/*
 * (c) Copyright 1993, 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 * Unpublished-- rights reserved under the copyright laws of the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(TM) is a trademark of Silicon Graphics, Inc.
 */
/*
 *  curve.c
 *  This program uses the Utility Library NURBS routines to
 *  draw a one-dimensional NURBS curve.
 */
#include <GL/gl.h>
#include <GL/glu.h>
#include "aux.h"

GLUnurbsObj *theNurb;

void myinit(void)
{
    glShadeModel (GL_FLAT);
    theNurb = gluNewNurbsRenderer();
    gluNurbsProperty (theNurb, GLU_SAMPLING_TOLERANCE, 10.0);
}

/*  This routine draws a B-spline curve.  Try a different 
 *  knot sequence for a Bezier curve.  For example,
    GLfloat knots[8] = {0.0, 1.0, 2.0, 3.0, 4.0, 5.0, 6.0, 7.0};
 */

void display(void)
{
    GLfloat ctlpoints[4][3] = {{-.75, -.75, 0.0}, 
	{-.5, .75, 0.0}, {.5, .75, 0.0}, {.75, -.75, 0.0}};
    GLfloat knots[8] = {0.0, 0.0, 0.0, 0.0, 1.0, 1.0, 1.0, 1.0}; 

    glClear(GL_COLOR_BUFFER_BIT);
    glColor3f (1.0, 1.0, 1.0);
    gluBeginCurve(theNurb);
    gluNurbsCurve(theNurb, 
	    8, knots,
	    3,
	    &ctlpoints[0][0], 
	    4,
	    GL_MAP1_VERTEX_3);
    gluEndCurve(theNurb);
    glFlush();
}

void myReshape(int w, int h)
{
    glViewport(0, 0, w, h);
    glMatrixMode(GL_PROJECTION);
    glLoadIdentity();
    if (w <= h)
	gluOrtho2D (-1.0, 1.0, -1.0 * (GLfloat) h/(GLfloat) w, 
	    1.0 * (GLfloat) h/(GLfloat) w);
    else
	gluOrtho2D (-1.0 * (GLfloat) w/(GLfloat) h,
	    1.0 * (GLfloat) w/(GLfloat) h, -1.0, 1.0);
    glMatrixMode(GL_MODELVIEW);
    glLoadIdentity();
}

/*  Main Loop 
 */
int main(int argc, char** argv)
{
    auxInitDisplayMode (AUX_SINGLE | AUX_RGB);
    auxInitPosition (0, 0, 500, 500);
    auxInitWindow (argv[0]);
    myinit();
    auxReshapeFunc (myReshape);
    auxMainLoop(display);
}