progs/redbook/texbind.c

   1 /*
   2  * Copyright (c) 1993-1997, Silicon Graphics, Inc.
   3  * ALL RIGHTS RESERVED
   4  * Permission to use, copy, modify, and distribute this software for
   5  * any purpose and without fee is hereby granted, provided that the above
   6  * copyright notice appear in all copies and that both the copyright notice
   7  * and this permission notice appear in supporting documentation, and that
   8  * the name of Silicon Graphics, Inc. not be used in advertising
   9  * or publicity pertaining to distribution of the software without specific,
  10  * written prior permission.
  11  *
  12  * THE MATERIAL EMBODIED ON THIS SOFTWARE IS PROVIDED TO YOU "AS-IS"
  13  * AND WITHOUT WARRANTY OF ANY KIND, EXPRESS, IMPLIED OR OTHERWISE,
  14  * INCLUDING WITHOUT LIMITATION, ANY WARRANTY OF MERCHANTABILITY OR
  15  * FITNESS FOR A PARTICULAR PURPOSE.  IN NO EVENT SHALL SILICON
  16  * GRAPHICS, INC.  BE LIABLE TO YOU OR ANYONE ELSE FOR ANY DIRECT,
  17  * SPECIAL, INCIDENTAL, INDIRECT OR CONSEQUENTIAL DAMAGES OF ANY
  18  * KIND, OR ANY DAMAGES WHATSOEVER, INCLUDING WITHOUT LIMITATION,
  19  * LOSS OF PROFIT, LOSS OF USE, SAVINGS OR REVENUE, OR THE CLAIMS OF
  20  * THIRD PARTIES, WHETHER OR NOT SILICON GRAPHICS, INC.  HAS BEEN
  21  * ADVISED OF THE POSSIBILITY OF SUCH LOSS, HOWEVER CAUSED AND ON
  22  * ANY THEORY OF LIABILITY, ARISING OUT OF OR IN CONNECTION WITH THE
  23  * POSSESSION, USE OR PERFORMANCE OF THIS SOFTWARE.
  24  *
  25  * US Government Users Restricted Rights
  26  * Use, duplication, or disclosure by the Government is subject to
  27  * restrictions set forth in FAR 52.227.19(c)(2) or subparagraph
  28  * (c)(1)(ii) of the Rights in Technical Data and Computer Software
  29  * clause at DFARS 252.227-7013 and/or in similar or successor
  30  * clauses in the FAR or the DOD or NASA FAR Supplement.
  31  * Unpublished-- rights reserved under the copyright laws of the
  32  * United States.  Contractor/manufacturer is Silicon Graphics,
  33  * Inc., 2011 N.  Shoreline Blvd., Mountain View, CA 94039-7311.
  34  *
  35  * OpenGL(R) is a registered trademark of Silicon Graphics, Inc.
  36  */
  37
  38 /*  texbind.c
  39  *  This program demonstrates using glBindTexture() by
  40  *  creating and managing two textures.
  41  */
  42 #include <GL/glut.h>
  43 #include <stdlib.h>
  44 #include <stdio.h>
  45
  46 #ifdef GL_VERSION_1_1
  47 /*      Create checkerboard texture     */
  48 #define checkImageWidth 64
  49 #define checkImageHeight 64
  50 static GLubyte checkImage[checkImageHeight][checkImageWidth][4];
  51 static GLubyte otherImage[checkImageHeight][checkImageWidth][4];
  52
  53 static GLuint texName[2];
  54
  55 static void makeCheckImages(void)
  56 {
  57    int i, j, c;
  58
  59    for (i = 0; i < checkImageHeight; i++) {
  60       for (j = 0; j < checkImageWidth; j++) {
  61          c = ((((i&0x8)==0)^((j&0x8)==0)))*255;
  62          checkImage[i][j][0] = (GLubyte) c;
  63          checkImage[i][j][1] = (GLubyte) c;
  64          checkImage[i][j][2] = (GLubyte) c;
  65          checkImage[i][j][3] = (GLubyte) 255;
  66          c = ((((i&0x10)==0)^((j&0x10)==0)))*255;
  67          otherImage[i][j][0] = (GLubyte) c;
  68          otherImage[i][j][1] = (GLubyte) 0;
  69          otherImage[i][j][2] = (GLubyte) 0;
  70          otherImage[i][j][3] = (GLubyte) 255;
  71       }
  72    }
  73 }
  74
  75 static void init(void)
  76 {
  77    glClearColor (0.0, 0.0, 0.0, 0.0);
  78    glShadeModel(GL_FLAT);
  79    glEnable(GL_DEPTH_TEST);
  80
  81    makeCheckImages();
  82    glPixelStorei(GL_UNPACK_ALIGNMENT, 1);
  83
  84    glGenTextures(2, texName);
  85    glBindTexture(GL_TEXTURE_2D, texName[0]);
  86    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP);
  87    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP);
  88    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER,
  89                    GL_NEAREST);
  90    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER,
  91                    GL_NEAREST);
  92    glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, checkImageWidth,
  93                 checkImageHeight, 0, GL_RGBA, GL_UNSIGNED_BYTE,
  94                 checkImage);
  95
  96    glBindTexture(GL_TEXTURE_2D, texName[1]);
  97    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP);
  98    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP);
  99    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
 100    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
 101    glTexEnvf(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_DECAL);
 102    glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, checkImageWidth,
 103                 checkImageHeight, 0, GL_RGBA, GL_UNSIGNED_BYTE,
 104                 otherImage);
 105    glEnable(GL_TEXTURE_2D);
 106 }
 107
 108 static void display(void)
 109 {
 110    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
 111    glBindTexture(GL_TEXTURE_2D, texName[0]);
 112    glBegin(GL_QUADS);
 113    glTexCoord2f(0.0, 0.0); glVertex3f(-2.0, -1.0, 0.0);
 114    glTexCoord2f(0.0, 1.0); glVertex3f(-2.0, 1.0, 0.0);
 115    glTexCoord2f(1.0, 1.0); glVertex3f(0.0, 1.0, 0.0);
 116    glTexCoord2f(1.0, 0.0); glVertex3f(0.0, -1.0, 0.0);
 117    glEnd();
 118    glBindTexture(GL_TEXTURE_2D, texName[1]);
 119    glBegin(GL_QUADS);
 120    glTexCoord2f(0.0, 0.0); glVertex3f(1.0, -1.0, 0.0);
 121    glTexCoord2f(0.0, 1.0); glVertex3f(1.0, 1.0, 0.0);
 122    glTexCoord2f(1.0, 1.0); glVertex3f(2.41421, 1.0, -1.41421);
 123    glTexCoord2f(1.0, 0.0); glVertex3f(2.41421, -1.0, -1.41421);
 124    glEnd();
 125    glFlush();
 126 }
 127
 128 static void reshape(int w, int h)
 129 {
 130    glViewport(0, 0, (GLsizei) w, (GLsizei) h);
 131    glMatrixMode(GL_PROJECTION);
 132    glLoadIdentity();
 133    gluPerspective(60.0, (GLfloat) w/(GLfloat) h, 1.0, 30.0);
 134    glMatrixMode(GL_MODELVIEW);
 135    glLoadIdentity();
 136    glTranslatef(0.0, 0.0, -3.6);
 137 }
 138
 139 /* ARGSUSED1 */
 140 static void keyboard(unsigned char key, int x, int y)
 141 {
 142    switch (key) {
 143       case 27:
 144          exit(0);
 145          break;
 146    }
 147 }
 148
 149 int main(int argc, char** argv)
 150 {
 151    glutInit(&argc, argv);
 152    glutInitDisplayMode(GLUT_SINGLE | GLUT_RGB | GLUT_DEPTH);
 153    glutInitWindowSize(250, 250);
 154    glutInitWindowPosition(100, 100);
 155    glutCreateWindow(argv[0]);
 156    init();
 157    glutReshapeFunc(reshape);
 158    glutDisplayFunc(display);
 159    glutKeyboardFunc (keyboard);
 160    glutMainLoop();
 161    return 0;
 162 }
 163 #else
 164 int main(int argc, char** argv)
 165 {
 166     fprintf (stderr, "This program demonstrates a feature which is not in OpenGL Version 1.0.\n");
 167     fprintf (stderr, "If your implementation of OpenGL Version 1.0 has the right extensions,\n");
 168     fprintf (stderr, "you may be able to modify this program to make it run.\n");
 169     return 0;
 170 }
 171 #endif