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-rw-r--r--progs/demos/lodbias.c44
1 files changed, 41 insertions, 3 deletions
diff --git a/progs/demos/lodbias.c b/progs/demos/lodbias.c
index 3533241be5..bee06da80b 100644
--- a/progs/demos/lodbias.c
+++ b/progs/demos/lodbias.c
@@ -27,6 +27,7 @@
*/
+#include <assert.h>
#include <stdlib.h>
#include <stdio.h>
#include <math.h>
@@ -191,16 +192,53 @@ static void SpecialKey( int key, int x, int y )
static void Init( void )
{
- const char *exten = (const char *) glGetString(GL_EXTENSIONS);
GLfloat maxBias;
- if (!strstr(exten, "GL_EXT_texture_lod_bias")) {
+ if (!glutExtensionSupported("GL_EXT_texture_lod_bias")) {
printf("Sorry, GL_EXT_texture_lod_bias not supported by this renderer.\n");
exit(1);
}
glPixelStorei(GL_UNPACK_ALIGNMENT, 1);
- if (!LoadRGBMipmaps(TEXTURE_FILE, GL_RGB)) {
+
+ if (glutExtensionSupported("GL_SGIS_generate_mipmap")) {
+ /* 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 to 256 x 256 */
+ if (width != 256 || height != 256) {
+ GLubyte *newImage = malloc(256 * 256 * 4);
+ gluScaleImage(format, width, height, GL_UNSIGNED_BYTE, image,
+ 256, 256, 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, 256, 256, 0,
+ format, GL_UNSIGNED_BYTE, image);
+ free(image);
+
+ /* make sure mipmap was really generated correctly */
+ width = height = 256;
+ for (i = 0; i < 9; 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);
+ assert(w == width);
+ assert(h == height);
+ width /= 2;
+ height /= 2;
+ }
+
+ }
+ else if (!LoadRGBMipmaps(TEXTURE_FILE, GL_RGB)) {
printf("Error: could not load texture image %s\n", TEXTURE_FILE);
exit(1);
}