[OpenLayers-Users] offset polygon
Stephen Woodbridge
woodbri at swoodbridge.com
Fri May 4 14:10:44 EDT 2012
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
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