progs/redbook/texturesurf.c

   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  34  * Unpublished-- rights reserved under the copyright laws of the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 /*  texturesurf.c
  41  *  This program uses evaluators to generate a curved
  42  *  surface and automatically generated texture coordinates.
  43  */
  44
  45 #include <stdlib.h>
  46 #include <GL/glut.h>
  47 #include <math.h>
  48
  49 GLfloat ctrlpoints[4][4][3] = {
  50     {{ -1.5, -1.5, 4.0}, { -0.5, -1.5, 2.0},
  51         {0.5, -1.5, -1.0}, {1.5, -1.5, 2.0}},
  52     {{ -1.5, -0.5, 1.0}, { -0.5, -0.5, 3.0},
  53         {0.5, -0.5, 0.0}, {1.5, -0.5, -1.0}},
  54     {{ -1.5, 0.5, 4.0}, { -0.5, 0.5, 0.0},
  55         {0.5, 0.5, 3.0}, {1.5, 0.5, 4.0}},
  56     {{ -1.5, 1.5, -2.0}, { -0.5, 1.5, -2.0},
  57         {0.5, 1.5, 0.0}, {1.5, 1.5, -1.0}}
  58 };
  59
  60 GLfloat texpts[2][2][2] = {{{0.0, 0.0}, {0.0, 1.0}},
  61                         {{1.0, 0.0}, {1.0, 1.0}}};
  62
  63 void display(void)
  64 {
  65     glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
  66     glColor3f(1.0, 1.0, 1.0);
  67     glEvalMesh2(GL_FILL, 0, 20, 0, 20);
  68     glFlush();
  69 }
  70
  71 #define imageWidth 64
  72 #define imageHeight 64
  73 GLubyte image[3*imageWidth*imageHeight];
  74
  75 void makeImage(void)
  76 {
  77     int i, j;
  78     float ti, tj;
  79
  80     for (i = 0; i < imageWidth; i++) {
  81         ti = 2.0*3.14159265*i/imageWidth;
  82         for (j = 0; j < imageHeight; j++) {
  83             tj = 2.0*3.14159265*j/imageHeight;
  84
  85             image[3*(imageHeight*i+j)] = (GLubyte) 127*(1.0+sin(ti));
  86             image[3*(imageHeight*i+j)+1] = (GLubyte) 127*(1.0+cos(2*tj));
  87             image[3*(imageHeight*i+j)+2] = (GLubyte) 127*(1.0+cos(ti+tj));
  88         }
  89     }
  90 }
  91
  92 void myinit(void)
  93 {
  94     glMap2f(GL_MAP2_VERTEX_3, 0, 1, 3, 4,
  95             0, 1, 12, 4, &ctrlpoints[0][0][0]);
  96     glMap2f(GL_MAP2_TEXTURE_COORD_2, 0, 1, 2, 2,
  97             0, 1, 4, 2, &texpts[0][0][0]);
  98     glEnable(GL_MAP2_TEXTURE_COORD_2);
  99     glEnable(GL_MAP2_VERTEX_3);
 100     glMapGrid2f(20, 0.0, 1.0, 20, 0.0, 1.0);
 101     makeImage();
 102     glTexEnvf(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_DECAL);
 103     glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT);
 104     glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT);
 105     glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
 106     glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
 107     glTexImage2D(GL_TEXTURE_2D, 0, 3, imageWidth, imageHeight, 0,
 108                  GL_RGB, GL_UNSIGNED_BYTE, image);
 109     glEnable(GL_TEXTURE_2D);
 110     glEnable(GL_DEPTH_TEST);
 111     glEnable(GL_NORMALIZE);
 112     glShadeModel (GL_FLAT);
 113 }
 114
 115 void myReshape(int w, int h)
 116 {
 117     glViewport(0, 0, w, h);
 118     glMatrixMode(GL_PROJECTION);
 119     glLoadIdentity();
 120     if (w <= h)
 121         glOrtho(-4.0, 4.0, -4.0*(GLfloat)h/(GLfloat)w,
 122             4.0*(GLfloat)h/(GLfloat)w, -4.0, 4.0);
 123     else
 124         glOrtho(-4.0*(GLfloat)w/(GLfloat)h,
 125             4.0*(GLfloat)w/(GLfloat)h, -4.0, 4.0, -4.0, 4.0);
 126     glMatrixMode(GL_MODELVIEW);
 127     glLoadIdentity();
 128     glRotatef(85.0, 1.0, 1.0, 1.0);
 129 }
 130
 131 static void
 132 key(unsigned char k, int x, int y)
 133 {
 134   switch (k) {
 135   case 27:  /* Escape */
 136     exit(0);
 137     break;
 138   default:
 139     return;
 140   }
 141   glutPostRedisplay();
 142 }
 143
 144 int main(int argc, char** argv)
 145 {
 146     glutInit(&argc, argv);
 147     glutInitDisplayMode (GLUT_SINGLE | GLUT_RGB | GLUT_DEPTH);
 148     glutCreateWindow (argv[0]);
 149     myinit();
 150     glutReshapeFunc (myReshape);
 151     glutDisplayFunc(display);
 152     glutKeyboardFunc(key);
 153     glutMainLoop();
 154     return 0;             /* ANSI C requires main to return int. */
 155 }