Refactor event bus to use non-retrievable events;

update collision handling and add new inventory initialization;
add torch lighting in fog shader;

utils/bus.rb

@@ -2,12 +2,11 @@ class EventBus
   def initialize
     # store callbacks with owner: {event => [ {callback:, owner:} ] }
     @events = Hash.new { |h, k| h[k] = [] }
-    @retrievable_events = {}
   end
 
   # Emit an event
   def emit(event, *args)
-    @events[event].each do |h|
+    @events[event].dup.each do |h|
       h[:callback].call(*args)
     end
   end
@@ -28,30 +27,34 @@ class EventBus
     on(event, owner: owner, &wrapper)
   end
 
+  # Unsubscribe from an event
   def off(event, &callback)
     @events[event].reject! { |h| h[:callback] == callback }
   end
 
-  # Register a retrievable event (only one allowed)
-  def on_retrievable(event, owner = nil, &callback)
-    owner ||= callback.binding.eval("self")
-    @retrievable_events[event] = { callback: callback, owner: owner }
-  end
-
-  # Get data from a retrievable event
+  # For events that return a value (e.g. queries), get the first non-nil response
   def get(event, *args)
-    if @retrievable_events[event]
-      @retrievable_events[event][:callback].call(*args)
-    else
-      nil
+    @events[event].dup.each do |h|
+      result = h[:callback].call(*args)
+      return result unless result.nil?
     end
+    nil
   end
 
-  # Unsubscribe from an object's events
-  def unlisten_owner(owner)
+  # For events that return multiple values (e.g. queries), get all non-nil responses
+  def get_all(event, *args)
+    results = []
+    @events[event].dup.each do |h|
+      result = h[:callback].call(*args)
+      results << result unless result.nil?
+    end
+    results
+  end
+
+  # Unsubscribe all events for a given owner (e.g. when an object is destroyed)
+  def remove_owner(owner)
     @events.each do |event, handlers|
       handlers.reject! { |h| h[:owner] == owner }
     end
-    @retrievable_events.delete_if { |_, h| h[:owner] == owner }
   end
 end