I'm with troubles loading TGAs with transparency(Alpha channel), using SDL + OpenGL and SDLImage to load the TGA(Since SDL only loads bmp). The image loads, but it's been disfigurated? The colors become crazy or someting... Only using the SDL to display the image with the SDLsurface, the image looks great. But using a OpenGL surface, becomes crazy. What happens? Look at: http://geocities.yahoo.com.br/megaspeedlinux/snap.jpg

happybara

312

December 16, 2004 10:53 AM

show yours glTexImage2D call. it looks like you are using GL_RGB for its format parameter, instead of GL_RGBA or GL_BGRA...

Dolphins - The sharks of the sea.

Tsumuji

Author

144

December 16, 2004 11:57 AM

OK! That's it.
But the image do'nt show the alpha.
The rose color is a alpha channel, but is showing?

Look at:
http://geocities.yahoo.com.br/megaspeedlinux/snap1.jpg

reiko

290

December 16, 2004 12:00 PM

Are you using blending? Without it, the alpha won't be used.

Try glEnable(GL_BLEND); and glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA); for example.

Tsumuji

Author

144

December 16, 2004 12:11 PM

Wow! That's great! Works very well. Thank you!!
Result:
http://geocities.yahoo.com.br/megaspeedlinux/snap2.jpg

Tsumuji

Author

144

January 03, 2005 10:47 AM

Strange... I tried now with other image(a bit different), but the image don't load correctly
-> http://geocities.yahoo.com.br/megaspeedlinux/img.tga.zip
This is the image i'm trying to load, and i'm using like said:
glEnable( GL_BLEND );
glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);

and...
glTranslatef( -0.578f, 0.2f, -1.4f );
glBindTexture( GL_TEXTURE_2D, texture[72] );
glBegin(GL_QUADS);
glTexCoord2f( 0.0f, 1.0f ); glVertex3f( -0.11f, -0.11f, 0.0f );
glTexCoord2f( 1.0f, 1.0f ); glVertex3f( 0.11f, -0.11f, 0.0f );
glTexCoord2f( 1.0f, 0.0f ); glVertex3f( 0.11f, 0.1f, 0.0f );
glTexCoord2f( 0.0f, 0.0f ); glVertex3f( -0.11f, 0.1f, 0.0f );
glEnd( );

Works for the other textures, but not for that. What is wrong?