kicad-developers team mailing list archive

[jean-pierre charras - INPG <jean-pierre.charras@...>]

Vesa Solonen a écrit :
> Thank you for your through explanation of KiCad history. It was really
> interesting.
>
> On Fri, 23 Jan 2009, jean-pierre. charras@inpg. fr 
> <mailto:jean-pierre.charras%40inpg.fr> wrote:
>
> > I did not say: do not use wxDC capabilities,
> > but i believe the clipping at kicad level remains useful, and perhaps
> > (Alas!) mandatory for some graphic shapes.(to be tested for arcs ...)
>
> Couldn't these overflow problems be easily gone by using wxCG for
> graphics. Double precision float coordinates won't owerflow in the near
> future.
Overflows are not in wxDC ou wxWidget code
In wxDC, all scaling calculations are already made in double, and 
coordinates use long, like kicad and often doubles ).
I am pretty sure wxWidgets is not guilty.
They were at low level code (Windows 95/98 graphic layer is known to 
handle pixel coordinates using shorts; I did not tested XP graphic layer),
and we cannot do anything but clip items to draw before send them to the 
low level graphic functions that creates problems.

I believe overflows under Linux are also at low level code (not in 
wxWidget code).

So I am not sure wxCG solves these problems, if it sends objets to low 
level graphic functions without clipping.
(also note: wxCG is easy to use under Linux, but very tricky under 
Windows, if using gcc)

--
Jean-Pierre CHARRAS
Maître de conférences
Directeur d'études 2ieme année.
Génie Electrique et Informatique Industrielle 2
Institut Universitaire de Technologie 1 de Grenoble
BP 67, 38402 St Martin d'Heres Cedex

Recherche :
Grenoble Image Parole Signal Automatique (GIPSA - INPG)
Grenoble France