progs/redbook/surface.c

   1 /* aux2glut conversion Copyright (c) Mark J. Kilgard, 1994, 1995 */
   2
   3 /**
   4  * (c) Copyright 1993, Silicon Graphics, Inc.
   5  * ALL RIGHTS RESERVED
   6  * Permission to use, copy, modify, and distribute this software for
   7  * any purpose and without fee is hereby granted, provided that the above
   8  * copyright notice appear in all copies and that both the copyright notice
   9  * and this permission notice appear in supporting documentation, and that
  10  * the name of Silicon Graphics, Inc. not be used in advertising
  11  * or publicity pertaining to distribution of the software without specific,
  12  * written prior permission.
  13  *
  14  * THE MATERIAL EMBODIED ON THIS SOFTWARE IS PROVIDED TO YOU "AS-IS"
  15  * AND WITHOUT WARRANTY OF ANY KIND, EXPRESS, IMPLIED OR OTHERWISE,
  16  * INCLUDING WITHOUT LIMITATION, ANY WARRANTY OF MERCHANTABILITY OR
  17  * FITNESS FOR A PARTICULAR PURPOSE.  IN NO EVENT SHALL SILICON
  18  * GRAPHICS, INC.  BE LIABLE TO YOU OR ANYONE ELSE FOR ANY DIRECT,
  19  * SPECIAL, INCIDENTAL, INDIRECT OR CONSEQUENTIAL DAMAGES OF ANY
  20  * KIND, OR ANY DAMAGES WHATSOEVER, INCLUDING WITHOUT LIMITATION,
  21  * LOSS OF PROFIT, LOSS OF USE, SAVINGS OR REVENUE, OR THE CLAIMS OF
  22  * THIRD PARTIES, WHETHER OR NOT SILICON GRAPHICS, INC.  HAS BEEN
  23  * ADVISED OF THE POSSIBILITY OF SUCH LOSS, HOWEVER CAUSED AND ON
  24  * ANY THEORY OF LIABILITY, ARISING OUT OF OR IN CONNECTION WITH THE
  25  * POSSESSION, USE OR PERFORMANCE OF THIS SOFTWARE.
  26  *
  27  * US Government Users Restricted Rights
  28  * Use, duplication, or disclosure by the Government is subject to
  29  * restrictions set forth in FAR 52.227.19(c)(2) or subparagraph
  30  * (c)(1)(ii) of the Rights in Technical Data and Computer Software
  31  * clause at DFARS 252.227-7013 and/or in similar or successor
  32  * clauses in the FAR or the DOD or NASA FAR Supplement.
  33  * Unpublished-- rights reserved under the copyright laws of the
  34  * United States.  Contractor/manufacturer is Silicon Graphics,
  35  * Inc., 2011 N.  Shoreline Blvd., Mountain View, CA 94039-7311.
  36  *
  37  * OpenGL(TM) is a trademark of Silicon Graphics, Inc.
  38  */
  39 /**
  40  *  surface.c
  41  *  This program draws a NURBS surface in the shape of a
  42  *  symmetrical hill.
  43  */
  44 #include <GL/glut.h>
  45
  46 GLfloat ctlpoints[4][4][3];
  47 int showPoints = 0;
  48
  49 GLUnurbsObj *theNurb;
  50
  51 /*
  52  *  Initializes the control points of the surface to a small hill.
  53  *  The control points range from -3 to +3 in x, y, and z
  54  */
  55 void init_surface(void)
  56 {
  57     int u, v;
  58     for (u = 0; u < 4; u++) {
  59         for (v = 0; v < 4; v++) {
  60             ctlpoints[u][v][0] = 2.0*((GLfloat)u - 1.5);
  61             ctlpoints[u][v][1] = 2.0*((GLfloat)v - 1.5);
  62
  63             if ( (u == 1 || u == 2) && (v == 1 || v == 2))
  64                 ctlpoints[u][v][2] = 7.0;
  65             else
  66                 ctlpoints[u][v][2] = -3.0;
  67         }
  68     }
  69 }
  70
  71 /*  Initialize material property and depth buffer.
  72  */
  73 void myinit(void)
  74 {
  75     GLfloat mat_diffuse[] = { 0.7, 0.7, 0.7, 1.0 };
  76     GLfloat mat_specular[] = { 1.0, 1.0, 1.0, 1.0 };
  77     GLfloat mat_shininess[] = { 100.0 };
  78
  79     glClearColor (0.0, 0.0, 0.0, 1.0);
  80     glMaterialfv(GL_FRONT, GL_DIFFUSE, mat_diffuse);
  81     glMaterialfv(GL_FRONT, GL_SPECULAR, mat_specular);
  82     glMaterialfv(GL_FRONT, GL_SHININESS, mat_shininess);
  83
  84     glEnable(GL_LIGHTING);
  85     glEnable(GL_LIGHT0);
  86     glDepthFunc(GL_LESS);
  87     glEnable(GL_DEPTH_TEST);
  88     glEnable(GL_AUTO_NORMAL);
  89     glEnable(GL_NORMALIZE);
  90
  91     init_surface();
  92
  93     theNurb = gluNewNurbsRenderer();
  94     gluNurbsProperty(theNurb, GLU_SAMPLING_TOLERANCE, 25.0);
  95     gluNurbsProperty(theNurb, GLU_DISPLAY_MODE, GLU_FILL);
  96
  97     glMatrixMode(GL_MODELVIEW);
  98     glLoadIdentity();
  99     glTranslatef (0.0, 0.0, -5.0);
 100 }
 101
 102 void display(void)
 103 {
 104     GLfloat knots[8] = {0.0, 0.0, 0.0, 0.0, 1.0, 1.0, 1.0, 1.0};
 105     int i, j;
 106
 107     glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
 108
 109     glPushMatrix();
 110     glRotatef(330.0, 1.,0.,0.);
 111     glScalef (0.25, 0.25, 0.25);
 112
 113     gluBeginSurface(theNurb);
 114     gluNurbsSurface(theNurb,
 115             8, knots,
 116             8, knots,
 117             4 * 3,
 118             3,
 119             &ctlpoints[0][0][0],
 120             4, 4,
 121             GL_MAP2_VERTEX_3);
 122     gluEndSurface(theNurb);
 123
 124     if(showPoints) {
 125     glPointSize(5.0);
 126     glDisable(GL_LIGHTING);
 127     glColor3f(1.0, 1.0, 0.0);
 128     glBegin(GL_POINTS);
 129     for(i=0;i<4;i++) {
 130       for(j=0;j<4;j++) {
 131         glVertex3f(ctlpoints[i][j][0], ctlpoints[i][j][1], ctlpoints[i][j][2]);
 132       }
 133     }
 134     glEnd();
 135     glEnable(GL_LIGHTING);
 136     }
 137
 138     glPopMatrix();
 139     glutSwapBuffers();
 140 }
 141
 142 void reshape(int w, int h)
 143 {
 144     glViewport(0, 0, w, h);
 145     glMatrixMode(GL_PROJECTION);
 146     glLoadIdentity();
 147     gluPerspective (45.0, (GLdouble)w/(GLdouble)h, 3.0, 8.0);
 148
 149     glMatrixMode(GL_MODELVIEW);
 150 }
 151
 152 void
 153 menu(int value)
 154 {
 155     switch (value) {
 156     case 0:
 157     case 1:
 158         showPoints = value;
 159         break;
 160     case 2:
 161         gluNurbsProperty(theNurb, GLU_DISPLAY_MODE, GLU_FILL);
 162         break;
 163     case 3:
 164         gluNurbsProperty(theNurb, GLU_DISPLAY_MODE, GLU_OUTLINE_POLYGON);
 165         break;
 166     }
 167     glutPostRedisplay();
 168 }
 169
 170 int down = 0, lastx;
 171
 172 /* ARGSUSED1 */
 173 void
 174 motion(int x, int y)
 175 {
 176     if (down) {
 177         glRotatef(lastx - x, 0, 1, 0);
 178         lastx = x;
 179         glutPostRedisplay();
 180     }
 181 }
 182
 183 /* ARGSUSED3 */
 184 void
 185 mouse(int button, int state, int x, int y)
 186 {
 187     if (button == GLUT_LEFT_BUTTON) {
 188         if (state == GLUT_DOWN) {
 189             lastx = x;
 190             down = 1;
 191         } else {
 192             down = 0;
 193         }
 194     }
 195 }
 196
 197 static void
 198 key(unsigned char k, int x, int y)
 199 {
 200   switch (k) {
 201   case 27:  /* Escape */
 202     exit(0);
 203     break;
 204   default:
 205     return;
 206   }
 207   glutPostRedisplay();
 208 }
 209
 210 /* Main Loop */
 211 int
 212 main(int argc, char** argv)
 213 {
 214     glutInit(&argc, argv);
 215     glutInitDisplayMode(GLUT_DEPTH | GLUT_DOUBLE | GLUT_RGB);
 216     glutCreateWindow(argv[0]);
 217     myinit();
 218     glutReshapeFunc(reshape);
 219     glutDisplayFunc(display);
 220     glutCreateMenu(menu);
 221     glutAddMenuEntry("Show control points", 1);
 222     glutAddMenuEntry("Hide control points", 0);
 223     glutAddMenuEntry("Solid", 2);
 224     glutAddMenuEntry("Wireframe", 3);
 225     glutAttachMenu(GLUT_RIGHT_BUTTON);
 226     glutMouseFunc(mouse);
 227     glutMotionFunc(motion);
 228     glutKeyboardFunc(key);
 229     glutMainLoop();
 230     return 0;             /* ANSI C requires main to return int. */
 231 }