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add simplex noise test (/simplex.html)

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Norman Köhring 2023-02-12 20:17:01 +01:00
parent 7711c112e2
commit 9ba37c04a7
2 changed files with 58 additions and 0 deletions
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simplex.html Normal file
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<!DOCTYPE html>
<html>
<head>
<title>Simplex Noise Test</title>
<style>
body, html { width: 100%; height: 100%; padding: 0; margin: 0; overflow: hidden; background: black; }
canvas { display: block; width: 1024px; height: 768px; margin: calc(50vh - 768px / 2) auto 0; border: 2px solid #333; }
</style>
</head>
<body>
<canvas></canvas>
<script type="module" src="/src/simplex-demo.ts"></script>
</body>
</html>

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src/simplex-demo.ts Normal file
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import alea from 'alea'
import { createNoise2D } from "simplex-noise";
const canvas = document.getElementsByTagName('canvas')[0];
canvas.width = 1024;
canvas.height = 768;
const ctx = canvas.getContext('2d');
if (!ctx) throw new Error('cannot create drawing context')
const image = ctx.createImageData(canvas.width, canvas.height);
const data = image.data;
const seedFromUrl = decodeURIComponent(location.search.slice(1))
const seed = seedFromUrl || 'Dig dat seed!'
const prng = alea(seed)
const noise = createNoise2D(prng)
function paint(data: Uint8ClampedArray, w: number, h: number, steps = 100, threshold = 0, inverse = false) {
for (let x = 0; x < w; x++) {
for (let y = 0; y < h; y++) {
let value = noise(x / steps, y / steps);
value = 128 - 128 * value;
// value = Math.abs(256 * value);
const cell = (x + y * w) * 4;
if (threshold) value = value < threshold ? 0 : 255
if (inverse) value = 255 - value
data[cell] = value * x / y; // red
data[cell + 1] = value * y / x; // green
data[cell + 2] = 0; // blue
// data[cell] += Math.max(0, (25 - value) * 8);
data[cell + 3] = 255; // alpha.
}
}
}
console.time('simplex canvas')
paint(data, 1024, 768, 100)
console.timeEnd('simplex canvas')
ctx.fillStyle = 'black'
ctx.fillRect(0, 0, 100, 100);
ctx.putImageData(image, 0, 0);