instance_evalの使い道

tes.rb

#coding:utf-8
# 2015 09 24  Req
require"dxruby"

class O
  attr_accessor :x,:y,:d,:f,:task
  def initialize h = {}
    @x = h[:x]
    @y = h[:y]
    @d = h[:d]
    @f = ->{ yield self }
    @task = []
  end
  def update
    @f[]
  end
end

task = []
task << O.new( x:100 , y:400 , d:Image.new(50,50,[200,200,150])) do |o|
  o.instance_eval do
    Window.draw x , y , d
    @x += Input.x * 2
    @y += Input.y * 2
    if Input.keyDown? K_Z
      task << O.new( x:x , y:y , d:Image.new(5,10,[100,100,100])) do |o|
        o.instance_eval do
          Window.draw x , y , d
          @y -= 2
        end
      end
    end # if
    
  end
end

Window.loop do
  task.map do |m|
    m.update
    m.task.map do |m|
      m.update
    end
  end
  exit if Input.keyDown? K_F9
end