 * y * y) return true;

                // 周期2气泡条件
                const dx = x + 1;
                const bulbQ = dx * dx + y * y;
                if (bulbQ <= 0.0625) return true; // 0.25^2

                return false;
            }

            // 曼德博集迭代函数
            function mandelbrotIterate(c_re, c_im) {
                let z_re = c_re, z_im = c_im;
                for (let n = 0; n < MAX_ITER; n++) {
                    const z_re2 = z_re * z_re;
                    con