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  33  * Unpublished-- rights reserved under the copyright laws of the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 <stdlib.h>
  45 #include <GL/glut.h>
  46
  47 GLfloat ctlpoints[4][4][3];
  48 int showPoints = 0;
  49
  50 GLUnurbsObj *theNurb;
  51
  52 /*
  53  *  Initializes the control points of the surface to a small hill.
  54  *  The control points range from -3 to +3 in x, y, and z
  55  */
  56 static void init_surface(void)
  57 {
  58     int u, v;
  59     for (u = 0; u < 4; u++) {
  60         for (v = 0; v < 4; v++) {
  61             ctlpoints[u][v][0] = 2.0*((GLfloat)u - 1.5);
  62             ctlpoints[u][v][1] = 2.0*((GLfloat)v - 1.5);
  63
  64             if ( (u == 1 || u == 2) && (v == 1 || v == 2))
  65                 ctlpoints[u][v][2] = 7.0;
  66             else
  67                 ctlpoints[u][v][2] = -3.0;
  68         }
  69     }
  70 }
  71
  72 /*  Initialize material property and depth buffer.
  73  */
  74 static void myinit(void)
  75 {
  76     GLfloat mat_diffuse[] = { 0.7, 0.7, 0.7, 1.0 };
  77     GLfloat mat_specular[] = { 1.0, 1.0, 1.0, 1.0 };
  78     GLfloat mat_shininess[] = { 100.0 };
  79
  80     glClearColor (0.0, 0.0, 0.0, 1.0);
  81     glMaterialfv(GL_FRONT, GL_DIFFUSE, mat_diffuse);
  82     glMaterialfv(GL_FRONT, GL_SPECULAR, mat_specular);
  83     glMaterialfv(GL_FRONT, GL_SHININESS, mat_shininess);
  84
  85     glEnable(GL_LIGHTING);
  86     glEnable(GL_LIGHT0);
  87     glDepthFunc(GL_LESS);
  88     glEnable(GL_DEPTH_TEST);
  89     glEnable(GL_AUTO_NORMAL);
  90     glEnable(GL_NORMALIZE);
  91
  92     init_surface();
  93
  94     theNurb = gluNewNurbsRenderer();
  95     gluNurbsProperty(theNurb, GLU_SAMPLING_TOLERANCE, 25.0);
  96     gluNurbsProperty(theNurb, GLU_DISPLAY_MODE, GLU_FILL);
  97
  98     glMatrixMode(GL_MODELVIEW);
  99     glLoadIdentity();
 100     glTranslatef (0.0, 0.0, -5.0);
 101 }
 102
 103 static void display(void)
 104 {
 105     GLfloat knots[8] = {0.0, 0.0, 0.0, 0.0, 1.0, 1.0, 1.0, 1.0};
 106     int i, j;
 107
 108     glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
 109
 110     glPushMatrix();
 111     glRotatef(330.0, 1.,0.,0.);
 112     glScalef (0.25, 0.25, 0.25);
 113
 114     gluBeginSurface(theNurb);
 115     gluNurbsSurface(theNurb,
 116             8, knots,
 117             8, knots,
 118             4 * 3,
 119             3,
 120             &ctlpoints[0][0][0],
 121             4, 4,
 122             GL_MAP2_VERTEX_3);
 123     gluEndSurface(theNurb);
 124
 125     if(showPoints) {
 126     glPointSize(5.0);
 127     glDisable(GL_LIGHTING);
 128     glColor3f(1.0, 1.0, 0.0);
 129     glBegin(GL_POINTS);
 130     for(i=0;i<4;i++) {
 131       for(j=0;j<4;j++) {
 132         glVertex3f(ctlpoints[i][j][0], ctlpoints[i][j][1], ctlpoints[i][j][2]);
 133       }
 134     }
 135     glEnd();
 136     glEnable(GL_LIGHTING);
 137     }
 138
 139     glPopMatrix();
 140     glutSwapBuffers();
 141 }
 142
 143 static void reshape(int w, int h)
 144 {
 145     glViewport(0, 0, w, h);
 146     glMatrixMode(GL_PROJECTION);
 147     glLoadIdentity();
 148     gluPerspective (45.0, (GLdouble)w/(GLdouble)h, 3.0, 8.0);
 149
 150     glMatrixMode(GL_MODELVIEW);
 151 }
 152
 153 static void
 154 menu(int value)
 155 {
 156     switch (value) {
 157     case 0:
 158     case 1:
 159         showPoints = value;
 160         break;
 161     case 2:
 162         gluNurbsProperty(theNurb, GLU_DISPLAY_MODE, GLU_FILL);
 163         break;
 164     case 3:
 165         gluNurbsProperty(theNurb, GLU_DISPLAY_MODE, GLU_OUTLINE_POLYGON);
 166         break;
 167     }
 168     glutPostRedisplay();
 169 }
 170
 171 int down = 0, lastx;
 172
 173 /* ARGSUSED1 */
 174 static void
 175 motion(int x, int y)
 176 {
 177     if (down) {
 178         glRotatef(lastx - x, 0, 1, 0);
 179         lastx = x;
 180         glutPostRedisplay();
 181     }
 182 }
 183
 184 /* ARGSUSED3 */
 185 static void
 186 mouse(int button, int state, int x, int y)
 187 {
 188     if (button == GLUT_LEFT_BUTTON) {
 189         if (state == GLUT_DOWN) {
 190             lastx = x;
 191             down = 1;
 192         } else {
 193             down = 0;
 194         }
 195     }
 196 }
 197
 198 static void
 199 key(unsigned char k, int x, int y)
 200 {
 201   switch (k) {
 202   case 27:  /* Escape */
 203     exit(0);
 204     break;
 205   default:
 206     return;
 207   }
 208   glutPostRedisplay();
 209 }
 210
 211 /* Main Loop */
 212 int
 213 main(int argc, char** argv)
 214 {
 215     glutInit(&argc, argv);
 216     glutInitDisplayMode(GLUT_DEPTH | GLUT_DOUBLE | GLUT_RGB);
 217     glutCreateWindow(argv[0]);
 218     myinit();
 219     glutReshapeFunc(reshape);
 220     glutDisplayFunc(display);
 221     glutCreateMenu(menu);
 222     glutAddMenuEntry("Show control points", 1);
 223     glutAddMenuEntry("Hide control points", 0);
 224     glutAddMenuEntry("Solid", 2);
 225     glutAddMenuEntry("Wireframe", 3);
 226     glutAttachMenu(GLUT_RIGHT_BUTTON);
 227     glutMouseFunc(mouse);
 228     glutMotionFunc(motion);
 229     glutKeyboardFunc(key);
 230     glutMainLoop();
 231     return 0;             /* ANSI C requires main to return int. */
 232 }