Programatically alter Polylines/Polygons on TTMSFNCMaps

FNC TMS FNC Maps
1

I need to draw a log of polylines on a TTMSFNCMap. Programatically, I then need to be able to modify the properties of the n-th polyline. In particular, I need to adjust the number and value of the points making up the polyline. I'm guessing that I need to execute TTMSFNCMap.Polylines[n].Coordinates.Clear
and then iteratively add to the TTMSFNCMap.Polylines[n].Coordinates, but I'm not sure how.

I then also need to do the same thing with polygons. (I'm assuming there will be some commonality to the polylines answer)

Thanks!

2

I've partially answered my own question with relation to polygons, where all polygons on the TTMSFNCMap have a fixed number of points.

Iterating through the TTMSFNCMap.Polygons[n].Coordiantes, I can change the .Latitude and .Longitude values, and then set TTMSFNCMap.Polygons[n].Recreate := TRUE to redraw the polygon. This seems to work, and I trust is a suitable method.

However, I am still battling to understand how to I might change the number of Coordinates in the polygon (or polyline).

(This may be because I have not got an understanding of the TTMSFNCMapsCoordinateItem?)

3

Hi,

Coordinates is a collection, so you can add/remove/update items as in any collection.

4

Thanks Pieter

I obviously need to get to grips with TCollection and such-like!

In the meantime, I found that the following also does the trick, given that I have initially added the number of polygons (or polylines) that I need:


    map.Polygons[n].Coordinates.Clear;
    for p := 0 to Length(polyPoints)-1 do
    begin
      map.Polygons[n].Coordinates.Add;
      map.Polygons[n].Coordinates[p].Latitude := polyPoints[p].latitude;
      map.Polygons[n].Coordinates[p].Longitude := polyPoints[p].longitude;
    end;
    map.Polygons[n].Recreate := TRUE;
    map.Polygons[n].Visible := TRUE;
5

Yep, that should indeed do the trick.