yaoyansi - 2010-01-09

hi,
I use devil1.7.8.
I save a bmp texture which contains alpha data to PNG format, but the alpha data is lost in PNG file.
here is my function:

ILboolean LoadAndSaveToPNG( const string &from, const string &to)
{
    ilInit();
    printf("DevIL has been initialized\n");
    // Loading an image
    ILboolean result = ilLoadImage( from.c_str() ) ;
    printf("load %s\n", from.c_str());
    if( result == IL_TRUE )
    {
        printf("the image loaded successfully\n");
    } else {
        printf("The image failed to load\n" ) ;
        ILenum err = ilGetError() ;
        printf( "error %d, error string:%s.\n", err, ilGetString( err ) );
        return IL_FALSE;
    }
    //  printf("save %s\n\n", to.c_str());
    //  string lowerformat(format);
    //  transform(format.begin(),format.end(),lowerformat.begin(),tolower);
    ILboolean bSave;
    bSave = ilSave( IL_PNG, to.c_str() ) ;
    assert( (bSave==IL_TRUE)&&"Save Error." );
    printf("\n");
    return bSave;
}

And here is my test project package.
http://xyzhojo.googlecode.com/files/bmp2png.rar