Minor shader refactor

src/utils/media-highlight-frag.glsl

 if (hubs_HighlightInteractorOne || hubs_HighlightInteractorTwo) {
-  float dist1, dist2;
-
-  if (hubs_HighlightInteractorOne) {
-    dist1 = distance(hubs_WorldPosition, hubs_InteractorOnePos);
-  }
-
-  if (hubs_HighlightInteractorTwo) {
-    dist2 = distance(hubs_WorldPosition, hubs_InteractorTwoPos);
-  }
+  float ratio = 0.0;
 
   if (hubs_EnableSweepingEffect) {
     float size = hubs_SweepParams.t - hubs_SweepParams.s;
     float line = mod(hubs_Time / 3000.0 * size, size * 2.0) + hubs_SweepParams.s - size / 2.0;
 
-    float ratio = 0.0;
     if (hubs_WorldPosition.y < line) {
       // Highlight with an sweeping gradient
       ratio = max(0.0, 1.0 - (line - hubs_WorldPosition.y) / size * 3.0);
@@ -23,9 +14,11 @@ if (hubs_HighlightInteractorOne || hubs_HighlightInteractorTwo) {
   float pulse = sin(hubs_Time / 1000.0) + 1.0;
   // Highlight with a gradient falling off with distance.
   if (hubs_HighlightInteractorOne) {
+    float dist1 = distance(hubs_WorldPosition, hubs_InteractorOnePos);
     ratio += -min(1.0, pow(dist1 * (9.0 + 3.0 * pulse), 3.0)) + 1.0;
   } 
   if (hubs_HighlightInteractorTwo) {
+    float dist2 = distance(hubs_WorldPosition, hubs_InteractorTwoPos);
     ratio += -min(1.0, pow(dist2 * (9.0 + 3.0 * pulse), 3.0)) + 1.0;
   }