On Wed, 2003-07-16 at 02:04, Matthew Allen wrote: > Hi, > > I'm wondering whether there is a single pass method to draw text with a background using Xft? Just flat color, nothing special. > > Something like XftDrawStringUtf8 with an extra couple of parameters for a rectangle and color. > > This would make it much easier to write flicker free code. Currently I have to fill the area behind the text using a > rectangle primitive and then overlay the text, and of course this doesn't happen instantly so between the 2 operations you > get background color only on the screen... and thus flicker. Yes I know double buffering fixes this, but the speed + memory > hit is a bit much for simple things like standard GUI widgets (tree/list/button etc). > > This is one reason windows _looks_ a lot smoother than most X applications, because they can do this. I don't see why it can't be done > (maybe I'm missing something in the API?) because it's fairly simple at a technical level. I think you'll find that in any more than simplistic situation, you can't reliably a "DrawImageString" type primitive to prevent flicker - e.g., modern toolkits allow buttons to have themed buttons with a gradient or pixmap. Double buffer. It's not the speed hit you think it is; blits are *fast* these days. And there is no reason to keep double buffers around permanently. Regards, Owen (Note that there are *performance* reasons to special case drawing on a solid background, but it's possible to optimize that without complicating the API with just a bit of cleverness.)
