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  39  * Unpublished-- rights reserved under the copyright laws of the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
  63 InitValues(void)
  64 {
  65    BaseLevel = 0;
  66    MaxLevel = 8;
  67    MinLod = -1;
  68    MaxLod = 9;
  69    LodBias = 0.0;
  70    NearestFilter = GL_TRUE;
  71 }
  72
  73
  74 static void MakeImage(int level, int width, int height, const GLubyte color[4])
  75 {
  76    const int makeStripes = 0;
  77    GLubyte img[256*256*3];
  78    int i, j;
  79    for (i = 0; i < height; i++) {
  80       for (j = 0; j < width; j++) {
  81          int k = (i * width + j) * 3;
  82          int p = (i/8) & makeStripes;
  83          if (p == 0) {
  84             img[k + 0] = color[0];
  85             img[k + 1] = color[1];
  86             img[k + 2] = color[2];
  87          }
  88          else {
  89             img[k + 0] = 0;
  90             img[k + 1] = 0;
  91             img[k + 2] = 0;
  92          }
  93       }
  94    }
  95
  96    glTexImage2D(GL_TEXTURE_2D, level, GL_RGB, width, height, 0,
  97                 GL_RGB, GL_UNSIGNED_BYTE, img);
  98 }
  99
 100
 101 static void makeImages(void)
 102 {
 103    static const GLubyte colors[8][3] = {
 104       {128, 128, 128 },
 105       { 0, 255, 255 },
 106       { 255, 255, 0 },
 107       { 255, 0, 255 },
 108       { 255, 0, 0 },
 109       { 0, 255, 0 },
 110       { 0, 0, 255 },
 111       { 255, 255, 255 }
 112    };
 113    int i, sz = 128;
 114
 115    for (i = 0; i < 8; i++) {
 116       MakeImage(i, sz, sz, colors[i]);
 117       sz /= 2;
 118    }
 119 }
 120
 121 static void myinit(void)
 122 {
 123     InitValues();
 124
 125     glEnable(GL_DEPTH_TEST);
 126     glDepthFunc(GL_LESS);
 127     glShadeModel(GL_FLAT);
 128
 129     glTranslatef(0.0, 0.0, -3.6);
 130
 131     glPixelStorei(GL_UNPACK_ALIGNMENT, 1);
 132     makeImages();
 133     glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT);
 134     glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT);
 135     glTexEnvf(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_DECAL);
 136     glEnable(GL_TEXTURE_2D);
 137 }
 138
 139 static void display(void)
 140 {
 141    GLfloat tcm = 4.0;
 142     printf("BASE_LEVEL=%d  MAX_LEVEL=%d  MIN_LOD=%.2g  MAX_LOD=%.2g  Bias=%.2g  Filter=%s\n",
 143            BaseLevel, MaxLevel, MinLod, MaxLod, LodBias,
 144            NearestFilter ? "NEAREST" : "LINEAR");
 145     glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_BASE_LEVEL, BaseLevel);
 146     glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAX_LEVEL, MaxLevel);
 147
 148     glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MIN_LOD, MinLod);
 149     glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MAX_LOD, MaxLod);
 150
 151     if (NearestFilter) {
 152        glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
 153        glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER,
 154                        GL_NEAREST_MIPMAP_NEAREST);
 155     }
 156     else {
 157        glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
 158        glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER,
 159                        GL_LINEAR_MIPMAP_LINEAR);
 160     }
 161
 162     glTexEnvf(GL_TEXTURE_FILTER_CONTROL_EXT, GL_TEXTURE_LOD_BIAS_EXT, LodBias);
 163
 164     glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
 165     glBegin(GL_QUADS);
 166     glTexCoord2f(0.0, 0.0); glVertex3f(-2.0, -1.0, 0.0);
 167     glTexCoord2f(0.0, tcm); glVertex3f(-2.0, 1.0, 0.0);
 168     glTexCoord2f(tcm, tcm); glVertex3f(3000.0, 1.0, -6000.0);
 169     glTexCoord2f(tcm, 0.0); glVertex3f(3000.0, -1.0, -6000.0);
 170     glEnd();
 171     glFlush();
 172 }
 173
 174 static void myReshape(int w, int h)
 175 {
 176     glViewport(0, 0, w, h);
 177     glMatrixMode(GL_PROJECTION);
 178     glLoadIdentity();
 179     gluPerspective(60.0, 1.0*(GLfloat)w/(GLfloat)h, 1.0, 30000.0);
 180     glMatrixMode(GL_MODELVIEW);
 181     glLoadIdentity();
 182 }
 183
 184 static void
 185 key(unsigned char k, int x, int y)
 186 {
 187   (void) x;
 188   (void) y;
 189   switch (k) {
 190   case 'b':
 191      BaseLevel--;
 192      if (BaseLevel < 0)
 193         BaseLevel = 0;
 194      break;
 195   case 'B':
 196      BaseLevel++;
 197      if (BaseLevel > 10)
 198         BaseLevel = 10;
 199      break;
 200   case 'm':
 201      MaxLevel--;
 202      if (MaxLevel < 0)
 203         MaxLevel = 0;
 204      break;
 205   case 'M':
 206      MaxLevel++;
 207      if (MaxLevel > 10)
 208         MaxLevel = 10;
 209      break;
 210   case 'l':
 211      LodBias -= 0.25;
 212      break;
 213   case 'L':
 214      LodBias += 0.25;
 215      break;
 216   case 'n':
 217      MinLod -= 0.25;
 218      break;
 219   case 'N':
 220      MinLod += 0.25;
 221      break;
 222   case 'x':
 223      MaxLod -= 0.25;
 224      break;
 225   case 'X':
 226      MaxLod += 0.25;
 227      break;
 228   case 'f':
 229      NearestFilter = !NearestFilter;
 230      break;
 231   case ' ':
 232      InitValues();
 233      break;
 234   case 27:  /* Escape */
 235     exit(0);
 236     break;
 237   default:
 238     return;
 239   }
 240   glutPostRedisplay();
 241 }
 242
 243
 244 static void usage(void)
 245 {
 246    printf("usage:\n");
 247    printf("  b/B    decrease/increase GL_TEXTURE_BASE_LEVEL\n");
 248    printf("  m/M    decrease/increase GL_TEXTURE_MAX_LEVEL\n");
 249    printf("  n/N    decrease/increase GL_TEXTURE_MIN_LOD\n");
 250    printf("  x/X    decrease/increase GL_TEXTURE_MAX_LOD\n");
 251    printf("  l/L    decrease/increase GL_TEXTURE_LOD_BIAS\n");
 252    printf("  f      toggle nearest/linear filtering\n");
 253    printf("  SPACE  reset values\n");
 254 }
 255
 256
 257 int main(int argc, char** argv)
 258 {
 259     glutInit(&argc, argv);
 260     glutInitDisplayMode (GLUT_SINGLE | GLUT_RGB | GLUT_DEPTH);
 261     glutInitWindowSize (600, 600);
 262     glutCreateWindow (argv[0]);
 263     myinit();
 264     glutReshapeFunc (myReshape);
 265     glutDisplayFunc(display);
 266     glutKeyboardFunc(key);
 267     usage();
 268     glutMainLoop();
 269     return 0;             /* ANSI C requires main to return int. */
 270 }