#
# Copyright (c) 1993-1997, 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# Unpublished-- rights reserved under the copyright laws of the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(R) is a registered trademark of Silicon Graphics, Inc.
#/

#  texbind.c
#  This program demonstrates using glBindTexture() by 
#  creating and managing two textures.
#/

#define	checkImageWidth 64
#define	checkImageHeight 64

require "opengl"
require "glut"
require "mathn"

CheckImageWidth = 64
CheckImageHeight = 64
#$checkImage = MDArray.new(CheckImageHeight, CheckImageWidth, 4)
#$otherImage = MDArray.new(CheckImageHeight, CheckImageWidth, 4)
$checkImage = []
$otherImage = []

$texName = [];

def makeCheckImages
   for i in (0..CheckImageHeight-1)
      for j in (0..CheckImageWidth-1)
 	 if ((i&0x8==0)!=(j&0x8==0)) then tmp = 1; else tmp=0; end
         #c = ((((i&0x8)==0)^((j&0x8))==0))*255;
         c = tmp * 255;
         $checkImage[i*CheckImageWidth*4+j*4+0] = c;
         $checkImage[i*CheckImageWidth*4+j*4+1] = c;
         $checkImage[i*CheckImageWidth*4+j*4+2] = c;
         $checkImage[i*CheckImageWidth*4+j*4+3] = 255;
         #c = ((((i&0x10)==0)^((j&0x10))==0))*255;
 	 if ((i&0x10==0)!=(j&0x10==0)) then tmp = 1; else tmp=0; end
         c = tmp * 255;
         $otherImage[i*CheckImageWidth*4+j*4+0] = c;
         $otherImage[i*CheckImageWidth*4+j*4+1] = 0;
         $otherImage[i*CheckImageWidth*4+j*4+2] = 0;
         $otherImage[i*CheckImageWidth*4+j*4+3] = 255;
      end
   end
end

def init
   GL.ClearColor(0.0, 0.0, 0.0, 0.0);
   GL.ShadeModel(GL::FLAT);
   GL.Enable(GL::DEPTH_TEST);

   makeCheckImages();
   GL.PixelStorei(GL::UNPACK_ALIGNMENT, 1);

   $texName = GL.GenTextures(2);
   GL.BindTexture(GL::TEXTURE_2D, $texName[0]);
   GL.TexParameteri(GL::TEXTURE_2D, GL::TEXTURE_WRAP_S, GL::CLAMP);
   GL.TexParameteri(GL::TEXTURE_2D, GL::TEXTURE_WRAP_T, GL::CLAMP);
   GL.TexParameteri(GL::TEXTURE_2D, GL::TEXTURE_MAG_FILTER,GL::NEAREST);
   GL.TexParameteri(GL::TEXTURE_2D, GL::TEXTURE_MIN_FILTER,GL::NEAREST);
   GL.TexImage2D(GL::TEXTURE_2D, 0, GL::RGBA, CheckImageWidth,
		CheckImageHeight, 0, GL::RGBA, GL::UNSIGNED_BYTE,
                $checkImage.pack("C*"));

   GL.BindTexture(GL::TEXTURE_2D, $texName[1]);
   GL.TexParameteri(GL::TEXTURE_2D, GL::TEXTURE_WRAP_S, GL::CLAMP);
   GL.TexParameteri(GL::TEXTURE_2D, GL::TEXTURE_WRAP_T, GL::CLAMP);
   GL.TexParameteri(GL::TEXTURE_2D, GL::TEXTURE_MAG_FILTER, GL::NEAREST);
   GL.TexParameteri(GL::TEXTURE_2D, GL::TEXTURE_MIN_FILTER, GL::NEAREST);
   GL.TexEnvf(GL::TEXTURE_ENV, GL::TEXTURE_ENV_MODE, GL::DECAL);
   GL.TexImage2D(GL::TEXTURE_2D, 0, GL::RGBA, CheckImageWidth, 
                CheckImageHeight, 0, GL::RGBA, GL::UNSIGNED_BYTE, 
                $otherImage.pack("C*"));
   GL.Enable(GL::TEXTURE_2D);
end

display = Proc.new {
   GL.Clear(GL::COLOR_BUFFER_BIT | GL::DEPTH_BUFFER_BIT);
   GL.BindTexture(GL::TEXTURE_2D, $texName[0]);
   GL.Begin(GL::QUADS);
   GL.TexCoord(0.0, 0.0); GL.Vertex(-2.0, -1.0, 0.0);
   GL.TexCoord(0.0, 1.0); GL.Vertex(-2.0, 1.0, 0.0);
   GL.TexCoord(1.0, 1.0); GL.Vertex(0.0, 1.0, 0.0);
   GL.TexCoord(1.0, 0.0); GL.Vertex(0.0, -1.0, 0.0);
   GL.End();
   GL.BindTexture(GL::TEXTURE_2D, $texName[1]);
   GL.Begin(GL::QUADS);
   GL.TexCoord(0.0, 0.0); GL.Vertex(1.0, -1.0, 0.0);
   GL.TexCoord(0.0, 1.0); GL.Vertex(1.0, 1.0, 0.0);
   GL.TexCoord(1.0, 1.0); GL.Vertex(2.41421, 1.0, -1.41421);
   GL.TexCoord(1.0, 0.0); GL.Vertex(2.41421, -1.0, -1.41421);
   GL.End();
   GL.Flush();
}

reshape = Proc.new {|w, h|
   GL.Viewport(0, 0,  w, h);
   GL.MatrixMode(GL::PROJECTION);
   GL.LoadIdentity();
   GLU.Perspective(60.0, w/h, 1.0, 30.0);
   GL.MatrixMode(GL::MODELVIEW);
   GL.LoadIdentity();
   GL.Translate(0.0, 0.0, -3.6);
}

#* ARGSUSED1 */
keyboard = Proc.new {|key, x, y|
   case (key)
      when 27
         exit(0);
   end
}

   GLUT.Init
   GLUT.InitDisplayMode(GLUT::SINGLE | GLUT::RGB | GLUT::DEPTH);
   GLUT.InitWindowSize(250, 250);
   GLUT.InitWindowPosition(100, 100);
   GLUT.CreateWindow($0);
   init();
   GLUT.ReshapeFunc(reshape);
   GLUT.DisplayFunc(display);
   GLUT.KeyboardFunc(keyboard);
   GLUT.MainLoop();