Corner Void

Ported from ShaderToy Pink Void https://www.shadertoy.com/view/wt2Gzc

Shader code
shader_type canvas_item;

// FBM implementation from
// https://github.com/MaxBittker/glsl-fractal-brownian-noise

vec3 mod289(vec3 x) {
  return x - floor(x * (1.0 / 289.0)) * 289.0;
}

vec4 mod2891(vec4 x) {
  return x - floor(x * (1.0 / 289.0)) * 289.0;
}

vec4 permute(vec4 x) {
     return mod2891(((x*34.0)+1.0)*x);
}

vec4 taylorInvSqrt(vec4 r)
{
  return 1.79284291400159 - 0.85373472095314 * r;
}

float snoise(vec3 v)
  {
  const vec2  C = vec2(1.0/6.0, 1.0/3.0) ;
  const vec4  D = vec4(0.0, 0.5, 1.0, 2.0);

// First corner
  vec3 i  = floor(v + dot(v, C.yyy) );
  vec3 x0 =   v - i + dot(i, C.xxx) ;

// Other corners
  vec3 g = step(x0.yzx, x0.xyz);
  vec3 l = 1.0 - g;
  vec3 i1 = min( g.xyz, l.zxy );
  vec3 i2 = max( g.xyz, l.zxy );

  //   x0 = x0 - 0.0 + 0.0 * C.xxx;
  //   x1 = x0 - i1  + 1.0 * C.xxx;
  //   x2 = x0 - i2  + 2.0 * C.xxx;
  //   x3 = x0 - 1.0 + 3.0 * C.xxx;
  vec3 x1 = x0 - i1 + C.xxx;
  vec3 x2 = x0 - i2 + C.yyy; // 2.0*C.x = 1/3 = C.y
  vec3 x3 = x0 - D.yyy;      // -1.0+3.0*C.x = -0.5 = -D.y

// Permutations
  i = mod289(i);
  vec4 p = permute( permute( permute(
             i.z + vec4(0.0, i1.z, i2.z, 1.0 ))
           + i.y + vec4(0.0, i1.y, i2.y, 1.0 ))
           + i.x + vec4(0.0, i1.x, i2.x, 1.0 ));

// Gradients: 7x7 points over a square, mapped onto an octahedron.
// The ring size 17*17 = 289 is close to a multiple of 49 (49*6 = 294)
  float n_ = 0.142857142857; // 1.0/7.0
  vec3  ns = n_ * D.wyz - D.xzx;

  vec4 j = p - 49.0 * floor(p * ns.z * ns.z);  //  mod(p,7*7)

  vec4 x_ = floor(j * ns.z);
  vec4 y_ = floor(j - 7.0 * x_ );    // mod(j,N)

  vec4 x = x_ *ns.x + ns.yyyy;
  vec4 y = y_ *ns.x + ns.yyyy;
  vec4 h = 1.0 - abs(x) - abs(y);

  vec4 b0 = vec4( x.xy, y.xy );
  vec4 b1 = vec4( x.zw, y.zw );

  //vec4 s0 = vec4(lessThan(b0,0.0))*2.0 - 1.0;
  //vec4 s1 = vec4(lessThan(b1,0.0))*2.0 - 1.0;
  vec4 s0 = floor(b0)*2.0 + 1.0;
  vec4 s1 = floor(b1)*2.0 + 1.0;
  vec4 sh = -step(h, vec4(0.0));

  vec4 a0 = b0.xzyw + s0.xzyw*sh.xxyy ;
  vec4 a1 = b1.xzyw + s1.xzyw*sh.zzww ;

  vec3 p0 = vec3(a0.xy,h.x);
  vec3 p1 = vec3(a0.zw,h.y);
  vec3 p2 = vec3(a1.xy,h.z);
  vec3 p3 = vec3(a1.zw,h.w);

//Normalise gradients
  vec4 norm = taylorInvSqrt(vec4(dot(p0,p0), dot(p1,p1), dot(p2, p2), dot(p3,p3)));
  p0 *= norm.x;
  p1 *= norm.y;
  p2 *= norm.z;
  p3 *= norm.w;

// Mix final noise value
  vec4 m = max(0.6 - vec4(dot(x0,x0), dot(x1,x1), dot(x2,x2), dot(x3,x3)), 0.0);
  m = m * m;
  return 42.0 * dot( m*m, vec4( dot(p0,x0), dot(p1,x1),
                                dot(p2,x2), dot(p3,x3) ) );
  }



float fbm3d(vec3 x, const in int it) {
    float v = 0.0;
    float a = 0.5;
    vec3 shift = vec3(100);

    
    for (int i = 0; i < 32; ++i) {
        if(i<it) {
            v += a * snoise(x);
            x = x * 2.0 + shift;
            a *= 0.5;
        }
    }
    return v;
}

void fragment()
{
    float t = TIME * .2;
    
    vec2 uv = (FRAGCOORD.xy * 0.3) / 1080.0;
    vec2 st = vec2(
        length( uv ) * 1.5,
        atan( uv.y, uv.x )
    );
    
    st.y += st.x * 1.1;
        
    float x = fbm3d(
        vec3(
            sin( st.y ),
            cos( st.y ),
            pow( st.x, .3 ) + t * .1
        ),
        3
    );
	float y = fbm3d(
        vec3(
            cos( 1. - st.y ),
            sin( 1. - st.y ),
            pow( st.x, .5 ) + t * .1
        ),
        4
    );
    
    float r = fbm3d(
        vec3(
            x,
            y,
            st.x + t * .3
        ),
        5
    );
    r = fbm3d(
        vec3(
            r - x,
            r - y,
            r + t * .3
        ),
        6
    );
    
    float c = ( r + st.x * 5. ) / 6.;
    
    COLOR = vec4(
        smoothstep( .3, .5, c ),
        smoothstep( .4, .55, c ),
        smoothstep( .2, .55, c ),
        1
    );
}
Tags
#shadertoy, corner, pink, void
The shader code and all code snippets in this post are under CC0 license and can be used freely without the author's permission. Images and videos, and assets depicted in those, do not fall under this license. For more info, see our License terms.

Related shaders

set corner radius for texture

4 corner gradient

guest

0 Comments
Inline Feedbacks
View all comments