//-----------------SETTINGS-----------------

//#define TIMES_DETAILED (sin(time*32.0)+1.0)
#define TIMES_DETAILED (1.0+.1*sin(time*PI*1.0))
#define SPIRAL_BLUR_SCALAR (1.0+.1*sin(time*PI*1.0))

//-----------------USEFUL-----------------

#define MOUSE_X (iMouse.x/iResolution.x)
#define MOUSE_Y (iMouse.y/iResolution.y)

#define PI 3.14159265359
#define E 2.7182818284
#define GR 1.61803398875
#define EPS .001

#define time ((saw(float(__LINE__))+1.0)*(iTime+12345.12345)/PI/2.0)
#define sphereN(uv) (normalize(vec3((uv).xy, sqrt(clamp(1.0-length((uv)), 0.0, 1.0)))))
#define rotatePoint(p,n,theta) (p*cos(theta)+cross(n,p)*sin(theta)+n*dot(p,n) *(1.0-cos(theta)))
float seedling;

float saw(float x)
{
    x/= PI;
    float f = mod(floor(abs(x)), 2.0);
    float m = mod(abs(x), 1.0);
    return f*(1.0-m)+(1.0-f)*m;
}
vec2 saw(vec2 x)
{
    return vec2(saw(x.x), saw(x.y));
}

vec3 saw(vec3 x)
{
    return vec3(saw(x.x), saw(x.y), saw(x.z));
}
//-----------------SIMPLEX-----------------

vec3 random3(vec3 c) {
    float j = 4096.0*sin(dot(c,vec3(17.0, 59.4, 15.0)));
    vec3 r;
    r.z = fract(512.0*j);
    j *= .125;
    r.x = fract(512.0*j);
    j *= .125;
    r.y = fract(512.0*j);
    return r-0.5;
}

float simplex3d(vec3 p) {
    const float F3 =  0.3333333;
    const float G3 =  0.1666667;

    vec3 s = floor(p + dot(p, vec3(F3)));
    vec3 x = p - s + dot(s, vec3(G3));

    vec3 e = step(vec3(0.0), x - x.yzx);
    vec3 i1 = e*(1.0 - e.zxy);
    vec3 i2 = 1.0 - e.zxy*(1.0 - e);

    vec3 x1 = x - i1 + G3;
    vec3 x2 = x - i2 + 2.0*G3;
    vec3 x3 = x - 1.0 + 3.0*G3;

    vec4 w, d;

    w.x = dot(x, x);
    w.y = dot(x1, x1);
    w.z = dot(x2, x2);
    w.w = dot(x3, x3);

    w = max(0.6 - w, 0.0);

    d.x = dot(random3(s), x);
    d.y = dot(random3(s + i1), x1);
    d.z = dot(random3(s + i2), x2);
    d.w = dot(random3(s + 1.0), x3);

    w *= w;
    w *= w;
    d *= w;

    return dot(d, vec4(52.0));
}

//-----------------IMAGINARY-----------------

vec2 cmul(vec2 v1, vec2 v2) {
	return vec2(v1.x * v2.x - v1.y * v2.y, v1.y * v2.x + v1.x * v2.y);
}

vec2 cdiv(vec2 v1, vec2 v2) {
	return vec2(v1.x * v2.x + v1.y * v2.y, v1.y * v2.x - v1.x * v2.y) / dot(v2, v2);
}

//-----------------RENDERING-----------------
float zoom;

vec2 mobius(vec2 uv)
{
	vec2 a = sin(seedling+vec2(time, time*GR/E));
	vec2 b = sin(seedling+vec2(time, time*GR/E));
	vec2 c = sin(seedling+vec2(time, time*GR/E));
	vec2 d = sin(seedling+vec2(time, time*GR/E));
	return cdiv(cmul(uv, a) + b, cmul(uv, c) + d);
}

vec2 map(vec2 uv)
{
    return saw(mobius(zoom*(uv*2.0-1.0))*2.0*PI);
}

vec2 iterate(vec2 uv, vec2 dxdy, out float magnification)
{
    vec2 a = uv+vec2(0.0, 		0.0);
    vec2 b = uv+vec2(dxdy.x, 	0.0);
    vec2 c = uv+vec2(dxdy.x, 	dxdy.y);
    vec2 d = uv+vec2(0.0, 		dxdy.y);//((fragCoord.xy + vec2(0.0, 1.0)) / iResolution.xy * 2.0 - 1.0) * aspect;

    vec2 ma = map(a);
    vec2 mb = map(b);
    vec2 mc = map(c);
    vec2 md = map(d);

    float da = length(mb-ma);
    float db = length(mc-mb);
    float dc = length(md-mc);
    float dd = length(ma-md);

	float stretch = max(max(max(da/dxdy.x,db/dxdy.y),dc/dxdy.x),dd/dxdy.y);

    magnification = stretch;

    return map(uv);
}

void mainImage( out vec4 fragColor, in vec2 fragCoord )
{
    float aspect = iResolution.y/iResolution.x;

    vec2 uv = fragCoord.xy/iResolution.xy;

    zoom = (2.5+2.0*sin(time));


   	const int max_i = 5;
    float stretch = 1.0;
    float ifs = 1.0;
    float depth = 0.0;
    float magnification;

    for(int i = 0; i < max_i; i++)
    {
        seedling += fract(float(i)*123456.123456);
        vec2 next = iterate(uv, .5/iResolution.xy, magnification);
        float weight = pow(ifs, 1.0/float(i+1));
        ifs *= smoothstep(0.0, 1.0/TIMES_DETAILED, sqrt(1.0/(1.0+magnification)));
        uv = next*weight+uv*(1.0-weight);
        depth += ifs;
    }


    fragColor = vec4(uv, 0.0, 1.0);

    //depth /= float(max_i);
    float shift = time;

    float stripes = depth*PI*15.0;
    float black = smoothstep(0.0, .75, saw(stripes));
    float white = smoothstep(0.75, 1.0, saw(stripes));


    vec3 final = (
        				vec3(cos(depth*PI*2.0+shift),
                	  		cos(4.0*PI/3.0+depth*PI*2.0+shift),
                	  		cos(2.0*PI/3.0+depth*PI*2.0+shift)
                 		)*.5+.5
        		 )*black
        		 +white;

    fragColor = vec4(vec3(ifs), 1.0);

    fragColor = vec4(saw((depth)));
    fragColor = vec4(final, 1.0);
}