Brian Paul | aa80e29 | 2000-03-20 22:00:22 +0000 | [diff] [blame] | 1 | /* |
| 2 | * GL_EXT_texture_lod_bias demo |
| 3 | * |
| 4 | * Thanks to Michael Vance for implementing this extension in Mesa. |
| 5 | * |
| 6 | * Brian Paul |
| 7 | * 20 March 2000 |
| 8 | * |
| 9 | * Copyright (C) 2000 Brian Paul All Rights Reserved. |
| 10 | * |
| 11 | * Permission is hereby granted, free of charge, to any person obtaining a |
| 12 | * copy of this software and associated documentation files (the "Software"), |
| 13 | * to deal in the Software without restriction, including without limitation |
| 14 | * the rights to use, copy, modify, merge, publish, distribute, sublicense, |
| 15 | * and/or sell copies of the Software, and to permit persons to whom the |
| 16 | * Software is furnished to do so, subject to the following conditions: |
| 17 | * |
| 18 | * The above copyright notice and this permission notice shall be included |
| 19 | * in all copies or substantial portions of the Software. |
| 20 | * |
| 21 | * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS |
| 22 | * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, |
| 23 | * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL |
| 24 | * BRIAN PAUL BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN |
| 25 | * AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN |
| 26 | * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. |
| 27 | */ |
| 28 | |
| 29 | |
Brian Paul | 76d2a77 | 2002-12-10 16:51:28 +0000 | [diff] [blame] | 30 | #include <assert.h> |
Brian Paul | aa80e29 | 2000-03-20 22:00:22 +0000 | [diff] [blame] | 31 | #include <stdlib.h> |
| 32 | #include <stdio.h> |
| 33 | #include <math.h> |
| 34 | #include <GL/glut.h> |
| 35 | #include <GL/glext.h> |
| 36 | |
Brian Paul | 575d24a | 2005-01-09 17:15:41 +0000 | [diff] [blame] | 37 | #include "readtex.h" |
Brian Paul | aa80e29 | 2000-03-20 22:00:22 +0000 | [diff] [blame] | 38 | |
| 39 | #define TEXTURE_FILE "../images/girl.rgb" |
| 40 | |
| 41 | static GLfloat Xrot = 0, Yrot = -30, Zrot = 0; |
| 42 | static GLboolean Anim = GL_TRUE; |
Brian Paul | d21cdb6 | 2000-03-22 18:38:47 +0000 | [diff] [blame] | 43 | static GLint Bias = 0, BiasStepSign = +1; /* ints avoid fp precision problem */ |
Brian Paul | 87c964d | 2001-11-06 15:53:00 +0000 | [diff] [blame] | 44 | static GLint BiasMin = -400, BiasMax = 400; |
Brian Paul | 417719c | 2008-05-20 15:11:33 -0600 | [diff] [blame] | 45 | static int win = 0; |
Brian Paul | 7f86da6 | 2009-09-15 17:08:33 -0600 | [diff] [blame] | 46 | static GLuint TexObj = 0; |
Brian Paul | aa80e29 | 2000-03-20 22:00:22 +0000 | [diff] [blame] | 47 | |
| 48 | |
| 49 | static void |
| 50 | PrintString(const char *s) |
| 51 | { |
| 52 | while (*s) { |
| 53 | glutBitmapCharacter(GLUT_BITMAP_8_BY_13, (int) *s); |
| 54 | s++; |
| 55 | } |
| 56 | } |
| 57 | |
| 58 | static void Idle( void ) |
| 59 | { |
Brian Paul | d21cdb6 | 2000-03-22 18:38:47 +0000 | [diff] [blame] | 60 | static int lastTime = 0; |
| 61 | int time = glutGet(GLUT_ELAPSED_TIME); |
| 62 | int step; |
| 63 | |
| 64 | if (lastTime == 0) |
| 65 | lastTime = time; |
| 66 | else if (time - lastTime < 10) |
| 67 | return; |
| 68 | |
| 69 | step = (time - lastTime) / 10 * BiasStepSign; |
| 70 | lastTime = time; |
| 71 | |
| 72 | Bias += step; |
Brian Paul | aa80e29 | 2000-03-20 22:00:22 +0000 | [diff] [blame] | 73 | if (Bias < BiasMin) { |
| 74 | Bias = BiasMin; |
Brian Paul | d21cdb6 | 2000-03-22 18:38:47 +0000 | [diff] [blame] | 75 | BiasStepSign = +1; |
Brian Paul | aa80e29 | 2000-03-20 22:00:22 +0000 | [diff] [blame] | 76 | } |
| 77 | else if (Bias > BiasMax) { |
| 78 | Bias = BiasMax; |
Brian Paul | d21cdb6 | 2000-03-22 18:38:47 +0000 | [diff] [blame] | 79 | BiasStepSign = -1; |
Brian Paul | aa80e29 | 2000-03-20 22:00:22 +0000 | [diff] [blame] | 80 | } |
| 81 | |
| 82 | glutPostRedisplay(); |
| 83 | } |
| 84 | |
| 85 | |
| 86 | static void Display( void ) |
| 87 | { |
| 88 | char str[100]; |
| 89 | |
| 90 | glClear( GL_COLOR_BUFFER_BIT ); |
| 91 | |
| 92 | glMatrixMode( GL_PROJECTION ); |
| 93 | glLoadIdentity(); |
| 94 | glOrtho(-1, 1, -1, 1, -1, 1); |
| 95 | glMatrixMode( GL_MODELVIEW ); |
| 96 | glLoadIdentity(); |
| 97 | |
| 98 | glDisable(GL_TEXTURE_2D); |
| 99 | glColor3f(1,1,1); |
| 100 | glRasterPos3f(-0.9, -0.9, 0.0); |
| 101 | sprintf(str, "Texture LOD Bias = %4.1f", Bias * 0.01); |
| 102 | PrintString(str); |
| 103 | |
| 104 | glMatrixMode( GL_PROJECTION ); |
| 105 | glLoadIdentity(); |
| 106 | glFrustum( -1.0, 1.0, -1.0, 1.0, 5.0, 25.0 ); |
| 107 | glMatrixMode( GL_MODELVIEW ); |
| 108 | glLoadIdentity(); |
| 109 | glTranslatef( 0.0, 0.0, -8.0 ); |
| 110 | |
| 111 | glPushMatrix(); |
| 112 | glRotatef(Xrot, 1, 0, 0); |
| 113 | glRotatef(Yrot, 0, 1, 0); |
| 114 | glRotatef(Zrot, 0, 0, 1); |
| 115 | |
| 116 | glEnable(GL_TEXTURE_2D); |
| 117 | glTexEnvf(GL_TEXTURE_FILTER_CONTROL_EXT, GL_TEXTURE_LOD_BIAS_EXT, 0.01 * Bias); |
| 118 | |
| 119 | glBegin(GL_POLYGON); |
| 120 | glTexCoord2f(0, 0); glVertex2f(-1, -1); |
| 121 | glTexCoord2f(2, 0); glVertex2f( 1, -1); |
| 122 | glTexCoord2f(2, 2); glVertex2f( 1, 1); |
| 123 | glTexCoord2f(0, 2); glVertex2f(-1, 1); |
| 124 | glEnd(); |
| 125 | |
| 126 | glPopMatrix(); |
| 127 | |
| 128 | glutSwapBuffers(); |
| 129 | } |
| 130 | |
| 131 | |
| 132 | static void Reshape( int width, int height ) |
| 133 | { |
| 134 | glViewport( 0, 0, width, height ); |
| 135 | } |
| 136 | |
| 137 | |
| 138 | static void Key( unsigned char key, int x, int y ) |
| 139 | { |
| 140 | const GLfloat step = 3.0; |
| 141 | (void) x; |
| 142 | (void) y; |
| 143 | switch (key) { |
| 144 | case 'a': |
| 145 | Anim = !Anim; |
| 146 | if (Anim) |
| 147 | glutIdleFunc(Idle); |
| 148 | else |
| 149 | glutIdleFunc(NULL); |
| 150 | break; |
| 151 | case 'z': |
| 152 | Zrot -= step; |
| 153 | break; |
| 154 | case 'Z': |
| 155 | Zrot += step; |
| 156 | break; |
| 157 | case 'b': |
| 158 | Bias -= 10; |
| 159 | break; |
| 160 | case 'B': |
| 161 | Bias += 10; |
| 162 | break; |
Brian | 4697cee | 2008-02-11 09:46:10 -0700 | [diff] [blame] | 163 | case '0': |
| 164 | case '1': |
| 165 | case '2': |
| 166 | case '3': |
| 167 | case '4': |
| 168 | case '5': |
| 169 | case '6': |
| 170 | case '7': |
| 171 | case '8': |
| 172 | case '9': |
| 173 | Bias = 100.0 * (key - '0'); |
| 174 | break; |
Brian Paul | aa80e29 | 2000-03-20 22:00:22 +0000 | [diff] [blame] | 175 | case 27: |
Brian Paul | 417719c | 2008-05-20 15:11:33 -0600 | [diff] [blame] | 176 | glutDestroyWindow(win); |
Brian Paul | aa80e29 | 2000-03-20 22:00:22 +0000 | [diff] [blame] | 177 | exit(0); |
| 178 | break; |
| 179 | } |
| 180 | glutPostRedisplay(); |
| 181 | } |
| 182 | |
| 183 | |
| 184 | static void SpecialKey( int key, int x, int y ) |
| 185 | { |
| 186 | const GLfloat step = 3.0; |
| 187 | (void) x; |
| 188 | (void) y; |
| 189 | switch (key) { |
| 190 | case GLUT_KEY_UP: |
| 191 | Xrot -= step; |
| 192 | break; |
| 193 | case GLUT_KEY_DOWN: |
| 194 | Xrot += step; |
| 195 | break; |
| 196 | case GLUT_KEY_LEFT: |
| 197 | Yrot -= step; |
| 198 | break; |
| 199 | case GLUT_KEY_RIGHT: |
| 200 | Yrot += step; |
| 201 | break; |
| 202 | } |
| 203 | glutPostRedisplay(); |
| 204 | } |
| 205 | |
| 206 | |
| 207 | static void Init( void ) |
| 208 | { |
Brian Paul | 87c964d | 2001-11-06 15:53:00 +0000 | [diff] [blame] | 209 | GLfloat maxBias; |
| 210 | |
Brian Paul | 76d2a77 | 2002-12-10 16:51:28 +0000 | [diff] [blame] | 211 | if (!glutExtensionSupported("GL_EXT_texture_lod_bias")) { |
Brian Paul | aa80e29 | 2000-03-20 22:00:22 +0000 | [diff] [blame] | 212 | printf("Sorry, GL_EXT_texture_lod_bias not supported by this renderer.\n"); |
| 213 | exit(1); |
| 214 | } |
| 215 | |
| 216 | glPixelStorei(GL_UNPACK_ALIGNMENT, 1); |
Brian Paul | 76d2a77 | 2002-12-10 16:51:28 +0000 | [diff] [blame] | 217 | |
Brian Paul | 7f86da6 | 2009-09-15 17:08:33 -0600 | [diff] [blame] | 218 | glGenTextures(1, &TexObj); |
| 219 | glBindTexture(GL_TEXTURE_2D, TexObj); |
| 220 | |
Brian Paul | 76d2a77 | 2002-12-10 16:51:28 +0000 | [diff] [blame] | 221 | if (glutExtensionSupported("GL_SGIS_generate_mipmap")) { |
| 222 | /* test auto mipmap generation */ |
| 223 | GLint width, height, i; |
| 224 | GLenum format; |
| 225 | GLubyte *image = LoadRGBImage(TEXTURE_FILE, &width, &height, &format); |
| 226 | if (!image) { |
| 227 | printf("Error: could not load texture image %s\n", TEXTURE_FILE); |
| 228 | exit(1); |
| 229 | } |
| 230 | /* resize to 256 x 256 */ |
| 231 | if (width != 256 || height != 256) { |
| 232 | GLubyte *newImage = malloc(256 * 256 * 4); |
| 233 | gluScaleImage(format, width, height, GL_UNSIGNED_BYTE, image, |
| 234 | 256, 256, GL_UNSIGNED_BYTE, newImage); |
| 235 | free(image); |
| 236 | image = newImage; |
| 237 | } |
| 238 | printf("Using GL_SGIS_generate_mipmap\n"); |
| 239 | glTexParameteri(GL_TEXTURE_2D, GL_GENERATE_MIPMAP_SGIS, GL_TRUE); |
| 240 | glTexImage2D(GL_TEXTURE_2D, 0, format, 256, 256, 0, |
| 241 | format, GL_UNSIGNED_BYTE, image); |
| 242 | free(image); |
| 243 | |
| 244 | /* make sure mipmap was really generated correctly */ |
| 245 | width = height = 256; |
| 246 | for (i = 0; i < 9; i++) { |
| 247 | GLint w, h; |
| 248 | glGetTexLevelParameteriv(GL_TEXTURE_2D, i, GL_TEXTURE_WIDTH, &w); |
| 249 | glGetTexLevelParameteriv(GL_TEXTURE_2D, i, GL_TEXTURE_HEIGHT, &h); |
| 250 | printf("Level %d size: %d x %d\n", i, w, h); |
| 251 | assert(w == width); |
| 252 | assert(h == height); |
| 253 | width /= 2; |
| 254 | height /= 2; |
| 255 | } |
| 256 | |
| 257 | } |
| 258 | else if (!LoadRGBMipmaps(TEXTURE_FILE, GL_RGB)) { |
Brian Paul | aa80e29 | 2000-03-20 22:00:22 +0000 | [diff] [blame] | 259 | printf("Error: could not load texture image %s\n", TEXTURE_FILE); |
| 260 | exit(1); |
| 261 | } |
| 262 | |
| 263 | /* mipmapping required for this extension */ |
| 264 | glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR_MIPMAP_LINEAR); |
| 265 | glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR); |
| 266 | glTexEnvi(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_MODULATE); |
Brian Paul | 87c964d | 2001-11-06 15:53:00 +0000 | [diff] [blame] | 267 | |
| 268 | glGetFloatv(GL_MAX_TEXTURE_LOD_BIAS_EXT, &maxBias); |
| 269 | printf("LOD bias range: [%g, %g]\n", -maxBias, maxBias); |
| 270 | BiasMin = -100 * maxBias; |
| 271 | BiasMax = 100 * maxBias; |
Brian Paul | f132413 | 2004-03-26 18:05:36 +0000 | [diff] [blame] | 272 | |
| 273 | /* Since we have (about) 8 mipmap levels, no need to bias beyond |
| 274 | * the range [-1, +8]. |
| 275 | */ |
| 276 | if (BiasMin < -100) |
| 277 | BiasMin = -100; |
| 278 | if (BiasMax > 800) |
| 279 | BiasMax = 800; |
Brian Paul | aa80e29 | 2000-03-20 22:00:22 +0000 | [diff] [blame] | 280 | } |
| 281 | |
| 282 | |
| 283 | int main( int argc, char *argv[] ) |
| 284 | { |
Brian Paul | aa80e29 | 2000-03-20 22:00:22 +0000 | [diff] [blame] | 285 | glutInitWindowSize( 350, 350 ); |
Brian Paul | 263f432 | 2009-12-18 08:12:55 -0700 | [diff] [blame] | 286 | glutInit( &argc, argv ); |
Brian Paul | aa80e29 | 2000-03-20 22:00:22 +0000 | [diff] [blame] | 287 | glutInitDisplayMode( GLUT_RGB | GLUT_DOUBLE ); |
Brian Paul | 417719c | 2008-05-20 15:11:33 -0600 | [diff] [blame] | 288 | win = glutCreateWindow(argv[0]); |
Brian Paul | aa80e29 | 2000-03-20 22:00:22 +0000 | [diff] [blame] | 289 | glutReshapeFunc( Reshape ); |
| 290 | glutKeyboardFunc( Key ); |
| 291 | glutSpecialFunc( SpecialKey ); |
| 292 | glutDisplayFunc( Display ); |
| 293 | if (Anim) |
| 294 | glutIdleFunc(Idle); |
| 295 | Init(); |
| 296 | glutMainLoop(); |
| 297 | return 0; |
| 298 | } |