remove glu from gemfile, added InputMapper, using InputMapper for Camera and Player.

lib/managers/input_mapper.rb

@@ -0,0 +1,45 @@
+class IMICFPS
+  class InputMapper
+    @@keymap = {}
+
+    def self.get(category, action)
+      key = @@keymap.dig(category, action)
+    end
+
+    def self.set(category, action, key)
+      raise "category must be a symbol"  unless category.is_a?(Symbol)
+      raise "action must be a symbol"    unless action.is_a?(Symbol)
+      raise "key must be a whole number or Array of whole numbers, got #{key}" unless key.is_a?(Integer) || key.is_a?(Array)
+
+      @@keymap[category] ||= {}
+
+      warn "InputMapper.set(:#{category}, :#{action}) is already defined as #{@@keymap[category][action]}" if @@keymap[category][action]
+
+      @@keymap[category][action] = key
+    end
+
+    def self.down?(category, action)
+      keys = get(category, action)
+
+      if keys.is_a?(Array)
+        keys.detect do |key|
+          Gosu.button_down?(key)
+        end
+      else
+        Gosu.button_down?(keys)
+      end
+    end
+
+    def self.is?(category, action, query_key)
+      keys = get(category, action)
+
+      if keys.is_a?(Array)
+        keys.detect do |key|
+          query_key == key
+        end
+      else
+        query_key == keys
+      end
+    end
+  end
+end