wrap.c revision 32001f49 
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31 * Unpublished-- rights reserved under the copyright laws of the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
56static GLubyte checkImage[checkImageHeight][checkImageWidth][4];
57
58#ifdef GL_VERSION_1_1
59static GLuint texName;
60#endif
61
62static 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
77static 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
104static 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
128static 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 */
140static 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
167int 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}
181