115 lines
3.7 KiB
C
115 lines
3.7 KiB
C
/*
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* Copyright (c) 1993-1997, Silicon Graphics, Inc.
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* ALL RIGHTS RESERVED
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* Permission to use, copy, modify, and distribute this software for
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* any purpose and without fee is hereby granted, provided that the above
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* copyright notice appear in all copies and that both the copyright notice
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* and this permission notice appear in supporting documentation, and that
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* the name of Silicon Graphics, Inc. not be used in advertising
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* or publicity pertaining to distribution of the software without specific,
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* written prior permission.
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*
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* THE MATERIAL EMBODIED ON THIS SOFTWARE IS PROVIDED TO YOU "AS-IS"
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* AND WITHOUT WARRANTY OF ANY KIND, EXPRESS, IMPLIED OR OTHERWISE,
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* INCLUDING WITHOUT LIMITATION, ANY WARRANTY OF MERCHANTABILITY OR
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* FITNESS FOR A PARTICULAR PURPOSE. IN NO EVENT SHALL SILICON
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* GRAPHICS, INC. BE LIABLE TO YOU OR ANYONE ELSE FOR ANY DIRECT,
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* SPECIAL, INCIDENTAL, INDIRECT OR CONSEQUENTIAL DAMAGES OF ANY
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* KIND, OR ANY DAMAGES WHATSOEVER, INCLUDING WITHOUT LIMITATION,
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* LOSS OF PROFIT, LOSS OF USE, SAVINGS OR REVENUE, OR THE CLAIMS OF
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* THIRD PARTIES, WHETHER OR NOT SILICON GRAPHICS, INC. HAS BEEN
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* ADVISED OF THE POSSIBILITY OF SUCH LOSS, HOWEVER CAUSED AND ON
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* ANY THEORY OF LIABILITY, ARISING OUT OF OR IN CONNECTION WITH THE
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* POSSESSION, USE OR PERFORMANCE OF THIS SOFTWARE.
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*
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* US Government Users Restricted Rights
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* Use, duplication, or disclosure by the Government is subject to
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* restrictions set forth in FAR 52.227.19(c)(2) or subparagraph
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* (c)(1)(ii) of the Rights in Technical Data and Computer Software
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* clause at DFARS 252.227-7013 and/or in similar or successor
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* clauses in the FAR or the DOD or NASA FAR Supplement.
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* Unpublished-- rights reserved under the copyright laws of the
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* United States. Contractor/manufacturer is Silicon Graphics,
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* Inc., 2011 N. Shoreline Blvd., Mountain View, CA 94039-7311.
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*
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* OpenGL(R) is a registered trademark of Silicon Graphics, Inc.
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*/
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/* bezcurve.c
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* This program uses evaluators to draw a Bezier curve.
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*/
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#include <stdlib.h>
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#include <GL/glut.h>
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GLfloat ctrlpoints[4][3] = {
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{ -4.0, -4.0, 0.0}, { -2.0, 4.0, 0.0},
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{2.0, -4.0, 0.0}, {4.0, 4.0, 0.0}};
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void init(void)
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{
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glClearColor(0.0, 0.0, 0.0, 0.0);
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glShadeModel(GL_FLAT);
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glMap1f(GL_MAP1_VERTEX_3, 0.0, 1.0, 3, 4, &ctrlpoints[0][0]);
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glEnable(GL_MAP1_VERTEX_3);
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}
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void display(void)
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{
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int i;
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glClear(GL_COLOR_BUFFER_BIT);
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glColor3f(1.0, 1.0, 1.0);
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glBegin(GL_LINE_STRIP);
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for (i = 0; i <= 30; i++)
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glEvalCoord1f((GLfloat) i/30.0);
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glEnd();
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/* The following code displays the control points as dots. */
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glPointSize(5.0);
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glColor3f(1.0, 1.0, 0.0);
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glBegin(GL_POINTS);
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for (i = 0; i < 4; i++)
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glVertex3fv(&ctrlpoints[i][0]);
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glEnd();
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glFlush();
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}
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void reshape(int w, int h)
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{
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glViewport(0, 0, (GLsizei) w, (GLsizei) h);
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glMatrixMode(GL_PROJECTION);
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glLoadIdentity();
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if (w <= h)
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glOrtho(-5.0, 5.0, -5.0*(GLfloat)h/(GLfloat)w,
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5.0*(GLfloat)h/(GLfloat)w, -5.0, 5.0);
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else
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glOrtho(-5.0*(GLfloat)w/(GLfloat)h,
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5.0*(GLfloat)w/(GLfloat)h, -5.0, 5.0, -5.0, 5.0);
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glMatrixMode(GL_MODELVIEW);
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glLoadIdentity();
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}
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/* ARGSUSED1 */
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void keyboard(unsigned char key, int x, int y)
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{
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switch (key) {
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case 27:
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exit(0);
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break;
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}
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}
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int main(int argc, char** argv)
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{
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glutInit(&argc, argv);
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glutInitDisplayMode (GLUT_SINGLE | GLUT_RGB);
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glutInitWindowSize (500, 500);
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glutInitWindowPosition (100, 100);
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glutCreateWindow (argv[0]);
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init ();
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glutDisplayFunc(display);
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glutReshapeFunc(reshape);
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glutKeyboardFunc (keyboard);
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glutMainLoop();
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return 0;
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}
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