mirror of
https://github.com/denoland/rusty_v8.git
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69 lines
1.3 KiB
JavaScript
69 lines
1.3 KiB
JavaScript
// Copyright 2019-2021 the Deno authors. All rights reserved. MIT license.
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function DrawFrame(frameLen) {
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const u8 = new Uint8Array(frameLen);
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const width = 800;
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const height = 800;
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let x = y = 0;
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for (let i = 0; i < u8.byteLength; i += 4) {
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if (x == width) {
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y++;
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x = 0;
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}
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x += 1;
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let r = Math.floor(0.3 * x);
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let b = Math.floor(0.3 * y);
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u8.set([r, 0x00, b, 0xff], i);
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}
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let scale_x = 3.0 / width;
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let scale_y = 3.0 / height;
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for (let x = 0; x < width; x++) {
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for (let y = 0; y < height; y++) {
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let cx = y * scale_x - 1.5;
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let cy = x * scale_y - 1.5;
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let c = new Complex(-0.4, 0.6);
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let z = new Complex(cx, cy);
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let i = 0;
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while (i < 100 && z.abs() < 2) {
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z = z.mul(z).add(c);
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i++;
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}
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u8.set([0x00, i, 0x00, 0xff], (y * width + x) * 4);
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}
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}
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return u8.buffer;
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}
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class Complex {
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constructor(real, imag) {
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this.real = real;
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this.imag = imag;
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}
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mul(other) {
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return new Complex(
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this.real * other.real - this.imag * other.imag,
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this.real * other.imag + this.imag * other.real,
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);
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}
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add(other) {
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return new Complex(
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this.real + other.real,
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this.imag + other.imag,
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);
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}
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abs() {
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return Math.sqrt(this.real * this.real + this.imag * this.imag);
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}
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}
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