texprox.c

OpenGL学习资料

/*
 * Copyright (c) 1993-1999, 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 * Unpublished-- rights reserved under the copyright laws of the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.
 */

/*
 *  texprox.c
 *  The brief program illustrates use of texture proxies.
 *  This program only prints out some messages about whether
 *  certain size textures are supported and then exits.
 */
#include <GL/glut.h>
#include <stdlib.h>
#include <stdio.h>

#ifdef GL_VERSION_1_1
void init(void) 
{
   GLint proxyComponents;

   glTexImage2D(GL_PROXY_TEXTURE_2D, 0, GL_RGBA8,
                64, 64, 0,
                GL_RGBA, GL_UNSIGNED_BYTE, NULL);
   glGetTexLevelParameteriv(GL_PROXY_TEXTURE_2D, 0, 
                            GL_TEXTURE_COMPONENTS, &proxyComponents);
   printf ("proxyComponents are %d\n", proxyComponents);
   if (proxyComponents == GL_RGBA8)
      printf ("proxy allocation succeeded\n");
   else
      printf ("proxy allocation failed\n");

   glTexImage2D(GL_PROXY_TEXTURE_2D, 0, GL_RGBA16,
                2048, 2048, 0,
                GL_RGBA, GL_UNSIGNED_SHORT, NULL);
   glGetTexLevelParameteriv(GL_PROXY_TEXTURE_2D, 0, 
                            GL_TEXTURE_COMPONENTS, &proxyComponents);
   printf ("proxyComponents are %d\n", proxyComponents);
   if (proxyComponents == GL_RGBA16)
      printf ("proxy allocation succeeded\n");
   else
      printf ("proxy allocation failed\n");
}

void display(void)
{
   exit(0);
}

void reshape (int w, int h)
{
   glViewport (0, 0, (GLsizei) w, (GLsizei) h); 
   glMatrixMode (GL_PROJECTION);
   glLoadIdentity ();
}

int main(int argc, char** argv)
{
   glutInit(&argc, argv);
   glutInitDisplayMode (GLUT_SINGLE | GLUT_RGB);
   glutInitWindowSize (500, 500); 
   glutInitWindowPosition (100, 100);
   glutCreateWindow (argv[0]);
   init ();
   glutDisplayFunc(display); 
   glutReshapeFunc(reshape);
   glutMainLoop();
   return 0;
}
#else
int main(int argc, char** argv)
{
    fprintf (stderr, "This program demonstrates a feature which is not in OpenGL Version 1.0.\n");
    fprintf (stderr, "If your implementation of OpenGL Version 1.0 has the right extensions,\n");
    fprintf (stderr, "you may be able to modify this program to make it run.\n");
    return 0;
}
#endif