Class: FelFlame::Entities

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

Overview

Creates and manages Entities. Allows iterating or accessing Entities using array methods directly on the class. Entities are just collections of Components.

Instance Method Summary collapse

Constructor Details

#initialize(*components) ⇒ Entity

Creating a new Entity

Parameters:

  • components (Components) —

    Can be any number of components, identical duplicates will be automatically purged however different components from the same component manager are allowed.



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

def initialize(*components)
  # Add each component
  add(*components)

  # Fancy method redirection for when the `component` method is called
  @component_redirect = Object.new
  @component_redirect.instance_variable_set(:@entity, self)
  @component_redirect.define_singleton_method(:[]) do |component_manager|
    instance_variable_get(:@entity).component(component_manager)
  end

  self.class._data.push self
end

Instance Method Details

#add(*components_to_add) ⇒ Boolean

Add any number components to the Entity.

Parameters:

  • components_to_add (Component) —

    Any number of components created from any component manager

Returns:

  • (Boolean) —

    true



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# File 'lib/felflame/entity_manager.rb', line 63

def add(*components_to_add)
  components_to_add.each do |component|
    if components[component.class].nil?
      components[component.class] = [component]
      component.entities.push self
      check_systems component, :addition_triggers
    elsif !components[component.class].include? component
      components[component.class].push component
      component.entities.push self
      check_systems component, :addition_triggers
    end
  end
  true
end

#component(manager = nil) ⇒ Component

A single component from a component manager. Use this if you expect the component to only belong to one entity and you want to access it. Access the component using either parameter notation or array notation.

Examples:

@entity.component[@component_manager] # array notation
@entity.component(@component_manager) # method notation

Parameters:

  • manager (ComponentManager) (defaults to: nil) —

    If you pass nil you can then use array notation to access the same value.

Returns:

  • (Component) 


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# File 'lib/felflame/entity_manager.rb', line 33

def component(manager = nil)
  if manager.nil?
    @component_redirect
  else
    if components[manager].nil?
      raise "This entity(#{self}) doesnt have any components of this type: #{manager}"
    elsif components[manager].length > 1
      Warning.warn("This entity has MANY of this component but you called the method that is intended for having a single of this component type.\nYou may have a bug in your logic.")
    end
    components[manager].first
  end
end

#components ⇒ Hash<Component_Manager, Array<Integer>>

A hash that uses component manager constant names as keys, and where the values of those keys are arrays that contain the the components attached to this entity.

Returns:

  • (Hash<Component_Manager, Array<Integer>>) 


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# File 'lib/felflame/entity_manager.rb', line 23

def components
  @components ||= {}
end

#delete ⇒ Boolean

Removes this Entity from the list and purges all references to this Entity from other Components, as well as its data.

Returns:

  • (Boolean) —

    true



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# File 'lib/felflame/entity_manager.rb', line 49

def delete
  components.each do |component_manager, component_array|
    component_array.reverse_each do |component|
      component.entities.delete(self)
    end
  end
  FelFlame::Entities._data.delete self
  @components = {}
  true
end

#remove(*components_to_remove) ⇒ Boolean

Remove a component from the Entity

Parameters:

  • components_to_remove (Component) —

    A component created from any component manager

Returns:

  • (Boolean) —

    true



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# File 'lib/felflame/entity_manager.rb', line 93

def remove(*components_to_remove)
  components_to_remove.each do |component|
    check_systems component, :removal_triggers if component.entities.include? self
    component.entities.delete self
    components[component.class].delete component
    if components[component.class].empty?
      components.delete component.class
    end
  end
  true
end