mandelbrot.js
No OneTemporary
Actions

Size

1 KB

Referenced Files

None

Subscribers

None

mandelbrot.js
View Options

	function mandelbrot(center_x, center_y, scale, w, h, max_it) {
	const colors = [14, 15, 7, 8, 0, 4, 12, 5, 13, 1, 9, 3, 11, 10, 2, 6];
	const numColors = colors.length;
	const fx = (scale * 0.5) / Math.min(w, h);
	const fy = fx * 2;
	const halfW = w * 0.5;
	const halfH = h * 0.5;

	const cxArr = new Float64Array(w);
	for (let x1 = 0; x1 < w; x1++) {
	cxArr[x1] = (x1 - halfW) * fx + center_x;
	}

	function iterate(cx, cy) {
	const q = (cx - 0.25) * (cx - 0.25) + cy * cy;
	if (q * (q + (cx - 0.25)) <= 0.25 * cy * cy) return max_it;

	const cx1 = cx + 1;
	if (cx1 * cx1 + cy * cy <= 0.0625) return max_it;

	let x = 0,
	y = 0,
	x2 = 0,
	y2 = 0;
	let i = 0;

	while (i < max_it && x2 + y2 < 4) {
	y = 2 * x * y + cy;
	x = x2 - y2 + cx;
	x2 = x * x;
	y2 = y * y;
	i++;
	}
	return i;
	}

	const output = [];

	for (let y1 = 0; y1 < h; y1++) {
	const cy0 = (y1 - halfH) * fy + center_y;
	const cy1 = (y1 + 0.5 - halfH) * fy + center_y;
	const chars = new Array(w + 1);

	for (let x1 = 0; x1 < w; x1++) {
	const cx = cxArr[x1];

	const i0 = iterate(cx, cy0);
	const i1 = iterate(cx, cy1);

	const c0 = i0 >= max_it ? 0 : colors[i0 % numColors];
	const c1 = i1 >= max_it ? 0 : colors[i1 % numColors];

	const fg = c0 >= 8 ? 82 + c0 : 30 + c0;
	const bg = c1 >= 8 ? 92 + c1 : 40 + c1;

	chars[x1] = '\x1b[' + fg + ';' + bg + 'm\u2580';
	}
	chars[w] = '\x1b[0m';
	output.push(chars.join(''));
	}

	console.log(output.join('\n'));
	}

	mandelbrot(-0.75, 0.0, 2.0, 80, 25, 50);