kicad-developers team mailing list archive

[Dick Hollenbeck <dick@xxxxxxxxxxx>]

On 12/07/2010 03:08 AM, Marco Mattila wrote:
> I tested the output with gerbview and gerbv. In gerbv everything's ok.
> Now that I checked again with gerbview the negative layer kind of
> works. However, since negative layers in gerbview are taken care of by
> drawing them in background color, the negative stuff will be
> "subtracted" from all layers below the negative layer. Fixing this
> probably requires that the drawing of a layer is first done onto a
> temporary device context/bitmap and blitting the result to the main
> window. I can take a look at this.

Just having a single bitmap will not change anything that I can see. 
You did not mention having multiple layer specific bitmaps and then
doing combinational logic on their bits into a final destination.  What
if you just draw the negative layer last onto the screen?  Or is the
problem a matter of "looking ahead" to detect the negative layer before
beginning drawing?  Is gerbview losing the "sequence" of operations
established in the gerber file?  If so, the way the gerber file loading
takes place could be an issue, and the container that holds the drawing
primitives.


>  Anyways, the default value of
> subtractMaskFromSilk can be changed to false.
>   

I agree, but:  at one time there were retentative preferences for all
these gerber output settings.  I had at one time gone through and added
most if not all the settings to a "save to disk mechanism".  I don't
know that I got all of them, and I don't know that some have been added
that recently that did not make it into that savable category.

You are familiar with this code now.  It was 2 years since I looked at
it.  It would be wonderful if we could save all the settings.  The
non-conforming issue there is the layer choices, since they are board
specific.  Most the other settings are not necessarily board specific. 
I had once argued for putting more of these kinds of board specific
settings into the BOARD, but that was never truly fulfilled.  When we
get to redoing the BOARD format, we should take a long hard look at this
again.


> By the way, there's still a problem with the function header in
> plot_common.h. The third patch I submitted is correct, I think.
>   

I just saw that 3rd this morning, missed it yesterday because I reacted
to the original patch too quickly. 

Thanks,

Dick


> marco
>
> On Tue, Dec 7, 2010 at 12:48 AM, Dick Hollenbeck <dick@xxxxxxxxxxx> wrote:
>   
>> On 12/06/2010 04:20 PM, Dick Hollenbeck wrote:
>>     
>>> Hi,
>>>
>>>       
>>>> Board manufacturers typically do not print silkscreen on areas without
>>>> soldermask. Nevertheless, it would be nice to have proper gerbers to
>>>> begin with, i.e., gerbers with no silkscreen in soldermaskless areas.
>>>> Of course, most of the problem can be taken care of by drawing the
>>>> footprints properly. However, sometimes the silkscreen of one
>>>> footprint ends up on the pads of another one (think components under a
>>>> so-dimm card, for example). The attached patch adds an option to
>>>> subtract the soldermask from the silkscreen when doing gerber output.
>>>>
>>>> marco
>>>>
>>>>
>>>>         
>>> Committed in version 2644.
>>>
>>> Fixed in version 2645.
>>>
>>> Fixes:  function header, space above single line comments, expandable
>>> dialog box problems.
>>>
>>> Dick
>>>
>>>       
>> Marco,
>>
>> Did you test the gerber output with gerbview?
>>
>> I am not sure that gerbview can display a file created with the negative
>> layer.
>>
>> If it cannot, I think we should reverse the default setting that you
>> chose, or I would ask you to see if you can patch gerbview.  I think it
>> would be bad for pcbnew to generate a gerber that gerbview cannot display.
>>
>> Thanks,
>>
>> Dick
>>
>>
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