wallpaper.glsl

#define PI 3.14159265358979323846

float random (in vec2 st) {
  return fract(sin(dot(st.xy, vec2(12.9898,78.233))) * 43758.5453123);
}

vec2 random2(vec2 st){
  st = vec2( dot(st,vec2(127.1,311.7)), dot(st,vec2(269.5,183.3)));
  return -1.0 + 2.0*fract(sin(st)*43758.5453123);
}

// Value noise by Inigo Quilez - iq/2013
// https://www.shadertoy.com/view/lsf3WH
float noise(vec2 st) {
  vec2 i = floor(st);
  vec2 f = fract(st);
  vec2 u = f*f*(3.0-2.0*f);
  return mix( mix( random( i + vec2(0.0,0.0) ),
		   random( i + vec2(1.0,0.0) ), u.x),
	      mix( random( i + vec2(0.0,1.0) ),
		   random( i + vec2(1.0,1.0) ), u.x), u.y);
}

float gnoise(vec2 st) {
  vec2 i = floor(st);
  vec2 f = fract(st);

  vec2 u = f*f*(3.0-2.0*f);

  return mix( mix( dot( random2(i + vec2(0.0,0.0) ), f - vec2(0.0,0.0) ),
		   dot( random2(i + vec2(1.0,0.0) ), f - vec2(1.0,0.0) ), u.x),
	      mix( dot( random2(i + vec2(0.0,1.0) ), f - vec2(0.0,1.0) ),
		   dot( random2(i + vec2(1.0,1.0) ), f - vec2(1.0,1.0) ), u.x), u.y);
}

mat2 rotate2d(float angle){
  return mat2(cos(angle),-sin(angle),
	      sin(angle),cos(angle));
}

mat2 scale(vec2 _scale){
  return mat2(_scale.x, 0.0, 0.0, _scale.y);
}

float lines(in vec2 pos, float b){
  float scale = 10.0;
  pos *= scale;
  return smoothstep(0.0,
                    .5+b*.5,
                    abs((sin(pos.x*3.1415)+b*2.0))*.5);
}

float polygon(in vec2 st, in int edges, in float size) {
  vec2 _st = st * 2. - 1.;
  float a = atan(_st.x,_st.y)+PI;
  float r = (PI*2.)/float(edges);
  float d = cos(floor(0.5+a/r)*r-a)*length(_st);
  return 1.0-smoothstep(size,size+0.01,d);
}

float hline(in vec2 st, in float width) {
  width = .5 - width / 2.;
  return step(step(width, st.x) - width, st.x);
}

float vline(in vec2 st, in float width) {
  width = (.5 - width / 2.);
  return smoothstep(
		    gnoise(st * 3000.),
		    smoothstep(
			       width,
			       width + 0.001,
			       st.y
			       ) - width,
		    st.y);
}

void mainImage(out vec4 fragColor, in vec2 fragCoord) {
  vec2 st = fragCoord.xy/iResolution.xy;
  st.y *= iResolution.y/iResolution.x;
  vec3 color = vec3(0.);
  vec2 pos = st.xy;
  pos = rotate2d(sin(atan(gnoise(pos * 12.)) / 12.)) * pos;
  float pattern = 1. - vline(fract(pos * 15.), 0.3);
  color = mix(color, vec3(1.), pattern);
  fragColor = vec4(color, 1.0);
}