adding-frag-shader for loadFilterShader

Author: perminder-17

docs/yuidoc-p5-theme/assets/shader.frag

@@ -0,0 +1,16 @@
+precision highp float; varying vec2 vPos;
+uniform vec2 p;
+uniform float r;
+const int I = 500;
+void main() {
+  vec2 c = p + vPos * r, z = c;
+  float n = 0.0;
+  for (int i = I; i > 0; i --) {
+    if(z.x*z.x+z.y*z.y > 4.0) {
+      n = float(i)/float(I);
+      break;
+    }
+    z = vec2(z.x*z.x-z.y*z.y, 2.0*z.x*z.y) + c;
+  }
+  gl_FragColor = vec4(0.5-cos(n*17.0)/2.0,0.5-cos(n*13.0)/2.0,0.5-cos(n*23.0)/2.0,1.0);
+}