mandel-6502/sim.js

import {toFixed, toFloat, mul} from './fixed.js';

let max = 256;
let width = 256;
let height = 256;
let zoom = 1;

let black = 0xff000000;
let tricolor = [
    0xffff0000,
    0xff00ff00,
    0xff0000ff,
];

let palette = new Uint32Array(256);
palette[0] = black;
for (let i = 0; i < 255; i++) {
    palette[i + 1] = tricolor[i % 3];
}
function nap() {
    return new Promise((resolve) => setTimeout(() => resolve()));
}

async function setup(id, iterfunc) {
    let canvas = document.getElementById(id);
    let ctx = canvas.getContext('2d');
    let imageData = ctx.createImageData(width, height);
    let rgba = new Uint32Array(imageData.data.buffer);
    for (let y = 0; y < height; y++) {
        let cy = (y * 2 - height) / (height / 2);
        for (let x = 0; x < width; x++) {
            let cx = (x * 2 - width) / (width / 2);
            let i = iterfunc(cx, cy);
            let color = palette[i];
            rgba[y * width + x] = color;
            rgba[(256 - y) * width + x] = color;

            if (x % 16 == 15) {
                ctx.putImageData(imageData, 0, 0);
                await nap();
            }
        }
    }
}

setup('float', (cx, cy) => {
    let zx = 0;
    let zy = 0;
    let zx_2 = 0;
    let zy_2 = 0;
    let zx_zy = 0;
    for (let i = 1; i < max; i++) {
        zx = zx_2 - zy_2 + cx;
        zy = zx_zy + zx_zy + cy;
        zx_2 = zx * zx;
        zy_2 = zy * zy;
        zx_zy = zx * zy;
        if (zx_2 >= 4 || zy_2 >= 4 || zx_2 + zy_2 >= 4) {
            return i;
        }
    }
    return 0;
}).then(() => {
    console.log('done');
})