Class: Baku::EntityManager

Inherits:
Object
  • Object
show all
Defined in:
lib/baku/entity_manager.rb

Overview

The EntityManager stores entities in such a way that they can be retrieved efficiently by either ComponentMask or tag. Before storing any entities, the ComponentMasks that we wish to match on should be registered. This step is performed transparently by the World whenever a System is added.

Instance Method Summary collapse

Constructor Details

#initialize ⇒ EntityManager

Returns a new instance of EntityManager.



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# File 'lib/baku/entity_manager.rb', line 7

def initialize
  @entities_by_component_mask = {}
  @entities_by_tag = {}
end

Instance Method Details

#add_entity(entity) ⇒ Object 



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# File 'lib/baku/entity_manager.rb', line 21

def add_entity(entity)
  add_entity_to_matching_component_lists(entity)
  
  entity.add_event_listener(:component_added,
                            method(:on_entity_component_added))
  entity.add_event_listener(:component_removed,
                            method(:on_entity_component_removed))

  entity.tags.each do |tag|
    @entities_by_tag[tag] ||= []
    @entities_by_tag[tag] << entity
  end
end

#dispose ⇒ Object 



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# File 'lib/baku/entity_manager.rb', line 12

def dispose
  @entities_by_component_mask.clear
  @entities_by_tag.clear
end

#get_entities(component_mask) ⇒ Object 



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# File 'lib/baku/entity_manager.rb', line 52

def get_entities(component_mask)
  @entities_by_component_mask[component_mask] || []
end

#get_entities_by_tag(tag) ⇒ Object 



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# File 'lib/baku/entity_manager.rb', line 56

def get_entities_by_tag(tag)
  @entities_by_tag[tag] || []
end

#register_component_mask(component_mask) ⇒ Object 



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# File 'lib/baku/entity_manager.rb', line 17

def register_component_mask(component_mask)
  @entities_by_component_mask[component_mask] = []
end

#remove_entity(entity) ⇒ Object 



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# File 'lib/baku/entity_manager.rb', line 35

def remove_entity(entity)
  entity.tags.each do |tag|
    @entities_by_tag[tag].delete(entity)
  end
  
  entity.remove_event_listener(:component_added,
                               method(:on_entity_component_added))
  entity.remove_event_listener(:component_removed,
                               method(:on_entity_component_removed))

  @entities_by_component_mask.each do |component_mask, entities|
    if component_mask.matches?(entity.component_mask)
      entities.delete(entity)
    end
  end
end