progs/tests/mipmap_limits.c

   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  39  * Unpublished-- rights reserved under the copyright laws of the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/glut.h>
  55
  56 static GLint BaseLevel = 0, MaxLevel = 8;
  57 static GLfloat MinLod = -1, MaxLod = 9;
  58 static GLfloat LodBias = 0.0;
  59 static GLboolean NearestFilter = GL_TRUE;
  60
  61
  62 static void MakeImage(int level, int width, int height, const GLubyte color[4])
  63 {
  64    const int makeStripes = 0;
  65    GLubyte img[256*256*3];
  66    int i, j;
  67    for (i = 0; i < height; i++) {
  68       for (j = 0; j < width; j++) {
  69          int k = (i * width + j) * 3;
  70          int p = (i/8) & makeStripes;
  71          if (p == 0) {
  72             img[k + 0] = color[0];
  73             img[k + 1] = color[1];
  74             img[k + 2] = color[2];
  75          }
  76          else {
  77             img[k + 0] = 0;
  78             img[k + 1] = 0;
  79             img[k + 2] = 0;
  80          }
  81       }
  82    }
  83
  84    glTexImage2D(GL_TEXTURE_2D, level, GL_RGB, width, height, 0,
  85                 GL_RGB, GL_UNSIGNED_BYTE, img);
  86 }
  87
  88
  89 static void makeImages(void)
  90 {
  91    static const GLubyte colors[8][3] = {
  92       {128, 128, 128 },
  93       { 0, 255, 255 },
  94       { 255, 255, 0 },
  95       { 255, 0, 255 },
  96       { 255, 0, 0 },
  97       { 0, 255, 0 },
  98       { 0, 0, 255 },
  99       { 255, 255, 255 }
 100    };
 101    int i, sz = 128;
 102
 103    for (i = 0; i < 8; i++) {
 104       MakeImage(i, sz, sz, colors[i]);
 105       sz /= 2;
 106    }
 107 }
 108
 109 static void myinit(void)
 110 {
 111     glEnable(GL_DEPTH_TEST);
 112     glDepthFunc(GL_LESS);
 113     glShadeModel(GL_FLAT);
 114
 115     glTranslatef(0.0, 0.0, -3.6);
 116
 117     glPixelStorei(GL_UNPACK_ALIGNMENT, 1);
 118     makeImages();
 119     glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT);
 120     glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT);
 121     glTexEnvf(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_DECAL);
 122     glEnable(GL_TEXTURE_2D);
 123 }
 124
 125 static void display(void)
 126 {
 127    GLfloat tcm = 4.0;
 128     printf("BASE_LEVEL = %d  MAX_LEVEL = %d  MIN_LOD = %f MAX_LOD = %f Bias = %.2g  filter = %s\n",
 129            BaseLevel, MaxLevel, MinLod, MaxLod, LodBias,
 130            NearestFilter ? "NEAREST" : "LINEAR");
 131     glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_BASE_LEVEL, BaseLevel);
 132     glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAX_LEVEL, MaxLevel);
 133
 134     glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_LOD, MinLod);
 135     glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAX_LOD, MaxLod);
 136
 137     if (NearestFilter) {
 138        glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
 139        glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER,
 140                        GL_NEAREST_MIPMAP_NEAREST);
 141     }
 142     else {
 143        glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
 144        glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER,
 145                        GL_LINEAR_MIPMAP_LINEAR);
 146     }
 147
 148     glTexEnvf(GL_TEXTURE_FILTER_CONTROL_EXT, GL_TEXTURE_LOD_BIAS_EXT, LodBias);
 149
 150     glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
 151     glBegin(GL_QUADS);
 152     glTexCoord2f(0.0, 0.0); glVertex3f(-2.0, -1.0, 0.0);
 153     glTexCoord2f(0.0, tcm); glVertex3f(-2.0, 1.0, 0.0);
 154     glTexCoord2f(tcm, tcm); glVertex3f(3000.0, 1.0, -6000.0);
 155     glTexCoord2f(tcm, 0.0); glVertex3f(3000.0, -1.0, -6000.0);
 156     glEnd();
 157     glFlush();
 158 }
 159
 160 static void myReshape(int w, int h)
 161 {
 162     glViewport(0, 0, w, h);
 163     glMatrixMode(GL_PROJECTION);
 164     glLoadIdentity();
 165     gluPerspective(60.0, 1.0*(GLfloat)w/(GLfloat)h, 1.0, 30000.0);
 166     glMatrixMode(GL_MODELVIEW);
 167     glLoadIdentity();
 168 }
 169
 170 static void
 171 key(unsigned char k, int x, int y)
 172 {
 173   (void) x;
 174   (void) y;
 175   switch (k) {
 176   case 'b':
 177      BaseLevel--;
 178      if (BaseLevel < 0)
 179         BaseLevel = 0;
 180      break;
 181   case 'B':
 182      BaseLevel++;
 183      if (BaseLevel > 10)
 184         BaseLevel = 10;
 185      break;
 186   case 'm':
 187      MaxLevel--;
 188      if (MaxLevel < 0)
 189         MaxLevel = 0;
 190      break;
 191   case 'M':
 192      MaxLevel++;
 193      if (MaxLevel > 10)
 194         MaxLevel = 10;
 195      break;
 196   case 'l':
 197      LodBias -= 0.02;
 198      break;
 199   case 'L':
 200      LodBias += 0.02;
 201      break;
 202   case 'n':
 203      MinLod -= 0.02;
 204      break;
 205   case 'N':
 206      MinLod += 0.02;
 207      break;
 208   case 'x':
 209      MaxLod -= 0.02;
 210      break;
 211   case 'X':
 212      MaxLod += 0.02;
 213      break;
 214   case 'f':
 215      NearestFilter = !NearestFilter;
 216      break;
 217   case 27:  /* Escape */
 218     exit(0);
 219     break;
 220   default:
 221     return;
 222   }
 223   glutPostRedisplay();
 224 }
 225
 226
 227 static void usage(void)
 228 {
 229    printf("usage:\n");
 230    printf("  b/B  decrease/increase GL_TEXTURE_BASE_LEVEL\n");
 231    printf("  m/M  decrease/increase GL_TEXTURE_MAX_LEVEL\n");
 232    printf("  n/N  decrease/increase GL_TEXTURE_MIN_LOD\n");
 233    printf("  x/X  decrease/increase GL_TEXTURE_MAX_LOD\n");
 234    printf("  l/L  decrease/increase GL_TEXTURE_LOD_BIAS\n");
 235    printf("  f    toggle nearest/linear filtering\n");
 236 }
 237
 238
 239 int main(int argc, char** argv)
 240 {
 241     glutInit(&argc, argv);
 242     glutInitDisplayMode (GLUT_SINGLE | GLUT_RGB | GLUT_DEPTH);
 243     glutInitWindowSize (600, 600);
 244     glutCreateWindow (argv[0]);
 245     myinit();
 246     glutReshapeFunc (myReshape);
 247     glutDisplayFunc(display);
 248     glutKeyboardFunc(key);
 249     usage();
 250     glutMainLoop();
 251     return 0;             /* ANSI C requires main to return int. */
 252 }