在codev中关于棱镜使用的介绍中，the “face length” of the prism is the full width of the reference face of the prism. The reference face depends on the particular prism design—either experiment with sizes (making frequent use of Undo), or take a look at the comments in the source code for the macro (found in the CV_MACRO: directory).我对这里的关于这个face length不太理解 那位高手能用通俗易懂的话给我解释下。送人玫瑰，手有余香！！谢谢你！
