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