25 Aug
2009
25 Aug
'09
8:45 p.m.
Hello, When I compute union or intersection of two rectangles rotated by 45 degree that form an X, I don't necessarily get a 45 degree polygon, namely when the intersection point is not an integer. For example when one polygon has an edge 0,0 -- 10,10 and the other polygon has an edge -1,10 -- 9,9 then they intersect mathematically at 4.5,4.5 but as you snap to an integer, you get for example 5,5 Now -1,10 -- 5,5 is no longer a 45 degree edge. Isn't the fact that the set of 45 degree polygons is not closed under Boolean operations with snap rounding bothersome (even in practice). Best regards, andreas fabri