Class: FelFlame::Systems

Inherits:
Object
  • Object
show all
Extended by:
Enumerable
Defined in:
lib/felflame.rb,
lib/felflame/system_manager.rb

Overview

Creates an manages Systems. Systems are the logic of the game and do not contain any data within them.

TODO: Improve Systems overview

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(name, priority: 0, &block) ⇒ Systems

Creates a new System which can be accessed as a constant under the namespace FelFlame::Systems. The name given is what constant the system is assigned to

Examples:

FelFlame::Systems.new('PassiveHeal', priority: -2) do
  FelFlame::Components::Health.each do |component|
    component.hp += 5
  end
end
# Give it a low priority so other systems such as a
#   Poison system would kill the player first

Parameters:

  • name (String)

    The name this system will use. Needs to to be in the Ruby Constant format.

  • priority (Integer) (defaults to: 0)

    Which priority order this system should be executed in relative to other systems. Higher means executed earlier.

  • block (Proc)

    The code you wish to be executed when the system is triggered. Can be defined by using a do end block or using { } braces.



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# File 'lib/felflame/system_manager.rb', line 71

def initialize(name, priority: 0, &block)
  FelFlame::Systems.const_set(name, self)
  @const_name = name
  @priority = priority
  @block = block
end

Instance Attribute Details

#addition_triggersArray<Component>

Stores references to components or their managers that trigger this component when a component or component from that manager is added to an entity. Do not edit this hash as it is managed by FelFlame automatically.

Returns:

  • (Array<Component>)


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# File 'lib/felflame/system_manager.rb', line 24

def addition_triggers
  @addition_triggers ||= []
end

#attr_triggersHash<Symbol, Array<Symbol>>

Stores references to systems that should be triggered when an attribute from this manager is changed Do not edit this hash as it is managed by FelFlame automatically.

Returns:

  • (Hash<Symbol, Array<Symbol>>)


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# File 'lib/felflame/system_manager.rb', line 42

def attr_triggers
  @attr_triggers ||= {}
end

#const_nameObject (readonly)

The Constant name assigned to this System



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

def const_name
  @const_name
end

#priorityObject

How early this System should be executed in a list of Systems



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# File 'lib/felflame/system_manager.rb', line 4

def priority
  @priority
end

#removal_triggersArray<Component>

Stores references to components or their managers that trigger this component when a component or component from that manager is removed from an entity. Do not edit this hash as it is managed by FelFlame automatically.

Returns:

  • (Array<Component>)


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

def removal_triggers
  @removal_triggers ||= []
end

Class Method Details

.each(&block) ⇒ Enumerator

Iterate over all Systems, sorted by their priority. You also call other enumerable methods instead of each, such as each_with_index or select

Returns:

  • (Enumerator)


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# File 'lib/felflame/system_manager.rb', line 51

def each(&block)
  constants.map { |sym| const_get(sym) }.sort_by(&:priority).reverse.each(&block)
end

Instance Method Details

#callObject

Manually execute the system a single time



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# File 'lib/felflame/system_manager.rb', line 79

def call
  @block.call
end

#clear_triggers(*trigger_types, component_or_manager: nil) ⇒ Boolean

Removes triggers from this system. This function is fairly flexible so it can accept a few different inputs For addition and removal triggers, you can optionally pass in a component, or a manager to clear specifically the relevant triggers for that one component or manager. If you do not pass a component or manager then it will clear triggers for all components and managers. For attr_triggers

Examples:

# To clear all triggers that execute this system when a component is added:
FelFlame::Systems::ExampleSystem.clear_triggers :addition_triggers
# Same as above but for when a component is removed instead
FelFlame::Systems::ExampleSystem.clear_triggers :removal_triggers
# Same as above but for when a component has a certain attribute changed
FelFlame::Systems::ExampleSystem.clear_triggers :attr_triggers

# Clear a trigger from a specific component
FelFlame::Systems::ExampleSystem.clear_triggers :addition_triggers, FelFlame::Component::ExampleComponent[0]
# Clear a trigger from a specific component manager
FelFlame::Systems::ExampleSystem.clear_triggers :addition_triggers, FelFlame::Component::ExampleComponent

# Clear the trigger that executes a system when the ':example_attr' is changes
FelFlame::Systems::ExampleSystem.clear_triggers :attr_triggers, :example_attr

Parameters:

  • trigger_types (:Symbols)

    One or more of the following trigger types: :addition_triggers, :removal_triggers, or :attr_triggers. If attr_triggers is used then you may pass attributes you wish to be cleared as symbols in this parameter as well

  • component_or_manager (Component or ComponentManager) (defaults to: nil)

    The object to clear triggers from. Use Nil to clear triggers from all components associated with this system.

Returns:

  • (Boolean)

    true



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# File 'lib/felflame/system_manager.rb', line 111

def clear_triggers(*trigger_types, component_or_manager: nil)
  trigger_types = [:addition_triggers, :removal_triggers, :attr_triggers] if trigger_types.empty?

  if trigger_types.include? :attr_triggers
    if (trigger_types - [:addition_triggers,
        :removal_triggers,
        :attr_triggers]).empty?

      if component_or_manager.nil?
        #remove all attrs
        self.attr_triggers.each do |cmp_or_mgr, attrs|
          attrs.each do |attr|
            next if cmp_or_mgr.attr_triggers[attr].nil?

            cmp_or_mgr.attr_triggers[attr].delete self
          end
          self.attr_triggers = {}
        end
      else
        #remove attrs relevant to comp_or_man
        unless self.attr_triggers[component_or_manager].nil?
          self.attr_triggers[component_or_manager].each do |attr|
            component_or_manager.attr_triggers[attr].delete self
          end
          self.attr_triggers[component_or_manager] = []
        end
      end

    else

      if component_or_manager.nil?
        (trigger_types - [:addition_triggers, :removal_triggers, :attr_triggers]).each do |attr|
          #remove attr
          self.attr_triggers.each do |cmp_or_mgr, attrs|
            cmp_or_mgr.attr_triggers[attr].delete self
          end
        end
        self.attr_triggers.delete (trigger_types - [:addition_triggers,
                                                    :removal_triggers,
                                                    :attr_triggers])
      else
        #remove attr from component_or_manager
        (trigger_types - [:addition_triggers, :removal_triggers, :attr_triggers]).each do |attr|
          next if component_or_manager.attr_triggers[attr].nil?
          component_or_manager.attr_triggers[attr].delete self
        end
        self.attr_triggers[component_or_manager] -= trigger_types unless self.attr_triggers[component_or_manager].nil?
      end

    end
  end

  (trigger_types & [:removal_triggers, :addition_triggers] - [:attr_triggers]).each do |trigger_type|
    if component_or_manager.nil?
      #remove all removal triggers
      self.send(trigger_type).each do |trigger|
        trigger.send(trigger_type).delete self
      end
      self.send("#{trigger_type.to_s}=", [])
    else
      #remove removal trigger relevant to comp/man
      self.send(trigger_type).delete component_or_manager
      component_or_manager.send(trigger_type).delete self
    end
  end
  true
end

#redefine(&block) ⇒ Object

Redefine what code is executed by this System when it is called upon.

Parameters:

  • block (Proc)

    The code you wish to be executed when the system is triggered. Can be defined by using a do end block or using { } braces.



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# File 'lib/felflame/system_manager.rb', line 84

def redefine(&block)
  @block = block
end

#trigger_when_added(component_or_manager) ⇒ Boolean

Add a component or component manager so that it triggers this system when the component or a component from the component manager is added to an entity

Parameters:

  • component_or_manager (Component or ComponentManager)

    The component or component manager to trigger this system when added

Returns:

  • (Boolean)

    true



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# File 'lib/felflame/system_manager.rb', line 182

def trigger_when_added(component_or_manager)
  self.addition_triggers |= [component_or_manager]
  component_or_manager.addition_triggers |= [self]
  true
end

#trigger_when_is_changed(component_or_manager, attr) ⇒ Boolean

Add a component or component manager so that it triggers this system when a component's attribute is changed.

Returns:

  • (Boolean)

    true



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# File 'lib/felflame/system_manager.rb', line 199

def trigger_when_is_changed(component_or_manager, attr)
  if component_or_manager.attr_triggers[attr].nil?
    component_or_manager.attr_triggers[attr] = [self]
  else
    component_or_manager.attr_triggers[attr] |= [self]
  end
  if self.attr_triggers[component_or_manager].nil?
    self.attr_triggers[component_or_manager] = [attr]
  else
    self.attr_triggers[component_or_manager] |= [attr]
  end
  true
end

#trigger_when_removed(component_or_manager) ⇒ Boolean

Add a component or component manager so that it triggers this system when the component or a component from the component manager is removed from an entity

Parameters:

  • component_or_manager (Component or ComponentManager)

    The component or component manager to trigger this system when removed

Returns:

  • (Boolean)

    true



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# File 'lib/felflame/system_manager.rb', line 191

def trigger_when_removed(component_or_manager)
  self.removal_triggers |= [component_or_manager]
  component_or_manager.removal_triggers |= [self]
  true
end