If a function needs to maintain the state of some data over successive calls, such as a working buffer or a pointer, the caller should provide this data.
如果函数需要在一系列调用期间维持某些数据的状态,比如工作缓存或指针,那么调用者应该提供此数据。
2
This pre-conversion is critical for maintaining color state through transitions of different frames as their portions are blitted to the buffer and, eventually, the screen.