Math&graphic

[hani]

Hi,
How i can know if point is inside polygon or not




Thanks

[Kambiz]

Code: Select all

function PtInPolygon(const Polygon: array of TPoint; const Pt: TPoint): Boolean;
var
  Rgn: HRGN;
begin
  Rgn := CreatePolygonRgn(Polygon, Length(Polygon), WINDING);
  try
    Result := PtInRegion(Rgn, Pt.X, Pt.Y);
  finally
    DeleteObject(Rgn);
  end;
end;

[kokkoras]

Is PtInRegion a win API call?

[HPW]

Yes, from the delphi windows SDK help:

Code: Select all

BOOL PtInRegion(

    HRGN hrgn,   // handle of region
    int X,   // x-coordinate of point 
    int Y    // y-coordinate of point 
   );