1. Computing

The Main Loop


5 of 5

The Main Loop

The following is the complete code for the main loop program. Running it will display a grey window. It will be useful to keep this program around to use as a template for future game projects.

 #!/usr/bin/env ruby
require 'rubygems'
require 'rubygame'
include Rubygame

# The main loop method. This is called at the
# bottom of the file. This contains the infinite
# main loop, and is exited when a QuitEvent
# is received.
def main_loop
# Set up the objects the main loop will
# need.

# The screen is the window displayed on the
# screen.
screen = Screen.new [640, 480]

# The event queue handles events from the
# operating system
queue = EventQueue.new

# The clock limits the framerate to 30fps
clock = Clock.new
clock.target_framerate = 30

# This is the infinite main loop
loop do
# Pause the program for a short amount of
# time so it doesn't exceed 30fps

# Process all events, return if the window
# was closed
queue.each do|e|
return if e.is_a? QuitEvent

# Fill the screen with a grey color and
# display it on the monitor
screen.fill [200, 200, 200]


# If this file was the one executed from the
# command line, run the main loop.
if $0 == __FILE__
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