| /* 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| * Unpublished-- rights reserved under the copyright laws of the |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/glew.h> |
| #include <GL/glut.h> |
| |
| #include "readtex.h" |
| |
| #define TEXTURE_FILE "../images/girl.rgb" |
| |
| static GLint BaseLevel = 0, MaxLevel = 9; |
| static GLfloat MinLod = -1, MaxLod = 9; |
| static GLfloat LodBias = 0.0; |
| static GLboolean NearestFilter = GL_TRUE; |
| static GLuint texImage, texColor, texCurrent; |
| |
| |
| static void |
| InitValues(void) |
| { |
| BaseLevel = 0; |
| MaxLevel = 9; |
| MinLod = -1; |
| MaxLod = 9; |
| LodBias = 0.0; |
| NearestFilter = GL_TRUE; |
| } |
| |
| |
| static void |
| MakeImage(int level, int width, int height, const GLubyte color[4]) |
| { |
| const int makeStripes = 0; |
| GLubyte img[512 * 512 * 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(int image) |
| { |
| #define WIDTH 512 |
| #define HEIGHT 512 |
| if (glutExtensionSupported("GL_SGIS_generate_mipmap") && image) { |
| /* test auto mipmap generation */ |
| GLint width, height, i; |
| GLenum format; |
| GLubyte *image = LoadRGBImage(TEXTURE_FILE, &width, &height, &format); |
| if (!image) { |
| printf("Error: could not load texture image %s\n", TEXTURE_FILE); |
| exit(1); |
| } |
| /* resize */ |
| if (width != WIDTH || height != HEIGHT) { |
| GLubyte *newImage = malloc(WIDTH * HEIGHT * 4); |
| gluScaleImage(format, width, height, GL_UNSIGNED_BYTE, image, |
| WIDTH, HEIGHT, GL_UNSIGNED_BYTE, newImage); |
| free(image); |
| image = newImage; |
| } |
| printf("Using GL_SGIS_generate_mipmap\n"); |
| glTexParameteri(GL_TEXTURE_2D, GL_GENERATE_MIPMAP_SGIS, GL_TRUE); |
| glTexImage2D(GL_TEXTURE_2D, 0, format, WIDTH, HEIGHT, 0, |
| format, GL_UNSIGNED_BYTE, image); |
| glTexParameteri(GL_TEXTURE_2D, GL_GENERATE_MIPMAP_SGIS, GL_FALSE); |
| free(image); |
| |
| /* make sure mipmap was really generated correctly */ |
| width = WIDTH; |
| height = HEIGHT; |
| for (i = 0; i < 10; i++) { |
| GLint w, h; |
| glGetTexLevelParameteriv(GL_TEXTURE_2D, i, GL_TEXTURE_WIDTH, &w); |
| glGetTexLevelParameteriv(GL_TEXTURE_2D, i, GL_TEXTURE_HEIGHT, &h); |
| printf("Level %d size: %d x %d\n", i, w, h); |
| width /= 2; |
| height /= 2; |
| } |
| } |
| else { |
| static const GLubyte colors[10][3] = { |
| {128, 128, 128}, |
| {0, 255, 255}, |
| {255, 255, 0}, |
| {255, 0, 255}, |
| {255, 0, 0}, |
| {0, 255, 0}, |
| {0, 0, 255}, |
| {0, 255, 255}, |
| {255, 255, 0}, |
| {255, 255, 255} |
| }; |
| int i, sz = 512; |
| |
| for (i = 0; i < 10; i++) { |
| MakeImage(i, sz, sz, colors[i]); |
| printf("Level %d size: %d x %d\n", i, sz, sz); |
| sz /= 2; |
| } |
| } |
| } |
| |
| static void |
| myinit(void) |
| { |
| InitValues(); |
| |
| glEnable(GL_DEPTH_TEST); |
| glDepthFunc(GL_LESS); |
| glShadeModel(GL_FLAT); |
| |
| glTranslatef(0.0, 0.0, -3.6); |
| |
| glPixelStorei(GL_UNPACK_ALIGNMENT, 1); |
| glGenTextures(1, &texImage); |
| glBindTexture(GL_TEXTURE_2D, texImage); |
| makeImages(1); |
| glGenTextures(1, &texColor); |
| glBindTexture(GL_TEXTURE_2D, texColor); |
| makeImages(0); |
| |
| texCurrent = texImage; |
| |
| 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 = 1.0; |
| glBindTexture(GL_TEXTURE_2D, texCurrent); |
| |
| printf |
| ("BASE_LEVEL=%d MAX_LEVEL=%d MIN_LOD=%.2g MAX_LOD=%.2g 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); |
| |
| glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MIN_LOD, MinLod); |
| glTexParameterf(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 * 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 |
| 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"); |
| printf(" t toggle texture color/image\n"); |
| printf(" SPACE reset values\n"); |
| } |
| |
| 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 -= 0.25; |
| break; |
| case 'L': |
| LodBias += 0.25; |
| break; |
| case 'n': |
| MinLod -= 0.25; |
| break; |
| case 'N': |
| MinLod += 0.25; |
| break; |
| case 'x': |
| MaxLod -= 0.25; |
| break; |
| case 'X': |
| MaxLod += 0.25; |
| break; |
| case 'f': |
| NearestFilter = !NearestFilter; |
| break; |
| case 't': |
| if (texCurrent == texColor) |
| texCurrent = texImage; |
| else |
| texCurrent = texColor; |
| break; |
| case ' ': |
| InitValues(); |
| /* fall-through */ |
| case 'u': |
| usage(); |
| break; |
| case 27: /* Escape */ |
| exit(0); |
| break; |
| default: |
| return; |
| } |
| glutPostRedisplay(); |
| } |
| |
| |
| int |
| main(int argc, char **argv) |
| { |
| glutInit(&argc, argv); |
| glutInitDisplayMode(GLUT_SINGLE | GLUT_RGB | GLUT_DEPTH); |
| 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. */ |
| } |