Re: [GD-General] Graphic Library and market share

[brian s. <pud...@po...>]

You should leave your back buffer in video memory and do your rendering 
into a screen-sized surface in system memory.  Then just copy the 
sysmem surface to the back buffer every frame.  That gets you back on 
the well-tested driver path, and it isn't any more expensive - you have 
to copy a screen's worth of data from sysmem to vidmem in either case, 
and the flip of the vidmem back buffer to the front is free.

--brian

On Saturday, January 17, 2004, at 07:27  AM, Marin Kovacic wrote:

> However, be careful with this because
> there is a whole range of old nVidia drivers with broken DDraw
> support that exibit rather severe visual glitches when your backbuffer
> is in system memory (which it needs to be for alpha-blending). This
> has been an endless source of pain for us.