Hello ,
I have recently tried one of your exercises called mutitex.c. This I tried on a Suse 7.2 linux running Glu version 1.1 with Mesa 3.4.1 with OpenGL 1.2 version under X Windows. The number of texturing units available were 2 from running
glGetIntegerv(GL_MAX_TEXTURE_UNITS_ARB,…)
Also extensions available with this implementation were found out by running
glGetString(GL_EXTENSIONS)
And gave the following listing of
GL_ARB_multitexture
GL_ARB_texture_cube_map
GL_ARB_tranpose_matrix
GL_EXT_abgr
GL_EXT_blend_color
GL_EXT_blend_func_separate
GL_EXT_blend_logic_op
GL_EXT_blend_minmax
GL_EXT_blend_subtract
GL_EXT_clip_volume_hint
GL_EXT_compiled_vertex_array
GL_EXT_histogram
GL_EXT_packed_pixels
GL_EXT_paletted_texture
GL_EXT_point_parameters
GL_EXT_polygon_offset
GL_EXT_rescale_normal
GL_EXT_shared_texture_palette
GL_EXT_stencil_wrap
GL_EXT_texture3D
GL_EXT_texture_env_add
GL_EXT_texture_env_combine
GL_EXT_texture_env_dot3
GL_EXT_texture_object
GL_EXT_texture_lod_bias
GL_EXT_vertex_array
GL_HP_occlusion_test
GL_INGR_blend_func_separate
GL_MESA_window_pos
GL_MESA_resize_buffers
GL_NV_texgen_reflection
GL_PGI_misc_hints
GL_SGI_color_matrix
GL_SGI_color_table
GL_SGIS_pixel_texture
GL_SGIS_texture_edge_clamp
GL_SGIX_pixel_texture
You will notice that GL_ARB_imaging is not included. When I compiled and ran multitex.c, (see below), I only got a black screen. Why is this? Have I done something wrong?
I look forward to your reply.
David Olivieri
multitex.c programme was taken from Redbook OpenGL Programming Guide 1.2.
See below :-
/*
* 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.
*/
/* multitex.c
*/
#include <GL/glut.h>
#include <stdlib.h>
#include <stdio.h>
#ifdef GL_VERSION_1_2
static GLubyte texels0[32][32][4];
static GLubyte texels1[16][16][4];
void makeCheckImages(void)
{
int i, j;
for (i = 0; i < 32; i++) {
for (j = 0; j < 32; j++) {
texels0[i][j][0] = (GLubyte) i;
texels0[i][j][1] = (GLubyte) j;
texels0[i][j][2] = (GLubyte) (i*j)/255;
texels0[i][j][3] = (GLubyte) 255;
}
}
for (i = 0; i < 16; i++) {
for (j = 0; j < 16; j++) {
texels1[i][j][0] = (GLubyte) 255;
texels1[i][j][1] = (GLubyte) i;
texels1[i][j][2] = (GLubyte) j;
texels1[i][j][3] = (GLubyte) 255;
}
}
}
void init(void)
{
GLuint texNames[2];
glClearColor (0.0, 0.0, 0.0, 0.0);
glShadeModel(GL_FLAT);
glEnable(GL_DEPTH_TEST);
makeCheckImages();
glPixelStorei(GL_UNPACK_ALIGNMENT, 1);
glGenTextures(2, texNames);
glBindTexture(GL_TEXTURE_2D, texNames[0]);
glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, 32, 32, 0, GL_RGBA,
GL_UNSIGNED_BYTE, texels0);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER,
GL_NEAREST);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER,
GL_NEAREST);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT);
glBindTexture(GL_TEXTURE_2D, texNames[1]);
glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, 16, 16, 0, GL_RGBA,
GL_UNSIGNED_BYTE, texels1);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
/* Use the two texture objects to define two texture units
* for use in multitexturing */
glActiveTextureARB (GL_TEXTURE0_ARB);
glEnable(GL_TEXTURE_2D);
glBindTexture(GL_TEXTURE_2D, texNames[0]);
glTexEnvi (GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_REPLACE);
glMatrixMode (GL_TEXTURE);
glLoadIdentity();
glTranslatef(0.5f, 0.5f, 0.0f);
glRotatef(45.0f, 0.0f, 0.0f, 1.0f);
glTranslatef(-0.5f, -0.5f, 0.0f);
glMatrixMode (GL_MODELVIEW);
glActiveTextureARB (GL_TEXTURE1_ARB);
glEnable(GL_TEXTURE_2D);
glBindTexture(GL_TEXTURE_2D, texNames[1]);
glTexEnvi (GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_MODULATE);
}
void display(void)
{
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
glBegin(GL_TRIANGLES);
glMultiTexCoord2fARB (GL_TEXTURE0_ARB, 0.0, 0.0);
glMultiTexCoord2fARB (GL_TEXTURE1_ARB, 1.0, 0.0);
glVertex2f(0.0, 0.0);
glMultiTexCoord2fARB (GL_TEXTURE0_ARB, 0.5, 1.0);
glMultiTexCoord2fARB (GL_TEXTURE1_ARB, 0.5, 0.0);
glVertex2f(50.0, 100.0);
glMultiTexCoord2fARB (GL_TEXTURE0_ARB, 1.0, 0.0);
glMultiTexCoord2fARB (GL_TEXTURE1_ARB, 1.0, 1.0);
glVertex2f(100.0, 0.0);
glEnd();
glFlush();
}
void reshape(int w, int h)
{
glViewport(0, 0, (GLsizei) w, (GLsizei) h);
glMatrixMode(GL_PROJECTION);
glLoadIdentity();
if (w <= h)
gluOrtho2D(0.0, 100.0, 0.0, 100.0 * (GLdouble)h/(GLdouble)w);
else
gluOrtho2D(0.0, 100.0 * (GLdouble)w/(GLdouble)h, 0.0, 100.0);
glMatrixMode(GL_MODELVIEW);
glLoadIdentity();
}
void keyboard(unsigned char key, int x, int y)
{
switch (key) {
case 27:
exit(0);
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();
glutReshapeFunc(reshape);
glutDisplayFunc(display);
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 or 1.1.\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
