Check of point inside/outside polygon

[CRAIG DILLABAUGH via Digitalmars-d-learn]

On Wednesday, 27 July 2016 at 14:56:13 UTC, Suliman wrote:
> On Wednesday, 27 July 2016 at 12:47:14 UTC, chmike wrote:
>> On Wednesday, 27 July 2016 at 09:39:18 UTC, Suliman wrote:
clip
>
> Sorry, its my issue I am thinging about polygons, but for me 
> would be enought points.
> The problem is next. I am writhing geo portal where user can 
> draw shape. I need to get users images that user shape cross. 
> But as temporal solution it would be enough to detect if image 
> central point inside this polygon (I know its coordinates).
>
> I can do its on DB level, but I would like to use SQLite that 
> do bot have geometry support. So i am looking for any solution. 
> I can use gdal but its _very_ heavy

So when you say you want polygon intersection, is one of the 
polygons you are interested in the shape of the images (ie. 
roughly a rectangle)?

If this is the case then you can likely just take the bounding 
rectangle (easily calculated) of your polygon and check if that 
intersects the bounding rectangle for the the image and that 
should work 95% of the time.