Quick test that shows the shader now just work on any UI element.

ritual_ui.cpp

@@ -42,6 +42,7 @@ namespace gui {
       auto button = $gui.entity(name);
 
       if(name == "circle_area") {
+        $gui.set<Shader>(button, {0.4f});
         $gui.set<Sprite>(button, {"the_ritual_circle"});
         $gui.set<Clickable>(button, {
             [&](auto ent, auto){ ritual_circle_clicked(ent); }
@@ -49,6 +50,7 @@ namespace gui {
       } else if(name.starts_with("inv_slot")) {
         $gui.set<Sprite>(button, {
             fmt::format("{}-64", junk_list[button % junk_list.size()])});
+        $gui.set<Shader>(button, {0.4f});
         $gui.set<Clickable>(button, {
             [&](auto ent, auto){ inv_slot_clicked(ent); }
         });