271 lines
7.5 KiB
C
271 lines
7.5 KiB
C
/* Test GL_TEXTURE_BASE_LEVEL and GL_TEXTURE_MAX_LEVEL
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* Brian Paul
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* 10 May 2006
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*/
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/* Copyright (c) Mark J. Kilgard, 1994. */
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/*
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* (c) Copyright 1993, Silicon Graphics, Inc.
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* ALL RIGHTS RESERVED
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* Permission to use, copy, modify, and distribute this software for
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* any purpose and without fee is hereby granted, provided that the above
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* copyright notice appear in all copies and that both the copyright notice
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* and this permission notice appear in supporting documentation, and that
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* the name of Silicon Graphics, Inc. not be used in advertising
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* or publicity pertaining to distribution of the software without specific,
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* written prior permission.
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*
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* THE MATERIAL EMBODIED ON THIS SOFTWARE IS PROVIDED TO YOU "AS-IS"
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* AND WITHOUT WARRANTY OF ANY KIND, EXPRESS, IMPLIED OR OTHERWISE,
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* INCLUDING WITHOUT LIMITATION, ANY WARRANTY OF MERCHANTABILITY OR
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* FITNESS FOR A PARTICULAR PURPOSE. IN NO EVENT SHALL SILICON
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* GRAPHICS, INC. BE LIABLE TO YOU OR ANYONE ELSE FOR ANY DIRECT,
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* SPECIAL, INCIDENTAL, INDIRECT OR CONSEQUENTIAL DAMAGES OF ANY
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* KIND, OR ANY DAMAGES WHATSOEVER, INCLUDING WITHOUT LIMITATION,
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* LOSS OF PROFIT, LOSS OF USE, SAVINGS OR REVENUE, OR THE CLAIMS OF
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* THIRD PARTIES, WHETHER OR NOT SILICON GRAPHICS, INC. HAS BEEN
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* ADVISED OF THE POSSIBILITY OF SUCH LOSS, HOWEVER CAUSED AND ON
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* ANY THEORY OF LIABILITY, ARISING OUT OF OR IN CONNECTION WITH THE
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* POSSESSION, USE OR PERFORMANCE OF THIS SOFTWARE.
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*
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* US Government Users Restricted Rights
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* Use, duplication, or disclosure by the Government is subject to
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* restrictions set forth in FAR 52.227.19(c)(2) or subparagraph
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* (c)(1)(ii) of the Rights in Technical Data and Computer Software
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* clause at DFARS 252.227-7013 and/or in similar or successor
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* clauses in the FAR or the DOD or NASA FAR Supplement.
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* Unpublished-- rights reserved under the copyright laws of the
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* United States. Contractor/manufacturer is Silicon Graphics,
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* Inc., 2011 N. Shoreline Blvd., Mountain View, CA 94039-7311.
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*
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* OpenGL(TM) is a trademark of Silicon Graphics, Inc.
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*/
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/* mipmap.c
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* This program demonstrates using mipmaps for texture maps.
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* To overtly show the effect of mipmaps, each mipmap reduction
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* level has a solidly colored, contrasting texture image.
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* Thus, the quadrilateral which is drawn is drawn with several
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* different colors.
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*/
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#include <stdlib.h>
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#include <stdio.h>
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#include <GL/glut.h>
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static GLint BaseLevel = 0, MaxLevel = 8;
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static GLfloat MinLod = -1, MaxLod = 9;
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static GLfloat LodBias = 0.0;
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static GLboolean NearestFilter = GL_TRUE;
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static void
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InitValues(void)
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{
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BaseLevel = 0;
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MaxLevel = 8;
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MinLod = -1;
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MaxLod = 9;
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LodBias = 0.0;
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NearestFilter = GL_TRUE;
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}
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static void MakeImage(int level, int width, int height, const GLubyte color[4])
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{
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const int makeStripes = 0;
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GLubyte img[256*256*3];
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int i, j;
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for (i = 0; i < height; i++) {
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for (j = 0; j < width; j++) {
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int k = (i * width + j) * 3;
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int p = (i/8) & makeStripes;
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if (p == 0) {
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img[k + 0] = color[0];
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img[k + 1] = color[1];
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img[k + 2] = color[2];
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}
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else {
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img[k + 0] = 0;
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img[k + 1] = 0;
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img[k + 2] = 0;
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}
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}
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}
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glTexImage2D(GL_TEXTURE_2D, level, GL_RGB, width, height, 0,
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GL_RGB, GL_UNSIGNED_BYTE, img);
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}
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static void makeImages(void)
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{
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static const GLubyte colors[8][3] = {
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{128, 128, 128 },
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{ 0, 255, 255 },
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{ 255, 255, 0 },
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{ 255, 0, 255 },
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{ 255, 0, 0 },
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{ 0, 255, 0 },
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{ 0, 0, 255 },
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{ 255, 255, 255 }
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};
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int i, sz = 128;
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for (i = 0; i < 8; i++) {
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MakeImage(i, sz, sz, colors[i]);
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sz /= 2;
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}
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}
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static void myinit(void)
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{
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InitValues();
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glEnable(GL_DEPTH_TEST);
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glDepthFunc(GL_LESS);
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glShadeModel(GL_FLAT);
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glTranslatef(0.0, 0.0, -3.6);
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glPixelStorei(GL_UNPACK_ALIGNMENT, 1);
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makeImages();
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glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT);
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glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT);
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glTexEnvf(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_DECAL);
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glEnable(GL_TEXTURE_2D);
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}
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static void display(void)
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{
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GLfloat tcm = 4.0;
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printf("BASE_LEVEL=%d MAX_LEVEL=%d MIN_LOD=%.2g MAX_LOD=%.2g Bias=%.2g Filter=%s\n",
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BaseLevel, MaxLevel, MinLod, MaxLod, LodBias,
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NearestFilter ? "NEAREST" : "LINEAR");
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glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_BASE_LEVEL, BaseLevel);
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glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAX_LEVEL, MaxLevel);
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glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MIN_LOD, MinLod);
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glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MAX_LOD, MaxLod);
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if (NearestFilter) {
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glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
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glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER,
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GL_NEAREST_MIPMAP_NEAREST);
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}
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else {
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glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
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glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER,
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GL_LINEAR_MIPMAP_LINEAR);
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}
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glTexEnvf(GL_TEXTURE_FILTER_CONTROL_EXT, GL_TEXTURE_LOD_BIAS_EXT, LodBias);
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glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
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glBegin(GL_QUADS);
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glTexCoord2f(0.0, 0.0); glVertex3f(-2.0, -1.0, 0.0);
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glTexCoord2f(0.0, tcm); glVertex3f(-2.0, 1.0, 0.0);
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glTexCoord2f(tcm, tcm); glVertex3f(3000.0, 1.0, -6000.0);
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glTexCoord2f(tcm, 0.0); glVertex3f(3000.0, -1.0, -6000.0);
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glEnd();
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glFlush();
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}
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static void myReshape(int w, int h)
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{
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glViewport(0, 0, w, h);
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glMatrixMode(GL_PROJECTION);
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glLoadIdentity();
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gluPerspective(60.0, 1.0*(GLfloat)w/(GLfloat)h, 1.0, 30000.0);
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glMatrixMode(GL_MODELVIEW);
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glLoadIdentity();
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}
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static void
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key(unsigned char k, int x, int y)
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{
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(void) x;
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(void) y;
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switch (k) {
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case 'b':
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BaseLevel--;
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if (BaseLevel < 0)
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BaseLevel = 0;
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break;
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case 'B':
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BaseLevel++;
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if (BaseLevel > 10)
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BaseLevel = 10;
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break;
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case 'm':
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MaxLevel--;
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if (MaxLevel < 0)
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MaxLevel = 0;
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break;
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case 'M':
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MaxLevel++;
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if (MaxLevel > 10)
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MaxLevel = 10;
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break;
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case 'l':
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LodBias -= 0.25;
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break;
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case 'L':
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LodBias += 0.25;
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break;
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case 'n':
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MinLod -= 0.25;
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break;
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case 'N':
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MinLod += 0.25;
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break;
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case 'x':
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MaxLod -= 0.25;
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break;
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case 'X':
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MaxLod += 0.25;
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break;
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case 'f':
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NearestFilter = !NearestFilter;
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break;
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case ' ':
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InitValues();
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break;
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case 27: /* Escape */
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exit(0);
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break;
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default:
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return;
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}
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glutPostRedisplay();
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}
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static void usage(void)
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{
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printf("usage:\n");
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printf(" b/B decrease/increase GL_TEXTURE_BASE_LEVEL\n");
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printf(" m/M decrease/increase GL_TEXTURE_MAX_LEVEL\n");
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printf(" n/N decrease/increase GL_TEXTURE_MIN_LOD\n");
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printf(" x/X decrease/increase GL_TEXTURE_MAX_LOD\n");
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printf(" l/L decrease/increase GL_TEXTURE_LOD_BIAS\n");
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printf(" f toggle nearest/linear filtering\n");
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printf(" SPACE reset values\n");
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}
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int main(int argc, char** argv)
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{
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glutInit(&argc, argv);
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glutInitDisplayMode (GLUT_SINGLE | GLUT_RGB | GLUT_DEPTH);
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glutInitWindowSize (600, 600);
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glutCreateWindow (argv[0]);
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myinit();
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glutReshapeFunc (myReshape);
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glutDisplayFunc(display);
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glutKeyboardFunc(key);
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usage();
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glutMainLoop();
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return 0; /* ANSI C requires main to return int. */
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}
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