From: brabuhr@...
Date: 2009-12-05T00:10:08+09:00
Subject: Re: Graphics mode again

On Fri, Dec 4, 2009 at 8:37 AM, Teodor Carstea <teodorcarstea@yahoo.com> wrote:
>>Hi, all! here is my prog: it calculates the trajectory of a cannon shell:
> [...]
>>this is the output if speed=45km/h and angle=45 degrees
>
>  give angle(degrees):
> 45
>  give speed(km/h)
> 45
>  convert degrees to radian:
> 0.785398163397448
>  flight trajectory:
> x=31.8198051533946  y=26.9198051533946
> x=63.6396103067893  y=44.0396103067893
> x=95.4594154601839  y=51.3594154601839
> x=127.279220613579  y=48.8792206135786
> x=159.099025766973  y=36.5990257669732
> x=190.918830920368  y=14.5188309203678
> x=222.738636073762  y=-17.3613639262375
>
>>help me to see it, I mean, a graphic application (or console application), or >whatever... I want to see a shell flying on the screen. I am able to do it in
>>C++, but I wanna make it in Ruby, how can I use graphics mode?

Google: ruby gnome canvas
http://ruby-gnome2.sourceforge.jp/hiki.cgi?Gnome+Canvas+Clock

Based on that:

#!/usr/bin/env ruby

require 'gnomecanvas2'

class Foozle < Gtk::Window
  def initialize
    super

    @canvas = Gnome::Canvas.new(true)

    @foozle = Gnome::CanvasEllipse.new(
      @canvas.root,
      {
        :x1 => 10, :y1 => 20,
        :x2 => 30, :y2 => 40,
        :fill_color => "white",
        :outline_color => "steelblue",
        :width_pixels => 1
      }
    )

    @canvas.show
    add(@canvas)
  end
end

Gtk.init()
Foozle.new.show
Gtk.main()

Draws a single ball on the screen.

There are of course (as others have pointed out) other libraries that
may be more or less suited to your needs.