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34  * Unpublished-- rights reserved under the copyright laws of the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 /*
41  *  nurbs.c
42  *  This program shows a NURBS (Non-uniform rational B-splines)
43  *  surface, shaped like a heart.
44  */
45 #include <stdlib.h>
46 #include "glut_wrap.h"
47 
48 #define S_NUMPOINTS 13
49 #define S_ORDER     3
50 #define S_NUMKNOTS  (S_NUMPOINTS + S_ORDER)
51 #define T_NUMPOINTS 3
52 #define T_ORDER     3
53 #define T_NUMKNOTS  (T_NUMPOINTS + T_ORDER)
54 #define SQRT2    1.41421356237309504880
55 
56 /* initialized local data */
57 
58 GLfloat sknots[S_NUMKNOTS] =
59     {-1.0, -1.0, -1.0, 0.0, 1.0, 2.0, 3.0, 4.0,
60       4.0,  5.0,  6.0, 7.0, 8.0, 9.0, 9.0, 9.0};
61 GLfloat tknots[T_NUMKNOTS] = {1.0, 1.0, 1.0, 2.0, 2.0, 2.0};
62 
63 GLfloat ctlpoints[S_NUMPOINTS][T_NUMPOINTS][4] = {
64 {   {4.,2.,2.,1.},{4.,1.6,2.5,1.},{4.,2.,3.0,1.}    },
65 {   {5.,4.,2.,1.},{5.,4.,2.5,1.},{5.,4.,3.0,1.} },
66 {   {6.,5.,2.,1.},{6.,5.,2.5,1.},{6.,5.,3.0,1.} },
67 {   {SQRT2*6.,SQRT2*6.,SQRT2*2.,SQRT2},
68     {SQRT2*6.,SQRT2*6.,SQRT2*2.5,SQRT2},
69     {SQRT2*6.,SQRT2*6.,SQRT2*3.0,SQRT2}  },
70 {   {5.2,6.7,2.,1.},{5.2,6.7,2.5,1.},{5.2,6.7,3.0,1.}   },
71 {   {SQRT2*4.,SQRT2*6.,SQRT2*2.,SQRT2},
72     {SQRT2*4.,SQRT2*6.,SQRT2*2.5,SQRT2},
73     {SQRT2*4.,SQRT2*6.,SQRT2*3.0,SQRT2}  },
74 {   {4.,5.2,2.,1.},{4.,4.6,2.5,1.},{4.,5.2,3.0,1.}  },
75 {   {SQRT2*4.,SQRT2*6.,SQRT2*2.,SQRT2},
76     {SQRT2*4.,SQRT2*6.,SQRT2*2.5,SQRT2},
77     {SQRT2*4.,SQRT2*6.,SQRT2*3.0,SQRT2}  },
78 {   {2.8,6.7,2.,1.},{2.8,6.7,2.5,1.},{2.8,6.7,3.0,1.}   },
79 {   {SQRT2*2.,SQRT2*6.,SQRT2*2.,SQRT2},
80     {SQRT2*2.,SQRT2*6.,SQRT2*2.5,SQRT2},
81     {SQRT2*2.,SQRT2*6.,SQRT2*3.0,SQRT2}  },
82 {   {2.,5.,2.,1.},{2.,5.,2.5,1.},{2.,5.,3.0,1.} },
83 {   {3.,4.,2.,1.},{3.,4.,2.5,1.},{3.,4.,3.0,1.} },
84 {   {4.,2.,2.,1.},{4.,1.6,2.5,1.},{4.,2.,3.0,1.}    }
85 };
86 
87 GLUnurbsObj *theNurb;
88 
89 /*  Initialize material property, light source, lighting model,
90  *  and depth buffer.
91  */
myinit(void)92 static void myinit(void)
93 {
94     GLfloat mat_ambient[] = { 1.0, 1.0, 1.0, 1.0 };
95     GLfloat mat_diffuse[] = { 1.0, 0.2, 1.0, 1.0 };
96     GLfloat mat_specular[] = { 1.0, 1.0, 1.0, 1.0 };
97     GLfloat mat_shininess[] = { 50.0 };
98 
99     GLfloat light0_position[] = { 1.0, 0.1, 1.0, 0.0 };
100     GLfloat light1_position[] = { -1.0, 0.1, 1.0, 0.0 };
101 
102     GLfloat lmodel_ambient[] = { 0.3, 0.3, 0.3, 1.0 };
103 
104     glMaterialfv(GL_FRONT, GL_AMBIENT, mat_ambient);
105     glMaterialfv(GL_FRONT, GL_DIFFUSE, mat_diffuse);
106     glMaterialfv(GL_FRONT, GL_SPECULAR, mat_specular);
107     glMaterialfv(GL_FRONT, GL_SHININESS, mat_shininess);
108     glLightfv(GL_LIGHT0, GL_POSITION, light0_position);
109     glLightfv(GL_LIGHT1, GL_POSITION, light1_position);
110     glLightModelfv(GL_LIGHT_MODEL_AMBIENT, lmodel_ambient);
111 
112     glEnable(GL_LIGHTING);
113     glEnable(GL_LIGHT0);
114     glEnable(GL_LIGHT1);
115     glDepthFunc(GL_LESS);
116     glEnable(GL_DEPTH_TEST);
117     glEnable(GL_AUTO_NORMAL);
118 
119     theNurb = gluNewNurbsRenderer();
120 
121     gluNurbsProperty(theNurb, GLU_SAMPLING_TOLERANCE, 25.0);
122     gluNurbsProperty(theNurb, GLU_DISPLAY_MODE, GLU_FILL);
123 }
124 
display(void)125 static void display(void)
126 {
127     glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
128 
129     glPushMatrix();
130     glTranslatef (4., 4.5, 2.5);
131     glRotatef (220.0, 1., 0., 0.);
132     glRotatef (115.0, 0., 1., 0.);
133     glTranslatef (-4., -4.5, -2.5);
134 
135     gluBeginSurface(theNurb);
136     gluNurbsSurface(theNurb,
137 	    S_NUMKNOTS, sknots,
138 	    T_NUMKNOTS, tknots,
139 	    4 * T_NUMPOINTS,
140 	    4,
141 	    &ctlpoints[0][0][0],
142 	    S_ORDER, T_ORDER,
143 	    GL_MAP2_VERTEX_4);
144     gluEndSurface(theNurb);
145 
146     glPopMatrix();
147     glFlush();
148 }
149 
myReshape(int w,int h)150 static void myReshape(int w, int h)
151 {
152     glViewport(0, 0, w, h);
153     glMatrixMode(GL_PROJECTION);
154     glLoadIdentity();
155     glFrustum(-1.0, 1.0, -1.5, 0.5, 0.8, 10.0);
156 
157     glMatrixMode(GL_MODELVIEW);
158     glLoadIdentity();
159     gluLookAt(7.0,4.5,4.0, 4.5,4.5,2.0, 6.0,-3.0,2.0);
160 }
161 
162 static void
key(unsigned char k,int x,int y)163 key(unsigned char k, int x, int y)
164 {
165   switch (k) {
166   case 27:  /* Escape */
167     exit(0);
168     break;
169   default:
170     return;
171   }
172   glutPostRedisplay();
173 }
174 
175 /*  Main Loop
176  *  Open window with initial window size, title bar,
177  *  RGBA display mode, and handle input events.
178  */
main(int argc,char ** argv)179 int main(int argc, char** argv)
180 {
181     glutInit(&argc, argv);
182     glutInitDisplayMode (GLUT_SINGLE | GLUT_RGB | GLUT_DEPTH);
183     glutCreateWindow (argv[0]);
184     myinit();
185     glutReshapeFunc (myReshape);
186     glutDisplayFunc(display);
187     glutKeyboardFunc(key);
188     glutMainLoop();
189     return 0;             /* ANSI C requires main to return int. */
190 }
191