commit 38b9d10e2872c56848ba6c8fdcc7d7ae1256410c
Author: polyfloyd <floyd@polyfloyd.net>
Date:   Sat May 19 14:24:13 2018 +0200

    Add acid.glsl

diff --git a/acid.glsl b/acid.glsl
new file mode 100644
index 0000000..23b791f
--- /dev/null
+++ b/acid.glsl
@@ -0,0 +1,24 @@
+#ifdef GL_ES
+precision mediump float;
+#extension GL_OES_standard_derivatives : enable
+#endif
+
+uniform float time;
+uniform vec2 mouse;
+uniform vec2 resolution;
+
+float floorSmooth(float x,float c){float a=fract(x);return((pow(a,c)-pow(1.-a,c))/2.)+floor(x);}
+vec3 hue(float hue){vec3 rgb=fract(hue+vec3(0.,2./3.,1./3.));rgb=abs(rgb*2.-1.);return clamp(rgb*3.-1.,0.,1.);}
+vec3 d(vec2 uv){uv-=.5;return (vec3((max(abs(uv.x),abs(uv.y))-.3)*6.)*hue(time+length(uv)+length(uv))*2.);}
+#define cl3(x) clamp(x,0.,1.)
+void main() {
+	vec2 uv=(gl_FragCoord.xy*2.-resolution.xy)/min(resolution.x,resolution.y)/12.0;
+	float th=floorSmooth(time*.1,27.);
+	uv*=mat2(cos(th),-cos(th),cos(th),cos(th));
+	float c=5.;float s=3.;float t=1.;
+	float t2=(time/2.)-(length(uv)*2.);
+	vec2 a=fract(uv*pow(2.,floorSmooth((fract(t2)*t)+s,c)));
+	vec2 b=fract(uv*pow(2.,floorSmooth(((fract(t2)-1.)*t)+s,c)));
+	vec3 col=mix(cl3(d(a)),cl3(d(b)),fract(t2));
+	gl_FragColor = vec4(col,1);
+}