#169 Polygon/area fills without a specified start location

open
Julian Lamb
None
5
2013-01-27
2013-01-25
OSHPark
No

I've encountered an issue with gerbers from the DesignSpark/EasyPC/Pulsonics family.

Their polygon fills don't include the starting coordinate, but instead assume the plotter will start at whatever the last coordinate was. For example:

X16Y198D02*
G36*
Y141D01*
X55*
G75*
G02X40Y198I97J57*
G01*
X16*
G37*

Gross. I've submitted this as a bug to NumberOne Systems, since I think it's incorrect-- or at least ambiguous-- behavior.

If you load the attached file "Bad-Polygon-Fills.ger", it will look okay. Gerbv actually parses and draws this properly in the UI. Now save / export the gerber and reload it. Mutilated polygon city.

I don't know what the right fix is. Should the current photo plotter position be recorded as the polgyon start if there isn't one inside the polygon definition?

Discussion

  • OSHPark
    OSHPark
    2013-01-25

    A file full of these danged things.

     
    Attachments
  • Julian Lamb
    Julian Lamb
    2013-01-27

    Hello,
    I haven't actually seen this variant before, and after reviewing the spec I'd definitely say this should be reported as a "bug" with the offending software. It looks like gerbv renders it correctly since it effectively uses the first D01 point after the G36 as the first point of the polygon. The renderer will then auto-close the polygon, effectively creating that last line automatically.
    Ideally, the gerbv exporter should clean this up, so I will leave this bug open to document that. I can't promise a quick fix though, since there doesn't look to be a trivial fix and I frankly don't have much time to hack on gerbv these days. :(

    Cheers--
    Julian

     
  • Julian Lamb
    Julian Lamb
    2013-01-27

    • assigned_to: spetm --> thepurlieu
    • labels: 354627 -->