Set polygon hole´s color!

Jul 1, 2015 at 10:48 PM
Hi,

I'm trying to load a shapefile that contains a polygon with holes but something is wrong because the holes does not appears transparent...

Thanks
Developer
Jul 2, 2015 at 8:45 AM
If the holes have the same color as the polygons then the holes coordinates are most probably in the wrong order. Try to reverse the holes coordinates.
Marked as answer by jany_ on 7/8/2015 at 10:40 PM
Jul 2, 2015 at 2:37 PM
Hi jany,

Thank you for your help now it´s working, but why this happens? Why should I draw the hole in the opposite direction that draw the polygon?

Thanks again.
Developer
Jul 2, 2015 at 5:49 PM
The shapefiles definition says that polygon shells are orientated clockwise and holes are orientated counterclockwise.
Jul 2, 2015 at 6:59 PM
Thaks you for all...
Oct 16, 2015 at 9:40 AM
For example ArcMap and the shape object viewer in SQL Server handles this and excludes the holes when displaying the feature, even if the coordinates of the holes are clockwise oriented. Would it be possible to add this behaviour to DotSpatial as well?
Developer
Oct 16, 2015 at 1:29 PM
I don't think it would be correct to show a hole as a hole if it isn't one according to definition. That would cause the user to think that everything is alright although it's not. It would be better if we corrected the holes orientation so that the user has data that conforms to the definition.