   DirectX Clipping Help
  Hello,I am currently adding functionality to an old DirectX 8 game through reverse engineering and I am adding a custom GUI system.  However, unlike DirectX 9 and later, there is no such functionality for scissoring.After some searching, I discovered this post: http://www.gamedev.net/community/forums/topic.asp?topic_id=214763, and am having quite a hard time understanding the sample that was recommended at the end of the topic because the clip planes used in the sample are based off of 3-D world coordinates and I need to display textures within a 2-D space at the 0 z-level.So I was wondering how I would go about forming an equivalent to SetsSissorRect specifically for DirectX 8, with efficiency involved.  One poster suggested that changing the viewport and projection matrix before presenting would do the job and then restore it afterwards.Any help would be appreciated, given that I'm not that experienced with DirectX.   
  Basically I'm asking for a possible manual alternative to SetScissorRect.   