/*{
	"DESCRIPTION": "Kaleidoscopic domain-warped plasma with pulsing rings and film grain, animated continuously",
	"CATEGORIES": ["generative"],
	"INPUTS": []
}*/

precision highp float;

#define TAU 6.28318530718

float hash21(vec2 p) {
	p = fract(p * vec2(234.34, 435.345));
	p += dot(p, p + 34.23);
	return fract(p.x * p.y);
}

float noise2(vec2 p) {
	vec2 i = floor(p);
	vec2 f = fract(p);
	f = f * f * (3.0 - 2.0 * f);
	float a = hash21(i);
	float b = hash21(i + vec2(1.0, 0.0));
	float c = hash21(i + vec2(0.0, 1.0));
	float d = hash21(i + vec2(1.0, 1.0));
	return mix(mix(a, b, f.x), mix(c, d, f.x), f.y);
}

float fbm(vec2 p) {
	float v = 0.0;
	float amp = 0.5;
	for (int i = 0; i < 5; i++) {
		v += amp * noise2(p);
		p = p * 2.03 + vec2(1.7, 9.2);
		amp *= 0.5;
	}
	return v;
}

vec3 palette(float t) {
	return 0.5 + 0.5 * cos(TAU * (t + vec3(0.0, 0.33, 0.67)));
}

void main() {
	vec2 uv = isf_FragNormCoord;
	vec2 p = (uv - 0.5) * vec2(RENDERSIZE.x / RENDERSIZE.y, 1.0);

	float t = TIME * 0.15;

	// kaleidoscope fold
	float k = 6.0;
	float ang = atan(p.y, p.x);
	float rad = length(p);
	ang = mod(ang + t * 0.2, TAU / k);
	ang = abs(ang - (TAU / k) * 0.5);
	p = vec2(cos(ang), sin(ang)) * rad;
	p *= 2.0;

	// double domain warp
	vec2 q = vec2(fbm(p * 1.5 + vec2(0.0, t)),
	              fbm(p * 1.5 + vec2(5.2, -t)));
	vec2 r = vec2(fbm(p * 1.5 + 4.0 * q + vec2(1.7, 9.2) + t * 0.6),
	              fbm(p * 1.5 + 4.0 * q + vec2(8.3, 2.8) - t * 0.4));
	float f = fbm(p * 1.5 + 4.0 * r);

	vec3 col = palette(f + 0.5 * q.x + 0.25 * r.y + 0.1 * t);
	col = mix(col, vec3(0.05, 0.02, 0.1), smoothstep(0.9, 1.4, rad * 2.0));

	// pulsing rings
	col += 0.15 * sin(20.0 * rad - TIME * 2.0) * vec3(0.2, 0.4, 0.9);

	// grain
	float g = hash21(uv * RENDERSIZE + fract(TIME) * 100.0);
	col += (g - 0.5) * 0.05;

	// vignette
	float d = dot(uv - 0.5, uv - 0.5);
	col *= 1.0 - 0.8 * d;

	gl_FragColor = vec4(col, 1.0);
}