void incrPosition(sg_size_t incr) { current_position_ += incr; }
sg_size_t tell() { return current_position_; }
int seek(sg_offset_t offset, int origin);
void incrPosition(sg_size_t incr) { current_position_ += incr; }
sg_size_t tell() { return current_position_; }
int seek(sg_offset_t offset, int origin);