Ruby 2d Demo featuring a movable square with multikey listeners and a main background thread.

main.rb

require 'ruby2d'

#window config
set width: 300, height: 200
set title: ""
set background: 'black'
#set fullscreen: true

@square = Square.new(x: 10, y: 20, size: 25, color: 'blue')

# Define the initial speed (and direction).
@x_speed = 0
@y_speed = 0

@t=Thread.new{loop do ; sleep 1 ; puts "hi"; end}

# Define what happens when a specific key is pressed.
# Each keypress influences on the  movement along the x and y axis.
on :key_down do |event|
  if event.key == 'left'
    @x_speed = -2
    #@y_speed = 0
  end
end
on :key_down do |event|
  if event.key == 'right'
    @x_speed = 2
    #@y_speed = 0
  end
end
on :key_down do |event|
  if event.key == 'up'
    #@x_speed = 0
    @y_speed = -2
  end
end
on :key_down do |event|
  if event.key == 'down'
    #@x_speed = 0
    @y_speed = 2
  end
end

on :key_up do |event|
  if event.key == 'left' 
    @x_speed = 0
    #@y_speed = 0
  end
end
on :key_up do |event|
  if event.key == 'right'
    @x_speed = 0
	#@y_speed = 0
  end
end
on :key_up do |event|
  if event.key == 'up'
    #@x_speed = 0
    @y_speed = 0
  end
end
on :key_up do |event|
  if event.key == 'down'
    #@x_speed = 0
    @y_speed = 0
  end
end

update do
  @square.x += @x_speed
  @square.y += @y_speed
end

show