/* Test GL_TEXTURE_BASE_LEVEL and GL_TEXTURE_MAX_LEVEL * Brian Paul * 10 May 2006 */ /* Copyright (c) Mark J. Kilgard, 1994. */ /* * (c) Copyright 1993, Silicon Graphics, Inc. * ALL RIGHTS RESERVED * Permission to use, copy, modify, and distribute this software for * any purpose and without fee is hereby granted, provided that the above * copyright notice appear in all copies and that both the copyright notice * and this permission notice appear in supporting documentation, and that * the name of Silicon Graphics, Inc. not be used in advertising * or publicity pertaining to distribution of the software without specific, * written prior permission. * * THE MATERIAL EMBODIED ON THIS SOFTWARE IS PROVIDED TO YOU "AS-IS" * AND WITHOUT WARRANTY OF ANY KIND, EXPRESS, IMPLIED OR OTHERWISE, * INCLUDING WITHOUT LIMITATION, ANY WARRANTY OF MERCHANTABILITY OR * FITNESS FOR A PARTICULAR PURPOSE. IN NO EVENT SHALL SILICON * GRAPHICS, INC. BE LIABLE TO YOU OR ANYONE ELSE FOR ANY DIRECT, * SPECIAL, INCIDENTAL, INDIRECT OR CONSEQUENTIAL DAMAGES OF ANY * KIND, OR ANY DAMAGES WHATSOEVER, INCLUDING WITHOUT LIMITATION, * LOSS OF PROFIT, LOSS OF USE, SAVINGS OR REVENUE, OR THE CLAIMS OF * THIRD PARTIES, WHETHER OR NOT SILICON GRAPHICS, INC. HAS BEEN * ADVISED OF THE POSSIBILITY OF SUCH LOSS, HOWEVER CAUSED AND ON * ANY THEORY OF LIABILITY, ARISING OUT OF OR IN CONNECTION WITH THE * POSSESSION, USE OR PERFORMANCE OF THIS SOFTWARE. * * US Government Users Restricted Rights * Use, duplication, or disclosure by the Government is subject to * restrictions set forth in FAR 52.227.19(c)(2) or subparagraph * (c)(1)(ii) of the Rights in Technical Data and Computer Software * clause at DFARS 252.227-7013 and/or in similar or successor * clauses in the FAR or the DOD or NASA FAR Supplement. * Unpublished-- rights reserved under the copyright laws of the * United States. Contractor/manufacturer is Silicon Graphics, * Inc., 2011 N. Shoreline Blvd., Mountain View, CA 94039-7311. * * OpenGL(TM) is a trademark of Silicon Graphics, Inc. */ #include <stdlib.h> #include <stdio.h> #include <GL/glew.h> #include <GL/glut.h> #include "readtex.h" static GLfloat LodBias = 6.0; /* make smallest miplevel visible */ static GLuint texImage; #define WIDTH 2 #define HEIGHT 2 static void InitValues(void) { LodBias = 6.0; /* make smallest miplevel visible */ } static void MakeImage(void) { const GLubyte color0[4] = { 0xff, 0x80, 0x20, 0xff }; const GLubyte color1[4] = { 0x10, 0x20, 0x40, 0xff }; GLubyte img[WIDTH*HEIGHT*3]; int i, j; for (i = 0; i < HEIGHT; i++) { for (j = 0; j < WIDTH; j++) { int k = (i * WIDTH + j) * 3; int p = ((i+j)%2); if (p == 0) { img[k + 0] = color0[0]; img[k + 1] = color0[1]; img[k + 2] = color0[2]; } else { img[k + 0] = color1[0]; img[k + 1] = color1[1]; img[k + 2] = color1[2]; } } } glTexParameteri(GL_TEXTURE_2D, GL_GENERATE_MIPMAP_SGIS, GL_TRUE); glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB, WIDTH, HEIGHT, 0, GL_RGB, GL_UNSIGNED_BYTE, img); glTexParameteri(GL_TEXTURE_2D, GL_GENERATE_MIPMAP_SGIS, GL_FALSE); } static void myinit(void) { InitValues(); glShadeModel(GL_FLAT); glTranslatef(0.0, 0.0, -3.6); glPixelStorei(GL_UNPACK_ALIGNMENT, 1); glGenTextures(1, &texImage); glBindTexture(GL_TEXTURE_2D, texImage); MakeImage(); glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT); glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT); glTexEnvf(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_DECAL); glEnable(GL_TEXTURE_2D); glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_BASE_LEVEL, 0); glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAX_LEVEL, 1); glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MIN_LOD, -1); glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MAX_LOD, 1); glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST); glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST_MIPMAP_NEAREST); } static void display(void) { GLfloat tcm = 1.0; glBindTexture(GL_TEXTURE_2D, texImage); printf("Bias=%.2g\n", LodBias); fflush(stdout); glTexEnvf(GL_TEXTURE_FILTER_CONTROL_EXT, GL_TEXTURE_LOD_BIAS_EXT, LodBias); glClear(GL_COLOR_BUFFER_BIT); glBegin(GL_QUADS); glTexCoord2f(0.0, 0.0); glVertex3f(-2.0, -1.0, 0.0); glTexCoord2f(0.0, tcm); glVertex3f(-2.0, 1.0, 0.0); glTexCoord2f(tcm * 3000.0, tcm); glVertex3f(3000.0, 1.0, -6000.0); glTexCoord2f(tcm * 3000.0, 0.0); glVertex3f(3000.0, -1.0, -6000.0); glEnd(); glFlush(); } static void myReshape(int w, int h) { glViewport(0, 0, w, h); glMatrixMode(GL_PROJECTION); glLoadIdentity(); gluPerspective(60.0, 1.0*(GLfloat)w/(GLfloat)h, 1.0, 30000.0); glMatrixMode(GL_MODELVIEW); glLoadIdentity(); } static void key(unsigned char k, int x, int y) { (void) x; (void) y; switch (k) { case 'l': LodBias -= 0.25; break; case 'L': LodBias += 0.25; break; case ' ': InitValues(); break; case 27: /* Escape */ exit(0); break; default: return; } glutPostRedisplay(); } static void usage(void) { printf("usage:\n"); printf(" l/L decrease/increase GL_TEXTURE_LOD_BIAS\n"); printf(" SPACE reset values\n"); } int main(int argc, char** argv) { glutInit(&argc, argv); glutInitDisplayMode (GLUT_SINGLE | GLUT_RGB ); glutInitWindowSize (600, 600); glutCreateWindow (argv[0]); glewInit(); myinit(); glutReshapeFunc (myReshape); glutDisplayFunc(display); glutKeyboardFunc(key); usage(); glutMainLoop(); return 0; /* ANSI C requires main to return int. */ }