progs/tests/mipgen.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  39  * Unpublished-- rights reserved under the copyright laws of the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
  46 #include <stdlib.h>
  47 #include <stdio.h>
  48 #include <GL/glew.h>
  49 #include <GL/glut.h>
  50
  51 #include "readtex.h"
  52
  53
  54 static GLfloat LodBias = 6.0;   /* make smallest miplevel visible */
  55 static GLuint texImage;
  56
  57 #define WIDTH 2
  58 #define HEIGHT 2
  59
  60 static void
  61 InitValues(void)
  62 {
  63    LodBias = 6.0;               /* make smallest miplevel visible */
  64 }
  65
  66
  67 static void MakeImage(void)
  68 {
  69    const GLubyte color0[4] = { 0xff, 0x80, 0x20, 0xff };
  70    const GLubyte color1[4] = { 0x10, 0x20, 0x40, 0xff };
  71
  72    GLubyte img[WIDTH*HEIGHT*3];
  73    int i, j;
  74    for (i = 0; i < HEIGHT; i++) {
  75       for (j = 0; j < WIDTH; j++) {
  76          int k = (i * WIDTH + j) * 3;
  77          int p = ((i+j)%2);
  78          if (p == 0) {
  79             img[k + 0] = color0[0];
  80             img[k + 1] = color0[1];
  81             img[k + 2] = color0[2];
  82          }
  83          else {
  84             img[k + 0] = color1[0];
  85             img[k + 1] = color1[1];
  86             img[k + 2] = color1[2];
  87          }
  88       }
  89    }
  90
  91    glTexParameteri(GL_TEXTURE_2D, GL_GENERATE_MIPMAP_SGIS, GL_TRUE);
  92    glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB, WIDTH, HEIGHT, 0,
  93                 GL_RGB, GL_UNSIGNED_BYTE, img);
  94    glTexParameteri(GL_TEXTURE_2D, GL_GENERATE_MIPMAP_SGIS, GL_FALSE);
  95 }
  96
  97
  98
  99 static void myinit(void)
 100 {
 101    InitValues();
 102
 103    glShadeModel(GL_FLAT);
 104
 105    glTranslatef(0.0, 0.0, -3.6);
 106
 107    glPixelStorei(GL_UNPACK_ALIGNMENT, 1);
 108    glGenTextures(1, &texImage);
 109    glBindTexture(GL_TEXTURE_2D, texImage);
 110    MakeImage();
 111
 112    glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT);
 113    glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT);
 114    glTexEnvf(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_DECAL);
 115    glEnable(GL_TEXTURE_2D);
 116
 117    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_BASE_LEVEL, 0);
 118    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAX_LEVEL, 1);
 119
 120    glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MIN_LOD, -1);
 121    glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MAX_LOD, 1);
 122
 123    glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
 124    glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER,
 125                    GL_NEAREST_MIPMAP_NEAREST);
 126 }
 127
 128
 129
 130 static void display(void)
 131 {
 132    GLfloat tcm = 1.0;
 133    glBindTexture(GL_TEXTURE_2D, texImage);
 134
 135    printf("Bias=%.2g\n", LodBias);
 136    fflush(stdout);
 137
 138    glTexEnvf(GL_TEXTURE_FILTER_CONTROL_EXT, GL_TEXTURE_LOD_BIAS_EXT, LodBias);
 139
 140    glClear(GL_COLOR_BUFFER_BIT);
 141    glBegin(GL_QUADS);
 142    glTexCoord2f(0.0, 0.0); glVertex3f(-2.0, -1.0, 0.0);
 143    glTexCoord2f(0.0, tcm); glVertex3f(-2.0, 1.0, 0.0);
 144    glTexCoord2f(tcm * 3000.0, tcm); glVertex3f(3000.0, 1.0, -6000.0);
 145    glTexCoord2f(tcm * 3000.0, 0.0); glVertex3f(3000.0, -1.0, -6000.0);
 146    glEnd();
 147    glFlush();
 148 }
 149
 150 static void myReshape(int w, int h)
 151 {
 152    glViewport(0, 0, w, h);
 153    glMatrixMode(GL_PROJECTION);
 154    glLoadIdentity();
 155    gluPerspective(60.0, 1.0*(GLfloat)w/(GLfloat)h, 1.0, 30000.0);
 156    glMatrixMode(GL_MODELVIEW);
 157    glLoadIdentity();
 158 }
 159
 160 static void
 161 key(unsigned char k, int x, int y)
 162 {
 163   (void) x;
 164   (void) y;
 165   switch (k) {
 166   case 'l':
 167      LodBias -= 0.25;
 168      break;
 169   case 'L':
 170      LodBias += 0.25;
 171      break;
 172   case ' ':
 173      InitValues();
 174      break;
 175   case 27:  /* Escape */
 176     exit(0);
 177     break;
 178   default:
 179     return;
 180   }
 181   glutPostRedisplay();
 182 }
 183
 184
 185 static void usage(void)
 186 {
 187    printf("usage:\n");
 188    printf("  l/L    decrease/increase GL_TEXTURE_LOD_BIAS\n");
 189    printf("  SPACE  reset values\n");
 190 }
 191
 192
 193 int main(int argc, char** argv)
 194 {
 195     glutInit(&argc, argv);
 196     glutInitDisplayMode (GLUT_SINGLE | GLUT_RGB );
 197     glutInitWindowSize (600, 600);
 198     glutCreateWindow (argv[0]);
 199     glewInit();
 200     myinit();
 201     glutReshapeFunc (myReshape);
 202     glutDisplayFunc(display);
 203     glutKeyboardFunc(key);
 204     usage();
 205     glutMainLoop();
 206     return 0;             /* ANSI C requires main to return int. */
 207 }