summaryrefslogtreecommitdiff
path: root/progs/redbook/combiner.c
blob: 7682e0c0324d839b4d2ec4d9e7531bf93d0ec7f0 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
/*
 * 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.
 */

/*  combiner.c
 *  This program renders a variety of quads showing different
 *  effects of texture combiner functions.
 *
 *  The first row renders an untextured polygon (so you can 
 *  compare the fragment colors) and then the 2 textures.
 *  The second row shows several different combiner functions
 *  on a single texture:  replace, modulate, add, add-signed,
 *  and subtract.  
 *  The third row shows the interpolate combiner function
 *  on a single texture with a constant color/alpha value,
 *  varying the amount of interpolation.  
 *  The fourth row uses multitexturing with two textures
 *  and different combiner functions.
 *  The fifth row are some combiner experiments:  using the
 *  scaling factor and reversing the order of subtraction
 *  for a combination function.
 */
#include <GL/glew.h>
#include <GL/glut.h>
#include <stdlib.h>
#include <stdio.h>

#define	imageWidth 8
#define	imageHeight 8
/*     arrays for two textures	    */
static GLubyte image0[imageHeight][imageWidth][4];
static GLubyte image1[imageHeight][imageWidth][4];

static GLuint texName[4];

static void makeImages(void)
{
   int i, j, c;
   for (i = 0; i < imageHeight; i++) {
      for (j = 0; j < imageWidth; j++) {
         c = ((i&2)==0)*255;   /*  horiz b & w stripes  */
         image0[i][j][0] = (GLubyte) c;
         image0[i][j][1] = (GLubyte) c;
         image0[i][j][2] = (GLubyte) c;
         image0[i][j][3] = (GLubyte) 255;
         c = ((j&4)!=0)*128;   /*  wider vertical 50% cyan and black stripes  */
         image1[i][j][0] = (GLubyte) 0;
         image1[i][j][1] = (GLubyte) c;
         image1[i][j][2] = (GLubyte) c;
         image1[i][j][3] = (GLubyte) 255;
      }
   }
}

static void init(void)
{    
   glClearColor (0.0, 0.0, 0.0, 0.0);
   glShadeModel(GL_SMOOTH);

   makeImages();
   glPixelStorei(GL_UNPACK_ALIGNMENT, 1);

   glGenTextures(4, texName);

   glBindTexture(GL_TEXTURE_2D, texName[0]);
   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, imageWidth, imageHeight, 
                0, GL_RGBA, GL_UNSIGNED_BYTE, image0);

   glBindTexture(GL_TEXTURE_2D, texName[1]);
   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, imageWidth, imageHeight, 
                0, GL_RGBA, GL_UNSIGNED_BYTE, image1);

/*  smooth-shaded polygon with multiple texture coordinates  */
   glNewList (1, GL_COMPILE);
   glBegin(GL_QUADS);
   glMultiTexCoord2fARB(GL_TEXTURE0_ARB, 0.0, 0.0); 
   glMultiTexCoord2fARB(GL_TEXTURE1_ARB, 0.0, 0.0); 
   glColor3f (0.5, 1.0, 0.25);
   glVertex3f(0.0, 0.0, 0.0);
   glMultiTexCoord2fARB(GL_TEXTURE0_ARB, 0.0, 2.0); 
   glMultiTexCoord2fARB(GL_TEXTURE1_ARB, 0.0, 2.0); 
   glColor3f (1.0, 1.0, 1.0);
   glVertex3f(0.0, 1.0, 0.0);
   glMultiTexCoord2fARB(GL_TEXTURE0_ARB, 2.0, 2.0); 
   glMultiTexCoord2fARB(GL_TEXTURE1_ARB, 2.0, 2.0); 
   glColor3f (1.0, 1.0, 1.0);
   glVertex3f(1.0, 1.0, 0.0);
   glMultiTexCoord2fARB(GL_TEXTURE0_ARB, 2.0, 0.0); 
   glMultiTexCoord2fARB(GL_TEXTURE1_ARB, 2.0, 0.0); 
   glColor3f (1.0, 0.5, 0.25);
   glVertex3f(1.0, 0.0, 0.0);
   glEnd();
   glEndList ();
}

static void display(void)
{
   static GLfloat constColor[4] = {0.0, 0.0, 0.0, 0.0};  /*  for use as constant texture color  */

   glClear(GL_COLOR_BUFFER_BIT);

   glDisable(GL_TEXTURE_2D);  /*  untextured polygon--see the "fragment" colors  */
   glPushMatrix();
   glTranslatef(0.0, 5.0, 0.0);
   glCallList(1);
   glPopMatrix();

   glEnable(GL_TEXTURE_2D);
/*  draw ordinary textured polys; 1 texture unit; combine mode disabled  */
   glTexEnvf(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_MODULATE);
   glPushMatrix();
   glBindTexture(GL_TEXTURE_2D, texName[0]);
   glTranslatef(1.0, 5.0, 0.0);
   glCallList(1);
   glPopMatrix();

   glPushMatrix();
   glBindTexture(GL_TEXTURE_2D, texName[1]);
   glTranslatef(2.0, 5.0, 0.0);
   glCallList(1);
   glPopMatrix();

/*  different combine modes enabled; 1 texture unit
 *  defaults are:
 *  glTexEnvf(GL_TEXTURE_ENV, GL_SOURCE0_RGB_ARB, GL_TEXTURE);
 *  glTexEnvf(GL_TEXTURE_ENV, GL_OPERAND0_RGB_ARB, GL_SRC_COLOR);
 *  glTexEnvf(GL_TEXTURE_ENV, GL_SOURCE1_RGB_ARB, GL_PREVIOUS_ARB);
 *  glTexEnvf(GL_TEXTURE_ENV, GL_OPERAND1_RGB_ARB, GL_SRC_COLOR);
 */
   glBindTexture(GL_TEXTURE_2D, texName[0]);
   glTexEnvf(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_COMBINE_ARB);
   glTexEnvf(GL_TEXTURE_ENV, GL_COMBINE_RGB_ARB, GL_REPLACE);
   glTexEnvf(GL_TEXTURE_ENV, GL_SOURCE0_RGB_ARB, GL_TEXTURE);
   glTexEnvf(GL_TEXTURE_ENV, GL_OPERAND0_RGB_ARB, GL_SRC_COLOR);
   glPushMatrix();
   glTranslatef(1.0, 4.0, 0.0);
   glCallList(1);
   glPopMatrix();

   glTexEnvf(GL_TEXTURE_ENV, GL_COMBINE_RGB_ARB, GL_MODULATE);
   glTexEnvf(GL_TEXTURE_ENV, GL_SOURCE1_RGB_ARB, GL_PREVIOUS_ARB);
   glTexEnvf(GL_TEXTURE_ENV, GL_OPERAND1_RGB_ARB, GL_SRC_COLOR);
   glPushMatrix();
   glTranslatef(2.0, 4.0, 0.0);
   glCallList(1);
   glPopMatrix();

   glTexEnvf(GL_TEXTURE_ENV, GL_COMBINE_RGB_ARB, GL_ADD);
   glPushMatrix();
   glTranslatef(3.0, 4.0, 0.0);
   glCallList(1);
   glPopMatrix();

   glTexEnvf(GL_TEXTURE_ENV, GL_COMBINE_RGB_ARB, GL_ADD_SIGNED_ARB);
   glPushMatrix();
   glTranslatef(4.0, 4.0, 0.0);
   glCallList(1);
   glPopMatrix();

   glTexEnvf(GL_TEXTURE_ENV, GL_COMBINE_RGB_ARB, GL_SUBTRACT_ARB);
   glPushMatrix();
   glTranslatef(5.0, 4.0, 0.0);
   glCallList(1);
   glPopMatrix();

/*  interpolate combine with constant color; 1 texture unit 
 *  use different alpha values for constant color
 *  defaults are:
 *  glTexEnvf(GL_TEXTURE_ENV, GL_SOURCE0_RGB_ARB, GL_TEXTURE);
 *  glTexEnvf(GL_TEXTURE_ENV, GL_OPERAND0_RGB_ARB, GL_SRC_COLOR);
 *  glTexEnvf(GL_TEXTURE_ENV, GL_SOURCE1_RGB_ARB, GL_PREVIOUS_ARB);
 *  glTexEnvf(GL_TEXTURE_ENV, GL_OPERAND1_RGB_ARB, GL_SRC_COLOR);
 *  glTexEnvf(GL_TEXTURE_ENV, GL_SOURCE2_RGB_ARB, GL_CONSTANT_ARB);
 *  glTexEnvf(GL_TEXTURE_ENV, GL_OPERAND2_RGB_ARB, GL_SRC_ALPHA);
 */
   constColor[3] = 0.2;
   glTexEnvfv(GL_TEXTURE_ENV, GL_TEXTURE_ENV_COLOR, constColor);
   glBindTexture(GL_TEXTURE_2D, texName[0]);
   glTexEnvf(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_COMBINE_ARB);
   glTexEnvf(GL_TEXTURE_ENV, GL_COMBINE_RGB_ARB, GL_INTERPOLATE_ARB);
   glTexEnvf(GL_TEXTURE_ENV, GL_SOURCE0_RGB_ARB, GL_TEXTURE);
   glTexEnvf(GL_TEXTURE_ENV, GL_OPERAND0_RGB_ARB, GL_SRC_COLOR);
   glTexEnvf(GL_TEXTURE_ENV, GL_SOURCE1_RGB_ARB, GL_PREVIOUS_ARB);
   glTexEnvf(GL_TEXTURE_ENV, GL_OPERAND1_RGB_ARB, GL_SRC_COLOR);
   glTexEnvf(GL_TEXTURE_ENV, GL_SOURCE2_RGB_ARB, GL_CONSTANT_ARB);
   glTexEnvf(GL_TEXTURE_ENV, GL_OPERAND2_RGB_ARB, GL_SRC_ALPHA);
   glPushMatrix();
   glTranslatef(1.0, 3.0, 0.0);
   glCallList(1);
   glPopMatrix();

   constColor[3] = 0.4;
   glTexEnvfv(GL_TEXTURE_ENV, GL_TEXTURE_ENV_COLOR, constColor);
   glPushMatrix();
   glTranslatef(2.0, 3.0, 0.0);
   glCallList(1);
   glPopMatrix();

   constColor[3] = 0.6;
   glTexEnvfv(GL_TEXTURE_ENV, GL_TEXTURE_ENV_COLOR, constColor);
   glPushMatrix();
   glTranslatef(3.0, 3.0, 0.0);
   glCallList(1);
   glPopMatrix();

   constColor[3] = 0.8;
   glTexEnvfv(GL_TEXTURE_ENV, GL_TEXTURE_ENV_COLOR, constColor);
   glPushMatrix();
   glTranslatef(4.0, 3.0, 0.0);
   glCallList(1);
   glPopMatrix();

/*  combine textures 0 & 1
 *  defaults are:
 *  glTexEnvf(GL_TEXTURE_ENV, GL_SOURCE0_RGB_ARB, GL_TEXTURE);
 *  glTexEnvf(GL_TEXTURE_ENV, GL_OPERAND0_RGB_ARB, GL_SRC_COLOR);
 *  glTexEnvf(GL_TEXTURE_ENV, GL_SOURCE1_RGB_ARB, GL_PREVIOUS_ARB);
 *  glTexEnvf(GL_TEXTURE_ENV, GL_OPERAND1_RGB_ARB, GL_SRC_COLOR);
 */

   glActiveTextureARB (GL_TEXTURE0_ARB);
   glEnable (GL_TEXTURE_2D);
   glBindTexture(GL_TEXTURE_2D, texName[0]);
   glTexEnvf(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_MODULATE);

   glActiveTextureARB (GL_TEXTURE1_ARB);
   glEnable (GL_TEXTURE_2D);
   glBindTexture(GL_TEXTURE_2D, texName[1]);
   glTexEnvf(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_COMBINE_ARB);
   glTexEnvf(GL_TEXTURE_ENV, GL_COMBINE_RGB_ARB, GL_REPLACE);
   glPushMatrix();
   glTranslatef(1.0, 2.0, 0.0);
   glCallList(1);
   glPopMatrix();

   /*  try different combiner modes of texture unit 1  */
   glTexEnvf(GL_TEXTURE_ENV, GL_COMBINE_RGB_ARB, GL_MODULATE);
   glPushMatrix();
   glTranslatef(2.0, 2.0, 0.0);
   glCallList(1);
   glPopMatrix();

   glTexEnvf(GL_TEXTURE_ENV, GL_COMBINE_RGB_ARB, GL_ADD);
   glPushMatrix();
   glTranslatef(3.0, 2.0, 0.0);
   glCallList(1);
   glPopMatrix();

   glTexEnvf(GL_TEXTURE_ENV, GL_COMBINE_RGB_ARB, GL_ADD_SIGNED_ARB);
   glPushMatrix();
   glTranslatef(4.0, 2.0, 0.0);
   glCallList(1);
   glPopMatrix();

   glTexEnvf(GL_TEXTURE_ENV, GL_COMBINE_RGB_ARB, GL_SUBTRACT_ARB);
   glPushMatrix();
   glTranslatef(5.0, 2.0, 0.0);
   glCallList(1);
   glPopMatrix();

/*  some experiments */

/*  see the effect of RGB_SCALE   */
   glTexEnvf(GL_TEXTURE_ENV, GL_RGB_SCALE_ARB, 2.0);
   glTexEnvf(GL_TEXTURE_ENV, GL_COMBINE_RGB_ARB, GL_REPLACE);
   glPushMatrix();
   glTranslatef(1.0, 1.0, 0.0);
   glCallList(1);
   glPopMatrix();

   glTexEnvf(GL_TEXTURE_ENV, GL_COMBINE_RGB_ARB, GL_MODULATE);
   glPushMatrix();
   glTranslatef(2.0, 1.0, 0.0);
   glCallList(1);
   glPopMatrix();
   glTexEnvf(GL_TEXTURE_ENV, GL_RGB_SCALE_ARB, 1.0);

/*  using SOURCE0 and SOURCE1, reverse the order of subtraction Arg1-Arg0  */

   glTexEnvf(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_COMBINE_ARB);
   glTexEnvf(GL_TEXTURE_ENV, GL_COMBINE_RGB_ARB, GL_SUBTRACT_ARB);
   glTexEnvf(GL_TEXTURE_ENV, GL_SOURCE0_RGB_ARB, GL_PREVIOUS_ARB);
   glTexEnvf(GL_TEXTURE_ENV, GL_OPERAND0_RGB_ARB, GL_SRC_COLOR);
   glTexEnvf(GL_TEXTURE_ENV, GL_SOURCE1_RGB_ARB, GL_TEXTURE);
   glTexEnvf(GL_TEXTURE_ENV, GL_OPERAND1_RGB_ARB, GL_SRC_COLOR);
   glPushMatrix();
   glTranslatef(5.0, 1.0, 0.0);
   glCallList(1);
   glPopMatrix();

   glActiveTextureARB (GL_TEXTURE1_ARB);  /*  deactivate multitexturing  */
   glDisable (GL_TEXTURE_2D);
   glActiveTextureARB (GL_TEXTURE0_ARB);  /*  activate single texture unit  */

   glFlush();
}

static void reshape(int w, int h)
{
   glViewport(0, 0, (GLsizei) w, (GLsizei) h);
   glMatrixMode(GL_PROJECTION);
   glLoadIdentity();
   gluOrtho2D(0.0, 7.0, 0.0, 7.0);
   glMatrixMode(GL_MODELVIEW);
   glLoadIdentity();
}

static void keyboard (unsigned char key, int x, int y)
{
   switch (key) {
      case 27:
         exit(0);
         break;
      default:
         break;
   }
}

int main(int argc, char** argv)
{
   glutInit(&argc, argv);
   glutInitDisplayMode(GLUT_SINGLE | GLUT_RGB);
   glutInitWindowSize(400, 400);
   glutInitWindowPosition(100, 100);
   glutCreateWindow(argv[0]);
   glewInit();
   init();
   glutDisplayFunc(display);
   glutReshapeFunc(reshape);
   glutKeyboardFunc(keyboard);
   glutMainLoop();
   return 0; 
}