#!/usr/bin/env ruby

#/*
# * Copyright (c) 1993-1997, Silicon Graphics, Inc.
# * ALL RIGHTS RESERVED 
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# * LOSS OF PROFIT, LOSS OF USE, SAVINGS OR REVENUE, OR THE CLAIMS OF
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# * 
# * 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
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# * Unpublished-- rights reserved under the copyright laws of the
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# * Inc., 2011 N.  Shoreline Blvd., Mountain View, CA 94039-7311.
# *
# * OpenGL(R) is a registered trademark of Silicon Graphics, Inc.
# */
#
#/*
# This code was created by Jeff Molofee '99
# (ported to SDL by Sam Lantinga '2000)
#
# If you've found this code useful, please let me know.
#
# Visit me at www.demonews.com/hosted/nehe 
#
##################################################################### 
# Port of NeHe's OpenGL tutorials to Ruby (http://www.ruby-lang.org)
# by Martin Stannard (martin@optushome.com.au)
# 
# Requires the following Ruby libraries:
#
# opengl : http://www2.giganet.net/~yoshi/
# RUDL : http://froukepc.dhs.org/rudl/index.html
# 
# lesson05.rbw :
#
# rotating, vertex coloured triangle and square 
# 
# */

require 'RUDL'
include RUDL
require "opengl"
require 'glut'
require "rational"

include Constant

# rotation angle for the triangle. 
rtri = 0.0

# rotation angle for the quadrilateral.
rquad = 0.0

$ScreenWidth, $ScreenHeight = 640, 480

STDOUT.sync = TRUE # flush all output to screen immediately

$d = DisplaySurface.new([640,480], OPENGL|DOUBLEBUF) #|FULLSCREEN)

rot = 0.0

def init(w,h)
	GL.ClearColor(0.0, 0.0, 0.0, 0.0)
	GL.ClearDepth(1.0)
	GL.DepthFunc(GL::LESS)
	GL.Enable(GL::DEPTH_TEST)
	GL.ShadeModel(GL::SMOOTH)
   
	GL.MatrixMode(GL::PROJECTION)
	GL.LoadIdentity()
   
	GLU.Perspective(45.0, w.to_f/h.to_f, 0.1, 100.0)
	GL.MatrixMode(GL::MODELVIEW)
	GL.LoadIdentity()
	GLU.LookAt(0.0, 0.0, 5.0, 0.0, 0.0, 0.0, 0.0, 1.0, 0.0)
end

display = Proc.new {
	GL.Clear(GL::COLOR_BUFFER_BIT | GL::DEPTH_BUFFER_BIT) # Clear The Screen And The Depth Buffer
	GL.Color(1.0, 1.0, 1.0)
	GL.LoadIdentity()

	GL.Translate(-1.5, 0.0, -6.0) 	# Move Left 1.5 Units And Into The Screen 6.0
	GL.Rotate(rtri, 0.0, 1.0, 0.0)		# Rotate The Pyramid On Y
	# draw a pyramid (in smooth coloring mode)
	GL.Begin(GL::POLYGON);				# start drawing a pyramid

	# front face of pyramid
	GL.Color3f(1.0, 0.0, 0.0)			# Set The Color To Red
	GL.Vertex3f(0.0,  1.0,  0.0)		      	# Top of triangle (front)
	GL.Color3f(0.0, 1.0, 0.0)			# Set The Color To Green
	GL.Vertex3f(-1.0, -1.0,  1.0)		# left of triangle (front)
	GL.Color3f(0.0, 0.0, 1.0)			# Set The Color To Blue
	GL.Vertex3f(1.0, -1.0,  1.0)		      	# right of traingle (front)	

	# right face of pyramid
	GL.Color3f(1.0, 0.0, 0.0)			# Red
	GL.Vertex3f( 0.0,  1.0,  0.0)		# Top Of Triangle (Right)
	GL.Color3f(0.0, 0.0, 1.0)			# Blue
	GL.Vertex3f( 1.0, -1.0,  1.0)		# Left Of Triangle (Right)
	GL.Color3f(0.0, 1.0, 0.0)			# Green
	GL.Vertex3f( 1.0, -1.0,  -1.0)		# Right Of Triangle (Right)

	# back face of pyramid
	GL.Color3f(1.0, 0.0, 0.0)			# Red
	GL.Vertex3f( 0.0,  1.0,  0.0)		# Top Of Triangle (Back)
	GL.Color3f(0.0, 1.0, 0.0)			# Green
	GL.Vertex3f( 1.0, -1.0,  -1.0)		# Left Of Triangle (Back)
	GL.Color3f(0.0, 0.0, 1.0)			# Blue
	GL.Vertex3f(-1.0, -1.0,  -1.0)		# Right Of Triangle (Back)

	# left face of pyramid.
	GL.Color3f(1.0, 0.0, 0.0)			# Red
	GL.Vertex3f( 0.0,  1.0,  0.0)		# Top Of Triangle (Left)
	GL.Color3f(0.0, 0.0, 1.0)			# Blue
	GL.Vertex3f(-1.0, -1.0, -1.0)		# Left Of Triangle (Left)
	GL.Color3f(0.0, 1.0, 0.0)			# Green
	GL.Vertex3f(-1.0, -1.0,  1.0)		# Right Of Triangle (Left)

	GL.End();					# Done Drawing The Pyramid

	GL.LoadIdentity();				# make sure we're no longer rotated.
	GL.Translate(1.5, 0.0, -7.0)		# Move Right 3 Units, and back into the screen 7
	
	GL.Rotate(rquad, 1.0, 1.0, 1.0)		# Rotate The Cube On X, Y, and Z

	# draw a cube (6 quadrilaterals)
	GL.Begin(GL::QUADS);				# start drawing the cube.
  
	# top of cube
	GL.Color3f(0.0, 1.0, 0.0)			# Set The Color To Blue
	GL.Vertex3f( 1.0,  1.0, -1.0)		# Top Right Of The Quad (Top)
	GL.Vertex3f(-1.0,  1.0, -1.0)		# Top Left Of The Quad (Top)
	GL.Vertex3f(-1.0,  1.0,  1.0)		# Bottom Left Of The Quad (Top)
	GL.Vertex3f( 1.0,  1.0,  1.0)		# Bottom Right Of The Quad (Top)

	# bottom of cube
	GL.Color3f(1.0, 0.5, 0.0)			# Set The Color To Orange
	GL.Vertex3f( 1.0, -1.0,  1.0)		# Top Right Of The Quad (Bottom)
	GL.Vertex3f(-1.0, -1.0,  1.0)		# Top Left Of The Quad (Bottom)
	GL.Vertex3f(-1.0, -1.0, -1.0)		# Bottom Left Of The Quad (Bottom)
	GL.Vertex3f( 1.0, -1.0, -1.0)		# Bottom Right Of The Quad (Bottom)

	# front of cube
	GL.Color3f(1.0, 0.0, 0.0)			# Set The Color To Red
	GL.Vertex3f( 1.0,  1.0,  1.0)		# Top Right Of The Quad (Front)
	GL.Vertex3f(-1.0,  1.0,  1.0)		# Top Left Of The Quad (Front)
	GL.Vertex3f(-1.0, -1.0,  1.0)		# Bottom Left Of The Quad (Front)
	GL.Vertex3f( 1.0, -1.0,  1.0)		# Bottom Right Of The Quad (Front)

	# back of cube.
	GL.Color3f(1.0, 1.0, 0.0)			# Set The Color To Yellow
	GL.Vertex3f( 1.0, -1.0, -1.0)		# Top Right Of The Quad (Back)
	GL.Vertex3f(-1.0, -1.0, -1.0)		# Top Left Of The Quad (Back)
	GL.Vertex3f(-1.0,  1.0, -1.0)		# Bottom Left Of The Quad (Back)
	GL.Vertex3f( 1.0,  1.0, -1.0)		# Bottom Right Of The Quad (Back)

	# left of cube
	GL.Color3f(0.0, 0.0, 1.0)			# Blue
	GL.Vertex3f(-1.0,  1.0,  1.0)		# Top Right Of The Quad (Left)
	GL.Vertex3f(-1.0,  1.0, -1.0)		# Top Left Of The Quad (Left)
	GL.Vertex3f(-1.0, -1.0, -1.0)		# Bottom Left Of The Quad (Left)
	GL.Vertex3f(-1.0, -1.0,  1.0)		# Bottom Right Of The Quad (Left)

	# Right of cube
	GL.Color3f(1.0, 0.0, 1.0)			# Set The Color To Violet
	GL.Vertex3f( 1.0,  1.0, -1.0)	      	# Top Right Of The Quad (Right)
	GL.Vertex3f( 1.0,  1.0,  1.0)		# Top Left Of The Quad (Right)
	GL.Vertex3f( 1.0, -1.0,  1.0)		# Bottom Left Of The Quad (Right)
	GL.Vertex3f( 1.0, -1.0, -1.0)		# Bottom Right Of The Quad (Right)
	GL.End();					# Done Drawing The Cube	GL.Rotate(rtri, 0.0, 1.0, 0.0)	# Rotate The Triangle On The Y axis 
 
	rtri = rtri + 1.0				# Increase The Rotation Variable For The Triangle
	rquad = rquad - 1.0				# Decrease The Rotation Variable For The Quad 
}

reshape = Proc.new { |w, h|
	GL.Viewport(0, 0,  w,  h) 
	GL.MatrixMode(GL::PROJECTION)
	GL.LoadIdentity()
	GLU.Perspective(60.0, w.to_f/h.to_f, 1.0, 20.0)
	GL.MatrixMode(GL::MODELVIEW)
	GL.LoadIdentity()
	GLU.LookAt(0.0, 0.0, 5.0, 0.0, 0.0, 0.0, 0.0, 1.0, 0.0)
}

init($ScreenWidth, $ScreenHeight)

Key.set_repeat(1,10)

done=false

while !done
	event=EventQueue.poll
	case event
		when QuitEvent
			done=true
		when KeyDownEvent
			case event.key
				when K_ESCAPE
					done=true
			end
	end
	reshape.call($ScreenWidth, $ScreenHeight)
	display.call
	$d.flip
end