47 lines
1.4 KiB
HTML
47 lines
1.4 KiB
HTML
<!DOCTYPE html>
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<title>Simplex noise</title>
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<style>
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body, html { width: 100%; height: 100%; padding: 0; margin: 0; overflow: hidden; background: black; }
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canvas { display: block; width: 1024px; height: 768px; margin: calc(50vh - 768px / 2) auto 0; border: 2px solid #333; }
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</style>
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<canvas></canvas>
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<script src='simplex.js?8'></script>
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<script>
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var canvas = document.getElementsByTagName('canvas')[0];
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canvas.width = 1024;
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canvas.height = 768;
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var ctx = canvas.getContext('2d');
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var image = ctx.createImageData(canvas.width, canvas.height);
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var data = image.data;
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var simplex = new SimplexNoise
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function paint(data, w, h, steps = 100, threshold = 0, inverse = false) {
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for (var x = 0; x < w; x++) {
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for (var y = 0; y < h; y++) {
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var value = simplex.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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var 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.fillColor = 'black';
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ctx.fillRect(0, 0, 100, 100);
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ctx.putImageData(image, 0, 0);
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</script>
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