X Y order */ 3813a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org } 3823a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org else { /* x0<y0 */ 3833a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org if (y0 < z0) { 3843a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org i1 = 0; 3853a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org j1 = 0; 3863a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org k1 = 1; 3873a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org i2 = 0; 3883a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org j2 = 1; 3893a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org k2 = 1; 3903a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org } /* Z Y X order */ 3913a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org else if (x0 < z0) { 3923a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org i1 = 0; 3933a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org j1 = 1; 3943a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org k1 = 0; 3953a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org i2 = 0; 3963a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org j2 = 1; 3973a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org k2 = 1; 3983a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org } /* Y Z X order */ 3993a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org else { 4003a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org i1 = 0; 4013a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org j1 = 1; 4023a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org k1 = 0; 4033a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org i2 = 1; 4043a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org j2 = 1; 4053a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org k2 = 0; 4063a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org } /* Y X Z order */ 4073a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org } 4083a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org 4093a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org /* A step of (1,0,0) in (i,j,k) means a step of (1-c,-c,-c) in 4103a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org * (x,y,z), a step of (0,1,0) in (i,j,k) means a step of 4113a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org * (-c,1-c,-c) in (x,y,z), and a step of (0,0,1) in (i,j,k) means a 4123a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org * step of (-c,-c,1-c) in (x,y,z), where c = 1/6. 4133a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org */ 4143a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org 4153a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org x1 = x0 - i1 + G3; /* Offsets for second corner in (x,y,z) coords */ 4163a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org y1 = y0 - j1 + G3; 4173a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org z1 = z0 - k1 + G3; 4183a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org x2 = x0 - i2 + 2.0f * G3; /* Offsets for third corner in (x,y,z) coords */ 4193a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org y2 = y0 - j2 + 2.0f * G3; 4203a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org z2 = z0 - k2 + 2.0f * G3; 4213a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org x3 = x0 - 1.0f + 3.0f * G3;/* Offsets for last corner in (x,y,z) coords */ 4223a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org y3 = y0 - 1.0f + 3.0f * G3; 4233a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org z3 = z0 - 1.0f + 3.0f * G3; 4243a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org 4253a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org /* Wrap the integer indices at 256 to avoid indexing perm[] out of bounds */ 4263a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org ii = i % 256; 4273a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org jj = j % 256; 4283a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org kk = k % 256; 4293a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org 4303a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org /* Calculate the contribution from the four corners */ 4313a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org t0 = 0.6f - x0 * x0 - y0 * y0 - z0 * z0; 4323a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org if (t0 < 0.0f) 4333a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org n0 = 0.0f; 4343a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org else { 4353a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org t0 *= t0; 4363a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org n0 = t0 * t0 * grad3(perm[ii + perm[jj + perm[kk]]], x0, y0, z0); 4373a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org } 4383a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org 4393a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org t1 = 0.6f - x1 * x1 - y1 * y1 - z1 * z1; 4403a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org if (t1 < 0.0f) 4413a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org n1 = 0.0f; 4423a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org else { 4433a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org t1 *= t1; 4443a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org n1 = 4453a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org t1 * t1 * grad3(perm[ii + i1 + perm[jj + j1 + perm[kk + k1]]], x1, 4463a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org y1, z1); 4473a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org } 4483a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org 4493a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org t2 = 0.6f - x2 * x2 - y2 * y2 - z2 * z2; 4503a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org if (t2 < 0.0f) 4513a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org n2 = 0.0f; 4523a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org else { 4533a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org t2 *= t2; 4543a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org n2 = 4553a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org t2 * t2 * grad3(perm[ii + i2 + perm[jj + j2 + perm[kk + k2]]], x2, 4563a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org y2, z2); 4573a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org } 4583a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org 4593a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org t3 = 0.6f - x3 * x3 - y3 * y3 - z3 * z3; 4603a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org if (t3 < 0.0f) 4613a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org n3 = 0.0f; 4623a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org else { 4633a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org t3 *= t3; 4643a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org n3 = 4653a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org t3 * t3 * grad3(perm[ii + 1 + perm[jj + 1 + perm[kk + 1]]], x3, y3, 4663a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org z3); 4673a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org } 4683a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org 4693a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org /* Add contributions from each corner to get the final noise value. 4703a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org * The result is scaled to stay just inside [-1,1] 4713a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org */ 4723a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org return 32.0f * (n0 + n1 + n2 + n3); /* TODO: The scale factor is preliminary! */ 4733a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org} 4743a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org 4753a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org 4763a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org/** 4D simplex noise */ 4773a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.orgGLfloat 4783a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org_mesa_noise4(GLfloat x, GLfloat y, GLfloat z, GLfloat w) 4793a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org{ 4803a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org /* The skewing and unskewing factors are hairy again for the 4D case */ 4813a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org#define F4 0.309016994f /* F4 = (Math.sqrt(5.0)-1.0)/4.0 */ 4823a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org#define G4 0.138196601f /* G4 = (5.0-Math.sqrt(5.0))/20.0 */ 4833a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org 4843a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org float n0, n1, n2, n3, n4; /* Noise contributions from the five corners */ 4853a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org 4863a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org /* Skew the (x,y,z,w) space to determine which cell of 24 simplices we're in */ 4873a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org float s = (x + y + z + w) * F4; /* Factor for 4D skewing */ 4883a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org float xs = x + s; 4893a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org float ys = y + s; 4903a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org float zs = z + s; 4913a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org float ws = w + s; 4923a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org int i = FASTFLOOR(xs); 4933a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org int j = FASTFLOOR(ys); 4943a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org int k = FASTFLOOR(zs); 4953a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org int l = FASTFLOOR(ws); 4963a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org 4973a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org float t = (i + j + k + l) * G4; /* Factor for 4D unskewing */ 4983a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org float X0 = i - t; /* Unskew the cell origin back to (x,y,z,w) space */ 4993a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org float Y0 = j - t; 5003a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org float Z0 = k - t; 5013a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org float W0 = l - t; 5023a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org 5033a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org float x0 = x - X0; /* The x,y,z,w distances from the cell origin */ 5043a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org float y0 = y - Y0; 5053a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org float z0 = z - Z0; 5063a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org float w0 = w - W0; 5073a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org 5083a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org /* For the 4D case, the simplex is a 4D shape I won't even try to describe. 5093a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org * To find out which of the 24 possible simplices we're in, we need to 5103a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org * determine the magnitude ordering of x0, y0, z0 and w0. 5113a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org * The method below is a good way of finding the ordering of x,y,z,w and 5123a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org * then find the correct traversal order for the simplex we're in. 5133a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org * First, six pair-wise comparisons are performed between each possible pair 5143a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org * of the four coordinates, and the results are used to add up binary bits 5153a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org * for an integer index. 5163a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org */ 5173a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org int c1 = (x0 > y0) ? 32 : 0; 5183a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org int c2 = (x0 > z0) ? 16 : 0; 5193a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org int c3 = (y0 > z0) ? 8 : 0; 5203a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org int c4 = (x0 > w0) ? 4 : 0; 5213a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org int c5 = (y0 > w0) ? 2 : 0; 5223a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org int c6 = (z0 > w0) ? 1 : 0; 5233a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org int c = c1 + c2 + c3 + c4 + c5 + c6; 5243a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org 5253a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org int i1, j1, k1, l1; /* The integer offsets for the second simplex corner */ 5263a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org int i2, j2, k2, l2; /* The integer offsets for the third simplex corner */ 5273a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org int i3, j3, k3, l3; /* The integer offsets for the fourth simplex corner */ 5283a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org 5293a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org float x1, y1, z1, w1, x2, y2, z2, w2, x3, y3, z3, w3, x4, y4, z4, w4; 5303a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org int ii, jj, kk, ll; 5313a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org float t0, t1, t2, t3, t4; 5323a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org 5333a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org /* 5343a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org * simplex[c] is a 4-vector with the numbers 0, 1, 2 and 3 in some 5353a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org * order. Many values of c will never occur, since e.g. x>y>z>w 5363a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org * makes x<z, y<w and x<w impossible. Only the 24 indices which 5373a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org * have non-zero entries make any sense. We use a thresholding to 5383a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org * set the coordinates in turn from the largest magnitude. The 5393a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org * number 3 in the "simplex" array is at the position of the 5403a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org * largest coordinate. 5413a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org */ 5423a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org i1 = simplex[c][0] >= 3 ? 1 : 0; 5433a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org j1 = simplex[c][1] >= 3 ? 1 : 0; 5443a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org k1 = simplex[c][2] >= 3 ? 1 : 0; 5453a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org l1 = simplex[c][3] >= 3 ? 1 : 0; 5463a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org /* The number 2 in the "simplex" array is at the second largest coordinate. */ 5473a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org i2 = simplex[c][0] >= 2 ? 1 : 0; 5483a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org j2 = simplex[c][1] >= 2 ? 1 : 0; 5493a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org k2 = simplex[c][2] >= 2 ? 1 : 0; 5503a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org l2 = simplex[c][3] >= 2 ? 1 : 0; 5513a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org /* The number 1 in the "simplex" array is at the second smallest coordinate. */ 5523a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org i3 = simplex[c][0] >= 1 ? 1 : 0; 5533a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org j3 = simplex[c][1] >= 1 ? 1 : 0; 5543a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org k3 = simplex[c][2] >= 1 ? 1 : 0; 5553a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org l3 = simplex[c][3] >= 1 ? 1 : 0; 5563a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org /* The fifth corner has all coordinate offsets = 1, so no need to look that up. */ 5573a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org 5583a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org x1 = x0 - i1 + G4; /* Offsets for second corner in (x,y,z,w) coords */ 5593a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org y1 = y0 - j1 + G4; 5603a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org z1 = z0 - k1 + G4; 5613a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org w1 = w0 - l1 + G4; 5623a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org x2 = x0 - i2 + 2.0f * G4; /* Offsets for third corner in (x,y,z,w) coords */ 5633a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org y2 = y0 - j2 + 2.0f * G4; 5643a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org z2 = z0 - k2 + 2.0f * G4; 5653a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org w2 = w0 - l2 + 2.0f * G4; 5663a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org x3 = x0 - i3 + 3.0f * G4; /* Offsets for fourth corner in (x,y,z,w) coords */ 5673a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org y3 = y0 - j3 + 3.0f * G4; 5683a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org z3 = z0 - k3 + 3.0f * G4; 5693a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org w3 = w0 - l3 + 3.0f * G4; 5703a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org x4 = x0 - 1.0f + 4.0f * G4; /* Offsets for last corner in (x,y,z,w) coords */ 5713a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org y4 = y0 - 1.0f + 4.0f * G4; 5723a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org z4 = z0 - 1.0f + 4.0f * G4; 5733a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org w4 = w0 - 1.0f + 4.0f * G4; 5743a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org 5753a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org /* Wrap the integer indices at 256, to avoid indexing perm[] out of bounds */ 5763a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org ii = i % 256; 5773a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org jj = j % 256; 5783a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org kk = k % 256; 5793a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org ll = l % 256; 5803a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org 5813a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org /* Calculate the contribution from the five corners */ 5823a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org t0 = 0.6f - x0 * x0 - y0 * y0 - z0 * z0 - w0 * w0; 5833a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org if (t0 < 0.0f) 5843a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org n0 = 0.0f; 5853a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org else { 5863a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org t0 *= t0; 5873a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org n0 = 5883a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org t0 * t0 * grad4(perm[ii + perm[jj + perm[kk + perm[ll]]]], x0, y0, 5893a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org z0, w0); 5903a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org } 5913a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org 5923a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org t1 = 0.6f - x1 * x1 - y1 * y1 - z1 * z1 - w1 * w1; 5933a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org if (t1 < 0.0f) 5943a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org n1 = 0.0f; 5953a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org else { 5963a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org t1 *= t1; 5973a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org n1 = 5983a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org t1 * t1 * 5993a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org grad4(perm[ii + i1 + perm[jj + j1 + perm[kk + k1 + perm[ll + l1]]]], 6003a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org x1, y1, z1, w1); 6013a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org } 6023a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org 6033a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org t2 = 0.6f - x2 * x2 - y2 * y2 - z2 * z2 - w2 * w2; 6043a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org if (t2 < 0.0f) 6053a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org n2 = 0.0f; 6063a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org else { 6073a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org t2 *= t2; 6083a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org n2 = 6093a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org t2 * t2 * 6103a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org grad4(perm[ii + i2 + perm[jj + j2 + perm[kk + k2 + perm[ll + l2]]]], 6113a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org x2, y2, z2, w2); 6123a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org } 6133a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org 6143a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org t3 = 0.6f - x3 * x3 - y3 * y3 - z3 * z3 - w3 * w3; 6153a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org if (t3 < 0.0f) 6163a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org n3 = 0.0f; 6173a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org else { 6183a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org t3 *= t3; 6193a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org n3 = 6203a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org t3 * t3 * 6213a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org grad4(perm[ii + i3 + perm[jj + j3 + perm[kk + k3 + perm[ll + l3]]]], 6223a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org x3, y3, z3, w3); 6233a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org } 6243a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org 6253a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org t4 = 0.6f - x4 * x4 - y4 * y4 - z4 * z4 - w4 * w4; 6263a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org if (t4 < 0.0f) 6273a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org n4 = 0.0f; 6283a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org else { 6293a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org t4 *= t4; 6303a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org n4 = 6313a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org t4 * t4 * 6323a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org grad4(perm[ii + 1 + perm[jj + 1 + perm[kk + 1 + perm[ll + 1]]]], x4, 6333a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org y4, z4, w4); 6343a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org } 6353a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org 6363a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org /* Sum up and scale the result to cover the range [-1,1] */ 6373a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org return 27.0f * (n0 + n1 + n2 + n3 + n4); /* TODO: The scale factor is preliminary! */ 6383a0db227ffe90888ad760c61a63226988c974e0apatrick@chromium.org} 639