/* 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 * Unpublished-- rights reserved under the copyright laws of the * United States.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. */ /* mipmap.c * This program demonstrates using mipmaps for texture maps. * To overtly show the effect of mipmaps, each mipmap reduction * level has a solidly colored, contrasting texture image. * Thus, the quadrilateral which is drawn is drawn with several * different colors. */ #include <stdlib.h> #include <stdio.h> #include <GL/glut.h> static GLint BaseLevel = 0, MaxLevel = 8; static GLfloat MinLod = -1, MaxLod = 9; static GLfloat LodBias = 0.0; static GLboolean NearestFilter = GL_TRUE; static void MakeImage(int level, int width, int height, const GLubyte color[4]) { const int makeStripes = 0; GLubyte img[256*256*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/8) & makeStripes; if (p == 0) { img[k + 0] = color[0]; img[k + 1] = color[1]; img[k + 2] = color[2]; } else { img[k + 0] = 0; img[k + 1] = 0; img[k + 2] = 0; } } } glTexImage2D(GL_TEXTURE_2D, level, GL_RGB, width, height, 0, GL_RGB, GL_UNSIGNED_BYTE, img); } static void makeImages(void) { static const GLubyte colors[8][3] = { {128, 128, 128 }, { 0, 255, 255 }, { 255, 255, 0 }, { 255, 0, 255 }, { 255, 0, 0 }, { 0, 255, 0 }, { 0, 0, 255 }, { 255, 255, 255 } }; int i, sz = 128; for (i = 0; i < 8; i++) { MakeImage(i, sz, sz, colors[i]); sz /= 2; } } static void myinit(void) { glEnable(GL_DEPTH_TEST); glDepthFunc(GL_LESS); glShadeModel(GL_FLAT); glTranslatef(0.0, 0.0, -3.6); glPixelStorei(GL_UNPACK_ALIGNMENT, 1); makeImages(); 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); } static void display(void) { GLfloat tcm = 4.0; printf("BASE_LEVEL = %d MAX_LEVEL = %d MIN_LOD = %f MAX_LOD = %f Bias = %.2g filter = %s\n", BaseLevel, MaxLevel, MinLod, MaxLod, LodBias, NearestFilter ? "NEAREST" : "LINEAR"); glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_BASE_LEVEL, BaseLevel); glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAX_LEVEL, MaxLevel); glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_LOD, MinLod); glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAX_LOD, MaxLod); if (NearestFilter) { glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST); glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST_MIPMAP_NEAREST); } else { glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR); glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR_MIPMAP_LINEAR); } glTexEnvf(GL_TEXTURE_FILTER_CONTROL_EXT, GL_TEXTURE_LOD_BIAS_EXT, LodBias); glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_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, tcm); glVertex3f(3000.0, 1.0, -6000.0); glTexCoord2f(tcm, 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 'b': BaseLevel--; if (BaseLevel < 0) BaseLevel = 0; break; case 'B': BaseLevel++; if (BaseLevel > 10) BaseLevel = 10; break; case 'm': MaxLevel--; if (MaxLevel < 0) MaxLevel = 0; break; case 'M': MaxLevel++; if (MaxLevel > 10) MaxLevel = 10; break; case 'l': LodBias -= 0.02; break; case 'L': LodBias += 0.02; break; case 'n': MinLod -= 0.02; break; case 'N': MinLod += 0.02; break; case 'x': MaxLod -= 0.02; break; case 'X': MaxLod += 0.02; break; case 'f': NearestFilter = !NearestFilter; break; case 27: /* Escape */ exit(0); break; default: return; } glutPostRedisplay(); } static void usage(void) { printf("usage:\n"); printf(" b/B decrease/increase GL_TEXTURE_BASE_LEVEL\n"); printf(" m/M decrease/increase GL_TEXTURE_MAX_LEVEL\n"); printf(" n/N decrease/increase GL_TEXTURE_MIN_LOD\n"); printf(" x/X decrease/increase GL_TEXTURE_MAX_LOD\n"); printf(" l/L decrease/increase GL_TEXTURE_LOD_BIAS\n"); printf(" f toggle nearest/linear filtering\n"); } int main(int argc, char** argv) { glutInit(&argc, argv); glutInitDisplayMode (GLUT_SINGLE | GLUT_RGB | GLUT_DEPTH); glutInitWindowSize (600, 600); glutCreateWindow (argv[0]); myinit(); glutReshapeFunc (myReshape); glutDisplayFunc(display); glutKeyboardFunc(key); usage(); glutMainLoop(); return 0; /* ANSI C requires main to return int. */ }