How do you want corners handled? With curves? Does the distance only matter between two lines?
Frankly, I really don't know. In the case of certain corners (such as the vertex of a square or a triangle, it is intuitively quite simple. Ordinarily, every point on the outer polygon should be 'd' distance from the corresponding point in the inner polygon. Of course, a triangle's vertex creates an interesting problem. However, the vertex of the outer polygon can be 'd' distance from the vertex of the inner polygon in two different directions, with some kind of smoothing curve in between. This is geography, so accuracy is not as important as reliability. As long as we intuitively know that the resulting buffer is more or less correct, no one is going to quibble.

In reply to Re^2: polygon buffering algorithms by punkish
in thread polygon buffering algorithms by punkish

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