Godot Portal Shader

shader_type canvas_item;

float noise(vec2 x, sampler2D tex) {
	return texture(tex, x * 0.01).x;
}

float fbm(vec2 p, float time, sampler2D tex)
{
    vec4 tt=fract(vec4(time*0.15)+vec4(0.0,0.25,0.5,0.75));
    vec2 p1=p-normalize(p)*tt.x;
    vec2 p2=vec2(1.0)+p-normalize(p)*tt.y;
    vec2 p3=vec2(2.0)+p-normalize(p)*tt.z;
    vec2 p4=vec2(3.0)+p-normalize(p)*tt.w;
    vec4 tr=vec4(1.0)-abs(tt-vec4(0.5))*2.0;//*vec4(0.0,1.0,0.0,1.0);
	float z=2.0;
	vec4 rz = vec4(0.0);
	//for (float i= 1.0;i < 4.0;i++)
	//{
	rz+= abs((vec4(noise(p1, tex),noise(p2, tex),noise(p3, tex),noise(p4, tex))-vec4(0.5))*2.0)/z;
	z = z*2.0;
	p1 = p1*2.0;
    p2 = p2*2.0;
    p3 = p3*2.0;
    p4 = p4*2.0;


	//}
	return dot(rz,tr)*0.25;
}
float dualfbm(vec2 p, float time, sampler2D tex)
{
    //get two rotated fbm calls and displace the domain
	vec2 p2 = p*0.7;
	vec2 basis = vec2(fbm(p2-vec2(time*0.15*1.6, time*0.15*1.6), time, tex),fbm(p2+vec2(time*0.15*1.7, time*0.15*1.7), time, tex));
	basis = (basis-vec2(0.5, 0.5))*0.2;
	p += basis;

	//coloring
	return fbm(p, time, tex); //*makem2(time*2.0));
}

float circ(vec2 p)
{
	float r = length(p);
	r = log(sqrt(r));
	return abs(mod(r*2.0,6.2831)-4.54)*3.0+0.5;

}

void fragment() {
	//setup system
	vec2 p = UV;
	p -= vec2(1024.0, 600.0) * TEXTURE_PIXEL_SIZE * 0.5;
	p*=2.0;

	float rz = dualfbm(p, TIME, TEXTURE);

	//rings
	//p /= 7.0; //exp(mod(time*10.,3.14159));
	//rz *= pow(abs((0.0-circ(p))),.99);

	rz *= abs((-circ(vec2(p.x / 4.2, p.y / 7.0))));
	rz *= abs((-circ(vec2(p.x / 4.2, p.y / 7.0))));
	rz *= abs((-circ(vec2(p.x / 4.2, p.y / 7.0))));

	//final color
	vec3 col = vec3(.1,0.1,0.4)/rz;
	col=pow(abs(col),vec3(0.99));
	COLOR = vec4(col,1.0);
}