finished at the 8th card "high priestess" for today

learning/PixelSpirit/high_priestess.frag

@@ -0,0 +1,25 @@
+#ifdef GL_ES
+precision mediump float;
+#endif
+uniform vec2 u_resolution;
+uniform vec2 u_mouse;
+uniform float u_time;
+
+#define PI 3.14159265359
+
+float stroke(in float x_coor, float s, float width){
+  float d = step(s,x_coor+width*.5)-step(s,x_coor-width*.5);
+  return clamp(d, 0.,1.);
+}
+
+void main() {
+  vec2 st = gl_FragCoord.xy/u_resolution;
+  vec3 color = vec3(0.0,0.0,0.0);
+  float alpha = 1.0;
+  vec2 centre = vec2(.5);
+  // this was my original solution, going to look over the stroke version on the card now
+  //color += step(.25, distance(centre, st))-step(.27, distance(centre, st));
+color += stroke(length(st-.5)*2.,.5,.05);
+ 
+  gl_FragColor = vec4(color, alpha);
+}