Difference fails with overlapping edges

[w8r]

#80

[w8r]

@mfogel does this work in your version?

[mfogel]

Yeah, it does.

> subject = [[[10, 10], [80, 10], [80, 80], [10, 80], [10, 10]]]
[ [ [ 10, 10 ], [ 80, 10 ], [ 80, 80 ], [ 10, 80 ], [ 10, 10 ] ] ]
> clipping = [[[20, 10], [30, 10], [30, 80], [20, 80], [20, 10]]]
[ [ [ 20, 10 ], [ 30, 10 ], [ 30, 80 ], [ 20, 80 ], [ 20, 10 ] ] ]
> result = polygonClipping.difference(subject, clipping)
[ [ [ [Array], [Array], [Array], [Array], [Array] ] ],
  [ [ [Array], [Array], [Array], [Array], [Array] ] ] ]
> result[0]
[ [ [ 10, 10 ], [ 20, 10 ], [ 20, 80 ], [ 10, 80 ], [ 10, 10 ] ] ]
> result[1]
[ [ [ 30, 10 ], [ 80, 10 ], [ 80, 80 ], [ 30, 80 ], [ 30, 10 ] ] ]

[w8r]

@mfogel thanks!

[HansonYip]

I also found a similar problem about shared edge.

var p1 = [[[0,0],[2,2],[4,2],[2,0],[0,0]]];
var p2 = [[[1,0],[2,1],[3,1],[2,0],[1,0]]];
var differenced = difference(p1, p2);

But the result is

[[[[0,0],[1,0],[2,0],[2,1],[3,1],[4,2],[2,2],[0,0]]]]