sangohan · June 28, 2016 13:32 · Jun 28, 2016
diff --git a/shader b/shader
@@ -0,0 +1,65 @@
+//frag shader
+precision mediump float;
+uniform vec4 I;
+
+vec3 Z(vec3 p,float a){
+    return vec3(cos(a)*p.y+sin(a)*p.x,cos(a)*p.x-sin(a)*p.y,p.z);
+}
+
+
+float F(vec3 P) {
+    float R=sin((I.x+P.z*0.01)*3.176)*.45+.5,S=3.4312-sin(I.x*0.1);
+    vec4 p=vec4(P,1),o=p,s=vec4(S,S,S,abs(S))/R;
+    for(int i=0;i<24;i++){
+        if(i==3||i==7||i==11||i==15||i==19||i==23) 
+            R=sin((I.x+P.z*0.01+float(i)*0.25*sin(I.x*.012211154)*3.8)*3.176)*0.45+0.5;
+        p.xyz=clamp(p.xyz,-1.,1.)*2.-p.xyz;
+        float r2=dot(p.xyz,p.xyz);
+        if(r2>1000.)
+            break;
+        p=p*clamp(max(R/r2,R),0.,1.)*s+o;
+    }
+    return((length(p.xyz)-abs(S-1.))/p.w-pow(abs(S),float(1-24)));
+}
+
+float D(vec3 p){
+    vec3 c=vec3(10.,10.,8.);
+    p=mod(p,c)-.5*c;
+    vec3 q=abs(Z(p,p.z*3.1415/10.*4.));
+    float d2=max(q.z-10.,max((q.x*0.866025+q.y*0.5),q.y)-.08);
+    p=Z(p,p.z*3.1415/10.*(length(p.xy)-3.)*sin(I.x*.01)*.8);
+    return max(F(p),-d2);
+}
+
+vec3 R(vec3 p,vec3 d){
+    float td=0.,rd=0.;
+    for(int i=0;i<80;i++){
+        if((rd=D(p))<pow(td,1.5)*.004)
+            break;
+        td+=rd;
+        p+=d*rd;
+    }
+    float md=D(p),e=.0025;
+    vec3 n=normalize(vec3(D(p+vec3(e,0,0))-D(p-vec3(e,0,0)),D(p+vec3(0,e,0))-D(p-vec3(0,e,0)),D(p+vec3(0,0,e))-D(p-vec3(0,0,e))));
+    e*=.5;
+    float occ=1.+(D(p+n*.02+vec3(-e,0,0))+D(p+n*.02+vec3(+e,0,0))+D(p+n*.02+vec3(0,-e,0))+D(p+n*.02+vec3(0,e,0))+D(p+n*.02+vec3(0,0,-e))+D(p+n*.02+vec3(0,0,e))-.03)*20.;
+    occ=clamp(occ,0.,1.);
+    float br=(pow(clamp(dot(n,-normalize(d+vec3(.3,-.9,.4)))*.6+.4, 0.,1.),2.7)*.8+.2)*occ/(td*.5+1.);
+    float fog=clamp(1./(td*td*1.8+.4),0.,1.);
+    return mix(vec3(br,br/(td*td*.2+1.),br/(td+1.)),vec3(0.,0.,0.),1.-fog);
+}
+
+void main(void){
+    vec2 f=gl_FragCoord.xy;
+    vec3 d=vec3((f-vec2(213.,120.))/120.,1.);
+    vec3 c=pow(R(vec3(5.,5.,I.x*10.),normalize(d*vec3(1.,1.,1.-(length(d.xy)*.9)))),vec3(.6,.6,.6));
+    gl_FragColor=vec4(pow(floor(c*vec3(8.,8.,4.)+fract(f.x/4.+f.y/2.)/2.)/(vec3(7.,7.,3.)),vec3(1.5,1.5,1.5)),1.);
+}
+
+
+
+//vertex shader
+attribute vec2 P;
+void main(void){
+    gl_Position=vec4(P,0.,1.);
+}