Ruby library Gosu for creating 2D games

Gosu Features

• Gosu supports loading and displaying images in PNG, JPEG, and other formats. Animation is also supported through sprite sheets.
• The library allows displaying text using system fonts or loaded font files.
• Gosu supports playing sounds and music in WAV and MP3 formats, making it easy to add sound effects and musical accompaniment to the game.
• The library provides convenient handling of input from the keyboard and mouse, simplifying the control of characters and other game elements.
• Gosu allows creating smooth animations using timers and frame cycles.
• Thanks to its open-source nature and support for extensions, Gosu easily integrates with other libraries and allows adding new functionalities.

gem install gosu-examples

gosu-examples

If everything is installed correctly, a window will open with demos that you can explore. Here is the translation of the text from the main screen:

Welcome to the Gosu Example Box!

This little tool lets you launch any of Gosu’s example games from the list on the right hand side of the screen.

Every example can be run both from this tool and from the terminal/command line as a stand-alone Ruby script.

Keyboard shortcuts:

• To see the source code of an example or feature demo, press E.
• To open the ‘examples’ folder, press O.
• To quit this tool, press Esc.
• To toggle fullscreen mode, press Alt+Enter (Windows, Linux) or cmd+F (macOS).

Why not take a look at the code for this example right now? Simply press E.

require "gosu"

WIDTH, HEIGHT = 640, 480

class Welcome < (Example rescue Gosu::Window)
  PADDING = 20

  def initialize
    super WIDTH, HEIGHT

    self.caption = "Welcome!"

    text =
      "<b>Welcome to the Gosu Example Box!</b>

      This little tool lets you launch any of Gosu’s example games from the list on the right hand side of the screen.

      Every example can be run both from this tool <i>and</i> from the terminal/command line as a stand-alone Ruby script.

      Keyboard shortcuts:

      • To see the source code of an example or feature demo, press <b>E</b>.
      • To open the ‘examples’ folder, press <b>O</b>.
      • To quit this tool, press <b>Esc</b>.
      • To toggle fullscreen mode, press <b>Alt+Enter</b> (Windows, Linux) or <b>cmd+F</b> (macOS).

      Why not take a look at the code for this example right now? Simply press <b>E</b>."

    # Remove all leading spaces so the text is left-aligned
    text.gsub! /^ +/, ""

    @text = Gosu::Image.from_markup text, 20, width: WIDTH - 2 * PADDING

    @background = Gosu::Image.new "media/space.png"
  end

  def draw
    draw_rotating_star_backgrounds

    @text.draw PADDING, PADDING, 0
  end

  def draw_rotating_star_backgrounds
    # Disregard the math in this method, it doesn't look as good as I thought it
    # would. =(

    angle = Gosu.milliseconds / 50.0
    scale = (Gosu.milliseconds % 1000) / 1000.0

    [1, 0].each do |extra_scale|
      @background.draw_rot WIDTH * 0.5, HEIGHT * 0.75, 0, angle, 0.5, 0.5,
        scale + extra_scale, scale + extra_scale
    end
  end
end

Welcome.new.show if __FILE__ == $0