OpenGL 贴图
谁能给我一个简单的贴图例子，看教程看的我都晕 ，还是不太懂
[解决办法]
好久没有写过 OpenGL程序了， 不过电脑还是有全套的openGL的红皮书例子。。找了一个Image.c贴上来
/* * Copyright (c) 1993-2003, 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 Unpublished - rights * reserved under the copyright laws of the United States.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. * 1500 Crittenden Lane * Mountain View, CA 94043 * United State of America * * OpenGL(R) is a registered trademark of Silicon Graphics, Inc. *//* image.c * This program demonstrates drawing pixels and shows the effect * of glDrawPixels(), glCopyPixels(), and glPixelZoom(). * Interaction: moving the mouse while pressing the mouse button * will copy the image in the lower-left corner of the window * to the mouse position, using the current pixel zoom factors. * There is no attempt to prevent you from drawing over the original * image. If you press the 'r' key, the original image and zoom * factors are reset. If you press the 'z' or 'Z' keys, you change * the zoom factors. */#include <GL/glut.h>#include <stdlib.h>#include <stdio.h>/* Create checkerboard image */#define checkImageWidth 64#define checkImageHeight 64GLubyte checkImage[checkImageHeight][checkImageWidth][3];static GLdouble zoomFactor = 1.0;static GLint height;void makeCheckImage(void){ int i, j, c; for (i = 0; i < checkImageHeight; i++) { for (j = 0; j < checkImageWidth; j++) { c = ((((i&0x8)==0)^((j&0x8))==0))*255; checkImage[i][j][0] = (GLubyte) c; checkImage[i][j][1] = (GLubyte) c; checkImage[i][j][2] = (GLubyte) c; } }}void init(void){ glClearColor (0.0, 0.0, 0.0, 0.0); glShadeModel(GL_FLAT); makeCheckImage(); glPixelStorei(GL_UNPACK_ALIGNMENT, 1);}void display(void){ glClear(GL_COLOR_BUFFER_BIT); glRasterPos2i(0, 0); glDrawPixels(checkImageWidth, checkImageHeight, GL_RGB, GL_UNSIGNED_BYTE, checkImage); glFlush();}void reshape(int w, int h){ glViewport(0, 0, (GLsizei) w, (GLsizei) h); height = (GLint) h; glMatrixMode(GL_PROJECTION); glLoadIdentity(); gluOrtho2D(0.0, (GLdouble) w, 0.0, (GLdouble) h); glMatrixMode(GL_MODELVIEW); glLoadIdentity();}void motion(int x, int y){ static GLint screeny; screeny = height - (GLint) y; glRasterPos2i (x, screeny); glPixelZoom (zoomFactor, zoomFactor); glCopyPixels (0, 0, checkImageWidth, checkImageHeight, GL_COLOR); glPixelZoom (1.0, 1.0); glFlush ();}void keyboard(unsigned char key, int x, int y){ switch (key) { case 'r': case 'R': zoomFactor = 1.0; glutPostRedisplay(); printf ("zoomFactor reset to 1.0\n"); break; case 'z': zoomFactor += 0.5; if (zoomFactor >= 3.0) zoomFactor = 3.0; printf ("zoomFactor is now %4.1f\n", zoomFactor); break; case 'Z': zoomFactor -= 0.5; if (zoomFactor <= 0.5) zoomFactor = 0.5; printf ("zoomFactor is now %4.1f\n", zoomFactor); break; case 27: exit(0); break; default: break; }}int main(int argc, char** argv){ glutInit(&argc, argv); glutInitDisplayMode(GLUT_SINGLE | GLUT_RGB); glutInitWindowSize(250, 250); glutInitWindowPosition(100, 100); glutCreateWindow(argv[0]); init(); glutDisplayFunc(display); glutReshapeFunc(reshape); glutKeyboardFunc(keyboard); glutMotionFunc(motion); glutMainLoop(); return 0; }