mipmap_limits.c revision 32001f49 
1/* Test GL_TEXTURE_BASE_LEVEL and GL_TEXTURE_MAX_LEVEL
2 * Brian Paul
3 * 10 May 2006
4 */
5
6
7/* Copyright (c) Mark J. Kilgard, 1994. */
8
9/*
10 * (c) Copyright 1993, Silicon Graphics, Inc.
11 * ALL RIGHTS RESERVED
12 * Permission to use, copy, modify, and distribute this software for
13 * any purpose and without fee is hereby granted, provided that the above
14 * copyright notice appear in all copies and that both the copyright notice
15 * and this permission notice appear in supporting documentation, and that
16 * the name of Silicon Graphics, Inc. not be used in advertising
17 * or publicity pertaining to distribution of the software without specific,
18 * written prior permission.
19 *
20 * THE MATERIAL EMBODIED ON THIS SOFTWARE IS PROVIDED TO YOU "AS-IS"
21 * AND WITHOUT WARRANTY OF ANY KIND, EXPRESS, IMPLIED OR OTHERWISE,
22 * INCLUDING WITHOUT LIMITATION, ANY WARRANTY OF MERCHANTABILITY OR
23 * FITNESS FOR A PARTICULAR PURPOSE.  IN NO EVENT SHALL SILICON
24 * GRAPHICS, INC.  BE LIABLE TO YOU OR ANYONE ELSE FOR ANY DIRECT,
25 * SPECIAL, INCIDENTAL, INDIRECT OR CONSEQUENTIAL DAMAGES OF ANY
26 * KIND, OR ANY DAMAGES WHATSOEVER, INCLUDING WITHOUT LIMITATION,
27 * LOSS OF PROFIT, LOSS OF USE, SAVINGS OR REVENUE, OR THE CLAIMS OF
28 * THIRD PARTIES, WHETHER OR NOT SILICON GRAPHICS, INC.  HAS BEEN
29 * ADVISED OF THE POSSIBILITY OF SUCH LOSS, HOWEVER CAUSED AND ON
30 * ANY THEORY OF LIABILITY, ARISING OUT OF OR IN CONNECTION WITH THE
31 * POSSESSION, USE OR PERFORMANCE OF THIS SOFTWARE.
32 *
33 * US Government Users Restricted Rights
34 * Use, duplication, or disclosure by the Government is subject to
35 * restrictions set forth in FAR 52.227.19(c)(2) or subparagraph
36 * (c)(1)(ii) of the Rights in Technical Data and Computer Software
37 * clause at DFARS 252.227-7013 and/or in similar or successor
38 * clauses in the FAR or the DOD or NASA FAR Supplement.
39 * Unpublished-- rights reserved under the copyright laws of the
40 * United States.  Contractor/manufacturer is Silicon Graphics,
41 * Inc., 2011 N.  Shoreline Blvd., Mountain View, CA 94039-7311.
42 *
43 * OpenGL(TM) is a trademark of Silicon Graphics, Inc.
44 */
45/*  mipmap.c
46 *  This program demonstrates using mipmaps for texture maps.
47 *  To overtly show the effect of mipmaps, each mipmap reduction
48 *  level has a solidly colored, contrasting texture image.
49 *  Thus, the quadrilateral which is drawn is drawn with several
50 *  different colors.
51 */
52#include <stdlib.h>
53#include <stdio.h>
54#include <GL/glew.h>
55#include "glut_wrap.h"
56
57#include "readtex.h"
58
59#define TEXTURE_FILE DEMOS_DATA_DIR "girl.rgb"
60
61static GLint BaseLevel = 0, MaxLevel = 9;
62static GLfloat MinLod = -1, MaxLod = 9;
63static GLfloat LodBias = 0.0;
64static GLuint texImage, texColor, texCurrent;
65static GLboolean MagNearestFilter = GL_TRUE;
66static unsigned int MinFilterIndex = 0;
67static int Width = 600, Height = 600;
68
69static const struct
70{
71   GLint value;
72   const char *name;
73}
74min_filters[] =
75{
76   {GL_LINEAR_MIPMAP_LINEAR,   "LINEAR_MIPMAP_LINEAR"},
77   {GL_NEAREST_MIPMAP_LINEAR,  "NEAREST_MIPMAP_LINEAR"},
78   {GL_LINEAR_MIPMAP_NEAREST,  "LINEAR_MIPMAP_NEAREST"},
79   {GL_NEAREST_MIPMAP_NEAREST, "NEAREST_MIPMAP_NEAREST"},
80   {GL_LINEAR,                 "LINEAR"},
81   {GL_NEAREST,                "NEAREST"},
82};
83
84
85static void
86InitValues(void)
87{
88   BaseLevel = 0;
89   MaxLevel = 9;
90   MinLod = -1;
91   MaxLod = 9;
92   LodBias = 0.0;
93   MagNearestFilter = GL_TRUE;
94   MinFilterIndex = 0;
95}
96
97
98static void
99MakeImage(int level, int width, int height, const GLubyte color[4])
100{
101   const int makeStripes = 0;
102   GLubyte img[512 * 512 * 3];
103   int i, j;
104   for (i = 0; i < height; i++) {
105      for (j = 0; j < width; j++) {
106         int k = (i * width + j) * 3;
107         int p = (i / 8) & makeStripes;
108         if (p == 0) {
109            img[k + 0] = color[0];
110            img[k + 1] = color[1];
111            img[k + 2] = color[2];
112         }
113         else {
114            img[k + 0] = 0;
115            img[k + 1] = 0;
116            img[k + 2] = 0;
117         }
118      }
119   }
120
121   glTexImage2D(GL_TEXTURE_2D, level, GL_RGB, width, height, 0,
122                GL_RGB, GL_UNSIGNED_BYTE, img);
123}
124
125
126static void
127makeImages(int image)
128{
129#define WIDTH 512
130#define HEIGHT 512
131   if (glutExtensionSupported("GL_SGIS_generate_mipmap") && image) {
132      /* test auto mipmap generation */
133      GLint width, height, i;
134      GLenum format;
135      GLubyte *image = LoadRGBImage(TEXTURE_FILE, &width, &height, &format);
136      if (!image) {
137         printf("Error: could not load texture image %s\n", TEXTURE_FILE);
138         exit(1);
139      }
140      /* resize */
141      if (width != WIDTH || height != HEIGHT) {
142         GLubyte *newImage = malloc(WIDTH * HEIGHT * 4);
143         gluScaleImage(format, width, height, GL_UNSIGNED_BYTE, image,
144                       WIDTH, HEIGHT, GL_UNSIGNED_BYTE, newImage);
145         free(image);
146         image = newImage;
147      }
148      printf("Using GL_SGIS_generate_mipmap\n");
149      glTexParameteri(GL_TEXTURE_2D, GL_GENERATE_MIPMAP_SGIS, GL_TRUE);
150      glTexImage2D(GL_TEXTURE_2D, 0, format, WIDTH, HEIGHT, 0,
151                   format, GL_UNSIGNED_BYTE, image);
152      glTexParameteri(GL_TEXTURE_2D, GL_GENERATE_MIPMAP_SGIS, GL_FALSE);
153      free(image);
154
155      /* make sure mipmap was really generated correctly */
156      width = WIDTH;
157      height = HEIGHT;
158      for (i = 0; i < 10; i++) {
159         GLint w, h;
160         glGetTexLevelParameteriv(GL_TEXTURE_2D, i, GL_TEXTURE_WIDTH, &w);
161         glGetTexLevelParameteriv(GL_TEXTURE_2D, i, GL_TEXTURE_HEIGHT, &h);
162         printf("Level %d size: %d x %d\n", i, w, h);
163         width /= 2;
164         height /= 2;
165      }
166   }
167   else {
168      static const GLubyte colors[10][3] = {
169         {128, 128, 128},
170         {0, 255, 255},
171         {255, 255, 0},
172         {255, 0, 255},
173         {255, 0, 0},
174         {0, 255, 0},
175         {0, 0, 255},
176         {0, 255, 255},
177         {255, 255, 0},
178         {255, 255, 255}
179      };
180      int i, sz = 512;
181
182      for (i = 0; i < 10; i++) {
183         MakeImage(i, sz, sz, colors[i]);
184         printf("Level %d size: %d x %d\n", i, sz, sz);
185         sz /= 2;
186      }
187   }
188}
189
190static void
191myinit(void)
192{
193   InitValues();
194
195   glEnable(GL_DEPTH_TEST);
196   glDepthFunc(GL_LESS);
197   glShadeModel(GL_FLAT);
198
199   glTranslatef(0.0, 0.0, -3.6);
200
201   glPixelStorei(GL_UNPACK_ALIGNMENT, 1);
202   glGenTextures(1, &texImage);
203   glBindTexture(GL_TEXTURE_2D, texImage);
204   makeImages(1);
205   glGenTextures(1, &texColor);
206   glBindTexture(GL_TEXTURE_2D, texColor);
207   makeImages(0);
208
209   texCurrent = texImage;
210
211   glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT);
212   glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT);
213   glTexEnvf(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_DECAL);
214   glEnable(GL_TEXTURE_2D);
215}
216
217static void
218print_string(const char *s)
219{
220   while (*s) {
221      glutBitmapCharacter(GLUT_BITMAP_8_BY_13, (int) *s);
222      s++;
223   }
224}
225
226static void
227print_info(void)
228{
229   int dy = 17;
230   int x = Width-320, y = Height - dy;
231   char s[100];
232
233   glDisable(GL_TEXTURE_2D);
234   glColor3f(1, 1, 1);
235
236   glWindowPos2i(x, y);
237   sprintf(s, "MIN_FILTER (f/F): %s", min_filters[MinFilterIndex].name);
238   print_string(s);
239   y -= dy;
240
241   glWindowPos2i(x, y);
242   sprintf(s, "  MAG_FILTER (g): %s", MagNearestFilter ? "NEAREST" : "LINEAR");
243   print_string(s);
244   y -= dy;
245
246   glWindowPos2i(x, y);
247   sprintf(s, "Toggle Image (t):");
248   print_string(s);
249   y -= dy;
250
251   glWindowPos2i(x, y);
252   sprintf(s, "BASE_LEVEL (b/B): %d", BaseLevel);
253   print_string(s);
254   y -= dy;
255
256   glWindowPos2i(x, y);
257   sprintf(s, " MAX_LEVEL (m/M): %d", MaxLevel);
258   print_string(s);
259   y -= dy;
260
261   glWindowPos2i(x, y);
262   sprintf(s, "   MIN_LOD (n/N): %f", MinLod);
263   print_string(s);
264   y -= dy;
265
266   glWindowPos2i(x, y);
267   sprintf(s, "   MAX_LOD (x/X): %f", MaxLod);
268   print_string(s);
269   y -= dy;
270
271   glWindowPos2i(x, y);
272   sprintf(s, "  LOD_BIAS (l/L): %f", LodBias);
273   print_string(s);
274   y -= dy;
275
276   glWindowPos2i(x, y);
277   sprintf(s, "   RESET (space)");
278   print_string(s);
279   y -= dy;
280
281
282   glEnable(GL_TEXTURE_2D);
283}
284
285
286static void
287display(void)
288{
289   GLfloat tcm = 1.0;
290   glBindTexture(GL_TEXTURE_2D, texCurrent);
291
292   printf
293      ("BASE_LEVEL=%d  MAX_LEVEL=%d  MIN_LOD=%.2g  MAX_LOD=%.2g  Bias=%.2g  Filter=%s/%s\n",
294       BaseLevel, MaxLevel, MinLod, MaxLod, LodBias, min_filters[MinFilterIndex].name,
295       MagNearestFilter ? "NEAREST" : "LINEAR");
296   fflush(stdout);
297
298   glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_BASE_LEVEL, BaseLevel);
299   glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAX_LEVEL, MaxLevel);
300
301   glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MIN_LOD, MinLod);
302   glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MAX_LOD, MaxLod);
303
304   glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, min_filters[MinFilterIndex].value);
305   glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, MagNearestFilter ? GL_NEAREST : GL_LINEAR);
306
307   glTexEnvf(GL_TEXTURE_FILTER_CONTROL_EXT, GL_TEXTURE_LOD_BIAS_EXT, LodBias);
308
309   glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
310   glBegin(GL_QUADS);
311   glTexCoord2f(0.0, 0.0);
312   glVertex3f(-2.0, -1.0, 0.0);
313   glTexCoord2f(0.0, tcm);
314   glVertex3f(-2.0, 1.0, 0.0);
315   glTexCoord2f(tcm * 3000.0, tcm);
316   glVertex3f(3000.0, 1.0, -6000.0);
317   glTexCoord2f(tcm * 3000.0, 0.0);
318   glVertex3f(3000.0, -1.0, -6000.0);
319   glEnd();
320
321   print_info();
322
323   glFlush();
324}
325
326static void
327myReshape(int w, int h)
328{
329   Width = w;
330   Height = h;
331   glViewport(0, 0, w, h);
332   glMatrixMode(GL_PROJECTION);
333   glLoadIdentity();
334   gluPerspective(60.0, 1.0 * (GLfloat) w / (GLfloat) h, 1.0, 30000.0);
335   glMatrixMode(GL_MODELVIEW);
336   glLoadIdentity();
337}
338
339
340static void
341usage(void)
342{
343   printf("usage:\n");
344   printf("  b/B    decrease/increase GL_TEXTURE_BASE_LEVEL\n");
345   printf("  m/M    decrease/increase GL_TEXTURE_MAX_LEVEL\n");
346   printf("  n/N    decrease/increase GL_TEXTURE_MIN_LOD\n");
347   printf("  x/X    decrease/increase GL_TEXTURE_MAX_LOD\n");
348   printf("  l/L    decrease/increase GL_TEXTURE_LOD_BIAS\n");
349   printf("  f/F    cycle minification filter\n");
350   printf("  g      toggle nearest/linear magnification filter\n");
351   printf("  t      toggle texture color/image\n");
352   printf("  SPACE  reset values\n");
353   fflush(stdout);
354}
355
356static void
357key(unsigned char k, int x, int y)
358{
359   (void) x;
360   (void) y;
361   switch (k) {
362   case 'b':
363      BaseLevel--;
364      if (BaseLevel < 0)
365         BaseLevel = 0;
366      break;
367   case 'B':
368      BaseLevel++;
369      if (BaseLevel > 10)
370         BaseLevel = 10;
371      break;
372   case 'm':
373      MaxLevel--;
374      if (MaxLevel < 0)
375         MaxLevel = 0;
376      break;
377   case 'M':
378      MaxLevel++;
379      if (MaxLevel > 10)
380         MaxLevel = 10;
381      break;
382   case 'l':
383      LodBias -= 0.25;
384      break;
385   case 'L':
386      LodBias += 0.25;
387      break;
388   case 'n':
389      MinLod -= 0.25;
390      break;
391   case 'N':
392      MinLod += 0.25;
393      break;
394   case 'x':
395      MaxLod -= 0.25;
396      break;
397   case 'X':
398      MaxLod += 0.25;
399      break;
400   case 'f':
401      if (MinFilterIndex == 0)
402         MinFilterIndex = sizeof(min_filters) / sizeof(*min_filters);
403      MinFilterIndex--;
404      break;
405   case 'F':
406      MinFilterIndex++;
407      if (MinFilterIndex == sizeof(min_filters) / sizeof(*min_filters))
408         MinFilterIndex = 0;
409      break;
410   case 'g':
411      MagNearestFilter = !MagNearestFilter;
412      break;
413   case 't':
414      if (texCurrent == texColor)
415         texCurrent = texImage;
416      else
417         texCurrent = texColor;
418      break;
419   case ' ':
420      InitValues();
421      /* fall-through */
422   case 'u':
423      usage();
424      break;
425   case 27:                    /* Escape */
426      exit(0);
427      break;
428   default:
429      return;
430   }
431   glutPostRedisplay();
432}
433
434
435int
436main(int argc, char **argv)
437{
438   glutInit(&argc, argv);
439   glutInitDisplayMode(GLUT_SINGLE | GLUT_RGB | GLUT_DEPTH);
440   glutInitWindowSize(Width, Height);
441   glutCreateWindow(argv[0]);
442   glewInit();
443   myinit();
444   glutReshapeFunc(myReshape);
445   glutDisplayFunc(display);
446   glutKeyboardFunc(key);
447   usage();
448   glutMainLoop();
449   return 0;                    /* ANSI C requires main to return int. */
450}
451