bezmesh.c revision 32001f49 
1
2/* Copyright (c) Mark J. Kilgard, 1994. */
3
4/**
5 * (c) Copyright 1993, Silicon Graphics, Inc.
6 * ALL RIGHTS RESERVED
7 * Permission to use, copy, modify, and distribute this software for
8 * any purpose and without fee is hereby granted, provided that the above
9 * copyright notice appear in all copies and that both the copyright notice
10 * and this permission notice appear in supporting documentation, and that
11 * the name of Silicon Graphics, Inc. not be used in advertising
12 * or publicity pertaining to distribution of the software without specific,
13 * written prior permission.
14 *
15 * THE MATERIAL EMBODIED ON THIS SOFTWARE IS PROVIDED TO YOU "AS-IS"
16 * AND WITHOUT WARRANTY OF ANY KIND, EXPRESS, IMPLIED OR OTHERWISE,
17 * INCLUDING WITHOUT LIMITATION, ANY WARRANTY OF MERCHANTABILITY OR
18 * FITNESS FOR A PARTICULAR PURPOSE.  IN NO EVENT SHALL SILICON
19 * GRAPHICS, INC.  BE LIABLE TO YOU OR ANYONE ELSE FOR ANY DIRECT,
20 * SPECIAL, INCIDENTAL, INDIRECT OR CONSEQUENTIAL DAMAGES OF ANY
21 * KIND, OR ANY DAMAGES WHATSOEVER, INCLUDING WITHOUT LIMITATION,
22 * LOSS OF PROFIT, LOSS OF USE, SAVINGS OR REVENUE, OR THE CLAIMS OF
23 * THIRD PARTIES, WHETHER OR NOT SILICON GRAPHICS, INC.  HAS BEEN
24 * ADVISED OF THE POSSIBILITY OF SUCH LOSS, HOWEVER CAUSED AND ON
25 * ANY THEORY OF LIABILITY, ARISING OUT OF OR IN CONNECTION WITH THE
26 * POSSESSION, USE OR PERFORMANCE OF THIS SOFTWARE.
27 *
28 * US Government Users Restricted Rights
29 * Use, duplication, or disclosure by the Government is subject to
30 * restrictions set forth in FAR 52.227.19(c)(2) or subparagraph
31 * (c)(1)(ii) of the Rights in Technical Data and Computer Software
32 * clause at DFARS 252.227-7013 and/or in similar or successor
33 * clauses in the FAR or the DOD or NASA FAR Supplement.
34 * Unpublished-- rights reserved under the copyright laws of the
35 * United States.  Contractor/manufacturer is Silicon Graphics,
36 * Inc., 2011 N.  Shoreline Blvd., Mountain View, CA 94039-7311.
37 *
38 * OpenGL(TM) is a trademark of Silicon Graphics, Inc.
39 */
40/*  bezsurf.c
41 *  This program renders a lighted, filled Bezier surface,
42 *  using two-dimensional evaluators.
43 */
44#include <stdlib.h>
45#include "glut_wrap.h"
46
47GLfloat ctrlpoints[4][4][3] =
48{
49    {
50        {-1.5, -1.5, 4.0},
51        {-0.5, -1.5, 2.0},
52        {0.5, -1.5, -1.0},
53        {1.5, -1.5, 2.0}},
54    {
55        {-1.5, -0.5, 1.0},
56        {-0.5, -0.5, 3.0},
57        {0.5, -0.5, 0.0},
58        {1.5, -0.5, -1.0}},
59    {
60        {-1.5, 0.5, 4.0},
61        {-0.5, 0.5, 0.0},
62        {0.5, 0.5, 3.0},
63        {1.5, 0.5, 4.0}},
64    {
65        {-1.5, 1.5, -2.0},
66        {-0.5, 1.5, -2.0},
67        {0.5, 1.5, 0.0},
68        {1.5, 1.5, -1.0}}
69};
70
71static void
72initlights(void)
73{
74    GLfloat ambient[] =
75    {0.2, 0.2, 0.2, 1.0};
76    GLfloat position[] =
77    {0.0, 0.0, 2.0, 1.0};
78    GLfloat mat_diffuse[] =
79    {0.6, 0.6, 0.6, 1.0};
80    GLfloat mat_specular[] =
81    {1.0, 1.0, 1.0, 1.0};
82    GLfloat mat_shininess[] =
83    {50.0};
84
85    glEnable(GL_LIGHTING);
86    glEnable(GL_LIGHT0);
87
88    glLightfv(GL_LIGHT0, GL_AMBIENT, ambient);
89    glLightfv(GL_LIGHT0, GL_POSITION, position);
90
91    glMaterialfv(GL_FRONT, GL_DIFFUSE, mat_diffuse);
92    glMaterialfv(GL_FRONT, GL_SPECULAR, mat_specular);
93    glMaterialfv(GL_FRONT, GL_SHININESS, mat_shininess);
94}
95
96static void
97display(void)
98{
99    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
100    glPushMatrix();
101    glRotatef(85.0, 1.0, 1.0, 1.0);
102    glEvalMesh2(GL_FILL, 0, 20, 0, 20);
103    glPopMatrix();
104    glFlush();
105}
106
107static void
108myinit(void)
109{
110    glClearColor(0.0, 0.0, 0.0, 1.0);
111    glEnable(GL_DEPTH_TEST);
112    glMap2f(GL_MAP2_VERTEX_3, 0, 1, 3, 4,
113        0, 1, 12, 4, &ctrlpoints[0][0][0]);
114    glEnable(GL_MAP2_VERTEX_3);
115    glEnable(GL_AUTO_NORMAL);
116    glEnable(GL_NORMALIZE);
117    glMapGrid2f(20, 0.0, 1.0, 20, 0.0, 1.0);
118    initlights();       /* for lighted version only */
119}
120
121static void
122myReshape(int w, int h)
123{
124    glViewport(0, 0, w, h);
125    glMatrixMode(GL_PROJECTION);
126    glLoadIdentity();
127    if (w <= h)
128        glOrtho(-4.0, 4.0, -4.0 * (GLfloat) h / (GLfloat) w,
129            4.0 * (GLfloat) h / (GLfloat) w, -4.0, 4.0);
130    else
131        glOrtho(-4.0 * (GLfloat) w / (GLfloat) h,
132            4.0 * (GLfloat) w / (GLfloat) h, -4.0, 4.0, -4.0, 4.0);
133    glMatrixMode(GL_MODELVIEW);
134    glLoadIdentity();
135}
136
137static void
138key(unsigned char k, int x, int y)
139{
140  switch (k) {
141  case 27:  /* Escape */
142    exit(0);
143    break;
144  default:
145    return;
146  }
147  glutPostRedisplay();
148}
149
150int
151main(int argc, char **argv)
152{
153    glutInit(&argc, argv);
154    glutInitDisplayMode(GLUT_SINGLE | GLUT_RGB | GLUT_DEPTH);
155    glutCreateWindow(argv[0]);
156    myinit();
157    glutReshapeFunc(myReshape);
158    glutDisplayFunc(display);
159    glutKeyboardFunc(key);
160    glutMainLoop();
161    return 0;             /* ANSI C requires main to return int. */
162}
163