Kollision zweier 2dim Polygonen.

[igel457]

Wie wäre es damit? Ich hatte schonmal das selbe Problem...

http://www.coding-board.de/board/sho...6002#post96002

EDIT: Ich habe den Code mal hier her kopiert, um toten Links vorzubeugen:

Delphi-Quellcode:

type
  TPointArray = array of TPoint;

function PointInPolygon(const Polygon : TPointArray; const P : TPoint): boolean;
var
  ToTheLeftofPoint, ToTheRightofPoint : byte;
  np : integer;
  OpenPolygon : boolean;
  XIntersection : real;
begin
  ToTheLeftofPoint := 0;
  ToTheRightofPoint := 0;
  OpenPolygon := False;

  if not ((Polygon[0].X = Polygon[High(Polygon)].X) and
   (Polygon[0].Y = Polygon[High(Polygon)].Y)) then
   OpenPolygon := True;

  for np := 1 to High(Polygon) do
   if ((Polygon[np - 1].Y <= P.Y) and
     (Polygon[np].Y > P.Y)) or
     ((Polygon[np - 1].Y > P.Y) and
     (Polygon[np].Y <= P.Y)) then
   begin
     XIntersection := Polygon[np - 1].X +
      ((Polygon[np].X - Polygon[np - 1].X) /
      (Polygon[np].Y - Polygon[np - 1].Y)) * (P.Y - Polygon[np - 1].Y);

     if XIntersection < P.X then Inc(ToTheLeftofPoint);
     if XIntersection > P.X then Inc(ToTheRightofPoint);
   end;

  if OpenPolygon then
  begin
   np := High(Polygon);
   if ((Polygon[np].Y <= P.Y) and
     (Polygon[0].Y > P.Y)) or
     ((Polygon[np].Y > P.Y) and
     (Polygon[0].Y <= P.Y)) then
   begin
     XIntersection := Polygon[np].X +
      ((Polygon[0].X - Polygon[np].X) /
      (Polygon[0].Y - Polygon[np].Y)) * (P.Y - Polygon[np].Y);

     if XIntersection < P.X then Inc(ToTheLeftofPoint);
     if XIntersection > P.X then Inc(ToTheRightofPoint);
   end;
  end;

  if (ToTheLeftofPoint mod 2 = 1) and (ToTheRightofPoint mod 2 = 1) then
   Result := True
  else
   Result := False;
end;