const mat2 m = mat2(0.80, 0.60, -0.60, 0.80);

float noise(in vec2 p)
{
	return sin(p.x) * sin(p.y);
}

float fbm4(vec2 p)
{
	float f = 0.0;
	f += 0.5000 * noise(p); p = m * p * 2.02;
	f += 0.2500 * noise(p); p = m * p * 2.02;
	f += 0.1250 * noise(p); p = m * p * 2.02;
	f += 0.0625 * noise(p);
	return f / 0.9375;
}

float fbm6(vec2 p)
{
	float f = 0.0;
	f += 0.500000 * (0.5 + 0.5 * noise(p)); p = m * p * 2.02;
	f += 0.500000 * (0.5 + 0.5 * noise(p)); p = m * p * 2.02;
	f += 0.500000 * (0.5 + 0.5 * noise(p)); p = m * p * 2.02;
	f += 0.250000 * (0.5 + 0.5 * noise(p)); p = m * p * 2.02;
	return f / 0.96875;
}

vec2 fbm4_2(vec2 p)
{
	return vec2(fbm4(p), fbm4(p + vec2(7.8)));
}

vec2 fbm6_2(vec2 p)
{
	return vec2(fbm6(p + vec2(16.8)), fbm6(p + vec2(11.5)));
}

float func(vec2 q, float t)
{
	q += 0.03 * sin(vec2(0.27, 0.23) * t + length(q) * vec2(4.1, 4.3));
	vec2 o = fbm4_2(0.9 * q);
	o += 0.04 * sin(vec2(0.12, 0.14) * t + length(o));
	vec2 n = fbm6_2(3.0 * o);
	float f = 0.5 + 0.5 * fbm4(1.8 * q + 6.0 * n);
	return mix(f, f * f * f * 3.5, f * abs(n.x));
}

void mainImage(out vec4 fragColor, in vec2 fragCoord)
{
	vec2 uv = (2.0 * fragCoord.xy - iResolution.xy) / min(iResolution.x, iResolution.y);

	float f = func(uv, iTime * 4.0);
	vec3 col = f * (0.5 + 0.5 * cos(iTime + uv.xyx + vec3(0.0, 2.0, 4.0)));
	fragColor = vec4(col, 1.0);
}