kicad-developers team mailing list archive

[Jeff Young <jeff@xxxxxxxxx>]

Question for you polygon folks:

The old algorithm used to add a lot of pads to a “holes” polygon, then did a Simplify() on it, and then a BooleanSubtract() from the filled area.

The new code does a Simplify() and BooleanSubtract() per pad.  Since the holes are all discrete in either case (ie: not overlapping or otherwise interacting with each other), I thought this would have similar performance, and it makes the code easier to understand. But perhaps this is the source of the performance issue?

Cheers,
Jeff.


> On 21 Jun 2019, at 14:16, jp charras <jp.charras@xxxxxxxxxx> wrote:
> 
> Le 21/06/2019 à 14:57, Seth Hillbrand a écrit :
>> Hi Wayne-
>> 
>> I don't think that the relief chamfering is controlled by that option. 
>> We also don't chamfer the connection on the way into the pad, so I'd
>> tend to agree with Jeff that the extra corner chamfer on only one side
>> of the connection might be unnecessary.
>> 
>> It looks like the original knockout code was JP's so I'd be curious to
>> hear why they were originally added.
>> 
>> -Seth
>> 
> 
> The main reason was a problem with the polygon library Kicad was using
> at this time.
> 
> This library frequently created bad polygon shapes due to thermal shapes
> when filling a zone.
> 
> I noticed the bad polygon shapes were much less frequent with the
> chamfered shapes, and when the thermal stubs shape is a X instead of a +
> for round pads.
> 
> Beside, chamfers avoid acute angles in thermal reliefs, especially for
> round (and oval) shapes.
> 
> They are not mandatory, because I am pretty sure most of other ECAD
> tools do not use chamfers, but they create a better shape.
> 
> For me, the main (blocking) issue with the new algo is the calculation time.
> 
> -- 
> Jean-Pierre CHARRAS
> 
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