[Freeciv-Dev] Re: (PR#11507) use pixbufs for gtk2 sprites

["Jason Short" <jdorje@xxxxxxxxxxxxxxxxxxxxx>]

<URL: http://bugs.freeciv.org/Ticket/Display.html?id=11507 >

Andreas Røsdal wrote:
> <URL: http://bugs.freeciv.org/Ticket/Display.html?id=11507 >
> 
> On Mon, 13 Dec 2004, Jason Short wrote:
> 
>>This demo patch uses pixbufs (rather than pixmaps + sprites) for the
>>sprites in the gtk2 client.
>>
>>This should allow use of transparency in tilesets, which is very good.
>>It also makes for 40-50% slower drawing, which is very bad.
> 
> 
> So this means Pixbufs are too slow to be usable? Can you think of any way
> to improve the drawing speed?

I've been toying with a system that uses pixbufs whenever an alpha level 
is detected and converts to pixmaps when it is not.  This should be just 
as fast as the current system, unless a tileset that actually uses alpha 
is used.

> What would the speed impact be of rendering transparent fog do you think?
> - to compare with the speed of fogging by darkening pixmaps.

Using alpha only for fog shouldn't have much impact.  It is 50% slower 
but fog only makes up a small portion of the total sprites drawn.

> Also, are there other uses for transparency/alpha blending besides fog of
> war? If this can be done easier by darkening the sprite?

Anti-aliasing can be of use in many places.  In 
http://www.freeciv.org/index.php/User:Yautja there was experimentation 
with using it for specials (but he couldn't use alpha levels so he ran 
into problems).

-jason