performance question

["Aykut Ozak" <aozak@ixir.com>]

have been working on d3d8 and will be very pleased if someone enlightens me on these questions

-as written in documentation we should avoid clearing the viewport as many as we can,so how can we move objects without doing so,

-and if we have to clear it anyway I think defining a primitive (for ex.) box and assigning a texture which is the previous scene rendered excluding the object/s we are moving would be the way to reach a normal rate of fps. so how can we get the rendered scene as a texture? i mean just getting a screen snapshot- i think i got the surface as IDirect3DSurface8 interface with GetFrontBuffer(...) , but how do we assign it as texture over an object

-and how do we get a surface interface to backbuffer and do operations like 2d blitting - for text operations maybe

 

thanks in advance,

aykut