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geopoly_overlap return codes

geopoly_overlap return codes

(1) By Boris (boris.gontar) on 2020-04-22 21:39:54 [link] [source]

The source code of geopoly.c contains very useful comment on return codes of geopoly_overlap:

**   0     The two polygons are disjoint
**   1     They overlap
**   2     P1 is completely contained within P2
**   3     P2 is completely contained within P1
**   4     P1 and P2 are the same polygon
**   NULL  Either P1 or P2 or both are not valid polygons

The doc page only mentions zero and non-zero return codes. Is it intentional and it's better not to rely on the comment above?

(2) By Richard Hipp (drh) on 2020-04-22 23:28:37 in reply to 1 [source]

I left the description a little vague with the idea that I might change or enhance it in the future. When you promise to support something for decades into the future, it is important to leave wiggle room.

I don't have any plans to change the return values of the geopoly_overlap() function. You can probably go ahead and use them if you want to. But if in the future I do need to change them - no tears. OK?

(3) By Boris (boris.gontar) on 2020-04-23 00:12:40 in reply to 2 [link] [source]