Initial revision

progs/redbook/trim.c

@@ -0,0 +1,187 @@
+/*
+ * Copyright (c) 1993-1997, Silicon Graphics, Inc.
+ * ALL RIGHTS RESERVED 
+ * Permission to use, copy, modify, and distribute this software for 
+ * any purpose and without fee is hereby granted, provided that the above
+ * copyright notice appear in all copies and that both the copyright notice
+ * and this permission notice appear in supporting documentation, and that 
+ * the name of Silicon Graphics, Inc. not be used in advertising
+ * or publicity pertaining to distribution of the software without specific,
+ * written prior permission. 
+ *
+ * THE MATERIAL EMBODIED ON THIS SOFTWARE IS PROVIDED TO YOU "AS-IS"
+ * AND WITHOUT WARRANTY OF ANY KIND, EXPRESS, IMPLIED OR OTHERWISE,
+ * INCLUDING WITHOUT LIMITATION, ANY WARRANTY OF MERCHANTABILITY OR
+ * FITNESS FOR A PARTICULAR PURPOSE.  IN NO EVENT SHALL SILICON
+ * GRAPHICS, INC.  BE LIABLE TO YOU OR ANYONE ELSE FOR ANY DIRECT,
+ * SPECIAL, INCIDENTAL, INDIRECT OR CONSEQUENTIAL DAMAGES OF ANY
+ * KIND, OR ANY DAMAGES WHATSOEVER, INCLUDING WITHOUT LIMITATION,
+ * LOSS OF PROFIT, LOSS OF USE, SAVINGS OR REVENUE, OR THE CLAIMS OF
+ * THIRD PARTIES, WHETHER OR NOT SILICON GRAPHICS, INC.  HAS BEEN
+ * ADVISED OF THE POSSIBILITY OF SUCH LOSS, HOWEVER CAUSED AND ON
+ * ANY THEORY OF LIABILITY, ARISING OUT OF OR IN CONNECTION WITH THE
+ * POSSESSION, USE OR PERFORMANCE OF THIS SOFTWARE.
+ * 
+ * US Government Users Restricted Rights 
+ * Use, duplication, or disclosure by the Government is subject to
+ * restrictions set forth in FAR 52.227.19(c)(2) or subparagraph
+ * (c)(1)(ii) of the Rights in Technical Data and Computer Software
+ * clause at DFARS 252.227-7013 and/or in similar or successor
+ * clauses in the FAR or the DOD or NASA FAR Supplement.
+ * Unpublished-- rights reserved under the copyright laws of the
+ * United States.  Contractor/manufacturer is Silicon Graphics,
+ * Inc., 2011 N.  Shoreline Blvd., Mountain View, CA 94039-7311.
+ *
+ * OpenGL(R) is a registered trademark of Silicon Graphics, Inc.
+ */
+
+/*
+ *  trim.c
+ *  This program draws a NURBS surface in the shape of a 
+ *  symmetrical hill, using both a NURBS curve and pwl
+ *  (piecewise linear) curve to trim part of the surface.
+ */
+#include <stdlib.h>
+#include <GL/glut.h>
+#include <stdio.h>
+
+
+#ifndef CALLBACK
+#define CALLBACK
+#endif
+
+
+GLfloat ctlpoints[4][4][3];
+
+GLUnurbsObj *theNurb;
+
+/*
+ *  Initializes the control points of the surface to a small hill.
+ *  The control points range from -3 to +3 in x, y, and z
+ */
+void init_surface(void)
+{
+   int u, v;
+   for (u = 0; u < 4; u++) {
+      for (v = 0; v < 4; v++) {
+         ctlpoints[u][v][0] = 2.0*((GLfloat)u - 1.5);
+         ctlpoints[u][v][1] = 2.0*((GLfloat)v - 1.5);
+
+         if ( (u == 1 || u == 2) && (v == 1 || v == 2))
+            ctlpoints[u][v][2] = 3.0;
+         else
+            ctlpoints[u][v][2] = -3.0;
+      }
+   }
+}
+
+void nurbsError(GLenum errorCode)
+{
+   const GLubyte *estring;
+
+   estring = gluErrorString(errorCode);
+   fprintf (stderr, "Nurbs Error: %s\n", estring);
+   exit (0);
+}
+			
+/*  Initialize material property and depth buffer.
+ */
+void init(void)
+{
+   GLfloat mat_diffuse[] = { 0.7, 0.7, 0.7, 1.0 };
+   GLfloat mat_specular[] = { 1.0, 1.0, 1.0, 1.0 };
+   GLfloat mat_shininess[] = { 100.0 };
+
+   glClearColor (0.0, 0.0, 0.0, 0.0);
+   glMaterialfv(GL_FRONT, GL_DIFFUSE, mat_diffuse);
+   glMaterialfv(GL_FRONT, GL_SPECULAR, mat_specular);
+   glMaterialfv(GL_FRONT, GL_SHININESS, mat_shininess);
+
+   glEnable(GL_LIGHTING);
+   glEnable(GL_LIGHT0);
+   glEnable(GL_DEPTH_TEST);
+   glEnable(GL_AUTO_NORMAL);
+   glEnable(GL_NORMALIZE);
+
+   init_surface();
+
+   theNurb = gluNewNurbsRenderer();
+   gluNurbsProperty(theNurb, GLU_SAMPLING_TOLERANCE, 25.0);
+   gluNurbsProperty(theNurb, GLU_DISPLAY_MODE, GLU_FILL);
+   gluNurbsCallback(theNurb, GLU_ERROR, 
+                    (GLvoid (CALLBACK*) ()) nurbsError);
+}
+
+void display(void)
+{
+   GLfloat knots[8] = {0.0, 0.0, 0.0, 0.0, 1.0, 1.0, 1.0, 1.0};
+   GLfloat edgePt[5][2] = /* counter clockwise */
+      {{0.0, 0.0}, {1.0, 0.0}, {1.0, 1.0}, {0.0, 1.0}, {0.0, 0.0}};
+   GLfloat curvePt[4][2] = /* clockwise */ 
+      {{0.25, 0.5}, {0.25, 0.75}, {0.75, 0.75}, {0.75, 0.5}};
+   GLfloat curveKnots[8] = 
+      {0.0, 0.0, 0.0, 0.0, 1.0, 1.0, 1.0, 1.0};
+   GLfloat pwlPt[4][2] = /* clockwise */ 
+      {{0.75, 0.5}, {0.5, 0.25}, {0.25, 0.5}};
+
+   glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
+   glPushMatrix();
+   glRotatef(330.0, 1.,0.,0.);
+   glScalef (0.5, 0.5, 0.5);
+
+   gluBeginSurface(theNurb);
+   gluNurbsSurface(theNurb, 8, knots, 8, knots,
+                   4 * 3, 3, &ctlpoints[0][0][0], 
+                   4, 4, GL_MAP2_VERTEX_3);
+   gluBeginTrim (theNurb);
+      gluPwlCurve (theNurb, 5, &edgePt[0][0], 2, GLU_MAP1_TRIM_2);
+   gluEndTrim (theNurb);
+   gluBeginTrim (theNurb);
+      gluNurbsCurve (theNurb, 8, curveKnots, 2, 
+                     &curvePt[0][0], 4, GLU_MAP1_TRIM_2);
+      gluPwlCurve (theNurb, 3, &pwlPt[0][0], 2, GLU_MAP1_TRIM_2);
+   gluEndTrim (theNurb);
+   gluEndSurface(theNurb);
+        
+   glPopMatrix();
+   glFlush();
+}
+
+void reshape(int w, int h)
+{
+   glViewport(0, 0, (GLsizei) w, (GLsizei) h);
+   glMatrixMode(GL_PROJECTION);
+   glLoadIdentity();
+   gluPerspective (45.0, (GLdouble)w/(GLdouble)h, 3.0, 8.0);
+
+   glMatrixMode(GL_MODELVIEW);
+   glLoadIdentity();
+   glTranslatef (0.0, 0.0, -5.0);
+}
+
+/* ARGSUSED1 */
+void keyboard(unsigned char key, int x, int y)
+{
+   switch (key) {
+      case 27:
+         exit(0);
+         break;
+   }
+}
+
+/*  Main Loop 
+ */
+int main(int argc, char** argv)
+{
+   glutInit(&argc, argv);
+   glutInitDisplayMode (GLUT_SINGLE | GLUT_RGB | GLUT_DEPTH);
+   glutInitWindowSize (500, 500);
+   glutInitWindowPosition (100, 100);
+   glutCreateWindow(argv[0]);
+   init();
+   glutReshapeFunc(reshape);
+   glutDisplayFunc(display);
+   glutKeyboardFunc (keyboard);
+   glutMainLoop();
+   return 0; 
+}