Adding ViroKit. Needs AWSCore :(

mobile/ios/ViroKit.framework/equirect_to_cube_fsh.glsl

@@ -0,0 +1,20 @@
+#version 300 es
+
+in highp vec3 v_world_position;
+out highp vec4 frag_color;
+uniform sampler2D equirectangular_map;
+
+const highp vec2 inv_atan = vec2(0.1591, 0.3183);
+
+highp vec2 sample_spherical_map(highp vec3 v) {
+    highp vec2 uv = vec2(atan(v.z, v.x), asin(v.y));
+    uv *= inv_atan;
+    uv += 0.5;
+    return uv;
+}
+
+void main() {
+    highp vec2 uv = sample_spherical_map(normalize(v_world_position));
+    highp vec3 color = texture(equirectangular_map, uv).rgb;
+    frag_color = vec4(color, 1.0);
+}