Re: [ferret_users] Why polygon fills unexpected regions?

[Ansley Manke <ansley.b.manke@xxxxxxxx>]

Hi all,
After working a bit on this off-line, we have determined that there is a 
long-standing bug in the Ferret graphics so that concave parts of 
polygons are incorrectly filled in when in -gif mode.  For instance, 
this figure should be filled in only inside the shape, but the upper and 
lower concave parts get filled in.  We'll see if we can find the cause 
of this.

Ansley

Yu, Hao-Cheng wrote:
> Dear ferret users,
>
> I try to use polygon command as land region to cover the interpolated 
> variable to avoid misunderstanding.
> The scripts works fine when I use normal mode (which shows on the 
> screen with X env.)
> However, when I try to produce gif file with gif mode (ferret -gif),
> scripts still works fine but polygon cut unexpected regions in my plot.
>
> I attach 2 figures to show the difference, first one is site1_01.gif 
> which is produced by ferret -gif mode,
> can easily found the salinity field was cut by polygon which suppose 
> only to overwrite the land region.
>
> normal.bmp is under normal mode ferret and extracted by print-screen.
>
> Any suggestions?
>
> Dan
>