More Ruby OpenGL explorations

This is an example taken from the ruby opengl examples, that I have modified to get to work with a compiled version of the library (ie not rubygem version) on my 64 bit linux box (Kubuntu 10.04 custom kernel with latest NVidia graphics driver).  Two changes are 'required', string entry from ruby 1.9 is not accepted, and the properties require a Struct rather than array. I have also converted Proc.new and old style lambda to new style stabby lambda just for the hell of it. I don't want any hassle so I'm also including the original c-code copyright notice which now seems kind of pointless.


#!/usr/bin/env ruby
#/* Copyright (c) Mark J. Kilgard, 1994. */
#
#/*
# * (c) Copyright 1993, Silicon Graphics, Inc.
# * ALL RIGHTS RESERVED
# * Permission to use, copy, modify, and distribute this software for
# * any purpose and without fee is hereby granted, provided that the above
# * copyright notice appear in all copies and that both the copyright notice
# * and this permission notice appear in supporting documentation, and that
# * the name of Silicon Graphics, Inc. not be used in advertising
# * or publicity pertaining to distribution of the software without specific,
# * written prior permission.
# *
# * THE MATERIAL EMBODIED ON THIS SOFTWARE IS PROVIDED TO YOU "AS-IS"
# * AND WITHOUT WARRANTY OF ANY KIND, EXPRESS, IMPLIED OR OTHERWISE,
# * INCLUDING WITHOUT LIMITATION, ANY WARRANTY OF MERCHANTABILITY OR
# * FITNESS FOR A PARTICULAR PURPOSE.  IN NO EVENT SHALL SILICON
# * GRAPHICS, INC.  BE LIABLE TO YOU OR ANYONE ELSE FOR ANY DIRECT,
# * SPECIAL, INCIDENTAL, INDIRECT OR CONSEQUENTIAL DAMAGES OF ANY
# * KIND, OR ANY DAMAGES WHATSOEVER, INCLUDING WITHOUT LIMITATION,
# * LOSS OF PROFIT, LOSS OF USE, SAVINGS OR REVENUE, OR THE CLAIMS OF
# * THIRD PARTIES, WHETHER OR NOT SILICON GRAPHICS, INC.  HAS BEEN
# * ADVISED OF THE POSSIBILITY OF SUCH LOSS, HOWEVER CAUSED AND ON
# * ANY THEORY OF LIABILITY, ARISING OUT OF OR IN CONNECTION WITH THE
# * POSSESSION, USE OR PERFORMANCE OF THIS SOFTWARE.
# *
# * US Government Users Restricted Rights
# * Use, duplication, or disclosure by the Government is subject to
# * restrictions set forth in FAR 52.227.19(c)(2) or subparagraph
# * (c)(1)(ii) of the Rights in Technical Data and Computer Software
# * clause at DFARS 252.227-7013 and/or in similar or successor
# * clauses in the FAR or the DOD or NASA FAR Supplement.
# * Unpublished-- rights reserved under the copyright laws of the
# * United States.  Contractor/manufacturer is Silicon Graphics,
# * Inc., 2011 N.  Shoreline Blvd., Mountain View, CA 94039-7311.
# *
# * OpenGL(TM) is a trademark of Silicon Graphics, Inc.
# */
#/*
# *  plane.c
# *  This program demonstrates the use of local versus
# *  infinite lighting on a flat plane.
# */

require "gl"
require "glut"

Property = Struct.new("Property", :a, :b, :c, :d)
# /*  Initialize material property, light source, and lighting model.
# */
def myinit   
    mat_ambient = Property.new(0.0, 0.0, 0.0, 1.0)
#/*   mat_specular and mat_shininess are NOT default values     */
    mat_diffuse = Property.new(0.4, 0.4, 0.4, 1.0)
    mat_specular = Property.new(1.0, 1.0, 1.0, 1.0)
    mat_shininess = 15.0 
    light_ambient = Property.new(0.0, 0.0, 0.0, 1.0)
    light_diffuse = Property.new(1.0, 1.0, 1.0, 1.0)
    light_specular = Property.new(1.0, 1.0, 1.0, 1.0)
    lmodel_ambient = Property.new(0.2, 0.2, 0.2, 1.0)

    Gl.glMaterial(Gl::GL_FRONT, Gl::GL_AMBIENT, mat_ambient)
    Gl.glMaterial(Gl::GL_FRONT, Gl::GL_DIFFUSE, mat_diffuse)
    Gl.glMaterial(Gl::GL_FRONT, Gl::GL_SPECULAR, mat_specular)
    Gl.glMaterial(Gl::GL_FRONT, Gl::GL_SHININESS, mat_shininess)
    Gl.glLight(Gl::GL_LIGHT0, Gl::GL_AMBIENT, light_ambient)
    Gl.glLight(Gl::GL_LIGHT0, Gl::GL_DIFFUSE, light_diffuse)
    Gl.glLight(Gl::GL_LIGHT0, Gl::GL_SPECULAR, light_specular)
    Gl.glLightModel(Gl::GL_LIGHT_MODEL_AMBIENT, lmodel_ambient)

    Gl.glEnable(Gl::GL_LIGHTING)
    Gl.glEnable(Gl::GL_LIGHT0)
    Gl.glDepthFunc(Gl::GL_LESS)
    Gl.glEnable(Gl::GL_DEPTH_TEST)
end

def drawPlane
    Gl.glBegin(Gl::GL_QUADS)
    Gl.glNormal(0.0, 0.0, 1.0)
    Gl.glVertex(-1.0, -1.0, 0.0)
    Gl.glVertex(0.0, -1.0, 0.0)
    Gl.glVertex(0.0, 0.0, 0.0)
    Gl.glVertex(-1.0, 0.0, 0.0)

    Gl.glNormal(0.0, 0.0, 1.0)
    Gl.glVertex(0.0, -1.0, 0.0)
    Gl.glVertex(1.0, -1.0, 0.0)
    Gl.glVertex(1.0, 0.0, 0.0)
    Gl.glVertex(0.0, 0.0, 0.0)

    Gl.glNormal(0.0, 0.0, 1.0)
    Gl.glVertex(0.0, 0.0, 0.0)
    Gl.glVertex(1.0, 0.0, 0.0)
    Gl.glVertex(1.0, 1.0, 0.0)
    Gl.glVertex(0.0, 1.0, 0.0)

    Gl.glNormal(0.0, 0.0, 1.0)
    Gl.glVertex(0.0, 0.0, 0.0)
    Gl.glVertex(0.0, 1.0, 0.0)
    Gl.glVertex(-1.0, 1.0, 0.0)
    Gl.glVertex(-1.0, 0.0, 0.0)
    Gl.glEnd()
end

# Using ruby 1.9 stabby lambda syntax for callbacks
display = -> {
    infinite_light = Property.new(1.0, 1.0, 1.0, 0.0)
    local_light = Property.new(1.0, 1.0, 1.0, 1.0)
    Gl.glClear(Gl::GL_COLOR_BUFFER_BIT | Gl::GL_DEPTH_BUFFER_BIT)
    Gl.glPushMatrix()
    Gl.glTranslate(-1.5, 0.0, 0.0)
    Gl.glLight(Gl::GL_LIGHT0, Gl::GL_POSITION, infinite_light)
    drawPlane()
    Gl.glPopMatrix()
    Gl.glPushMatrix()
    Gl.glTranslate(1.5, 0.0, 0.0)
    Gl.glLight(Gl::GL_LIGHT0, Gl::GL_POSITION, local_light)
    drawPlane()
    Gl.glPopMatrix()
    Gl.glFlush()
}

myReshape = -> w, h {
    Gl.glViewport(0, 0, w, h)
    Gl.glMatrixMode(Gl::GL_PROJECTION)
    Gl.glLoadIdentity()
    (w <= h) ?  Gl.glOrtho(-1.5, 1.5, -1.5*h/w, 1.5*h/w, -10.0, 10.0) : Gl.glOrtho(-1.5*w/h, 1.5*w/h, -1.5, 1.5, -10.0, 10.0)
    Gl.glMatrixMode(Gl::GL_MODELVIEW)
}

# Keyboard handler to exit when ESC is typed
keyboard = -> key, x, y{
  case(key)
  when ?\e
    exit(0)
  end
}


Glut.glutInit
Glut.glutInitDisplayMode(Glut::GLUT_SINGLE | Glut::GLUT_RGB | Glut::GLUT_DEPTH)
Glut.glutInitWindowSize(500, 200)
Glut.glutCreateWindow([]) # empty array I can't figure out how to return cstring
myinit()
Glut.glutReshapeFunc(myReshape)
Glut.glutDisplayFunc(display)
Glut.glutKeyboardFunc(keyboard)
Glut.glutMainLoop()