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#/*
# * 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# * Unpublished-- rights reserved under the copyright laws of the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();
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