188 lines
6.4 KiB
C
188 lines
6.4 KiB
C
/*
|
|
* Copyright (c) 1993-1997, 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* Unpublished-- rights reserved under the copyright laws of the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.
|
|
*/
|
|
|
|
/* texsub.c
|
|
* This program texture maps a checkerboard image onto
|
|
* two rectangles. This program clamps the texture, if
|
|
* the texture coordinates fall outside 0.0 and 1.0.
|
|
* If the s key is pressed, a texture subimage is used to
|
|
* alter the original texture. If the r key is pressed,
|
|
* the original texture is restored.
|
|
*/
|
|
#include <GL/glut.h>
|
|
#include <stdlib.h>
|
|
#include <stdio.h>
|
|
|
|
#ifdef GL_VERSION_1_1
|
|
/* Create checkerboard textures */
|
|
#define checkImageWidth 64
|
|
#define checkImageHeight 64
|
|
#define subImageWidth 16
|
|
#define subImageHeight 16
|
|
static GLubyte checkImage[checkImageHeight][checkImageWidth][4];
|
|
static GLubyte subImage[subImageHeight][subImageWidth][4];
|
|
|
|
static GLuint texName;
|
|
|
|
void makeCheckImages(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;
|
|
checkImage[i][j][3] = (GLubyte) 255;
|
|
}
|
|
}
|
|
for (i = 0; i < subImageHeight; i++) {
|
|
for (j = 0; j < subImageWidth; j++) {
|
|
c = ((((i&0x4)==0)^((j&0x4)==0)))*255;
|
|
subImage[i][j][0] = (GLubyte) c;
|
|
subImage[i][j][1] = (GLubyte) 0;
|
|
subImage[i][j][2] = (GLubyte) 0;
|
|
subImage[i][j][3] = (GLubyte) 255;
|
|
}
|
|
}
|
|
}
|
|
|
|
void init(void)
|
|
{
|
|
glClearColor (0.0, 0.0, 0.0, 0.0);
|
|
glShadeModel(GL_FLAT);
|
|
glEnable(GL_DEPTH_TEST);
|
|
|
|
makeCheckImages();
|
|
glPixelStorei(GL_UNPACK_ALIGNMENT, 1);
|
|
|
|
glGenTextures(1, &texName);
|
|
glBindTexture(GL_TEXTURE_2D, texName);
|
|
|
|
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT);
|
|
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT);
|
|
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
|
|
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
|
|
glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, checkImageWidth, checkImageHeight,
|
|
0, GL_RGBA, GL_UNSIGNED_BYTE, checkImage);
|
|
}
|
|
|
|
void display(void)
|
|
{
|
|
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
|
|
glEnable(GL_TEXTURE_2D);
|
|
glTexEnvf(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_DECAL);
|
|
glBindTexture(GL_TEXTURE_2D, texName);
|
|
glBegin(GL_QUADS);
|
|
glTexCoord2f(0.0, 0.0); glVertex3f(-2.0, -1.0, 0.0);
|
|
glTexCoord2f(0.0, 1.0); glVertex3f(-2.0, 1.0, 0.0);
|
|
glTexCoord2f(1.0, 1.0); glVertex3f(0.0, 1.0, 0.0);
|
|
glTexCoord2f(1.0, 0.0); glVertex3f(0.0, -1.0, 0.0);
|
|
|
|
glTexCoord2f(0.0, 0.0); glVertex3f(1.0, -1.0, 0.0);
|
|
glTexCoord2f(0.0, 1.0); glVertex3f(1.0, 1.0, 0.0);
|
|
glTexCoord2f(1.0, 1.0); glVertex3f(2.41421, 1.0, -1.41421);
|
|
glTexCoord2f(1.0, 0.0); glVertex3f(2.41421, -1.0, -1.41421);
|
|
glEnd();
|
|
glFlush();
|
|
glDisable(GL_TEXTURE_2D);
|
|
}
|
|
|
|
void reshape(int w, int h)
|
|
{
|
|
glViewport(0, 0, (GLsizei) w, (GLsizei) h);
|
|
glMatrixMode(GL_PROJECTION);
|
|
glLoadIdentity();
|
|
gluPerspective(60.0, (GLfloat) w/(GLfloat) h, 1.0, 30.0);
|
|
glMatrixMode(GL_MODELVIEW);
|
|
glLoadIdentity();
|
|
glTranslatef(0.0, 0.0, -3.6);
|
|
}
|
|
|
|
/* ARGSUSED1 */
|
|
void keyboard (unsigned char key, int x, int y)
|
|
{
|
|
switch (key) {
|
|
case 's':
|
|
case 'S':
|
|
glBindTexture(GL_TEXTURE_2D, texName);
|
|
glTexSubImage2D(GL_TEXTURE_2D, 0, 12, 44, subImageWidth,
|
|
subImageHeight, GL_RGBA,
|
|
GL_UNSIGNED_BYTE, subImage);
|
|
glutPostRedisplay();
|
|
break;
|
|
case 'r':
|
|
case 'R':
|
|
glBindTexture(GL_TEXTURE_2D, texName);
|
|
glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, checkImageWidth,
|
|
checkImageHeight, 0, GL_RGBA,
|
|
GL_UNSIGNED_BYTE, checkImage);
|
|
glutPostRedisplay();
|
|
break;
|
|
case 27:
|
|
exit(0);
|
|
break;
|
|
default:
|
|
break;
|
|
}
|
|
}
|
|
|
|
int main(int argc, char** argv)
|
|
{
|
|
glutInit(&argc, argv);
|
|
glutInitDisplayMode(GLUT_SINGLE | GLUT_RGB | GLUT_DEPTH);
|
|
glutInitWindowSize(250, 250);
|
|
glutInitWindowPosition(100, 100);
|
|
glutCreateWindow(argv[0]);
|
|
init();
|
|
glutDisplayFunc(display);
|
|
glutReshapeFunc(reshape);
|
|
glutKeyboardFunc(keyboard);
|
|
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
|