2 * Compressed texture demo. Written by Daniel Borca.
3 * This program is in the public domain.
13 #include "readtex.c" /* I know, this is a hack. */
14 #define TEXTURE_FILE "../images/tree2.rgba"
17 static float Rot = 0.0;
18 static GLboolean Anim = 1;
33 static TEXTURE *Tx, t1, t2, t3;
34 static GLboolean fxt1, dxtc, s3tc;
37 static const char *TextureName (GLenum TC)
44 case GL_COMPRESSED_RGB:
45 return "COMPRESSED_RGB";
46 case GL_COMPRESSED_RGBA:
47 return "COMPRESSED_RGBA";
48 case GL_COMPRESSED_RGB_FXT1_3DFX:
49 return "GL_COMPRESSED_RGB_FXT1_3DFX";
50 case GL_COMPRESSED_RGBA_FXT1_3DFX:
51 return "GL_COMPRESSED_RGBA_FXT1_3DFX";
52 case GL_COMPRESSED_RGB_S3TC_DXT1_EXT:
53 return "GL_COMPRESSED_RGB_S3TC_DXT1_EXT";
54 case GL_COMPRESSED_RGBA_S3TC_DXT1_EXT:
55 return "GL_COMPRESSED_RGBA_S3TC_DXT1_EXT";
56 case GL_COMPRESSED_RGBA_S3TC_DXT3_EXT:
57 return "GL_COMPRESSED_RGBA_S3TC_DXT3_EXT";
58 case GL_COMPRESSED_RGBA_S3TC_DXT5_EXT:
59 return "GL_COMPRESSED_RGBA_S3TC_DXT5_EXT";
63 return "GL_RGB4_S3TC";
65 return "GL_RGBA_S3TC";
67 return "GL_RGBA4_S3TC";
69 return "Invalid format";
71 return "Unknown format";
77 PrintString(const char *s)
80 glutBitmapCharacter(GLUT_BITMAP_8_BY_13, (int) *s);
86 static void Idle( void )
88 float t = glutGet(GLUT_ELAPSED_TIME) * 0.001; /* in seconds */
89 Rot = t * 360 / 4; /* 1 rotation per 4 seconds */
94 static void Display( void )
96 /* draw background gradient */
97 glDisable(GL_TEXTURE_2D);
99 glColor3f(1.0, 0.0, 0.2); glVertex2f(-1.5, -1.0);
100 glColor3f(1.0, 0.0, 0.2); glVertex2f( 1.5, -1.0);
101 glColor3f(0.0, 0.0, 1.0); glVertex2f( 1.5, 1.0);
102 glColor3f(0.0, 0.0, 1.0); glVertex2f(-1.5, 1.0);
106 glRotatef(Rot, 0, 0, 1);
108 glEnable(GL_TEXTURE_2D);
110 glTexCoord2f(0, 1); glVertex2f(-1, -0.5);
111 glTexCoord2f(1, 1); glVertex2f( 1, -0.5);
112 glTexCoord2f(1, 0); glVertex2f( 1, 0.5);
113 glTexCoord2f(0, 0); glVertex2f(-1, 0.5);
119 glColor4f(1, 1, 1, 1);
121 glRasterPos3f(-1.2, -0.7, 0);
122 PrintString("Selected: ");
123 PrintString(TextureName(Tx->TC));
126 glRasterPos3f(-1.2, -0.8, 0);
127 PrintString("Internal: ");
128 PrintString(TextureName(Tx->cFormat));
129 glRasterPos3f(-1.2, -0.9, 0);
130 PrintString("Size : ");
131 sprintf(tmp, "%d (%d%% of %d)", Tx->cSize, Tx->cSize * 100 / Tx->size, Tx->size);
139 static void Reshape( int width, int height )
141 glViewport( 0, 0, width, height );
142 glMatrixMode( GL_PROJECTION );
144 glOrtho( -1.5, 1.5, -1.0, 1.0, -1.0, 1.0 );
145 glMatrixMode( GL_MODELVIEW );
150 static void ReInit( GLenum TC, TEXTURE *Tx )
154 if ((Tx->TC == TC) && (Tx->cData != NULL)) {
155 glCompressedTexImage2DARB(GL_TEXTURE_2D, /* target */
157 Tx->cFormat, /* real format */
158 Tx->w, /* original width */
159 Tx->h, /* original height */
161 Tx->cSize, /* compressed size*/
162 Tx->cData); /* compressed data*/
164 glTexImage2D(GL_TEXTURE_2D, /* target */
166 TC, /* internal format */
167 Tx->w, Tx->h, /* width, height */
169 Tx->format, /* texture format */
170 GL_UNSIGNED_BYTE, /* texture type */
171 Tx->data); /* the texture */
173 /* okay, now cache the compressed texture */
175 if (Tx->cData != NULL) {
179 glGetTexLevelParameteriv(GL_TEXTURE_2D, 0, GL_TEXTURE_COMPRESSED_ARB, &rv);
181 glGetTexLevelParameteriv(GL_TEXTURE_2D, 0, GL_TEXTURE_INTERNAL_FORMAT, (GLint *)&Tx->cFormat);
182 glGetTexLevelParameteriv(GL_TEXTURE_2D, 0, GL_TEXTURE_COMPRESSED_IMAGE_SIZE_ARB, (GLint *)&Tx->cSize);
183 if ((Tx->cData = malloc(Tx->cSize)) != NULL) {
184 glGetCompressedTexImageARB(GL_TEXTURE_2D, 0, Tx->cData);
191 static void Init( void )
193 /* HEIGHT * WIDTH + 1 (for trailing '\0') */
194 static char pattern[8 * 32 + 1] = {"\
207 GLubyte (*texture1)[8 * 32][4];
208 GLubyte (*texture2)[256][256][4];
212 t1.size = t1.w * t1.h * 4;
213 t1.data = malloc(t1.size);
217 texture1 = (GLubyte (*)[8 * 32][4])t1.data;
218 for (i = 0; i < sizeof(pattern) - 1; i++) {
219 switch (pattern[i]) {
222 (*texture1)[i][0] = 255;
223 (*texture1)[i][1] = 255;
224 (*texture1)[i][2] = 255;
225 (*texture1)[i][3] = 64;
228 (*texture1)[i][0] = 255;
229 (*texture1)[i][1] = 0;
230 (*texture1)[i][2] = 0;
231 (*texture1)[i][3] = 255;
234 (*texture1)[i][0] = 0;
235 (*texture1)[i][1] = 255;
236 (*texture1)[i][2] = 0;
237 (*texture1)[i][3] = 255;
240 (*texture1)[i][0] = 0;
241 (*texture1)[i][1] = 0;
242 (*texture1)[i][2] = 255;
243 (*texture1)[i][3] = 255;
246 (*texture1)[i][0] = 255;
247 (*texture1)[i][1] = 255;
248 (*texture1)[i][2] = 0;
249 (*texture1)[i][3] = 255;
256 t2.size = t2.w * t2.h * 4;
257 t2.data = malloc(t2.size);
261 texture2 = (GLubyte (*)[256][256][4])t2.data;
262 for (j = 0; j < t2.h; j++) {
263 for (i = 0; i < t2.w; i++) {
264 (*texture2)[j][i][0] = sqrt(i * j * 255 * 255 / (t2.w * t2.h));
265 (*texture2)[j][i][1] = 0;
266 (*texture2)[j][i][2] = 0;
267 (*texture2)[j][i][3] = 255;
271 t3.data = LoadRGBImage(TEXTURE_FILE, (GLint *)&t3.w, (GLint *)&t3.h, &t3.format);
272 t3.size = t3.w * t3.h * ((t3.format == GL_RGB) ? 3 : 4);
275 ReInit(GL_RGBA, Tx = &t1);
277 glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
278 glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
279 glTexEnvi(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_REPLACE);
280 glEnable(GL_TEXTURE_2D);
283 glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
287 static void Key( unsigned char key, int x, int y )
298 glutIdleFunc( Idle );
300 glutIdleFunc( NULL );
305 } else if (Tx == &t2) {
319 ReInit(GL_COMPRESSED_RGB, Tx);
322 ReInit(GL_COMPRESSED_RGBA, Tx);
325 if (fxt1) ReInit(GL_COMPRESSED_RGB_FXT1_3DFX, Tx);
328 if (fxt1) ReInit(GL_COMPRESSED_RGBA_FXT1_3DFX, Tx);
331 if (dxtc) ReInit(GL_COMPRESSED_RGB_S3TC_DXT1_EXT, Tx);
334 if (dxtc) ReInit(GL_COMPRESSED_RGBA_S3TC_DXT1_EXT, Tx);
337 if (dxtc) ReInit(GL_COMPRESSED_RGBA_S3TC_DXT3_EXT, Tx);
340 if (dxtc) ReInit(GL_COMPRESSED_RGBA_S3TC_DXT5_EXT, Tx);
343 if (s3tc) ReInit(GL_RGB_S3TC, Tx);
346 if (s3tc) ReInit(GL_RGB4_S3TC, Tx);
349 if (s3tc) ReInit(GL_RGBA_S3TC, Tx);
352 if (s3tc) ReInit(GL_RGBA4_S3TC, Tx);
359 int main( int argc, char *argv[] )
367 glutInit( &argc, argv );
368 glutInitWindowPosition( 0, 0 );
369 glutInitWindowSize( 400, 300 );
371 glutInitDisplayMode( GLUT_RGB | GLUT_DOUBLE );
373 if (glutCreateWindow(argv[0]) <= 0) {
375 printf("Couldn't create window\n");
379 gl_version = atof( (const char *) glGetString( GL_VERSION ) );
380 if ( (gl_version < 1.3)
381 && !glutExtensionSupported("GL_ARB_texture_compression") ) {
382 printf("Sorry, GL_ARB_texture_compression not supported\n");
385 if (glutExtensionSupported("GL_3DFX_texture_compression_FXT1")) {
388 if (glutExtensionSupported("GL_EXT_texture_compression_s3tc")) {
391 if (glutExtensionSupported("GL_S3_s3tc")) {
395 glGetIntegerv( GL_NUM_COMPRESSED_TEXTURE_FORMATS_ARB, & num_formats );
397 (void) memset( formats, 0, sizeof( formats ) );
398 glGetIntegerv( GL_COMPRESSED_TEXTURE_FORMATS_ARB, formats );
400 printf( "The following texture formats are supported:\n" );
401 for ( i = 0 ; i < num_formats ; i++ ) {
402 printf( "\t%s\n", TextureName( formats[i] ) );
407 glutReshapeFunc( Reshape );
408 glutKeyboardFunc( Key );
409 glutDisplayFunc( Display );
411 glutIdleFunc( Idle );