#/*
# * 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# * Unpublished-- rights reserved under the copyright laws of the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.
# */
#
#/*  bezcurve.c			
# *  This program uses evaluators to draw a Bezier curve.
# */

require "opengl"
require "glut"

$ctrlpoints = [
	[ -4.0, -4.0, 0.0], [ -2.0, 4.0, 0.0], 
	[2.0, -4.0, 0.0], [4.0, 4.0, 0.0]];

def init
   GL::ClearColor(0.0, 0.0, 0.0, 0.0);
   GL::ShadeModel(GL::FLAT);
   GL::Map1d(GL::MAP1_VERTEX_3, 0.0, 1.0, 3, 4, $ctrlpoints.flatten);
   GL::Enable(GL::MAP1_VERTEX_3);
end

display = proc {
   GL::Clear(GL::COLOR_BUFFER_BIT);
   GL::Color(1.0, 1.0, 1.0);
   GL::Begin(GL::LINE_STRIP);
      for i in 0...30
         GL::EvalCoord1d(i.to_f/30.0);
      end
   GL::End();
#   /* The following code displays the control points as dots. */
   GL::PointSize(5.0);
   GL::Color(1.0, 1.0, 0.0);
   GL::Begin(GL::POINTS);
      for i in 0...4
         GL::Vertex($ctrlpoints[i]);
      end
   GL::End();
   GL::Flush();
}

reshape = proc {|w, h|
   GL::Viewport(0, 0, w, h);
   GL::MatrixMode(GL::PROJECTION);
   GL::LoadIdentity();
   if (w <= h)
      GL::Ortho(-5.0, 5.0, -5.0*h/w, 5.0*h/w, -5.0, 5.0);
   else
      GL::Ortho(-5.0*w/h, 5.0*w/h, -5.0, 5.0, -5.0, 5.0);
   end
   GL::MatrixMode(GL::MODELVIEW);
   GL::LoadIdentity();
}

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

   GLUT::Init();
   GLUT::InitDisplayMode(GLUT::SINGLE | GLUT::RGB);
   GLUT::InitWindowSize(500, 500);
   GLUT::InitWindowPosition(100, 100);
   GLUT::CreateWindow();
   init();
   GLUT::DisplayFunc(display);
   GLUT::ReshapeFunc(reshape);
   GLUT::KeyboardFunc(keyboard);
   GLUT::MainLoop();