adding shaders to the repo

shader_experiments/Shaders/process/kaleidoscope.frag

@@ -0,0 +1,43 @@
+
+#ifdef GL_ES
+precision mediump float;
+#endif
+
+#define PI 3.1415926538979323846
+#define TWO_PI 2*PI
+
+varying vec2 v_texcoord;
+uniform sampler2D u_tex0;
+uniform vec2 u_resolution;
+uniform float u_time;
+uniform float u_x0;
+uniform float u_x1;
+uniform float u_x2;
+uniform float u_x3;
+
+//uniform float kangleRad = 0.0;
+//uniform vec2 u_resolution;
+
+void main(){
+    int ksectors = 1 + int(u_x0*20.0);
+    vec2 screenCenter = vec2(0.5, 0.5) ;
+    vec2 kcenter = screenCenter + vec2(u_x2, u_x3);
+    float kangleRad = u_time*u_x1;
+    float twoPi = 3.1415926538979323846 * 2.0;
+    vec2 pos = v_texcoord ;
+    vec2 v = pos.xy - screenCenter;
+    float r = length(v);
+    float a = atan (v.y, v.x);
+    
+    float A = twoPi / float(ksectors);
+    a = mod(a, A);
+    if (a > A/2.0 ){ a = A - a; }
+    a -= kangleRad;
+
+    vec2 u =vec2( cos(a), sin(a) ) * r;
+    u += kcenter;
+    gl_FragColor = texture2D(u_tex0, u);
+}
+
+
+