From: Tom Nakamura <imifumei@...>
Date: 2005-06-16T13:35:20+09:00
Subject: Help translating from GLUT to FXRuby??

Can some please help me translate smooth.rb (below) from yoshi's opengl
extension to FXRuby? I've never used opengl before, and am having
trouble translating from GLUT to FXRuby. My poor attempt is also
below...
Tom Nakamura


##
##smooth.rb sample from yoshi's opengl
##shows a pretty little triangle
##
require "opengl"
require "glut"

STDOUT.sync=TRUE
disp = Proc.new {
  GL.Clear(GL::COLOR_BUFFER_BIT)
  GL.Begin(GL::TRIANGLES)
    GL.Color(0.0, 0.0, 1.0)
    GL.Vertex(0, 0)
    GL.Color(0.0, 1.0, 0.0)
    GL.Vertex(200, 200)
    GL.Color(1.0, 0.0, 0.0)
    GL.Vertex(20, 200)
  GL.End
  GL.Flush
}

reshape = Proc.new {|w, h|
  GL.Viewport(0, 0, w, h)
  GL.MatrixMode(GL::PROJECTION)
  GL.LoadIdentity
  GL.Ortho(0, w, 0, h, -1, 1)
  GL.Scale(1, -1, 1)
  GL.Translate(0, -h, 0)
}
GLUT.Init
a =  GLUT.CreateWindow("single triangle");
GLUT.DisplayFunc(disp);
GLUT.ReshapeFunc(reshape);
GLUT.MainLoop;


##
##My rather pathetic attempt to translate above to FXRuby...
##
require 'fox'
require 'opengl'
include Fox

class GLWindow < FXMainWindow
  def initialize(app)
    super(app, "GLWindow")
    @visual = FXGLVisual.new(app, VISUAL_DOUBLEBUFFER)  
    @canvas = FXGLCanvas.new(self,@visual)
    @canvas.connect(SEL_PAINT) do
      display
    end
    FXButton.new(self,"display").connect(SEL_COMMAND) do |sender,
    selector, data|
      display
    end
  end
  
  def display
    @canvas.makeCurrent()
    GL.Viewport(0, 0, @canvas.width, @canvas.height)
    GL.ClearColor(1.0,1.0,1.0,1.0)
    GL.Clear(GL::COLOR_BUFFER_BIT|GL::DEPTH_BUFFER_BIT)
    GL.Disable(GL::DITHER)
    GL.MatrixMode(GL::PROJECTION)
    GL.LoadIdentity
    GL.Ortho(0, @canvas.width, 0, @canvas.height, -1, 1)
    GL.Scale(1, -1, 1)
    GL.Translate(0, -@canvas.height, 0)
    GL.Begin(GL::TRIANGLES)
      GL.Color(0.0, 0.0, 1.0)
      GL.Vertex(0, 0)
      GL.Color(0.0, 1.0, 0.0)
      GL.Vertex(200, 200)
      GL.Color(1.0, 0.0, 0.0)
      GL.Vertex(20, 200)
    GL.End
    GL.Flush
    @canvas.makeCurrent()
  end

  def create
    super
    show(PLACEMENT_SCREEN)
  end
end

app = FXApp.new
GLWindow.new(app)
app.create
app.run