Ramiro,
The C API function OGR_R_IsValid( OGRGeometryH ) may help you.
On Fri, Mar 26, 2010 at 2:02 AM, Ramiro Gonzalez <
ramirogonza...@suremptec.com.ar> wrote:
> I won't calculate the area. I'll show an 'invalid area' message to the
> user.
>
> Thanks.
>
> 2010/3/19 Peter J Halls
>
> Whilst I
I won't calculate the area. I'll show an 'invalid area' message to the user.
Thanks.
2010/3/19 Peter J Halls
> Whilst I agree with Chris that the 'winding' method for calculating polygon
> areas would need tweaking to work with a shape like this, the 'complementary
> areas' method or the trian
Whilst I agree with Chris that the 'winding' method for calculating polygon
areas would need tweaking to work with a shape like this, the 'complementary
areas' method or the triangulation method would. See Stephen Wise, GIS Basics,
London: Taylor & Francis (2002) pp61-64 or Joseph O'Rourke, Com
On 3/18/2010 10:20 AM, Ramiro Gonzalez wrote:
> I use gdal to calculate the area of polygons drawn by a user over a map.
> The points are added to the polygon in same order the user selects them.
> An hourglass shaped polygon can be created adding 4 points like a 'z'.
> When the polygon has the sha
I use gdal to calculate the area of polygons drawn by a user over a map. The
points are added to the polygon in same order the user selects them. An
hourglass shaped polygon can be created adding 4 points like a 'z'.
When the polygon has the shape of an hourglass, the measure returned by
get_Area(
