[SDL] [PATCH] DGA driver buggy and slow

[Sami Näätänen]

On Friday 01 November 2002 11:44, Glenn Maynard wrote:
> On Fri, Nov 01, 2002 at 10:13:15AM +0100, Cezary Kaliszyk wrote:
> > -	XFlush(DGA_Display);
> > +	if (!this->screen->flags & SDL_DOUBLEBUF) XFlush(DGA_Display);
> >  	DGA_AddBusySurface(dst);
> >  	UNLOCK_DISPLAY();
> >  	return(0);
> > @@ -856,7 +856,7 @@
> >  		SDL_NAME(XDGACopyArea)(DGA_Display, DGA_Screen,
> >  			srcx, srcy, w, h, dstx, dsty);
> >  	}
> > -	XFlush(DGA_Display);
> > +	if (!this->screen->flags & SDL_DOUBLEBUF) XFlush(DGA_Display);
>
> You probably mean
>
> 	if (!(this->screen->flags & SDL_DOUBLEBUF)) XFlush(DGA_Display);
>
> ! has higher precedence than &.

In fact in this case it doesn't mater. Although the later is much 
clearer way of presenting the test.

Explanation:
Inverse of the flags will reverse the result of the 'and' and thus do 
exactly the same thing as the other alternative.