30:[] 2e:{"title":"Perlin Noise 1D","cells":[{"id":0,"value":"md`# Perlin Noise 1D`","pinned":false,"hidden":false,"mode":"ojs"},{"id":40,"value":"viz = document.createElement(\"div\")","pinned":false,"hidden":false,"mode":"ojs"},{"id":142,"value":"viewof octaves = form(html``)","pinned":false,"hidden":false,"mode":"ojs"},{"id":82,"value":"perm = [ 151,160,137,91,90,15,131,13,201,95,96,53,194,233,7,225,140,36,103,30,69,142,8,99,37,240,21,10,\n\t\t 23,190,6,148,247,120,234,75,0,26,197,62,94,252,219,203,117,35,11,32,57,177,33,88,237,149,56,87,\n\t\t 174,20,125,136,171,168,68,175,74,165,71,134,139,48,27,166,77,146,158,231,83,111,229,122,60,211,\n\t\t 133,230,220,105,92,41,55,46,245,40,244,102,143,54,65,25,63,161,1,216,80,73,209,76,132,187,208,\n\t\t 89,18,169,200,196,135,130,116,188,159,86,164,100,109,198,173,186,3,64,52,217,226,250,124,123,5,\n\t\t 202,38,147,118,126,255,82,85,212,207,206,59,227,47,16,58,17,182,189,28,42,223,183,170,213,119,\n\t\t 248,152,2,44,154,163,70,221,153,101,155,167,43,172,9,129,22,39,253,19,98,108,110,79,113,224,232,\n\t\t 178,185,112,104,218,246,97,228,251,34,242,193,238,210,144,12,191,179,162,241,81,51,145,235,249,\n\t\t 14,239,107,49,192,214,31,181,199,106,157,184,84,204,176,115,121,50,45,127,4,150,254,138,236,205,\n\t\t 93,222,114,67,29,24,72,243,141,128,195,78,66,215,61,156,180]","pinned":false,"hidden":false,"mode":"ojs"},{"id":89,"value":"function fade(t) {\n return t * t * t * (t * (t * 6 - 15) + 10);\n}","pinned":false,"hidden":false,"mode":"ojs"},{"id":101,"value":"function grad(hash, x) {\n return (hash & 1) == 0 ? x : -x;\n}","pinned":false,"hidden":false,"mode":"ojs"},{"id":81,"value":"function noise(x) {\n const ix = Math.floor(x) & 0xff;\n const t = x - Math.floor(x);\n const u = fade(t);\n return math.fit01(u, grad(perm[ix], t), grad(perm[ix+1], t-1));\n}","pinned":false,"hidden":false,"mode":"ojs"},{"id":63,"value":"points = tx.transduce(\n tx.map(x => [x, tx.transduce(\n tx.map(n => math.fit11(noise(x * octaves[`freq${n}`]), 0, octaves[`amp${n}`] * 200)),\n tx.add(),\n tx.range(1,4))]),\n tx.push(),\n tx.range(width)\n)","pinned":false,"hidden":false,"mode":"ojs"},{"id":37,"value":"root = [\n \"svg\", { width, height: 200 },\n [\"polyline\", { points, stroke: \"black\", 'fill-opacity': 0 }]\n]","pinned":false,"hidden":false,"mode":"ojs"},{"id":99,"value":"math = {\n // some math utils stolen from @thi.ng/math\n \n const DEG2RAD = Math.PI / 180;\n const norm = (x, a, b) => b !== a ? (x - a) / (b - a) : 0;\n const clamp = (x, min, max) => x < min ? min : x > max ? max : x;\n const clamp01 = x => clamp(x, 0, 1);\n const clamp11 = x => (x < -1 ? -1 : x > 1 ? 1 : x);\n const mix = (a, b, t) => a + (b - a) * t;\n const fit = (x, a, b, c, d) => mix(c, d, norm(x, a, b));\n const fit01 = (x, a, b) => mix(a, b, clamp01(x));\n \n return {\n DEG2RAD,\n EPS: 1e-6,\n TAU: Math.PI * 2,\n HALF_PI: Math.PI * 0.5,\n SQRT3: Math.sqrt(3),\n COS30: Math.cos(30 * DEG2RAD),\n \n norm, clamp, clamp01, mix, fit, fit01,\n step: (edge, x) => x < edge ? 0 : 1,\n fit11: (x, a, b) => a + (b - a) * (0.5 + 0.5 * clamp11(x)),\n frac: v => v % 1,\n fitClamped: (x, a, b, c, d) => fit01(norm(x, a, b), c, d),\n };\n}","pinned":false,"hidden":false,"mode":"ojs"},{"id":28,"value":"md`### Dom Update`","pinned":false,"hidden":false,"mode":"ojs"},{"id":32,"value":"update = tx.step(txhdom.updateDOM({ root: viz }))","pinned":false,"hidden":false,"mode":"ojs"},{"id":48,"value":"update(root);","pinned":false,"hidden":false,"mode":"ojs"},{"id":26,"value":"md`### Imports`","pinned":false,"hidden":false,"mode":"ojs"},{"id":6,"value":"tx = require(\"https://bundle.run/@thi.ng/transducers@6.4.5\")","pinned":false,"hidden":false,"mode":"ojs"},{"id":8,"value":"txhdom = require(\"https://bundle.run/@thi.ng/transducers-hdom@2.0.44\")","pinned":false,"hidden":false,"mode":"ojs"},{"id":138,"value":"import {form} from \"@mbostock/form-input\"","pinned":false,"hidden":false,"mode":"ojs"},{"id":128,"value":"md`### References\n\n* [keijiro/PerlinNoise: 1D/2D/3D Perlin noise function for Unity](https://github.com/keijiro/PerlinNoise)\n* [One-dimensional Perlin noise](https://jameshfisher.com/2017/10/15/1d-perlin-noise/)\n* [Value Noise and Procedural Patterns: Part 1 (Creating a Simple 1D Noise)](https://www.scratchapixel.com/lessons/procedural-generation-virtual-worlds/procedural-patterns-noise-part-1/creating-simple-1D-noise)\n`","pinned":false,"hidden":false,"mode":"ojs"}],"files":"$W30","stdlib":"1","titling":"auto"}