Class: RGame::Engine::PlayerLayer

Inherits:
Node2D
  • Object
show all
Defined in:
lib/rgame/engine/player_layer.rb

Overview

One player's own corner of the screen.

layer = scene.add_node(PlayerLayer.new(player: players[1]))
layer.add_node(inventory)

Its subtree is drawn once, clipped to that player's viewport and translated to its corner, in screen space. That is the third kind of content a frame holds: the world is drawn once per viewport under a camera, a global overlay once across the whole window, and this once per player inside their own region.

It is also the :hud z band's structural counterpart: everything under here draws above everything in the world, whatever either asked for.

Its children are positioned relative to it

A node at (10, 10) under this layer is ten pixels inside that player's region, wherever the layout has put it. The layer's translate is what does that, so the same HUD class serves either player with nothing to configure — which is the point of it being a node rather than a rect a HUD looks up.

For laying out against the far edge, use the view's size: view.width - margin. view.x and view.y are where the region sits on the window and are the clip's business, not a layout origin; adding them would offset a second time.

It says whose input its subtree reads

input_owner is set to that player, and ownership is inherited, so a menu anywhere under here reads their controller and nobody else's. Two players with a menu open at once are independent without either one knowing the other exists — see docs/api/scene_graph.md, "Who a node answers to".

An empty region draws nothing

Viewports#screen_for is nil for a seat nobody is in, and for everybody while the split is collapsed — a cutscene is everyone looking at one thing, so per-player UI has no place to be. Either way this draws nothing and needs no guard at the call site.

Instance Attribute Summary

Attributes inherited from Node2D

#abs_angle, #abs_band, #abs_input_owner, #abs_x, #abs_y, #angle, #band, #children, #components, #context, #height, #input_owner, #parent, #paused, #scene, #sibling_order, #width, #x, #y, #z

Instance Method Summary collapse

Methods inherited from Node2D

#add_component, #add_node, #children_unsorted!, #control, #enter_tree, #exit_tree, #freed?, #get_component, #in_tree?, #on_add, #on_control, #on_draw, #on_remove, #on_update, #queue_free, #remove_component, #remove_node, #root, #sweep_freed, #system, #update

Methods included from Signal::DSL

#signal

Constructor Details

#initialize(player:) ⇒ PlayerLayer

:hud is this player's own screen space, above every world slot and below a global overlay. It is inherited, so a menu three nodes down is in it without saying so — which is the point of the band being structural rather than a number each widget carries.



49
50
51
52
 
# File 'lib/rgame/engine/player_layer.rb', line 49

def initialize(player:, **)
  super(band: :hud, **)
  self.input_owner = player
end

Instance Method Details

#draw(renderer, _view = nil) ⇒ Object 



58
59
60
61
62
63
64
65
66
67
 
# File 'lib/rgame/engine/player_layer.rb', line 58

def draw(renderer, _view = nil)
  region = system(Viewports).screen_for(player)
  return if region.nil?

  renderer.clipped(region.x, region.y, region.width, region.height) do
    renderer.translated(region.offset_x, region.offset_y) do
      super(renderer, region)
    end
  end
end

#player ⇒ Object

Whose layer this is. The same thing as input_owner, and stored only there: two fields would be two things to keep in step.



56
 
# File 'lib/rgame/engine/player_layer.rb', line 56

def player = input_owner