I am playing around with some C# logic to spin line segments indicating if polygons are on the left or right of the line segment. I am using ISpatialFilter and esriSpatialRelEnum.esriSpatialRelTouches relationship to find polygons that touch a line segment. I have seen references to the HitTest method to determine left and right side of the relationship based on the bRightSide flag. However, with my test layer of lines and polygons which looks like
Relative to the highlighted street segment, my program finds that it touches polygons A, B, and C but the polygons that I will be interested in are going to be A and C since they are the ones on the left and right of the line segment. B is just touch -- or in the case of a segment that is truly perpendicular to B -- so I would expect the bRightSide flag to be incorrect for HitTest in this case.
Any suggestions or a better solution?