#!/usr/bin/env ruby

#/*
# * Copyright (c) 1993-1997, Silicon Graphics, Inc.
# * ALL RIGHTS RESERVED 
# * Permission to use, copy, modify, and distribute this software for 
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# * 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,
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# * KIND, OR ANY DAMAGES WHATSOEVER, INCLUDING WITHOUT LIMITATION,
# * LOSS OF PROFIT, LOSS OF USE, SAVINGS OR REVENUE, OR THE CLAIMS OF
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# * ADVISED OF THE POSSIBILITY OF SUCH LOSS, HOWEVER CAUSED AND ON
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# * 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# * Unpublished-- rights reserved under the copyright laws of the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(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
# 
# lesson06.rbw :
#
# rotating texture mapped cube  
# 
# */

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

include Constant

$Textures = []

# rotation angles
rotx, roty, rotz = 0.0, 0.0, 0.0

$ScreenWidth, $ScreenHeight = 640, 480

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

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

# Load Bitmaps And Convert To Textures
def loadGLTextures
	# Load Texture
	raw_image = Surface.load_new("Data06/NeHe.bmp")
	if (raw_image.nil?)
		SDL_Quit
		exit (1)
	end
	# convert bmp from BGR to RGB - no BGR mask on Windows
    image = Surface.new(raw_image.size, SWSURFACE, 24, [0x000000FF, 0x0000FF00, 0x00FF0000, 0])
    image.blit(raw_image, [0,0])
	
	# Create Texture   
	$Textures = GL.GenTextures(1);
	GL.BindTexture(GL::TEXTURE_2D, $Textures[0]);
	
	GL.TexParameteri(GL::TEXTURE_2D, GL::TEXTURE_MAG_FILTER, GL::LINEAR);
	GL.TexParameteri(GL::TEXTURE_2D, GL::TEXTURE_MIN_FILTER, GL::LINEAR);
	# 2d texture, level of detail 0 (normal), 3 components (red, green, blue), x size from image, y size from image, 
	# border 0 (normal), rgb color data, unsigned byte data, and finally the data itself.
	puts "Pix len: [#{image.pixels.size}]"
	GL.TexImage2D(GL::TEXTURE_2D, 0, 3, image.w, image.h, 0, GL::RGB, GL::UNSIGNED_BYTE, image.pixels)

end

def init(w,h)
  	loadGLTextures
	GL.ClearColor(0.0, 0.0, 0.7, 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.Enable(GL::TEXTURE_2D);
	#	GL.TexEnvf(GL::TEXTURE_ENV, GL::TEXTURE_ENV_MODE, GL::DECAL);
	
	GL.LoadIdentity();				# make sure we're no longer rotated.
	GL.Translate(0.0, 0.0, -4.0)		# back into the screen 4 4 4 4 
	
	GL.Rotate(rotx, 1.0, 0.0, 0.0)		# Rotate The Cube On X, Y, and Z
	GL.Rotate(roty, 0.0, 1.0, 0.0)		# Rotate The Cube On X, Y, and Z
	GL.Rotate(rotz, 0.0, 0.0, 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.TexCoord(0.0, 1.0);	GL.Vertex3f( 1.0, 1.0, -1.0)		# Top Right Of The Quad (Top)
	GL.TexCoord(1.0, 1.0);	GL.Vertex3f(-1.0,  1.0, -1.0)		# Top Left Of The Quad (Top)
	GL.TexCoord(1.0, 0.0);	GL.Vertex3f(-1.0,  1.0,  1.0)		# Bottom Left Of The Quad (Top)
	GL.TexCoord(0.0, 0.0);	GL.Vertex3f( 1.0,  1.0,  1.0)		# Bottom Right Of The Quad (Top)

	# bottom of cube
	GL.TexCoord(0.0, 1.0);	GL.Vertex3f( 1.0, -1.0,  1.0)		# Top Right Of The Quad (Bottom)
	GL.TexCoord(1.0, 1.0);	GL.Vertex3f(-1.0, -1.0,  1.0)		# Top Left Of The Quad (Bottom)
	GL.TexCoord(1.0, 0.0);	GL.Vertex3f(-1.0, -1.0, -1.0)		# Bottom Left Of The Quad (Bottom)
	GL.TexCoord(0.0, 0.0);	GL.Vertex3f( 1.0, -1.0, -1.0)		# Bottom Right Of The Quad (Bottom)

	# front of cube
	GL.TexCoord(0.0, 1.0);	GL.Vertex3f( 1.0,  1.0,  1.0)		# Top Right Of The Quad (Front)
	GL.TexCoord(1.0, 1.0);	GL.Vertex3f(-1.0,  1.0,  1.0)		# Top Left Of The Quad (Front)
	GL.TexCoord(1.0, 0.0);	GL.Vertex3f(-1.0, -1.0,  1.0)		# Bottom Left Of The Quad (Front)
	GL.TexCoord(0.0, 0.0);	GL.Vertex3f( 1.0, -1.0,  1.0)		# Bottom Right Of The Quad (Front)

	# back of cube.
	GL.TexCoord(0.0, 1.0);  GL.Vertex3f( 1.0, -1.0, -1.0)		# Top Right Of The Quad (Back)
	GL.TexCoord(1.0, 1.0); 	GL.Vertex3f(-1.0, -1.0, -1.0)		# Top Left Of The Quad (Back)
	GL.TexCoord(1.0, 0.0); 	GL.Vertex3f(-1.0,  1.0, -1.0)		# Bottom Left Of The Quad (Back)
	GL.TexCoord(0.0, 0.0); 	GL.Vertex3f( 1.0,  1.0, -1.0)		# Bottom Right Of The Quad (Back)

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

	# Right of cube
	GL.TexCoord(0.0, 1.0);	GL.Vertex3f( 1.0,  1.0, -1.0)	      	# Top Right Of The Quad (Right)
	GL.TexCoord(1.0, 1.0);	GL.Vertex3f( 1.0,  1.0,  1.0)		# Top Left Of The Quad (Right)
	GL.TexCoord(1.0, 0.0);	GL.Vertex3f( 1.0, -1.0,  1.0)		# Bottom Left Of The Quad (Right)
	GL.TexCoord(0.0, 0.0);	GL.Vertex3f( 1.0, -1.0, -1.0)		# Bottom Right Of The Quad (Right)
	GL.End();

	GL.Disable(GL::TEXTURE_2D);
	rotx += 0.1
	roty += 0.1
	rotz += 0.1
}

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)

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