[OpenLayers-Users] offset polygon

[Stephen Woodbridge]

On 5/4/2012 11:26 AM, Steve Nelson wrote:
> Does anyone have a function that can create an offset polygon?
>
> In other words, if I have a polygon made up of 5 points have the same
> polygon shape, just a larger size?

Hi Steve,

These are not the same thing.

If you want the same shape only larger then you are looking a scale.
If you want and offset, this is MUCH more complicated because you have 
to deal with changes in topology, like if you have a small V shape then 
you offset might cause these to be removed like:

----------------- offset

------\  /------- curve
        \/

or if your polygon has a hole then an offset could result in a smaller 
hole or with the hole getting filled in and removed. There are many 
cases like this. These are just a couple of examples to give you the idea.

So what DO you need? Resizing via scale is easy, True offset is hard!

-Steve W