Just today somebody asked me why I am doing a pygame tutorial, since I am “a ruby guy”, whatever that’s supposed to mean. I never claimed to be “a ruby guy”. I program in Pascal as well. Go ahead and call me a “Pascal guy”. Or a “C guy”.
Anyways, such minor issues apart. There are Ruby bindings for SDL called (amazingly enough) Ruby/SDL. Now this is not “pygame in Ruby”. Ruby/SDL is a Ruby wrapper for SDL. As such, its API looks like the original SDL API. Pygame, is not a wrapper. It is a python library for developing multimedia applications that uses SDL internally. Confused? I hope not. Ruby/SDL is probably comparable to PySDL which seems to be a Python wrapper for SDL.
I started writing the pygame tutorial because a few people asked me to. Pygame is more popular than Ruby/SDL. (Note: I said more popular, not better. I have no opinion on which is better. I’m only interested in being able to use both). I’m not going to do a Ruby/SDL tutorial, at least not now, but I can at least give you something to get started. First of all, you need to get Ruby/SDL installed. On Debian that translates to:
# aptitude install libsdl-ruby1.8
at least if you are using Etch. If you are not on Debian or one of its derivates.
Once it is installed you can start off by going to
/usr/share/doc/libsdl-ruby1.8/examples and studying the examples there. They show you just about everything you need to know. I will also add a small example of my own, adapted from my pygame tutorial.
1 #! /usr/bin/ruby -w 2 3 require 'sdl' 4 5 SDL.init SDL::INIT_VIDEO 6 screen = SDL::set_video_mode 640, 480, 24, SDL::SWSURFACE 7 x = y = 0 8 9 BGCOLOR = screen.format.mapRGB 0, 0, 0 10 LINECOLOR = screen.format.mapRGB 255, 255, 255 11 12 running = true 13 14 while running 15 while event = SDL::Event2.poll 16 case event 17 when SDL::Event2::Quit 18 running = false 19 when SDL::Event2::MouseMotion 20 x = event.x 21 y = event.y 22 end 23 end 24 25 screen.fill_rect 0, 0, 640, 480, BGCOLOR 26 screen.draw_line x, 0, x, 479, LINECOLOR 27 screen.draw_line 0, y, 639, y, LINECOLOR 28 screen.flip 29 end
That’s it! Have fun..