Class: Draco::World

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

Overview

Public: The container for current Entities and Systems.

Defined Under Namespace

Classes: EntityStore

Class Attribute Summary collapse

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(entities: [], systems: []) ⇒ World

Public: Initializes a World.

entities - The Array of Entities for the World (default: []). systems - The Array of System Classes for the World (default: []).



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# File 'lib/draco.rb', line 585

def initialize(entities: [], systems: [])
  default_entities = self.class.default_entities.map do |default|
    klass, attributes = default
    name = attributes[:as]
    entity = klass.new(attributes)
    instance_variable_set("@#{name}", entity) if name

    entity
  end

  @entities = EntityStore.new(self, default_entities + entities)
  @systems = self.class.default_systems + systems
  after_initialize
end

Class Attribute Details

.default_entities ⇒ Object (readonly)

Internal: Returns the default Entities for the class.



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# File 'lib/draco.rb', line 569

def default_entities
  @default_entities
end

.default_systems ⇒ Object (readonly)

Internal: Returns the default Systems for the class.



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# File 'lib/draco.rb', line 572

def default_systems
  @default_systems
end

Instance Attribute Details

#entities ⇒ Object (readonly)

Public: Returns the Array of Entities.



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# File 'lib/draco.rb', line 579

def entities
  @entities
end

#systems ⇒ Object (readonly)

Public: Returns the Array of Systems.



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# File 'lib/draco.rb', line 576

def systems
  @systems
end

Class Method Details

.entity(entity, defaults = {}) ⇒ Object

Public: Adds a default Entity to the World.

entity - The class of the Entity to add by default. defaults - The Hash of default values for the Entity. (default: {})

Examples

entity(Player)

entity(Player, position: { x: 0, y: 0 })

Returns nothing.



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# File 'lib/draco.rb', line 545

def self.entity(entity, defaults = {})
  name = defaults[:as]
  @default_entities.push([entity, defaults])

  attr_reader(name.to_sym) if name
end

.inherited(sub) ⇒ Object

Internal: Resets the default components for each class that inherites Entity.

sub - The class that is inheriting Entity.

Returns nothing.



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# File 'lib/draco.rb', line 527

def self.inherited(sub)
  super
  sub.instance_variable_set(:@default_entities, [])
  sub.instance_variable_set(:@default_systems, [])
end

.systems(*systems) ⇒ Object

Public: Adds default Systems to the World.

systems - The System or Array list of System classes to add to the World.

Examples

systems(RenderSprites)

systems(RenderSprites, RenderLabels)

Returns nothing.



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# File 'lib/draco.rb', line 563

def self.systems(*systems)
  @default_systems += Array(systems).flatten
end

Instance Method Details

#after_initialize ⇒ Object

Public: Callback run after the world is initialized.

This is empty by default but is present to allow plugins to tie into.

Returns nothing.



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# File 'lib/draco.rb', line 605

def after_initialize; end

#after_tick(context, results) ⇒ Object

Public: Callback run after #tick is called.

This is empty by default but is present to allow plugins to tie into.

context - The context object of the current tick from the game engine. In DragonRuby this is args. results - The System instances that were run.

Returns nothing.



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# File 'lib/draco.rb', line 641

def after_tick(context, results); end

#before_tick(_context) ⇒ Object

Public: Callback run before #tick is called.

context - The context object of the current tick from the game engine. In DragonRuby this is args.

Returns the systems to run during this tick.



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# File 'lib/draco.rb', line 612

def before_tick(_context)
  systems.map do |system|
    entities = filter(system.filter)

    system.new(entities: entities, world: self)
  end
end

#component_added(entity, component) ⇒ Object

Public: Callback to run when a component is added to an existing Entity.

entity - The Entity the Component was added to. component - The Component that was added to the Entity.

Returns nothing.



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# File 'lib/draco.rb', line 649

def component_added(entity, component); end

#component_removed(entity, component) ⇒ Object

Public: Callback to run when a component is added to an existing Entity.

entity - The Entity the Component was removed from. component - The Component that was removed from the Entity.

Returns nothing.



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# File 'lib/draco.rb', line 657

def component_removed(entity, component); end

#filter(*components) ⇒ Object

Public: Finds all Entities that contain all of the given Components.

components - An Array of Component classes to match.

Returns an Array of matching Entities.



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# File 'lib/draco.rb', line 664

def filter(*components)
  entities[components.flatten]
end

#inspect ⇒ Object

Public: Returns a String representation of the World.



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# File 'lib/draco.rb', line 680

def inspect
  serialize.to_s
end

#serialize ⇒ Object

Public: Serializes the World to save the current state.

Returns a Hash representing the World.



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# File 'lib/draco.rb', line 671

def serialize
  {
    class: self.class.name.to_s,
    entities: @entities.map(&:serialize),
    systems: @systems.map { |system| system.name.to_s }
  }
end

#tick(context) ⇒ Object

Public: Runs all of the Systems every tick.

context - The context object of the current tick from the game engine. In DragonRuby this is args.

Returns nothing



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# File 'lib/draco.rb', line 625

def tick(context)
  results = before_tick(context).map do |system|
    system.call(context)
  end

  after_tick(context, results)
end

#to_s ⇒ Object

Public: Returns a String representation of the World.



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# File 'lib/draco.rb', line 685

def to_s
  serialize.to_s
end