mirror of
https://github.com/fluencelabs/assemblyscript
synced 2025-04-25 07:02:13 +00:00
124 lines
4.0 KiB
HTML
124 lines
4.0 KiB
HTML
<!DOCTYPE html>
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<html>
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<head>
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<title>Mandelbrot set - AssemblyScript</title>
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<link rel="icon" href="http://assemblyscript.org/favicon.ico" type="image/x-icon" />
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<style>
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html, body { height: 100%; margin: 0; overflow: hidden; color: #111; background: #fff; font-family: sans-serif; }
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h1 { padding: 20px; font-size: 12pt; margin: 0; }
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a { color: #111; text-decoration: none; }
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a:hover { color: #0074C1; text-decoration: underline; }
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canvas { position: absolute; top: 60px; left: 20px; width: calc(100% - 40px); height: calc(100% - 80px); background: #eee; }
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canvas.gradient { left: 0; top: 0px; height: 2px; width: 100%; }
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</style>
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</head>
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<body>
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<h1>
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<a href="https://en.wikipedia.org/wiki/Mandelbrot_set">Mandelbrot set</a> in
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<a href="http://assemblyscript.org">AssemblyScript</a>
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( <a href="https://github.com/AssemblyScript/assemblyscript/blob/master/examples/mandelbrot/assembly/index.ts">source</a> )
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</h1>
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<canvas></canvas>
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<script>"use strict";
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// Set this to false if you prefer a plain image instead.
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var animate = true;
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// Set up the canvas with a 2D rendering context
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var cnv = document.getElementsByTagName("canvas")[0];
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var ctx = cnv.getContext("2d");
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var bcr = cnv.getBoundingClientRect();
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// Compute the size of the viewport
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var width = bcr.width | 0;
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var height = bcr.height | 0;
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var size = width * height;
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var byteSize = size << 1; // discrete color indices in range [0, 2047] (here: 2b per pixel)
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cnv.width = width;
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cnv.height = height;
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// Compute the size of and instantiate the module's memory
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var memory = new WebAssembly.Memory({ initial: ((byteSize + 0xffff) & ~0xffff) >>> 16 });
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var mem = new Uint16Array(memory.buffer);
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var imageData = ctx.createImageData(width, height);
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var argb = new Uint32Array(imageData.data.buffer);
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// Fetch and instantiate the module
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fetch("build/optimized.wasm")
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.then(response => response.arrayBuffer())
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.then(buffer => WebAssembly.instantiate(buffer, {
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env: { memory: memory },
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JSMath: Math
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}))
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.then(module => {
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var exports = module.instance.exports;
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var computeLine = exports.computeLine;
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var updateLine = function(y) {
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var yx = y * width;
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for (let x = 0; x < width; ++x) argb[yx + x] = colors[mem[yx + x]];
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};
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// Compute an initial balanced version of the set.
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const limit = 40;
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for (let y = 0; y < height; ++y) {
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computeLine(y, width, height, limit);
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updateLine(y);
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}
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// Keep rendering the image buffer.
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(function render() {
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if (animate) requestAnimationFrame(render);
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ctx.putImageData(imageData, 0, 0);
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})();
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if (animate) {
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// Let it glow a bit by occasionally shifting the limit...
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var currentLimit = limit;
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var shiftRange = 10;
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(function updateShift() {
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currentLimit = limit + (2 * Math.random() * shiftRange - shiftRange) | 0
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setTimeout(updateShift, 1000 + (1500 * Math.random()) | 0);
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})();
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// ...while continously recomputing a subset of it.
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var flickerRange = 3;
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(function updateFlicker() {
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for (let i = 0, k = (0.05 * height) | 0; i < k; ++i) {
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let ry = (Math.random() * height) | 0;
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let rl = (2 * Math.random() * flickerRange - flickerRange) | 0;
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computeLine(ry, width, height, currentLimit + rl);
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updateLine(ry);
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}
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setTimeout(updateFlicker, 1000 / 30);
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})();
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}
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}).catch(err => {
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alert("Failed to load WASM: " + err.message + " (ad blocker, maybe?)");
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console.log(err.stack);
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});
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// Compute a nice set of colors using a gradient
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var colors = (() => {
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var cnv = document.createElement("canvas");
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cnv.width = 2048;
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cnv.height = 1;
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var ctx = cnv.getContext("2d");
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var grd = ctx.createLinearGradient(0, 0, 2048, 0);
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grd.addColorStop(0.00, "#000764");
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grd.addColorStop(0.16, "#2068CB");
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grd.addColorStop(0.42, "#EDFFFF");
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grd.addColorStop(0.6425, "#FFAA00");
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grd.addColorStop(0.8575, "#000200");
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ctx.fillStyle = grd;
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ctx.fillRect(0, 0, 2048, 1);
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cnv.className = "gradient";
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setTimeout(() => document.body.appendChild(cnv));
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return new Uint32Array(ctx.getImageData(0, 0, 2048, 1).data.buffer);
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})();
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</script>
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</body>
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</html>
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