kicad-developers team mailing list archive

[jean-pierre charras <jp.charras@xxxxxxxxxx>]

Le 14/12/2010 18:59, Dick Hollenbeck a écrit :
> > Thanks for the discussion on gerbview.
> >
> > 1920 x 1200 = 2304000 pixels
> > ---------------------------------  = 1.92
> >
> > 1200 x 1000  = 1200000 pixel
> >
> >
> > Yes, it seems you are correct, the area difference is no explanation for this large
> > difference in blit "mask with AND" mode.
>
>
> Well on second thought, it is not O(screen area).
>
> Screen area could be the entire reason.
>
> I will try it with a reduced resolution setting soon.
>
> Dick

I forgot:

If you are compiling with option USE_WX_ZOOM = ON, the patch has a bug in BOARD::Draw.
line
        aPanel->DrawBackGround( &screenDC );
must be
        aPanel->DoPrepareDC(screenDC);
        aPanel->DrawBackGround( &screenDC );

Otherwise, if the grid display option is ON, the grid is always drawn, regardless the grid size in pixels,
because in the current device context, the user scale is set to 1.0, and testing to see if the grid size in pixel is more than 10 
pixels fails.

For zoom values of 16 and more, the grid drawing routine is therefore very long and can easily explain 20 seconds to redraw the 
screen.
Roughly, the grid routine try to draw the grid on a screen size of zoom * screen_size_x * zoom * screen_size_y.
If the grid size is low and zoom value hight, it takes a while.

(Can be avoid if you switch the grid display OFF)


--
Jean-Pierre CHARRAS