src/redbook/wrap.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  31  * Unpublished-- rights reserved under the copyright laws of the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 /*  wrap.c
  39  *  This program texture maps a checkerboard image onto
  40  *  two rectangles.  This program demonstrates the wrapping
  41  *  modes, if the texture coordinates fall outside 0.0 and 1.0.
  42  *  Interaction: Pressing the 's' and 'S' keys switch the
  43  *  wrapping between clamping and repeating for the s parameter.
  44  *  The 't' and 'T' keys control the wrapping for the t parameter.
  45  *
  46  *  If running this program on OpenGL 1.0, texture objects are
  47  *  not used.
  48  */
  49 #include "glut_wrap.h"
  50 #include <stdlib.h>
  51 #include <stdio.h>
  52
  53 /*      Create checkerboard texture     */
  54 #define checkImageWidth 64
  55 #define checkImageHeight 64
  56 static GLubyte checkImage[checkImageHeight][checkImageWidth][4];
  57
  58 #ifdef GL_VERSION_1_1
  59 static GLuint texName;
  60 #endif
  61
  62 static void makeCheckImage(void)
  63 {
  64    int i, j, c;
  65
  66    for (i = 0; i < checkImageHeight; i++) {
  67       for (j = 0; j < checkImageWidth; j++) {
  68          c = (((i&0x8)==0)^((j&0x8)==0))*255;
  69          checkImage[i][j][0] = (GLubyte) c;
  70          checkImage[i][j][1] = (GLubyte) c;
  71          checkImage[i][j][2] = (GLubyte) c;
  72          checkImage[i][j][3] = (GLubyte) 255;
  73       }
  74    }
  75 }
  76
  77 static void init(void)
  78 {
  79    glClearColor (0.0, 0.0, 0.0, 0.0);
  80    glShadeModel(GL_FLAT);
  81    glEnable(GL_DEPTH_TEST);
  82
  83    makeCheckImage();
  84    glPixelStorei(GL_UNPACK_ALIGNMENT, 1);
  85
  86 #ifdef GL_VERSION_1_1
  87    glGenTextures(1, &texName);
  88    glBindTexture(GL_TEXTURE_2D, texName);
  89 #endif
  90
  91    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT);
  92    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT);
  93    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
  94    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
  95 #ifdef GL_VERSION_1_1
  96    glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, checkImageWidth, checkImageHeight,
  97                 0, GL_RGBA, GL_UNSIGNED_BYTE, checkImage);
  98 #else
  99    glTexImage2D(GL_TEXTURE_2D, 0, 4, checkImageWidth, checkImageHeight,
 100                 0, GL_RGBA, GL_UNSIGNED_BYTE, checkImage);
 101 #endif
 102 }
 103
 104 static void display(void)
 105 {
 106    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
 107    glEnable(GL_TEXTURE_2D);
 108    glTexEnvf(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_DECAL);
 109 #ifdef GL_VERSION_1_1
 110    glBindTexture(GL_TEXTURE_2D, texName);
 111 #endif
 112
 113    glBegin(GL_QUADS);
 114    glTexCoord2f(0.0, 0.0); glVertex3f(-2.0, -1.0, 0.0);
 115    glTexCoord2f(0.0, 3.0); glVertex3f(-2.0, 1.0, 0.0);
 116    glTexCoord2f(3.0, 3.0); glVertex3f(0.0, 1.0, 0.0);
 117    glTexCoord2f(3.0, 0.0); glVertex3f(0.0, -1.0, 0.0);
 118
 119    glTexCoord2f(0.0, 0.0); glVertex3f(1.0, -1.0, 0.0);
 120    glTexCoord2f(0.0, 3.0); glVertex3f(1.0, 1.0, 0.0);
 121    glTexCoord2f(3.0, 3.0); glVertex3f(2.41421, 1.0, -1.41421);
 122    glTexCoord2f(3.0, 0.0); glVertex3f(2.41421, -1.0, -1.41421);
 123    glEnd();
 124    glFlush();
 125    glDisable(GL_TEXTURE_2D);
 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 's':
 144          glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP);
 145          glutPostRedisplay();
 146          break;
 147       case 'S':
 148          glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT);
 149          glutPostRedisplay();
 150          break;
 151       case 't':
 152          glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP);
 153          glutPostRedisplay();
 154          break;
 155       case 'T':
 156          glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT);
 157          glutPostRedisplay();
 158          break;
 159       case 27:
 160          exit(0);
 161          break;
 162       default:
 163          break;
 164    }
 165 }
 166
 167 int main(int argc, char** argv)
 168 {
 169    glutInit(&argc, argv);
 170    glutInitDisplayMode(GLUT_SINGLE | GLUT_RGB | GLUT_DEPTH);
 171    glutInitWindowSize(250, 250);
 172    glutInitWindowPosition(100, 100);
 173    glutCreateWindow(argv[0]);
 174    init();
 175    glutDisplayFunc(display);
 176    glutReshapeFunc(reshape);
 177    glutKeyboardFunc(keyboard);
 178    glutMainLoop();
 179    return 0;
 180 }