DXSURFACE7 sloooooow wtf?
Hey,
I recently found out the following:
I set up dx7 in fullscreen with a backbuffer.
For my texture I used a LPDIRECTXSURFACE7 and loaded the bitmap into it.
For texturing I locked the backbuffer and the texturesurface
and copied between them.
Result 8fps
Ok, it''s for a free directional tunnel on a p233
Now, I replaced the texturesurface with a short[640*480] buffer for my texture (16BPP).
Now I copied shorts from the buffer into my locked backbuffer pointer.
Result 22fps
How can this happen? Is a DXSurface that slow? Or might it be that the surface was in VIDEO memory (dunno) and the read-to-SYS-mem-operation is so slow?
Can someone explain?
Gr,
BoRReL
The only point of keeping surfaces in video memory is to use hardware blitting/texturing etc. on them or if they are the primary surface and the other surfaces in the flipping chain. Almost all video cards ever made only support video->video blitting, and video memory texturing. In software, the speed of writing to , it goes like this:
video->video - dead slow
video->system - faster
system->video - a tiny bit faster than video->system
system->system - fastest
Edited by - furby100 on June 24, 2001 9:37:06 AM
video->video - dead slow
video->system - faster
system->video - a tiny bit faster than video->system
system->system - fastest
Edited by - furby100 on June 24, 2001 9:37:06 AM
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