fix compile warnings: '‘bct’, ‘voffset‘, ‘coffset‘ may be used uninitialized...
fix compile warnings: '‘bct’, ‘voffset‘, ‘coffset‘ may be used uninitialized in this function' and 'comparison between signed and unsigned integer expressions'
fix compile warnings: '‘bct’, ‘voffset‘, ‘coffset‘ may be used uninitialized in this function' and 'comparison between signed and unsigned integer expressions'