kicad-developers team mailing list archive

[Dick Hollenbeck <dick@xxxxxxxxxxx>]

On 12/12/2010 04:56 PM, Vesa Solonen wrote:
> On Sun, 12 Dec 2010, Dick Hollenbeck wrote:
>
>> Often screen memory is of a different format than the internal RAM resident bitmaps,
>> and this can be a CPU intensive thing, to convert each pixel.
>> The last remaining opportunity to reduce the time spent doing the last screen blit is
>> to optimize on the dirty area alone.  If we could reduce the size of the dirty area,
>> this would *dramatically* improve speed.  I think this is only possible though on the
>> layer show/hide clicks, where a layer is coming or going.  On the resizing operations,
>> especially when grid is on screen, the entire screen needs to be redrawn, mandating a
>> full sized blit.
> I think the above sums up the bigger problem of graphics very well. WxDC 
> technology is from the 90's and so is KiCad's usage of graphics hardware. 
> KiCad should not mess with low level bitmap operations, but just send the 
> vector data to the graphics processor (or optimized sw implementation, 
> like mesa softpipe). Dirty area optimizations were done as EXA protocol 
> for the X server... This really is not an application level problem, but 
> wxDC is making it one. The efforts might be better spent on finding 
> alternative solutions for drawing than wxDC.
>
> -Vesa

I agree.  I have lost all my enthusiasm for wxDC.  It is nothing I care to spend any
more time on.

We indeed need to find a better solution.  In the next few weeks I will be looking at
Hueter's work.

Dick