add LICENSE, shaders, Cargo.lock, and AUR package

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

shaders/rainbow_ring.frag

@@ -0,0 +1,50 @@
+#ifdef GL_ES
+precision mediump float;
+#endif
+
+#define PI 3.14159265359
+#define TWO_PI 6.28318530718
+
+uniform float time;
+uniform vec2 mouse;
+uniform vec2 resolution;
+
+vec3 hsb2rgb( in vec3 c ){
+    vec3 rgb = clamp(abs(mod(c.x*6.0+vec3(0.0,4.0,2.0),
+                             6.0)-3.0)-1.0,
+                     0.0,
+                     1.0 );
+    rgb = rgb*rgb*(3.0-2.0*rgb);
+    return c.z * mix(vec3(1.0), rgb, c.y);
+}
+
+vec3 rgb2hsb( in vec3 c ){
+    vec4 K = vec4(0.0, -1.0 / 3.0, 2.0 / 3.0, -1.0);
+    vec4 p = mix(vec4(c.bg, K.wz),
+                 vec4(c.gb, K.xy),
+                 step(c.b, c.g));
+    vec4 q = mix(vec4(p.xyw, c.r),
+                 vec4(c.r, p.yzx),
+                 step(p.x, c.r));
+    float d = q.x - min(q.w, q.y);
+    float e = 1.0e-10;
+    return vec3(abs(q.z + (q.w - q.y) / (6.0 * d + e)),
+                d / (q.x + e),
+                q.x);
+}
+
+void main() {
+	vec2 st = (gl_FragCoord.xy*2.0-resolution)/min(resolution.x,resolution.y);
+	vec2 pq = gl_FragCoord.xy/resolution;
+	
+	vec3 color=vec3(1.);
+
+    vec2 toCenter=st;
+    float angle=atan(toCenter.y,toCenter.x)/TWO_PI;
+    float radius=length(toCenter);
+    //color=hsb2rgb(vec3((angle/TWO_PI)+.5,1.,1.));
+    color = hsb2rgb(vec3((angle)+fract(time*2.),radius,1.0));
+    float circle = (0.03) / abs(0.6 - length(st));
+    color = color * circle;
+	gl_FragColor = vec4(color,1.0);
+}