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  39  * Unpublished-- rights reserved under the copyright laws of the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/glew.h>
  55 #include <GL/glut.h>
  56
  57 static GLint BaseLevel = 0, MaxLevel = 8;
  58 static GLfloat MinLod = -1, MaxLod = 9;
  59 static GLfloat LodBias = 0.0;
  60 static GLboolean NearestFilter = GL_TRUE;
  61
  62
  63 static void
  64 InitValues(void)
  65 {
  66    BaseLevel = 0;
  67    MaxLevel = 8;
  68    MinLod = -1;
  69    MaxLod = 9;
  70    LodBias = 0.0;
  71    NearestFilter = GL_TRUE;
  72 }
  73
  74
  75 static void MakeImage(int level, int width, int height, const GLubyte color[4])
  76 {
  77    const int makeStripes = 0;
  78    GLubyte img[256*256*3];
  79    int i, j;
  80    for (i = 0; i < height; i++) {
  81       for (j = 0; j < width; j++) {
  82          int k = (i * width + j) * 3;
  83          int p = (i/8) & makeStripes;
  84          if (p == 0) {
  85             img[k + 0] = color[0];
  86             img[k + 1] = color[1];
  87             img[k + 2] = color[2];
  88          }
  89          else {
  90             img[k + 0] = 0;
  91             img[k + 1] = 0;
  92             img[k + 2] = 0;
  93          }
  94       }
  95    }
  96
  97    glTexImage2D(GL_TEXTURE_2D, level, GL_RGB, width, height, 0,
  98                 GL_RGB, GL_UNSIGNED_BYTE, img);
  99 }
 100
 101
 102 static void makeImages(void)
 103 {
 104    static const GLubyte colors[8][3] = {
 105       {128, 128, 128 },
 106       { 0, 255, 255 },
 107       { 255, 255, 0 },
 108       { 255, 0, 255 },
 109       { 255, 0, 0 },
 110       { 0, 255, 0 },
 111       { 0, 0, 255 },
 112       { 255, 255, 255 }
 113    };
 114    int i, sz = 128;
 115
 116    for (i = 0; i < 8; i++) {
 117       MakeImage(i, sz, sz, colors[i]);
 118       sz /= 2;
 119    }
 120 }
 121
 122 static void myinit(void)
 123 {
 124     InitValues();
 125
 126     glEnable(GL_DEPTH_TEST);
 127     glDepthFunc(GL_LESS);
 128     glShadeModel(GL_FLAT);
 129
 130     glTranslatef(0.0, 0.0, -3.6);
 131
 132     glPixelStorei(GL_UNPACK_ALIGNMENT, 1);
 133     makeImages();
 134     glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT);
 135     glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT);
 136     glTexEnvf(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_DECAL);
 137     glEnable(GL_TEXTURE_2D);
 138 }
 139
 140 static void display(void)
 141 {
 142    GLfloat tcm = 4.0;
 143     printf("BASE_LEVEL=%d  MAX_LEVEL=%d  MIN_LOD=%.2g  MAX_LOD=%.2g  Bias=%.2g  Filter=%s\n",
 144            BaseLevel, MaxLevel, MinLod, MaxLod, LodBias,
 145            NearestFilter ? "NEAREST" : "LINEAR");
 146     glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_BASE_LEVEL, BaseLevel);
 147     glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAX_LEVEL, MaxLevel);
 148
 149     glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MIN_LOD, MinLod);
 150     glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MAX_LOD, MaxLod);
 151
 152     if (NearestFilter) {
 153        glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
 154        glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER,
 155                        GL_NEAREST_MIPMAP_NEAREST);
 156     }
 157     else {
 158        glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
 159        glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER,
 160                        GL_LINEAR_MIPMAP_LINEAR);
 161     }
 162
 163     glTexEnvf(GL_TEXTURE_FILTER_CONTROL_EXT, GL_TEXTURE_LOD_BIAS_EXT, LodBias);
 164
 165     glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
 166     glBegin(GL_QUADS);
 167     glTexCoord2f(0.0, 0.0); glVertex3f(-2.0, -1.0, 0.0);
 168     glTexCoord2f(0.0, tcm); glVertex3f(-2.0, 1.0, 0.0);
 169     glTexCoord2f(tcm, tcm); glVertex3f(3000.0, 1.0, -6000.0);
 170     glTexCoord2f(tcm, 0.0); glVertex3f(3000.0, -1.0, -6000.0);
 171     glEnd();
 172     glFlush();
 173 }
 174
 175 static void myReshape(int w, int h)
 176 {
 177     glViewport(0, 0, w, h);
 178     glMatrixMode(GL_PROJECTION);
 179     glLoadIdentity();
 180     gluPerspective(60.0, 1.0*(GLfloat)w/(GLfloat)h, 1.0, 30000.0);
 181     glMatrixMode(GL_MODELVIEW);
 182     glLoadIdentity();
 183 }
 184
 185 static void
 186 key(unsigned char k, int x, int y)
 187 {
 188   (void) x;
 189   (void) y;
 190   switch (k) {
 191   case 'b':
 192      BaseLevel--;
 193      if (BaseLevel < 0)
 194         BaseLevel = 0;
 195      break;
 196   case 'B':
 197      BaseLevel++;
 198      if (BaseLevel > 10)
 199         BaseLevel = 10;
 200      break;
 201   case 'm':
 202      MaxLevel--;
 203      if (MaxLevel < 0)
 204         MaxLevel = 0;
 205      break;
 206   case 'M':
 207      MaxLevel++;
 208      if (MaxLevel > 10)
 209         MaxLevel = 10;
 210      break;
 211   case 'l':
 212      LodBias -= 0.25;
 213      break;
 214   case 'L':
 215      LodBias += 0.25;
 216      break;
 217   case 'n':
 218      MinLod -= 0.25;
 219      break;
 220   case 'N':
 221      MinLod += 0.25;
 222      break;
 223   case 'x':
 224      MaxLod -= 0.25;
 225      break;
 226   case 'X':
 227      MaxLod += 0.25;
 228      break;
 229   case 'f':
 230      NearestFilter = !NearestFilter;
 231      break;
 232   case ' ':
 233      InitValues();
 234      break;
 235   case 27:  /* Escape */
 236     exit(0);
 237     break;
 238   default:
 239     return;
 240   }
 241   glutPostRedisplay();
 242 }
 243
 244
 245 static void usage(void)
 246 {
 247    printf("usage:\n");
 248    printf("  b/B    decrease/increase GL_TEXTURE_BASE_LEVEL\n");
 249    printf("  m/M    decrease/increase GL_TEXTURE_MAX_LEVEL\n");
 250    printf("  n/N    decrease/increase GL_TEXTURE_MIN_LOD\n");
 251    printf("  x/X    decrease/increase GL_TEXTURE_MAX_LOD\n");
 252    printf("  l/L    decrease/increase GL_TEXTURE_LOD_BIAS\n");
 253    printf("  f      toggle nearest/linear filtering\n");
 254    printf("  SPACE  reset values\n");
 255 }
 256
 257
 258 int main(int argc, char** argv)
 259 {
 260     glutInit(&argc, argv);
 261     glutInitDisplayMode (GLUT_SINGLE | GLUT_RGB | GLUT_DEPTH);
 262     glutInitWindowSize (600, 600);
 263     glutCreateWindow (argv[0]);
 264     glewInit();
 265     myinit();
 266     glutReshapeFunc (myReshape);
 267     glutDisplayFunc(display);
 268     glutKeyboardFunc(key);
 269     usage();
 270     glutMainLoop();
 271     return 0;             /* ANSI C requires main to return int. */
 272 }