kicad-developers team mailing list archive

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

Brian Sidebotham a écrit :
> 2009/9/8 dioiioib <dioiioib@yahoo. ca <mailto:dioiioib%40yahoo.ca>>:
> >
> >> > Yes (for pcbnew).
> >> > Pcbnew and Gerbview (but not eeschema) uses the OR mode to draw the
> >> > layers on screen (the transparency mode did not exists when i 
> wrote the
> >> > code)
> >> > I carefully chose the binary values of these colors in order to have
> >> > good results in OR mode in screen, to see layers like in 
> tranparency mode.
> >>
> >
> >
> > Is there a way to add more colours to this list. When working with 
> more than two layers it would be appreciated if you could pick some 
> colours that were not utilized by other items, under "tech layers" and 
> "other".
> >
>
> I am currently looking at this. I don't see why the bit patterns have
> to be anything special at the moment, but there is always a good
> reason for the code as is. The OR'd result should be correct for all
> colours, no matter what their bit pattern is. I need to do some
> testing. In the code I think it would be nice to get away from the
> colour lookup array and allow people to use a standard colour picker.
Some values are better than others when combining them.
Suppose you want have 2 green values for 2 different layers.
If you choose values 0x80 and 0x40 you can easily see the 3 value 
(0x80, 0x40 and 0xC0=0x80|0x40) on screen.
IThis is therefore a good choice.
f you choose values 0x7F (near from 0x80) and 0x40 you can see only 2 
value (0x7F, 0x40 and 0x7F = 0x7F | 0x40) on screen, and therefore no 
transparency effect.
This is therefore a bad choice.
The choice is more difficult for 3 or 4 layers with good OR effects.
The OR mode is simple but has limited possibilities.
The standard colour picker cannot allow the user to make a good choice 
easily

--
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