DIBEngine and gdi32/user32 controls drawing loop performance

[James McKenzie]

Amico Amico wrote:
> Hello,
> since I had a poor performance in drawing many buttons and text input 
> fields at the same time into a window with wine, I applied the 
> DIBEngine patch (http://wiki.winehq.org/DIBEngine) that is available 
> for wine 1.1.44 (http://bugs.winehq.org/attachment.cgi?id=27879) to 
> the 1.1.44 version of wine and started my application program that 
> needs to draw many button and text input fields in a single window 
> with the enviroment variable "WINEDIB=ON wine ./App.exe".
>
> Now that the DIBEngine patch is applied a little speedup in the 
> drawing of the buttons and the text input fields is shown, but now the 
> problem is that they are still drawn in blocks of a subset of the 
> total number and then wine waits a little bit, then it draws another 
> block of text input fields and buttons and then wine still waits, then 
> it draws, and so on. The result is that my App.exe application window 
> that is full of buttons and text input fields is drawn in subsequent 
> times, and groups of buttons and input fields are drawn in blocks with 
> a delay between the drawing of a group of controls and the others.
This does duplicate Windows performance as not all controls are drawn at 
the same time.  If you used a slower/older machine this is very 
apparent.  Because of the delays induced by Wine's use of opengl this
shows.
>
> The fact that not all the controls are drawn at a time but in more 
> times is frustrating, since the CPU is a core2duo, and I think that it 
> is powerful enough to draw all of the controls in the window at a 
> time, specially with the DIBEngine patch applied and the DIBEngine 
> activated. So I thought that the problem could be in the main event 
> loop that manages the App.exe application window, and in particular 
> the problem could be that the loop yields the drawing of the controls 
> after a certain number of controls have been drawn in order to avoid 
> CPU high load and then the loop starts again to draw other controls 
> after a while and then it stops and yields and waits again, and so on.
This is what Windows does as well.  It is very interesting to watch on 
my older PIII/750 machine running WindowsXP.

However, if you feel that you can improve performance, you are welcome 
to try. 

I plan on picking up and examining the DIB Engine code after the release 
of Wine 1.2 and building a few more features that are missing from richedit.

James McKenzie