4.4.6.1 GetPolygonIntersectArea_m2

GetPolygonIntersectArea_m2 function

Prototype:	function GetPolygonIntersectArea_m2(const LayerName1: string; const ID1: integer; const LayerName2: string; const ID2: integer): variant;
Description:	The GetPolygonIntersectArea_m2 function calculates the area of the intersection of two polygons.
Syntax:	variable := Project.GetPolygonIntersectArea_m2(Layer1Name, ID1, Layer2Name, ID2);
	Part	Description
	variable	A variable declared as a variant
	Project	A reference to the Field-Map project as defined in Field-Map Project Manager
	Layer1Name Layer2Name	A references to Field-Map layers as defined in Field-Map Project Manager, which contain polygons to intersect
	ID1 ID2	IDs of polygons to intersect

Return value:	the area of the intersection as variant

Example:

var

v : variant;

area,TotArea : double;

i,n,idCuttingArea,idSubCompartment,nCompartment,nSubCompartment : integer;

s,f,vdm : string;

c : char;

begin

...

idCuttingArea:= CuttingAreas['ID']; // ID of the active cutting area

...

Mensuration.First;

while not Mensuration.EOF do begin

s:=Mensuration['SubCompartmentName'];

n:=GetFieldCountFromString(s,',');

if n>1 then c:=','

else begin

n:=GetFieldCountFromString(s,'.');

c:='.';

end;

area:=0;

for i:=0 to n-1 do begin // goes through the list of the captured intersections

// finds out the number of the captured intersection - its ID is needed

f:=GetFieldFromString(s,i,c);

nSubCompartment:=StrToInt(f); // the number of the captured intersections

idSubCompartment:=SubCompartments.GetAttributeValue('ID',format('CompartmentName = %d AND SubCompartmentName = %d',[nCompartment,nSubCompartment]));

v:=Project.GetPolygonIntersectArea_m2('CuttingAreas',idCuttingArea,'SubCompartments',idSubCompartment);

if v<>null then area:=area+double(v); // a list of intersections included in Mensuration

vdm:=vdm+IntToStr(idSubCompartment)+'|';

end;

...

Mensuration.Next;

end;

end.