1/*
2 * Copyright (c) 1993-2003, Silicon Graphics, Inc.
3 * All Rights Reserved
4 *
5 * Permission to use, copy, modify, and distribute this software for any
6 * purpose and without fee is hereby granted, provided that the above
7 * copyright notice appear in all copies and that both the copyright
8 * notice and this permission notice appear in supporting documentation,
9 * and that the name of Silicon Graphics, Inc. not be used in
10 * advertising or publicity pertaining to distribution of the software
11 * without specific, written prior permission.
12 *
13 * THE MATERIAL EMBODIED ON THIS SOFTWARE IS PROVIDED TO YOU "AS-IS" AND
14 * WITHOUT WARRANTY OF ANY KIND, EXPRESS, IMPLIED OR OTHERWISE,
15 * INCLUDING WITHOUT LIMITATION, ANY WARRANTY OF MERCHANTABILITY OR
16 * FITNESS FOR A PARTICULAR PURPOSE.  IN NO EVENT SHALL SILICON
17 * GRAPHICS, INC.  BE LIABLE TO YOU OR ANYONE ELSE FOR ANY DIRECT,
18 * SPECIAL, INCIDENTAL, INDIRECT OR CONSEQUENTIAL DAMAGES OF ANY KIND,
19 * OR ANY DAMAGES WHATSOEVER, INCLUDING WITHOUT LIMITATION, LOSS OF
20 * PROFIT, LOSS OF USE, SAVINGS OR REVENUE, OR THE CLAIMS OF THIRD
21 * PARTIES, WHETHER OR NOT SILICON GRAPHICS, INC.  HAS BEEN ADVISED OF
22 * THE POSSIBILITY OF SUCH LOSS, HOWEVER CAUSED AND ON ANY THEORY OF
23 * LIABILITY, ARISING OUT OF OR IN CONNECTION WITH THE POSSESSION, USE
24 * OR PERFORMANCE OF THIS SOFTWARE.
25 *
26 * US Government Users Restricted Rights
27 * Use, duplication, or disclosure by the Government is subject to
28 * restrictions set forth in FAR 52.227.19(c)(2) or subparagraph
29 * (c)(1)(ii) of the Rights in Technical Data and Computer Software
30 * clause at DFARS 252.227-7013 and/or in similar or successor clauses
31 * in the FAR or the DOD or NASA FAR Supplement.  Unpublished - rights
32 * reserved under the copyright laws of the United States.
33 *
34 * Contractor/manufacturer is:
35 *	Silicon Graphics, Inc.
36 *	1500 Crittenden Lane
37 *	Mountain View, CA  94043
38 *	United State of America
39 *
40 * OpenGL(R) is a registered trademark of Silicon Graphics, Inc.
41 */
42
43/*  multitex.c
44 */
45#include <GL/glew.h>
46#include "glut_wrap.h"
47#include <stdlib.h>
48#include <stdio.h>
49
50
51static GLubyte texels0[32][32][4];
52static GLubyte texels1[16][16][4];
53
54static void makeCheckImages(void)
55{
56   int i, j;
57
58   for (i = 0; i < 32; i++) {
59      for (j = 0; j < 32; j++) {
60         texels0[i][j][0] = (GLubyte) (255 * i / 31);
61         texels0[i][j][1] = (GLubyte) (255 * j / 31);
62         texels0[i][j][2] = (GLubyte) (i*j)/255;
63         texels0[i][j][3] = (GLubyte) 255;
64      }
65   }
66
67   for (i = 0; i < 16; i++) {
68      for (j = 0; j < 16; j++) {
69         texels1[i][j][0] = (GLubyte) 255;
70         texels1[i][j][1] = (GLubyte) (255 * i / 15);
71         texels1[i][j][2] = (GLubyte) (255 * j / 15);
72         texels1[i][j][3] = (GLubyte) 255;
73      }
74   }
75}
76
77static void init(void)
78{
79   GLuint texNames[2];
80
81   glClearColor (0.0, 0.0, 0.0, 0.0);
82   glShadeModel(GL_FLAT);
83   glEnable(GL_DEPTH_TEST);
84
85   makeCheckImages();
86   glPixelStorei(GL_UNPACK_ALIGNMENT, 1);
87
88   glGenTextures(2, texNames);
89   glBindTexture(GL_TEXTURE_2D, texNames[0]);
90   glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, 32, 32, 0, GL_RGBA,
91		GL_UNSIGNED_BYTE, texels0);
92   glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER,
93                   GL_NEAREST);
94   glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER,
95                   GL_NEAREST);
96   glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT);
97   glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT);
98
99   glBindTexture(GL_TEXTURE_2D, texNames[1]);
100   glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, 16, 16, 0, GL_RGBA,
101		GL_UNSIGNED_BYTE, texels1);
102   glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
103   glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
104   glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
105   glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
106   /*  Use the two texture objects to define two texture units
107    *  for use in multitexturing  */
108   glActiveTextureARB (GL_TEXTURE0_ARB);
109   glEnable(GL_TEXTURE_2D);
110   glBindTexture(GL_TEXTURE_2D, texNames[0]);
111   glTexEnvi (GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_REPLACE);
112   glMatrixMode (GL_TEXTURE);
113      glLoadIdentity();
114      glTranslatef(0.5f, 0.5f, 0.0f);
115      glRotatef(45.0f, 0.0f, 0.0f, 1.0f);
116      glTranslatef(-0.5f, -0.5f, 0.0f);
117   glMatrixMode (GL_MODELVIEW);
118   glActiveTextureARB (GL_TEXTURE1_ARB);
119   glEnable(GL_TEXTURE_2D);
120   glBindTexture(GL_TEXTURE_2D, texNames[1]);
121   glTexEnvi (GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_MODULATE);
122}
123
124static void display(void)
125{
126   glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
127   glBegin(GL_TRIANGLES);
128   glMultiTexCoord2fARB (GL_TEXTURE0_ARB, 0.0, 0.0);
129   glMultiTexCoord2fARB (GL_TEXTURE1_ARB, 1.0, 0.0);
130   glVertex2f(0.0, 0.0);
131   glMultiTexCoord2fARB (GL_TEXTURE0_ARB, 0.5, 1.0);
132   glMultiTexCoord2fARB (GL_TEXTURE1_ARB, 0.5, 0.0);
133   glVertex2f(50.0, 100.0);
134   glMultiTexCoord2fARB (GL_TEXTURE0_ARB, 1.0, 0.0);
135   glMultiTexCoord2fARB (GL_TEXTURE1_ARB, 1.0, 1.0);
136   glVertex2f(100.0, 0.0);
137   glEnd();
138   glFlush();
139}
140
141static void reshape(int w, int h)
142{
143   glViewport(0, 0, (GLsizei) w, (GLsizei) h);
144   glMatrixMode(GL_PROJECTION);
145   glLoadIdentity();
146   if (w <= h)
147      gluOrtho2D(0.0, 100.0, 0.0, 100.0 * (GLdouble)h/(GLdouble)w);
148   else
149      gluOrtho2D(0.0, 100.0 * (GLdouble)w/(GLdouble)h, 0.0, 100.0);
150   glMatrixMode(GL_MODELVIEW);
151   glLoadIdentity();
152}
153
154static void keyboard(unsigned char key, int x, int y)
155{
156   switch (key) {
157      case 27:
158         exit(0);
159         break;
160   }
161}
162
163int main(int argc, char** argv)
164{
165   glutInit(&argc, argv);
166   glutInitDisplayMode(GLUT_SINGLE | GLUT_RGB | GLUT_DEPTH);
167   glutInitWindowSize(250, 250);
168   glutInitWindowPosition(100, 100);
169   glutCreateWindow(argv[0]);
170   glewInit();
171   init();
172   glutReshapeFunc(reshape);
173   glutDisplayFunc(display);
174   glutKeyboardFunc (keyboard);
175   glutMainLoop();
176   return 0;
177}
178