From ac28a775b87768760db2cdae115ae08bd9fea9a5 Mon Sep 17 00:00:00 2001
From: LordMZTE <lord@mzte.de>
Date: Sat, 28 Oct 2023 12:17:47 +0200
Subject: [PATCH] wlbg: swap shader

---
 scripts/wlbg/src/bg_frag.glsl | 90 ++++++++++++++++++++++-------------
 1 file changed, 58 insertions(+), 32 deletions(-)

diff --git a/scripts/wlbg/src/bg_frag.glsl b/scripts/wlbg/src/bg_frag.glsl
index 3b592db..e5a89ba 100644
--- a/scripts/wlbg/src/bg_frag.glsl
+++ b/scripts/wlbg/src/bg_frag.glsl
@@ -1,43 +1,69 @@
 #version 300 es
 
-precision mediump float;
+precision highp float;
 
 uniform float time;
 uniform vec2 offset;
 
 in vec2 fragCoord;
 
-/* "Quasar" by @kishimisu (2023) - https://www.shadertoy.com/view/msGyzc
-   449 => 443 chars thanks to @Xor
-   
-   This work is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License.
-*/
+// shader: https://www.shadertoy.com/view/tsXBzS
 
-#define r(a) mat2(cos(a + asin(vec4(0,1,-1,0)))),
-#define X(p) p *= r(round(atan(p.x, p.y) * 4.) / 4.)
-
-void main() {
-    vec2 F = fragCoord - offset + .5;
-    vec3 p, R = vec3(1.);
-    float i, t, d, a, b, T = time * .5 + .5;
-
-    vec4 O = vec4(0.);
-             
-    for(O  *= i; i++ < 44.;
-        O  += .04 * (1. + cos(a + t*.3 - T*.8 + vec4(0,1,2,0))) 
-                  / (1. + abs(d)*30.) )
-        
-        p = t * normalize(vec3(F+F-R.xy, R.y)),
-        p.z  -= 4.,
-        p.xz *= r(T/4.)
-        p.yz *= r(sin(T/4.)*.5)
-        X(p.zx)   a = p.x,
-        X(p.yx)
-        p.x = mod(b = p.x - T, .5) - .25,
-        
-        t  += d = length(p) - (2. - a - smoothstep(b+2., b, T)*30.)
-                            * (cos(T/6.+1.)+1.) / 2e2;
-
-    gl_FragColor = O;
+vec3 palette(float d){
+	return mix(vec3(0.2,0.0,0.0),vec3(.5,0.,0.),d);
 }
 
+vec2 rotate(vec2 p,float a){
+	float c = cos(a);
+    float s = sin(a);
+    return p*mat2(c,s,-s,c);
+}
+
+float map(vec3 p){
+    for( int i = 0; i<8; ++i){
+        float t = time*0.2;
+        p.xz =rotate(p.xz,t);
+        p.xy =rotate(p.xy,t*1.89);
+        p.xz = abs(p.xz);
+        p.xz-=.5;
+	}
+	return dot(sign(p),p)/5.;
+}
+
+vec4 rm (vec3 ro, vec3 rd){
+    float t = 0.;
+    vec3 col = vec3(0.);
+    float d;
+    for(float i =0.; i<64.; i++){
+		vec3 p = ro + rd*t;
+        d = map(p)*.5;
+        if(d<0.02){
+            break;
+        }
+        if(d>100.){
+        	break;
+        }
+        //col+=vec3(0.6,0.8,0.8)/(400.*(d));
+        col+=palette(length(p)*.1)/(400.*(d));
+        t+=d;
+    }
+    return vec4(col,1./(d*100.));
+}
+void main()
+{
+    vec2 uv = fragCoord / 5.0;
+	vec3 ro = vec3(0.,0.,-50.);
+    ro.xz = rotate(ro.xz,time);
+    vec3 cf = normalize(-ro);
+    vec3 cs = normalize(cross(cf,vec3(0.,1.,0.)));
+    vec3 cu = normalize(cross(cf,cs));
+    
+    vec3 uuv = ro+cf*3. + uv.x*cs + uv.y*cu;
+    
+    vec3 rd = normalize(uuv-ro);
+    
+    vec4 col = rm(ro,rd);
+    
+    
+    gl_FragColor = col;
+}